Journals >Chinese Journal of Lasers
Contents
2009
Volume: 36 Issue 6
54 Article(s)
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Research Article
High Pulse Power 2 μm Ring Laser
Qiao Liang, Hou Xia, and Chen Weibiao
Experimental results of laser diode lateral-pumped Tm,Ho:LuLF crystal 2-μm ring laser is reported. Using a ring cavity of six mirrors, the beam waist and diameter are determined after theoretically caculating the cavity parameters. And it is convenient for inserting Q-switch in the cavity. Three-direction lateral-pumpiExperimental results of laser diode lateral-pumped Tm,Ho:LuLF crystal 2-μm ring laser is reported. Using a ring cavity of six mirrors, the beam waist and diameter are determined after theoretically caculating the cavity parameters. And it is convenient for inserting Q-switch in the cavity. Three-direction lateral-pumping is implied for the better pumping homogeneity and getting high pulse energy laser. In the free running mode, when the pumping energy is 3.25 J, and the pulse repetition frequency is 1 Hz the maximum laser energy is 114 mJ per pulse with the optical efficiency of 3.5% and the slope efficiency of 8.0% in the system. In the Q-switched mode, when the pumping energy is 2.75 J, 35-mJ Q-switched laser with pulse duration of about 700 ns is obtained..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1327 (2009)
All-Solid-State CW 12.9 W TEM00 Mode Green Laser
Li Fengqin, Yu Lin, Shen Yumei, Zheng Yaohui, Zhang Kuanshou, and Peng Kunchi
A CW laser consisting of a low-doped Nd∶YVO4/YVO4 composite crystal and an I-type phase-matching LBO frequency-doubler with a three-mirror V-fold thermal unsensibility resonator is designed and constructed. A maximal output power of 12.9 W at 532 nm wavelength is obtained under a pump power of 30 W with an optical-optiA CW laser consisting of a low-doped Nd∶YVO4/YVO4 composite crystal and an I-type phase-matching LBO frequency-doubler with a three-mirror V-fold thermal unsensibility resonator is designed and constructed. A maximal output power of 12.9 W at 532 nm wavelength is obtained under a pump power of 30 W with an optical-optical conversion efficiency of 43%. The long term intensity fluctuation over 3 hours free-operation and the beam transfer factor M2 measured at the output power of 11.7 W were less than ±0.83% and 1.5, respectively..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1332 (2009)
Highly Efficient Laser Diode Side-Pumped Nd∶YAG Module
Yang Xiaodong, Bo Yong, Peng Qinjun, Xu Zuyan, Shao jianxin, Chen Meihua, and Zhou Jie
A parameter that quantificationally evaluates the homogeneity of the absorbed pump light distribution in a laser rod is proposed, which is root mean square error relative value of absorbed pump light distribution in the laser rod. By using this parameter and the ray tracing code, the couple efficiency and the pump lighA parameter that quantificationally evaluates the homogeneity of the absorbed pump light distribution in a laser rod is proposed, which is root mean square error relative value of absorbed pump light distribution in the laser rod. By using this parameter and the ray tracing code, the couple efficiency and the pump light distribution homogeneity of a five-fold side-pumped Nd∶YAG module for different distance between LD and the side surface of the Nd∶YAG rod are quantificationally investigated, and structure parameters are optimized. At 100 Hz and 2% duty cycle, the maximum average pump power of the module at 808 nm is 200 W. Arranging one such pump module in a plane-plane short cavity, 95 W multi-mode laser output at 1064 nm can be delivered. The corresponding optical to optical efficiency is 47.5%..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1337 (2009)
Compact LD End-Pumped Nd∶YVO4 Intracavity Frequency-Tripled 355 nm Laser
Liu Huan, and Gong Mali
A laser diode-end-pumped Nd∶YVO4 intracavity frequency-tripled quasi-continuous 355 nm laser has been demonstrated. The efficient second and third-harmonic generation with the high peak power and stable operation is generated by two lithium triborate (LBO) crystals. The laser cavity is a simple plane-to-plane linear caA laser diode-end-pumped Nd∶YVO4 intracavity frequency-tripled quasi-continuous 355 nm laser has been demonstrated. The efficient second and third-harmonic generation with the high peak power and stable operation is generated by two lithium triborate (LBO) crystals. The laser cavity is a simple plane-to-plane linear cavity with the cavity length of 108 mm. An average 355 nm laser with output power of 245 mW is obtained at a pump power of 6.76 W, a pulse repetition rate of 20 kHz and the highest optical-to-optical efficiency of 3.62%. The corresponding pulse width and pulse peak power are 8.0 ns and 1.52 kW, respectively. The instability is less than 4.2% and the beam quality is satisfactory. This technique can decrease some optical elements reduce the size and enhance the handiness of the laser. These advantages will benefit the broad applications of the ultraviolet lasers..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1341 (2009)
Output Power Stability of Dual-Wavelength Erbium-Doped Fiber Ring Laser
Xu Pan, Hu Zhengliang, Ma Lina, Meng Zhou, and Hu Yongming
The condition for equilibrium oscillation of dual-wavelength erbium-doped fiber ring laser is derived from the average inversion level model. According to this condition, a novel experiment setup is built to measure the influence of pump power, mode losses and wavelength interval on the output power. Experiment resultsThe condition for equilibrium oscillation of dual-wavelength erbium-doped fiber ring laser is derived from the average inversion level model. According to this condition, a novel experiment setup is built to measure the influence of pump power, mode losses and wavelength interval on the output power. Experiment results show that the multi-wavelength oscillation in erbium-doped fiber ring laser can be achieved by adjusting the loss spectrum of laser cavity, and the condition for equilibrium oscillation is valid when pump power is far away from the threshold point. The stability of variable optical attenuator has so great influence on the balance of dual-wavelength whose acceptable loss bias is less than 0.4 dB. However the stability of central wavelength of fiber Bragg grating (FBG) has little influence on the balance of dual-wavelength which won’t be broken by the wavelength bias less than 1 nm. Inhomogeneous effect of erbium-doped fiber allows tiny perturbation of the loss in state of equilibrium, which is helpful to improve the stability of the laser output power, and the power fluctuation of 1546 nm and 1556 nm over 30 minutes is less than 0.5 dB..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1347 (2009)
Tunable Er3+/Yb3+ Co-Doped Fiber Laser Based on Blazed Grating
Wu Zhuoliang, Zhao Shanghong, Chu Xingchun, Li Lin, and Zhan Shengbao
A widely tunable Er3+/Yb3+ co-doped fiber laser with simple structure is demonstrated. Using a blazed grating as the wavelength selection element, and a semiconductor laser diode as the pumping source, stable tunable output laser in 1550 nm wave-band is obtained with large-mode-area Er3+/Yb3+ co-doped double-cladding fA widely tunable Er3+/Yb3+ co-doped fiber laser with simple structure is demonstrated. Using a blazed grating as the wavelength selection element, and a semiconductor laser diode as the pumping source, stable tunable output laser in 1550 nm wave-band is obtained with large-mode-area Er3+/Yb3+ co-doped double-cladding fiber as the gain medium. The tuning range is 36 nm, covering almost the whole fluorescence spectrum. The linewidth is less than 0.08 nm for every tuned laser. For different wavelength, the output power is different, and the output power is higher than 400 mW within 25 nm tuning range. The maximum achieved power is 510 mW with the wavelength of 1543.86 nm and the calculated slope efficiency is 26%. With wide tunable range and narrow linewidth, this stable efficient laser can be used in dense wavelength division multiplexed (DWDM) optical fiber communication systems and high resolution fiber sensor systems..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1352 (2009)
Thermal Property of High Power 980 nm InGaAs/InGaAsP/InGaP Laser Diodes
Qiu Liping, Guo Weiling, Luo Dan, Cui Bifeng, Zhang Lei, and Shen Guangdi
An aluminum-free InGaAs/InGaAsP/InGaP single quantum well (SQW) laser diode (LD) is grown by low-pressure MOCVD. The P-I-V characteristics of Al-free and Al-containing 980-nm InGaAs lasers are tested in temperature range of 30-70 ℃. The variations with temperature of the two different LDs’ characteristic parameters, inAn aluminum-free InGaAs/InGaAsP/InGaP single quantum well (SQW) laser diode (LD) is grown by low-pressure MOCVD. The P-I-V characteristics of Al-free and Al-containing 980-nm InGaAs lasers are tested in temperature range of 30-70 ℃. The variations with temperature of the two different LDs’ characteristic parameters, including output power, threshold current, slope efficiency, and the wavelength, are analyzed contrastively. The reliability experiments on the InGaAs/InGaAsP/InGaP laser diodes are also carried out..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1356 (2009)
Stability Analysis for External Cavity Modes of Semiconductor Laser Subject to Optical Feedback
Wang Shaoqing, Wang Xiangzhao, and Bu Yang
The dynamics of semiconductor laser subject to optical feedback was studied analytically by the means of asymptotic analysis method. The stabilities of external cavity modes (ECMs) were analyzed, and the bifurcation boundaries of the ECMs were obtained. The stable regions of the ECMs are proposed and verified by numeriThe dynamics of semiconductor laser subject to optical feedback was studied analytically by the means of asymptotic analysis method. The stabilities of external cavity modes (ECMs) were analyzed, and the bifurcation boundaries of the ECMs were obtained. The stable regions of the ECMs are proposed and verified by numerically calculating the Poincare section of semiconductor laser carrier density. The bifurcation diagram of semiconductor laser carrier density at different effective injection currents was numerically calculated and the first Hopf bifurcation boundary was agrees with the first Hopf bifurcation boundary calculated by the asymptotic method under the low injection current conditions..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1360 (2009)
Rate Equations and Gain Characteristics of Quantum-Dot Semiconductor Optical Amplifiers
Li Ruigang, Liu Yumin, Yu Zhongyuan, Feng Hao, Lu Wenjuan, and Xu Zihuan
To investigate the properties of quantum-dot semiconductor optical amplifiers (QD-SOA), we establish a three-energy-system model in the conduction band of the QD-SOA. Optimize and compare the rate equations with those in references. Temporal solutions and distribution of electronic states derived by numerical calculatiTo investigate the properties of quantum-dot semiconductor optical amplifiers (QD-SOA), we establish a three-energy-system model in the conduction band of the QD-SOA. Optimize and compare the rate equations with those in references. Temporal solutions and distribution of electronic states derived by numerical calculation certify the discrete nature of the energy levels of the quantum-dot. Using the fact that the occupation probabilities of electrons and holes are linear in the ground state, we solve the rate equations at steady state to obtain the gain characteristics of QD-SOA and its relation to the occupation probabilities of electrons of the ground state. The results show that the QD-SOA has larger saturated optical gain, higher differential gain and lower operation current. The QD-SOA has more merits than the bulk or quantum-well optical amplifiers, which provide the instructions on designing optical amplifiers..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1366 (2009)
Influence of Reflection of Diffractive Optical Elements on High-Power Laser System
Li Ke, Liu Qiang, and Li Yongping
In high power laser system the light intensity distribution of surface reflection produced by diffractive optical element (DOE) used in beam smoothing was calculated. Calculation showed that with the increasing of transmission distance, the reflected light due to interference would produce a certain number of extreme pIn high power laser system the light intensity distribution of surface reflection produced by diffractive optical element (DOE) used in beam smoothing was calculated. Calculation showed that with the increasing of transmission distance, the reflected light due to interference would produce a certain number of extreme points, which could be harm to the front element. As a result, in the high-power laser system, it is necessary to place DOE with a tilt angle, so that the reflection light can deviate from the front element. The impact on beam smoothing with changing angle was calculated, and the sharp deterioration of smoothing was found and the corresponding qualitative results were observed in experiment. Phase compensation method was presented, to maintain the ability of the beam smoothing with DOE tilted, and the numerical simulation of phase compensation was given..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1371 (2009)
Possibility of Undulator Radiation as Short Length Laser by Periodically Bent Crystal
Luo Shiyu, and Shao Mingzhu
It is indicated that the serious difficulty will be encountered in order to obtain a short wave-length laser by the tradition technique, and new light source is seeked. Besides the channeling radiation, there is an undulator radiation in acoustically bent crystal. The undulator radiation is panalle to the beam at a maxIt is indicated that the serious difficulty will be encountered in order to obtain a short wave-length laser by the tradition technique, and new light source is seeked. Besides the channeling radiation, there is an undulator radiation in acoustically bent crystal. The undulator radiation is panalle to the beam at a maximum/minimum for the undulator obital, the case is simular to free electron lasers (FEL). An emied photon at successivelly a maximum/minimum of the undulator obital is stimulated, and radiation frequency is higher than FEL. The frequency and the spectral distribution of the channeling radiation and the undulator radiation are described in a harmonic approximation, the relationship between them is discussed. The possibilities of using the crystallographica undulator radiation as X-laser and γ-laser are analysed detailly..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1378 (2009)
Experimental Research on a Scannerless 3D Imaging Laser Radar
Jin Chenfei, Zhao Yuan, Zhang Yong, He Jiang, and Sun Xiudong
A scannerless 3D imaging laser radar is developed. A pulsed solid state laser is used as source with image intensified CCD (ICCD) as imaging detector. When the laser source transmits light pulse to a target scene, the image intensifier of ICCD is modulated with the monotone time-variant high voltage. High voltage signaA scannerless 3D imaging laser radar is developed. A pulsed solid state laser is used as source with image intensified CCD (ICCD) as imaging detector. When the laser source transmits light pulse to a target scene, the image intensifier of ICCD is modulated with the monotone time-variant high voltage. High voltage signal controls the image intensifier to produce the monotone time-variant gain modulation, which leads to different amplification factor on return light reflected from different range. By analyzing and comparing the energy of amplified signals, we can calculate the flight time of every return light and then get the range of the corresponding target. Results demonstrate that the system can effectively eliminate the effect of non-uniform of the return light intensity. An indoor imaging experiment is performed for demonstrating the feasibility of system, and range image of targets from 35 to 41 meters distance is successfully acquired and the range accuracy can be less than 1 meter..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1383 (2009)
Micro-Power Meter
Zhang Gangping, Huang Yaoxiong, and Li Shengli
We report a micro-laser power meter, which is made of silicon photoelectric cell for measuring the laser power from micro-focus systems. The power meter has the characteristics of wide spectrum response, excellent linearity, high sensitivity, good stability, fast speed, and convenience for using. The micro-laser power We report a micro-laser power meter, which is made of silicon photoelectric cell for measuring the laser power from micro-focus systems. The power meter has the characteristics of wide spectrum response, excellent linearity, high sensitivity, good stability, fast speed, and convenience for using. The micro-laser power meter, can be placed on the platforms in different kinds of microscope, even in the solutions of culturing biological samples, to measure the laser power projecting on samples for simulating the real environment and position of the samples. It is also suitable for the measurement of different wavelengths and different power levels (from 1～50 mW) of light..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1388 (2009)
Simulation of 100 kW Solid-State Laser Relay Mirror System
Wu Huiyun, Chen Jinbao, Wu Wuming, and Xu Xiaojun
The model of laser relay mirror system is established, to calculate the effect of telescope solid-state laser relay mirror system and the conventional high energy laser system on 1-km altitude,1-km/s speed target by using the “4-D” code of the laser atmosphere propagation. Because the relay mirror system has long time The model of laser relay mirror system is established, to calculate the effect of telescope solid-state laser relay mirror system and the conventional high energy laser system on 1-km altitude,1-km/s speed target by using the “4-D” code of the laser atmosphere propagation. Because the relay mirror system has long time effect on the target, its damage threshold standard for 3-cm bucket power is 28.27 kW and 5.655 kW. The analysis results show that the coverage range of the conventional high energy laser system is 4.6 km, and the coverage range of laser relay mirror system is 11.3 km. Compared with the conventional high energy laser system the relay mirror system reduces the influence of the atmosphere on the laser, and opens up the coverage range of the laser system..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1392 (2009)
Distortion Invariant Pattern Recognition Based on Amplitude-Modulated Phase-Only Filtering and Sliced Orthogonal Nonlinear Generalized Correlation
Wu Dan, Lu Yuan, Ling Yongshun, and Ma Chaojie
A new algorithm for distortion invariant optical correlation pattern recognition based on amplitude-modulated phase-only filtering and sliced orthogonal nonlinear generalized (SONG) correlation is proposed. An algorithm for distortion invariant pattern recognition is proposed by utilizing amplitude-modulated phase-onlyA new algorithm for distortion invariant optical correlation pattern recognition based on amplitude-modulated phase-only filtering and sliced orthogonal nonlinear generalized (SONG) correlation is proposed. An algorithm for distortion invariant pattern recognition is proposed by utilizing amplitude-modulated phase-only filtering with good discrimination and synthetic discriminant function, and the result of correlation output under the algorithm is much better than that of conventional synthetic discriminant function. The technique of SONG correlation with excellent discrimination and performance of resisting noise is introduced, and the new algorithm with several excellent capabilities for distortion invariant pattern recognition and combining these two techniques of nonlinear filtering is obtained. The results of simulation indicate that the new algorithm not only enhances the quality of correlation peak and multiple target discrimination, but also has a good performance of resisting noise. The discrimination capacity of more than 97% can be obtained under new algorithm even the input image is destroyed by noise badly. Compared with other algorithm for distortion invariant pattern recognition combined with SONG correlation, the new algorithm is more practical and generalized with better discrimination..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1397 (2009)
Visibility-Enhanced In-Line Fabry-Pérot Interferometers by the Use of Femtosecond Lasers
Deng Ming, Rao Yunjiang, and Zhu Tao
A novel in-line Fabry-Pérot interferometer is directly fabricated in a single mode fiber by the use of femtosecond lasers. The spectrum fringe of this interferometer has the visibility of ～5 dB due to the rough and slopped cavity surfaces, making it more difficult for post signal processing and reducing the measurA novel in-line Fabry-Pérot interferometer is directly fabricated in a single mode fiber by the use of femtosecond lasers. The spectrum fringe of this interferometer has the visibility of ～5 dB due to the rough and slopped cavity surfaces, making it more difficult for post signal processing and reducing the measurement accuracy and reliability. By choosing the optimal parameters, improving machining environments and methods, ideal Fabry-Pérot cavities are fabricated, which are so smooth and parallel that the fringe visibility is as high as ～18 dB. In addition, with an accessible cavity and all-fiber structure, this sensor can work in high temperatures up to 800 ℃, which is attractive for sensing applications in harsh environments..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1459 (2009)
Numerical Study of Ultrashort Optical Pulse Propagation and Switching in Active Three-Core Nonlinear Fiber Couplers
Li Qiliang, Xie Yuyong, Zhu Yinfang, and Lin Libin
Based on coupled nonlinear Schrdinger equations (CNLSEs) and the split-step Fourier method (SSFM), the ultrashort optical pulse propagation and switching in active three-core nonlinear fiber couplers are numerically investigated. The effects of linear gain coefficient and finite gain bandwidth on pulse propagation and Based on coupled nonlinear Schrdinger equations (CNLSEs) and the split-step Fourier method (SSFM), the ultrashort optical pulse propagation and switching in active three-core nonlinear fiber couplers are numerically investigated. The effects of linear gain coefficient and finite gain bandwidth on pulse propagation and switching have been highlighted, considering the influences of the first and second order coupling coefficient dispersion. It is demonstrated that the linear gain coefficient can sharpen the switching characteristic, lower considerably the switching critical energy, and increase significantly the switching efficiency. Though the finite gain bandwidth of the linear gain degrades the switching characteristics, it not only can suppress significantly the pulse compression and amplification induced by linear gain, but also can suppress effectively the pulse distortion even pulse breakup due to the first order coupling coefficient dispersion as well as the pulse high-frequency fluctuation caused by the second order coupling coefficient dispersion. Because of the effects of the finite gain bandwidth of the linear gain, optical pulses tend to restore periodical coupling propagation in active three-core nonlinear fiber couplers as in the case of the passive fiber couplers..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1463 (2009)
Acoustic Pressure Sensitivity of Yb3+/Er3+ Co-Doped Distributed Bragg Reflection Fiber Laser Hydrophone
Ma Lina, Hu Yongming, Luo Hong, Zhang Xueliang, and Meng Zhou
Experimental research on Yb3+/Er3+ co-doped distributed Bragg reflection fiber laser (DBR-FL) hydrophone is carried out. The Yb3+/Er3+ co-doped DBR-FL, with a resonator length of 8 cm, could gain an output of 0.263 mW when the pump power is 50 mW. A Michelson fiber interferometer with Faraday rotator mirror and phase gExperimental research on Yb3+/Er3+ co-doped distributed Bragg reflection fiber laser (DBR-FL) hydrophone is carried out. The Yb3+/Er3+ co-doped DBR-FL, with a resonator length of 8 cm, could gain an output of 0.263 mW when the pump power is 50 mW. A Michelson fiber interferometer with Faraday rotator mirror and phase generated carrier (PGC) demodulation scheme, is used to interrogate acoustic signal acted on the Yb3+/Er3+ co-doped DBR-FL hydrophone, and the acoustic pressure sensitivity is gained by comparison with the standard piezoelectricity hydrophone. The fluctuation of sensitivity at single frequency is less than ±0.6 dB during repetitious tests. The frequency response is gained from 80 Hz to 2.5 kHz. Comparison experiments are also carried out on DFB-FL hydrophone, which gains a similar frequency response, showing that the fluctuation of frequency response is caused by unsealed hydrophone structure and test system..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1473 (2009)
Digitalization of the Detection Circuit for Resonator Fiber Optic Gyro Based on the Phase Modulation Spectroscopy Technique
Peng Bo, Yang Zhihuai, Ma Huilian, and Jin Zhonghe
Resonator fiber optic gyro (R-FOG) is a novel optical rotation sensor whose resonant frequency is changed due to the Sagnac effect. In R-FOG using phase modulation (PM) spectroscope technology, a digital synchronous detection circuit based on the coordinate rotation digital computer (CORDIC) algorithm is studied. It caResonator fiber optic gyro (R-FOG) is a novel optical rotation sensor whose resonant frequency is changed due to the Sagnac effect. In R-FOG using phase modulation (PM) spectroscope technology, a digital synchronous detection circuit based on the coordinate rotation digital computer (CORDIC) algorithm is studied. It can make the R-FOG system more stable and flexible using a single field programmable gate array (FPGA) to realize the modulation signal generation, synchronous demodulation and signal processing synchronously. The frequency synthesis technology and synchronous detection circuit based on CORDIC algorithm are analyzed and tested. Applying the digital synchronous detection circuit to the R-FOG system, the gyro rotation signal is observed successfully..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1479 (2009)
High Temperature Strain Sensor Based on In-Line Fabry-Perot Interferometer Formed by Hollow-Core Photonic Crystal Fiber
Rao Yunjiang, Li Hong, Zhu Tao, and Deng Ming
Based on the characteristics of high temperature resistance and well temperature stability of hollow core photonic crystal fiber (HCPCF), high temperature strain response of the micro Fabry-Perot etalon(HCPCF F-P) fabricated by splicing a section of hollow core photonic crystal fiber in between two single-mode fibers iBased on the characteristics of high temperature resistance and well temperature stability of hollow core photonic crystal fiber (HCPCF), high temperature strain response of the micro Fabry-Perot etalon(HCPCF F-P) fabricated by splicing a section of hollow core photonic crystal fiber in between two single-mode fibers is reported. Experimental results show that the HCPCF F-P has good temperature stability in the range of 100 ℃ to 700 ℃, and the strain sensitivity and linearity of HCPCF F-P is ～5.94 nm/με and ～0.9997 at 600 ℃,respectively. The max cross-influence of temperature on the strain is just about 1.5%, and the measuring accuracy is about 0.08% FS. Furthermore, the theoretical and experimental results show that the temperature sensitivity and the influence of temperature on strain of the HCPCF F-P is low, while the sensitivity, linearity and repeatability of strain of the HCPCF F-P is very high. The strain sensor has large strain measure range and no hysteresis..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1484 (2009)
Beam Transmission
Coherent Combining of Two Beams Based on Polarization Phase Locking
Lu Changyong, Liu Xu, Liu Yang, Li Li, Wang Xiaobing, WanQiang, Guo Yanlong, and Wei Shangfang
Coherent combining of laser arrays is an important technique in realizing high power high brightness laser system. The coherent combining of two orthogonal polarized lasers is achieved by using polarization phase locking technique. Experimental results show that this scheme can achieve above 90% combining efficiency evCoherent combining of laser arrays is an important technique in realizing high power high brightness laser system. The coherent combining of two orthogonal polarized lasers is achieved by using polarization phase locking technique. Experimental results show that this scheme can achieve above 90% combining efficiency even when the power of the two lasers is highly imbalanced. The combining method can be scaled to a large number of lasers..
Chinese Journal of Lasers
- Publication Date: Aug. 07, 2021
- Vol. 36, Issue 6, 1437 (2009)
Relationship between Zernike Wavefront Errors and Beam Quality Factor β for Optics System
Ye Hongwei, Li Xinyang, Xian Hao, and Rao Changhui
Decomposed by Zernike polynomials of the wavefront, the relationship between beam quality factor β and static and dynamic aberration are analyzed. The formula between β and Zernike polynomials are obtained. After numerical calculation, the first 65 order fitted coefficients about the formula are offered. The approximatDecomposed by Zernike polynomials of the wavefront, the relationship between beam quality factor β and static and dynamic aberration are analyzed. The formula between β and Zernike polynomials are obtained. After numerical calculation, the first 65 order fitted coefficients about the formula are offered. The approximate formula corresponding to Kolmogorov atmosphere turbulence is given. These approximate formulas are compared and verified well with the results of numerical calculation..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1420 (2009)
New Design of Bireflective Parallel Distensible Beam Splitting Polarization Prism
Song Zhitang, Sheng Baoli, Li Guohua, Peng Handong, and Kong Fanmei
In order to improve the extender ratio of parallelism beam splitting, a new design scheme of bireflective parallel distensible beam splitting prism is proposed. By using prism expanded beam principle and Fresnel formula, some factors, such as structure angle and refractive index, which influence the extender ratio and In order to improve the extender ratio of parallelism beam splitting, a new design scheme of bireflective parallel distensible beam splitting prism is proposed. By using prism expanded beam principle and Fresnel formula, some factors, such as structure angle and refractive index, which influence the extender ratio and transmissivity are analyzed. The effects of increasing shear difference on the basis of high transmissivity and the optimal design of structure are properly realized in the new scheme. The scheme has the deflecting function which could decrease the linear length of rays path building and save space of flat roof in experiment. The testing results show that the transmissivity and the shear difference of this new polarization prism are perfect and the experimental values are in consistent with the theoretical analysis. It is an ideal parallel beam splitting polarization device and has important practical merits..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1428 (2009)
Study of Simulation and Experiment of the Aberration of Retro Reflector Array
Hu Shijie, Shen Feng, Xu Bing, and Wu Jian
The principle of the adaptive optics system for all-path aberration correction is presented. And the correction ability of the adaptive optics system for all-path aberration correction is confined by the aberration of the retro reflector array. Three kinds of the retro reflector arrays are numerically simulated for theThe principle of the adaptive optics system for all-path aberration correction is presented. And the correction ability of the adaptive optics system for all-path aberration correction is confined by the aberration of the retro reflector array. Three kinds of the retro reflector arrays are numerically simulated for the appointed wavelength adaptive optics system for all-path aberration correction. It is studied that the aberration of the retro reflector array can be neglected while all-angle error of cell of the retro reflector array lies in 2＂. The simulation result is approved by the all-angle error based on the aberration of retro reflector in retro reflector array measured by WYKO interferometer..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1433 (2009)
Propagation Performance of Adaptive Phase-Locked Fiber Laser Array in Turbulent Atmosphere
Zhou Pu, Liu Zejin, Xu Xiaojun, Xi Fengjie, Chu Xiuxiang, and Ma Haotong
An adaptive phase-locked fiber laser array with piston and tip-tilt error correction capability is investigated. The propagation performance of the adaptive phase-locked fiber laser array in different turbulent atmosphere is numerically studied by using multiple phase screen method. BPF is introduced as beam quality faAn adaptive phase-locked fiber laser array with piston and tip-tilt error correction capability is investigated. The propagation performance of the adaptive phase-locked fiber laser array in different turbulent atmosphere is numerically studied by using multiple phase screen method. BPF is introduced as beam quality factor to study the effect of turbulence atmosphere on the propagation performance quantitatively. The influence is neglectable and the field intensity distribution remains unchanged compared to free space when the intensity of turbulence is weak (C2n=1×10－15 m－2/3, propagation distance z=10 km, coherence length=4.3 cm). The BPF value becomes 86% and 70% of the idea case when C2n=5×10－15 m－2/3 and 1×10－14 m－2/3 (corresponding coherence length are 1.6 cm and 1 cm, respectively), while the BPF value for the fiber laser array propagating in the same atmosphere without correcting piston and tip-tilt error are 55% and 38% of the idea case. The calculation results reveal that the energy centrality can be advanced evidently by the adaptive phase-locked fiber laser array..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1442 (2009)
Biomedical Photonics and Laser Medicine
Simulation Study on Phase Distribution of Blood Cells by Virtual Imitation
Wang Yawei, Han Guangcai, LiuYing, Cheng Xiaonong, and Frank Wyrowski
In order to measure different life-cells with more scattering information of hologram, light propagation models of red blood cell (RBC) and white blood cell (WBC) are built based on their optical characters and the digit holograph function of the VirtualLabTM imitation system. The distributions of cells, scattering phaIn order to measure different life-cells with more scattering information of hologram, light propagation models of red blood cell (RBC) and white blood cell (WBC) are built based on their optical characters and the digit holograph function of the VirtualLabTM imitation system. The distributions of cells, scattering phase and their intensity are achieved after using this virtual imitation experiment system according to the digit phase microscopy (DPM) method and its experimental parameters. These distribution characters are studied and it is found that the phase distributions can be used as an important criterion for testing cells, distribution because of their relationship. Comparing the 3-D building method, this cell-constructing method based on the phase analysis needs fewer confine condition and less counting. It provides a breakthrough for developing cell’s measurement in technique and method..
Chinese Journal of Lasers
- Publication Date: Aug. 07, 2021
- Vol. 36, Issue 6, 1595 (2009)
Laser Manufacturing
Loading Mechanism of Metal Foil Forming under Laser Driven Flyer
Wang Xiao, Yang Kun, Liu Huixia, Wang Yun, Li Baochun, Gao Chuanyu, and Zhou Ming
The method of metal foil forming under laser-driven flyer loading was introduced and the speed of flyer was calculated through Gurney model. The 10 μm thickness aluminum flyer reached a speed of 250 m/s when laser power density was 0.64 GW/cm2. The impact pressure went up to 1.9 GPa which was about 3 times of laser indThe method of metal foil forming under laser-driven flyer loading was introduced and the speed of flyer was calculated through Gurney model. The 10 μm thickness aluminum flyer reached a speed of 250 m/s when laser power density was 0.64 GW/cm2. The impact pressure went up to 1.9 GPa which was about 3 times of laser induced at constraint model. It was shown that laser driven flyer loading had higher forming ability than laser shock. The micro-forming process of metal foil under laser-driven flyer loading was simulated by LS-DYNA. The flyer stress and speed was studied, the simulation results agreed well with theoretical calculations. And the mechanism of laser driven flyer loading was verified..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1569 (2009)
Pulse Modulation Characteristic of High Power Continuous CO2 Laser and its Application in Special Cladding
Liu Juan, Tang Xiahui, Peng Hao, and Qin Yingxiong
For cracks and deformations appeared in continuous laser cladding in aircraft engine turbine blade, we propose a new method on power supply control based on the 5-kW continuous transverse flow CO2 laser. Pulse laser power can be obtained by the control of software and interrelated components. The method can over come tFor cracks and deformations appeared in continuous laser cladding in aircraft engine turbine blade, we propose a new method on power supply control based on the 5-kW continuous transverse flow CO2 laser. Pulse laser power can be obtained by the control of software and interrelated components. The method can over come the problem of high costs and instability by using high power switch source supply. The pulse modulation frequency can reach 10 Hz and the duty cycle can be modulated between 5% and 100%. K403 alloy of the turbine blade is cladded with Stellite X-40 alloy powder in the surface using this kind of pulse laser power whose maximum laser power is 4 kW, and the repetitive frequency is 5 Hz with the duty cycle of 20%. The result shows that, compared with that using the continuous laser power, the heat affected zone is reduced 50%, and the microhardness is improved 5%. So the binding performance of the interface is as good as the base metal, and the cladding cracks and blade deformations disappear..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1575 (2009)
Laser Cladding Fe-Al Intermetallics Coatings on ZL101 Substrate
Wang Yanfang, Li Gang, and Wu Tongxia
Fe-Al Intermetallics coatings are prepared on ZL101 substrate by laser cladding pure Fe and pure Al powders. The microstructure and hardness of the coatings and interface between the coating and substrate are analyzed by using optical microscopy, SEM, X-ray diffraction (XRD), and microhardness testing machines. The resFe-Al Intermetallics coatings are prepared on ZL101 substrate by laser cladding pure Fe and pure Al powders. The microstructure and hardness of the coatings and interface between the coating and substrate are analyzed by using optical microscopy, SEM, X-ray diffraction (XRD), and microhardness testing machines. The results show that the bonding zones between substrate and coatings are sawtooth-liked structure. The coating mainly constitute of FeAl and Fe3Al phases. All the three coatings (Fe-Al, 2Fe-Al and 3Fe-Al)have high microhardness, which achieve 744 HV, 603 HV and 795 HV respectively..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1581 (2009)
Microstructures of Laser Forming Repair 7050 Aluminum Alloy with AlSi12 Powder
Wang Xiaoyan, Chen Jing, Lin Xin, Zhang Fang, and Huang Weidong
Laser forming repair pre-tensile 7050 aluminum alloy with AlSi12 powder was studied using 300 W YAG laser. The optimized process parameters were obtained in multi-trace and multi-layer laser repair experiment. The elimination measures of metallurgical defects and the microstructures distribution of repaired zone were aLaser forming repair pre-tensile 7050 aluminum alloy with AlSi12 powder was studied using 300 W YAG laser. The optimized process parameters were obtained in multi-trace and multi-layer laser repair experiment. The elimination measures of metallurgical defects and the microstructures distribution of repaired zone were analyzed. It is found that the metallurgical defects including illbond, porosities and liquefied cracks can be eliminated through chemical treatment for the substrate surface, optimizing the process parameters and changing the powder condition. The microstructure at the bottom of the repaired zone is composed of the α-Al solid solution dendrite and a small number of Al-Si eutectic. With the increasing of the cladding layers, the eutectic volume fraction increases continuously, the α-Al solid solution dendrite is refined and the transformations from columnar grain to equiaxed grain take place. Finally, the completely refined equiaxed grains are achieved at the top of the repaired zone..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1585 (2009)
Ni-Cr-C-CaF2 Composite Laser Cladding on γ-TiAl Intermetallic Alloy
Liu Xiubo, Shi Shihong, Fu Geyan, Liu Yuanfu, and Mu Junshi
Experiments of laser cladding Ni-Cr-C-CaF2 precursor mixed powders to form a high- temperature self lubrication wear resistant composite coating on γ-TiAl substrate was carried out. The microstructure of the coating was examined using X-ray diffraction (XRD),scanning electron microscope (SEM) and energy disperse spectrExperiments of laser cladding Ni-Cr-C-CaF2 precursor mixed powders to form a high- temperature self lubrication wear resistant composite coating on γ-TiAl substrate was carried out. The microstructure of the coating was examined using X-ray diffraction (XRD),scanning electron microscope (SEM) and energy disperse spectroscopy (EDS). The coating has a unique microstructure consisting of primary dendrite or short-stick TiC and secondary block Al4C3 carbides reinforcement as well as fine isolated spherical CaF2 solid lubrication particles uniformly dispersed in the ductile and tough NiCrAlTi (γ) matrix. The average microhardness of the composite coating is approximately HV 650 and it is 2-factor greater than that of the TiAl substrate..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1591 (2009)
Laser Physics
Experimental Study of Combustor of Combustion-Driven All Gas-Phase Iodine Laser
Tang Shukai, Duo Liping, Yu Haijun, Wang Jian, Sang Fengting, and Jin Yuqi
Combustor parameter of all gas-phase iodine laser is studied using the power of HF fundamental laser as a test criterion. The experimental results show that optimal F flow rate can be obtained as the excessive NF3 flow rate of 30%～70% is used for D2 flow rate of 10～20 mmol/s. Addition of attenuant He is a disadvantage Combustor parameter of all gas-phase iodine laser is studied using the power of HF fundamental laser as a test criterion. The experimental results show that optimal F flow rate can be obtained as the excessive NF3 flow rate of 30%～70% is used for D2 flow rate of 10～20 mmol/s. Addition of attenuant He is a disadvantage for the F atom production. F atoms can be replaced by Cl atoms with enough DCl added. A source of Cl atoms is prepared for the study of all gas-phase iodine laser..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1403 (2009)
A Novel Method of Measuring Fluorine Atom Flow Rate for Discharge Driven HF/DF Chemical Laser
Luo Wei, Li Wenyu, Wang Hongyan, Zhang Xuanzhe, Zhou Qiong, Guo Qian, and Chen Jingchun
We introduce a nove method of measuring fluorine atom flow rate which named titration-HF absorption method. It uses discharge driven single-line HF laser as detect light source, monitors the absorption of titration product-HF molecule, and gets the relationship between F atom flow rate and titration gas (hydrogen gas) We introduce a nove method of measuring fluorine atom flow rate which named titration-HF absorption method. It uses discharge driven single-line HF laser as detect light source, monitors the absorption of titration product-HF molecule, and gets the relationship between F atom flow rate and titration gas (hydrogen gas) flow rate. By this method, in the condition of different NF3 flow rates and different spectra lines, the fluorine atom flow rate of a discharge driven HF/DF chemical laser is measured. It is found that the absorption of lower rotational state line is stronger, and about 1.0～1.1 fluorine atom can be dissociated from one NF3 molecule we analyze the relationship between the transmittance and the fluorine atom flow rate along with the temperature. The factors that influence the measuring precision are also analyzed and the countermeasures are given for the future work. Experiment results prove that the titration-HF absorption method is a simple, useful method of fluorine atom flow rate measuring..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1407 (2009)
Laser Frequency Stabilization of Coherent Population Trapping Atomic Frequency Standard Realized with Digital Servo
Lü Liqiang, Du Runchang, Liu Chaoyang, and Gu Sihong
We present the locking laser frequency on a Doppler absorption peak for the small size coherent population trapping (CPT) atomic frequency standard by using digital control circuit with a field-programmable gate array (FPGA) core. With the similar scheme to lock microwave frequency, it is realized of the close loop locWe present the locking laser frequency on a Doppler absorption peak for the small size coherent population trapping (CPT) atomic frequency standard by using digital control circuit with a field-programmable gate array (FPGA) core. With the similar scheme to lock microwave frequency, it is realized of the close loop locking of the CPT frequency standard. There are many advantages of the digital servo system based on FPGA using Verilog language, such as compact structure, flexible parameter adjustment, easy debug, low power consumption, and small temperature coefficient, etc. Benefited from the characteristics of programming and digital circuit, the system is good in transplantation and consistency. With this digital servo scheme, the realized CPT frequency standard achieves 4-W power consumption and 6×10－11τ－1/2 frequency stability, which proves to be a feasible scheme..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1411 (2009)
Influence of Initial Plasma Temperature on Energetic Proton Generation From Laser-Plasma Interactions
Bin Jianhui, Lei Anle, and Yu Wei
The influence of initial plasma temperature on energetic proton generation from the intense laser plasma interactions is studied by using two dimensional particle-in-cell simulation. It is found that the time required for the shock formation can be affected by the initial plasma temperature, which influences the energeThe influence of initial plasma temperature on energetic proton generation from the intense laser plasma interactions is studied by using two dimensional particle-in-cell simulation. It is found that the time required for the shock formation can be affected by the initial plasma temperature, which influences the energetic proton generation in the shock. Simulations show that high proton yield can be obtained by increasing the initial plasma temperature moderately..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1416 (2009)
Materials and Thin Films
Fabrication and Characterization of Nd3+∶YAG Nanofibers
Gao Xubo, Dong Xiangting, Fan Lijia, Wang Jinxian, and Liu Guixia
PVP/[Y(NO3)3+Al(NO3)3+Nd(NO3)3] composite fibers are prepared by electrospinning, and Nd3+∶YAG nanofibers are fabricated by calcination of the prepared composite nanofibers. X-ray diffraction (XRD) results show that the composite nanofibers are amorphous in structure, and pure phase Nd3+∶YAG nanofibers are obtained by PVP/[Y(NO3)3+Al(NO3)3+Nd(NO3)3] composite fibers are prepared by electrospinning, and Nd3+∶YAG nanofibers are fabricated by calcination of the prepared composite nanofibers. X-ray diffraction (XRD) results show that the composite nanofibers are amorphous in structure, and pure phase Nd3+∶YAG nanofibers are obtained by calcination of the composite fibers at 900 ℃ for 10 h. Scanning electron microscope (SEM) analysis indicates that the diameter of the prepared Nd3+∶YAG nanofibers is about 75 nm, and the length is greater than 100 μm. Thermogravimetry and differential thermal analysis (TG-DTA) analysis reveals that the dimethylfomamide (DMF), organic compands, and nitrate salts in the composite nanofibers are decomposed and volatilized totally, the weight of the sample keeps constant when sintering temperature is above 550 ℃, and the total weight loss percentage is 84.7%. Fourier transform infrared spectrometer (FTIR) analysis manifestes that polycrystalline Nd3+∶YAG luminescant nanofibers are formed at 900 ℃. The luminescent property of Nd3+∶YAG nanofibers is investigated. The formation mechanism of the Nd3+∶YAG nanofibers is preliminarily discussed. This method can be applied to prepare other rare earths garnet-typed compound nanofibers..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1517 (2009)
Growth and Spectral Properties of Nd∶CaNb2O6 Crystal
Cheng Yan, Xin Zheng, Xu Xiaodong, Xu Jun, and Zhou Shengming
New single crystal Nd∶CaNb2O6 is successfully grown by using the Czochralski method along the c- direction. Absorption spectra are measured at room temperature. Peak absorption cross section is calculated to be 5.04×10-20 cm2 with a broad FWHM of 8 nm at 808 nm. Based on Judd-Ofelt theory, the parameters of line sNew single crystal Nd∶CaNb2O6 is successfully grown by using the Czochralski method along the c- direction. Absorption spectra are measured at room temperature. Peak absorption cross section is calculated to be 5.04×10-20 cm2 with a broad FWHM of 8 nm at 808 nm. Based on Judd-Ofelt theory, the parameters of line strengths Ωt(t=2, 4, 6) are fitted and the values are Ω2=5.321×10-20 cm2, Ω4=1.734×10-20 cm2, and Ω6=2.889×10-20 cm2. The radiative lifetime is 167.02 μs. The fluorescence branch ratios are calculated: β1 =36.03%, β2=52.29%, β3=11.15%, β4 =0.533%. Good spectroscopic properties show that the Nd∶CaNb2O6crystal is a potential laser gain medium of solid-state laser..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1523 (2009)
Photopolymerization Behaviors of Novel Two-Photon Absorption Initiators and Fabrication of Microdevices
Guo Fuquan, Hu Zhiyuan, Fu Xinjian, Zhang Qijing, Huang Wenhao, and Xia Andong
Three novel stilbene derivatives (named as BPSBP,BESBP and BCSBP respectively) with D-π-D molecular motif, used as two-photon absorption (TPA) initiators, are designed and synthesized aimed at the excitation source of 800 nm. TPA induced photopolymerization behaviors are studied with the pumping of a femtosecond laser.Three novel stilbene derivatives (named as BPSBP,BESBP and BCSBP respectively) with D-π-D molecular motif, used as two-photon absorption (TPA) initiators, are designed and synthesized aimed at the excitation source of 800 nm. TPA induced photopolymerization behaviors are studied with the pumping of a femtosecond laser. Effects of the concentrations of TPA initiators on initiation thresholds and effects of the concentrations of TPA initiators, the polymerized energy and the exposure time on the resolution in polymerization are discussed in detail. 3D periodic microstructure with submicrometer resolution is fabricated and characterized by scanning elletron microscope (SEM) under optimized conditions using BPSBP as TPA initiators with the concentration of 32 μmol/g and polymerized energy of 9×105 mJ/cm2..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1528 (2009)
Filter Characteristics of One-Dimensional Photonic Crystal with Complex Dielectric Constant
Su An, and Gao Yingjun
The transmission spectra of one-dimensional photonic crystal (ABCBA)m are calculated by means of the transfer matrix method. As the dielectric constant is a real number, the transmission resonance spectrum in photonic crystals is of multi-channel optical filtering properties. When the C medium is added with active mattThe transmission spectra of one-dimensional photonic crystal (ABCBA)m are calculated by means of the transfer matrix method. As the dielectric constant is a real number, the transmission resonance spectrum in photonic crystals is of multi-channel optical filtering properties. When the C medium is added with active matter, there is only one resonance peak. If the number of m is an odd, the rate of transmission is 0.05 at ω/ω0. If the number of m is even, then the rate is up to 104. The strength of the gain is closely related to the number of m and the value of the imaginary part. It provides theoretical guidance for designing new photonic instrument with properties of single-channel optical filter, multi-channel optical amplifiers and filters..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1535 (2009)
Affect of ZnO Thin Film of Pulsed Laser Deposition by Substrate Temperatures
Chen Jiangbo, Wang Li, Su Xueqiong, Liu Hongmei, and Wang Rongping
In this paper, pulsed laser deposition method was applied to grow ZnO films in different temperature, with ZnO ceramics as target, sapphire Al2O3 (0001) for substrate, and using the pulsed laser GCR-170 Nd∶YAG by Spectra-Physics. The thin film structure and superficial morphology quality have been researched in experimIn this paper, pulsed laser deposition method was applied to grow ZnO films in different temperature, with ZnO ceramics as target, sapphire Al2O3 (0001) for substrate, and using the pulsed laser GCR-170 Nd∶YAG by Spectra-Physics. The thin film structure and superficial morphology quality have been researched in experiment by atomic force microscope (AFM), photoluminescence (PL) and optical transmission spectrum, and optimize growth temperature was found to be 500 ℃ at which the ZnO films could obtain high-quality surface. The high violet light radiation have been found in experiment. The optical transmission spectrum versus the substrate temperature results showed that for the ZnO thin films prepared on sapphire, the surface morphology quality of the ZnO thin film was enhanced with increasing the substrate temperature from room temperature to 500 ℃..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1539 (2009)
1064 nm Laser Conditioning Effect of HfO2/SiO2 High Reflectors Deposited by E-Beam
Liu Xiaofeng, Li Dawei, Li Xiao, Zhao Yuan’an, and Shao Jianda
Laser conditioning is one of the important methods to improve the laser damage threshold of film optics. First, both 1-on-1 and R-on-1 test are done on the fundamental frequency high reflectors, which are evaporated from hafnia and silica by e-beam. Next, the typical damage morphologies occurred in the two measurementsLaser conditioning is one of the important methods to improve the laser damage threshold of film optics. First, both 1-on-1 and R-on-1 test are done on the fundamental frequency high reflectors, which are evaporated from hafnia and silica by e-beam. Next, the typical damage morphologies occurred in the two measurements are compared and analyzed. Obvious laser conditioning effect is observed in the R-on-1 test, the damage threshold of which is three times larger than that of 1-on-1 test. The typical morphology in 1-on-1 test is plasma scalding with a central flat-bottom pit and the typical morphology in R-on-1 test is plasma scalding only. The results of surface profiler measurement show that all the centers of the plasma scalds that occurred in the above two typical damage morphologies are raised. The two different damage morphologies imply that absorbing defect is the inducement of the damage and the macroscopical reason for the improved laser damage threshold in R-on-1 test, is presented as the mechanic stability of absorbing defects..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1545 (2009)
Study and Fabrication of Multi-Band Laser Filter Film
He Caimei, Fu Xiuhua, Sun Yulin, and Li Meixuan
In order to meet the optical instruments’ special demands for multi-spectral optical axis testing, we adopt electronic beaming vacuum depositing method with the aid of ion assistant deposition systems. Through analyzing the optical characters of coating material, film designing, monitoring thickness error, and optimiziIn order to meet the optical instruments’ special demands for multi-spectral optical axis testing, we adopt electronic beaming vacuum depositing method with the aid of ion assistant deposition systems. Through analyzing the optical characters of coating material, film designing, monitoring thickness error, and optimizing technical parameters, we deposit multi-band laser filter film on the substrate of ZnS to achieve beam split of multi-band spectrum. In condition of 30° incident angle on both coating surface, the average transmittance exceeds 90% through 400～700 nm wavelength. Moreover, it makes the transmittance over 92% in 10.6 μm, below 5% in wavelength 1064 nm and 1540 nm. In addition, our experiment improves the adhesion of the film. It can resist laser beams and conform to environmental stability standards, completely meet the demands of optical instruments..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1550 (2009)
Design and Realization of Extensive Optical Thin Film Mapping Measurement Platform
Lu Weijie, Zhang Rongjun, Chen Yiming, Zheng Yuxiang, Cheng Xu, Li Chuanwen, and Chen Liangyao
An extensive optical thin film mapping measurement platform was designed and realized using the module-based design model. Different types of mapping measurement can be supported by the platform through adding new device modules. The mapping transmittance spectrum of a wavelength-division-multiplex (WDM) filter is succAn extensive optical thin film mapping measurement platform was designed and realized using the module-based design model. Different types of mapping measurement can be supported by the platform through adding new device modules. The mapping transmittance spectrum of a wavelength-division-multiplex (WDM) filter is successfully measured with the platform..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1555 (2009)
Study on Surface Roughness of Substrates under Different Cleaning Techniques by Total Integrated Scatter
Hou Haihong, Shen Jian, Zhang Dawei, and Fan Zhengxiu
Total integrated scatter (TIS) is used to measure the root mean square (RMS) roughness of the fused quartz substrates cleaned by Kaufmann ion source and the K9 glass substrates cleaned by ultrasonic and End-hall ion source, respectively, to study the influence of the above cleaning methods on the surface micro-roughnesTotal integrated scatter (TIS) is used to measure the root mean square (RMS) roughness of the fused quartz substrates cleaned by Kaufmann ion source and the K9 glass substrates cleaned by ultrasonic and End-hall ion source, respectively, to study the influence of the above cleaning methods on the surface micro-roughness of substrates. It is found that the RMS roughness of the K9 glass substrates cleaned by ultrasonic under different conditions all increases due to the damnification of the substrate surfaces, while the surface RMS roughness of the samples cleaned by End-hall ion source and Kaufmann ion source is significantly affected by the experiment parameters, such as the beam current, the cleaning time, and the energy of the ion beam. The RMS roughness of the samples can be decreased under appropriate experiment conditions..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1559 (2009)
Error Analysis of Gires-Tournois Negative Dispersion Mirrors
Wang Yanzhi, Shao Jianda, Jin Yunxia, Huang Jianbin, Zhang Weili, Dong Hongcheng, He Hongbo, and Fan Zhengxiu
The compensation of negative-dispersion mirrors has very high request on design and preparation. The refractive index and physical thickness are the necessary parameters for the realization of the capability. Negative-dispersion mirrors are designed and prepared, which are analyzed from the main factors such as materiaThe compensation of negative-dispersion mirrors has very high request on design and preparation. The refractive index and physical thickness are the necessary parameters for the realization of the capability. Negative-dispersion mirrors are designed and prepared, which are analyzed from the main factors such as material refractive index, thickness, the sensitive layers and interface roughness considering the electric field distribution and the measurement result of group delay dispersion (GDD) and the scanning electron microscope. The research indicates: the refractive index in the design should be calculated from the experiment; increasing the thickness of total film and the cavity introduces the higher GDD; the electric field distribution decides the position of the sensitive layers; the thinnest layer may not be the most sensitive layer; the sensitive layers request high deposition accuracy ; interface roughness and inhomogeneity are both the important factors..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1563 (2009)
Measurement and Metrology
Quality Evaluation of Carbon Fiber Floor Coating with Infrared Thermal Wave Nondestructive Test
Li Yanhong, Zhao Yuejin, Feng Lichun, Zhang Cunlin, Wu Song, and Zhu Junhui
The traditional nondestructive technique can not realize the coatings quality evaluation on carbon fiber floors. Infrared thermal wave nondestructive technique was proposed to fulfill the coating thickness measurement and defects detection. The Infrared thermal wave nondestructive technique heats the sample actively, aThe traditional nondestructive technique can not realize the coatings quality evaluation on carbon fiber floors. Infrared thermal wave nondestructive technique was proposed to fulfill the coating thickness measurement and defects detection. The Infrared thermal wave nondestructive technique heats the sample actively, and uses an infrared camera to sequentially detect the surface temperature change. The thermal wave in the sample will change the conduction process once meeting the interface. Then the thickness can be measured based on the temperature break time. On the other hand, the thermal images captured by the focal plane infrared camera will display different depth information with interior defects. Coating thickness measurement samples were designed for each has three different thickness steps. The results show that in the range of 0.35～2 mm, the infrared thermal wave nondestructive measurement can realize the thickness measurement with error less then 0.1 mm and defects detection..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1489 (2009)
Power Balance Measurement Technique of Multi-Beam Laser
Sun Zhihong, Wang Wenyi, Liu Hua, Xia Yanwen, Peng Zhitao, Xu Longpo, Fu Xuejun, and Yuan Haoyu
The calculation methods have been developed for estimating the power and power imbalance, for that there is no disscussion on calculation method of power balance in detail currently. According to the results of theoretical simulation, the center position of temporal profile full width half maximum is fixed as the base The calculation methods have been developed for estimating the power and power imbalance, for that there is no disscussion on calculation method of power balance in detail currently. According to the results of theoretical simulation, the center position of temporal profile full width half maximum is fixed as the base point of power balance calculation for the flat-top pulse. Photo-electricity conversion component, oscillograph, and energy calorimeter are used to measure beam synchronization of arrive target, temporal profile and energy. Detailed results of the power and the power imbalance of laser facility from these calculations are proposed, and the uncertainty is analyzed. Consequently, the measurement technique and methods of multi-beam laser power balance are given..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1493 (2009)
Reconstruction of Vibration Signal from Laser Diode Self-Mixing Interference Signal
Hu Xianfeng
Reconstruction of vibration signal is one of the key technologies for laser diode (LD) self-mixing interference used in measurement of vibration. The vibration signal is retrieved by a frequency-voltage transform from self-mixing interference signal. The transform is realized by switched capacitor through charge transfReconstruction of vibration signal is one of the key technologies for laser diode (LD) self-mixing interference used in measurement of vibration. The vibration signal is retrieved by a frequency-voltage transform from self-mixing interference signal. The transform is realized by switched capacitor through charge transfer. There are two simulative switches in the transform: one driven by self-mixing interference signal making frequency of the switch equal to frequency of self-mixing interference signal, the other driven by stimulating signal of the vibration changing the pole of charging voltage of the capacitor with phase of the vibration. Output signal amplitude of the transform is proportional to vibration amplitude. The vibration waveform rebuilt by the transform is coincident with that of stimulating signal. The frequency-voltage transform can be use to rebuild signal of arbitrary vibration if period and phase of arbitrary vibration can be extracted from self-mixing interference signal..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1498 (2009)
Improved Algorithm Adapting to on-Line 3D Inspection
Zhong Lijun, Cao Yiping, and Yu Ruizhi
In order to apply the traditional phase measuring profilometry (PMP) to on-line 3D inspection, Stoilov’s algorithm is introduced. However, the formula of the original Stoilov’s algorithm includes evolution and division operators, and it is quite sensitive to the digitized influence of digital light projector or CCD camIn order to apply the traditional phase measuring profilometry (PMP) to on-line 3D inspection, Stoilov’s algorithm is introduced. However, the formula of the original Stoilov’s algorithm includes evolution and division operators, and it is quite sensitive to the digitized influence of digital light projector or CCD camera and the disturbance of the surrounding light, which leads to serious phase computing errors inevitably. Therefore, an improved algorithm based on the Stoilov’s algorithm is proposed in detail. The moving step S can be calibrated by pixel matching and the stripe period length L can be calibrated by computing the discrete phase with standard PMP, then the phase-shift quantity Δ can be calibrated, so as the sin Δ. The phase computing error can be minished in effect and the precision of on-line inspection can be improved. In order to verify its feasibility and validity, the experiments are carried on. They show that in on-line 3D measurement the reconstructed 3D object appears visible distortion with the original algorithm but remains fidelity with the improved algorithm instead..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1503 (2009)
Measurement of Bubble Diameter in a Flat Glass Based on Far-Field Interference
Li Jianmin, Wang Yunfen, Feng Tianbao, Yuan Zhicheng, Song Yuanjun, Chen Guiqiang, and Chu Runzeng
A method for measurement of bubble diameter in the flat glass is presentecl. With parallel He-Ne laser beam irradiating the bubble, circular interference fringe is produced in the far-field. Based on the far-field theoretical model, the angle position of interference fringes outside the flat glass is measured with specA method for measurement of bubble diameter in the flat glass is presentecl. With parallel He-Ne laser beam irradiating the bubble, circular interference fringe is produced in the far-field. Based on the far-field theoretical model, the angle position of interference fringes outside the flat glass is measured with spectrometer and converted into the angle position of interference fringes inside the flat glass according to Snell’s law and then the bubble diameter is calculated with mathematica. The measurement results indicate the bubble in the flat glass is ellipsoid. Suggestion of rapid measurement of bubble diameter is given. Because of far-field interference, the demand for the bubble location over platform is not strict. The interference caused by Fraunhofer screen diffraction fringes is analyzed and a completely new method is provided for measurement of the bubble diameter in the flat glass..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1508 (2009)
Stimulated Brillouin Scattering Based Detection of No-Reflection Object in Water
Zhao Zhigang, Huang Lixian, Xu De, Liu Chong, Chen Jun, and Xiang Zhen
An method for detection of underwater no-reflection object is introduced. It makes full use of the phase-conjugating characteristics of stimulated Brillouin scattering and the optical isolator’s finite aperture, which enhances the signal to noise ratio highly. After passing through the Fabry-Perot etalon, the light refAn method for detection of underwater no-reflection object is introduced. It makes full use of the phase-conjugating characteristics of stimulated Brillouin scattering and the optical isolator’s finite aperture, which enhances the signal to noise ratio highly. After passing through the Fabry-Perot etalon, the light reflected by water surface and scattered by water will form different interference rings’ clusters as a result of their different wavelengths. By observing the change of the interference pattern, whether there is a no-reflection object or not in water can be determined. Using photodiode to receive and digital oscillograph to display the signals, the interval between them can be gotten. The depth of the underwater no-reflection object can be calculated. Photodiodes are placed at appropriate position to ensure more higher SNR can be obtained. In experiments, a underwater no-reflection object located at the depth arange of 1-10 m is detected and the results obtained agree well with real condition..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1512 (2009)
Optical Communication
All-Optical Frequency Up-Conversion Utilizing High Nonlinear Fiber in Radio Over Fiber System
Yang Hongwu, Sun Junqiang, and Du Qiujiao
All-optical frequency up-conversion in radio over fiber (ROF) system based on cross-phase modulation in a high nonlinear fiber is proposed. The numerical calculation results show that the 40-GHz pulse pump beam with wavelength of 1.54 μm can make the weak signal with wavelength of 1.56 μm and nonreturn to zero code velAll-optical frequency up-conversion in radio over fiber (ROF) system based on cross-phase modulation in a high nonlinear fiber is proposed. The numerical calculation results show that the 40-GHz pulse pump beam with wavelength of 1.54 μm can make the weak signal with wavelength of 1.56 μm and nonreturn to zero code velocity of 2.5 Gbit/s split and generate two adjacent one-order sidebands, because of the modulation instability induced by cross-phase modulation. The carrier and sidebands are coherent with the spacing of 40 GHz. The pulse width, power of the pump beam, and fiber length all have great impact on the power difference of the carrier and sidebands. The simulation results verify the above principle and 2.5-Gbit/s data signal is up-converted into 40-GHz millimeter-wave in high nonlinear fiber. The optimized fiber length and pump power are 600 m and 17 dBm, respectively, when the power of the signal light is 0 dBm..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1448 (2009)
Optical Quantization Technique for Microwave Signal Based on Double Channel Sampling
Fu Xin, Zhang Hongming, and Yao Minyu
An improved scheme of intensity-modulating optical quantization technique for microwave signal is proposed and demonstrated by using double channel sampling. This scheme reduces the complexity and dramatically improves the operation bandwidth by eliminating the need of dual complementary-output intensity modulator. In An improved scheme of intensity-modulating optical quantization technique for microwave signal is proposed and demonstrated by using double channel sampling. This scheme reduces the complexity and dramatically improves the operation bandwidth by eliminating the need of dual complementary-output intensity modulator. In an experimental demonstration, 8-channel outputs of optical quantization system for microwave signal are obtained with quantization levels of 16. A sinusoidal microwave signal of 2.5 GHz is quantized using pulse sequence with repetition rate of 20 GHz. Good fit sinusoidal curve can be obtained from the quantization values, which proves the feasibility of the proposed scheme..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1454 (2009)
Reviews
Application and Development of Coated Fiber Grating
Gu Zhengtian, and Deng Chuanlu
Coated fiber grating has aroused more and more interest in optical communication and optical sensing recent years. Due to its good optical characteristics and flexible and adjustable design, coated fiber grating has an attractive application prospect. The structure and theory of coated fiber grating is introduced simplCoated fiber grating has aroused more and more interest in optical communication and optical sensing recent years. Due to its good optical characteristics and flexible and adjustable design, coated fiber grating has an attractive application prospect. The structure and theory of coated fiber grating is introduced simply briefly, and the calculation model of fiber grating coated dielectric film and metal film is given. The application of coated fiber grating in the sensing and communication area is emphasized. And the further outlook of its development direction is prospected..
Chinese Journal of Lasers
- Publication Date: Mar. 31, 2020
- Vol. 36, Issue 6, 1317 (2009)
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