Journals >Acta Photonica Sinica
Contents
2016
Volume: 45 Issue 6
28 Article(s)
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Research Article
Measurement and Correction of Linearity of Photon Counters
HU You-bo, LI Jian-jun, XIA Mao-peng, GAO Dong-yang, and ZHENG Xiao-bing
Linear measurement device was set up based on the linear relationship between pump power and photons in spontaneous parametric down conversion process. The nonlinearity errors mechanism, linear condition and correction model of photon counting detector were analyzed. For the sake of realizing the linear measurement of Linear measurement device was set up based on the linear relationship between pump power and photons in spontaneous parametric down conversion process. The nonlinearity errors mechanism, linear condition and correction model of photon counting detector were analyzed. For the sake of realizing the linear measurement of the photon counting, the pump power was adjusted to change incident photon rate, and the experimental measurements were corrected. The results show that the measurement precision can be improved by measurement and correction. The maximum linear range rate of the incident photon could be expanded from 105/s to 107/s result from lower non-linear errors..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 604001 (2016)
The Partition Noise Research of MCP Photon Counting Imager Detector Based on Vernier Anode
XING Yan, CHEN Bo, JIN Fang-yuan, WANG Hai-feng, ZHANG Hong-ji, and HE Ling-ping
To get rid of the interference of electronic noise in the micro channel plate photon counting imager detector, the theory of partition noise was studied and the finite element method of calculating partition noise by COMSOL software was proposed. The three dimensional model of imaging principle based on the Vernier anoTo get rid of the interference of electronic noise in the micro channel plate photon counting imager detector, the theory of partition noise was studied and the finite element method of calculating partition noise by COMSOL software was proposed. The three dimensional model of imaging principle based on the Vernier anode detector was built, the image of a set of pinhole array was simulated, and the centroid position offsets caused by the partition noise were calculated, which certifies the correctness of the position decoding algorithm and proves the feasibility of calculating partition noise. By adjusting the designed parameters of the Vernier anode, the influences of the partition noise on the centroid position offset of charge cloud were investigated. It is an effective way to reduce the partition noise by increasing the gains of micro-channel plates..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 604002 (2016)
The MTF Analysis of High Performance Proximity Image Intensifier
TAO Yu, JIN Wei-qi, WANG Yao, SHI Feng, and GUO Hong
In order to improve the performance of high performance image intensifier in low-light-level night vision systems, the modulation transfer function models of the proximity image intensifier and its parts were summarized, and the structures and electrical parameters of the Super Gen. II and Super Gen. III image intensifIn order to improve the performance of high performance image intensifier in low-light-level night vision systems, the modulation transfer function models of the proximity image intensifier and its parts were summarized, and the structures and electrical parameters of the Super Gen. II and Super Gen. III image intensifiers were reviewed. The image intensifier and its modulation transfer function distribution were studied respectively, further their impact on the resolution limit as well as the channel width of the image intensifier was investigated. The results show that the performance of the screen and the modulation transfer function distribution should be improved to further improve the performance of the image intensifier, channel width can be an effective parameter to evaluate the modulation transfer function distribution of the image intensifier. The results have theoretical significance for the development of high performance image intensifiers..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 604003 (2016)
Fabrication of Large-angle Diffractive Optical Element Based on Nanoimprint Lithography
LIU Xin, ZHANG Man, PANG Hui, SHI Li-fang, CAO A-xiu, and DENG Qi-ling
In order to fabricate the large-angle (more than 50°) diffractive optical elements with low cost and mass preparation, a fabrication method base on nanoimprint lithography was proposed. A diffractive optical elements master mold was prepared via conventional photolithography or electron beam lithography. The mold In order to fabricate the large-angle (more than 50°) diffractive optical elements with low cost and mass preparation, a fabrication method base on nanoimprint lithography was proposed. A diffractive optical elements master mold was prepared via conventional photolithography or electron beam lithography. The mold was then imprinted onto the nanoimprint resist with quartz substrate. The structure was transferred to the resist and the diffractive optical elements were achieved. In contrast to other techniques, the nanoimprint mold can be repeatedly used to lower production cost and improve the efficiency. Based on the method, diffractive optical elements with different feature sizes (minimum 250 nm, diffractive angle 70°) were fabricated for different diffractive patterns，which has a good diffractive efficiency, realizing high-fidelity replication of relief structure with high aspect ratio. The technology can fabricate diffraction optical elements from micron to nanometer scale with high fidelity, low cost and mass production..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 605001 (2016)
Use the Rigorous Coupled-wave Analysis to Test the Domain Structure of Periodically Polarized LiNbO3 Crystal
LU Xing, CHEN Shu-qiang, LIANG Wan-guo, and CHEN Huai-xi
In order to nondestructively measure the domain structure of periodically polarized crystal, the rigorous coupled-wave analysis was used to analysis the period and duty cycle of the microstructure. A laser with a wavelength of 532 nm and power of 20 mW was used as the light source. The beam with TE polarization is vertIn order to nondestructively measure the domain structure of periodically polarized crystal, the rigorous coupled-wave analysis was used to analysis the period and duty cycle of the microstructure. A laser with a wavelength of 532 nm and power of 20 mW was used as the light source. The beam with TE polarization is vertically incident on the periodically poled lithium niobate crystal surface, at the same time the voltage is applied to the crystal to increase the refractive index difference between the positive and negative domains. The power of each diffraction orders is detected by a photo detector . The period and duty cycle of the periodically poled lithium niobate crystal can be got by using the least squares method to fit the simulation results of the rigorous coupled-wave analysis and the experimental data. The experimental accuracy of the period and the duty cycle is 0.05 μm and 0.05 respectively. Compared with the period calculated by the Prague diffraction formula, the precision is improved by an order of magnitude..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 605002 (2016)
Temperature and Pressure Sensing System of Side Hole Fiber Grating Based on Scanning Laser
YANG Yun-duo, KANG Juan, XU Ben, ZHOU Peng-wei, QIU Yan-qing, and LI Yi
An optical fiber temperature and pressure simultaneous measurement system based on wavelength scanning laser was proposed. The fiber optic sensor head is fiber Bragg gratings based on side hole polarization maintaining fibers. Taking use of its unique double reflection peaks arising from birefringence, simultaneous meaAn optical fiber temperature and pressure simultaneous measurement system based on wavelength scanning laser was proposed. The fiber optic sensor head is fiber Bragg gratings based on side hole polarization maintaining fibers. Taking use of its unique double reflection peaks arising from birefringence, simultaneous measurement of temperature and pressure can be acheived. Embedded technology was applied in the system. The controls of laser wavelength scanning, acquisitions of spectral data and the data demodulations based on Newton least squares fitting algorithm, were highly integrated in one system, greatly reducing the size and cost of the fiber optic sensing system. Experimental results show that the double reflection peaks correspond to changes in temperature and pressure with a good linear characteristics, in the temperature range of 10~50 ℃ and the pressure range of 0~1.2 MPa. The wavelength demodulation accuracy of the system is up to 1 pm, corresponding to the resolution of temperature and pressure is up to 0.1 ℃ and 0.1 MPa, respectively. The proposed system can provide a low cost, small size, reliable system solutions to the simultaneous measurements of temperature and pressure..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 606001 (2016)
Fiber Optic Temperature Sensor Based on Second Order Loyt-Sagnac Interferometer
ZHU Meng-fang, SHAO Li-yang, ZHANG Zhi-yong, and YAN Lian-shan
The second order Loyt-Sagnac interferometer was constructed by inserting two sections of highly birefringence fibers into the fiber loop and adjusting the fusion splicing angle. The transmission spectrum of the highly birefringence fiber Sagnac interferometer was calculated by using the Jones matrix analysis. The polarThe second order Loyt-Sagnac interferometer was constructed by inserting two sections of highly birefringence fibers into the fiber loop and adjusting the fusion splicing angle. The transmission spectrum of the highly birefringence fiber Sagnac interferometer was calculated by using the Jones matrix analysis. The polarization angle of input light and the lengths of highly birefringence fibers were optimized. These two kinds of temperature sensors were simulated and experimented. The Simulation results show that the temperature sensitivity of the second order Loyt-Sagnac configuration can be enhanced because of its Vernier effect. The experimental results show that the temperature sensitivity is increased from －1.46 nm/℃ to －17.99 nm/℃ by using the proposed structure, increased 12.32 times..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 606002 (2016)
Fiber Bragg Grating Demodulation System Based on Fiber Fabry-Perot Etalon and Multi-gratings Calibrated
WANG Jin-hui, XU Xue-mei, DING Jia-feng, DING Yi-peng, and YIN Lin-zi
In order to eliminate the fiber Bragg grating demodulation error caused by the interference peak shifting of Fabry-Perot etalon, a method was proposed that multi-gratings were utilized to calibrate the wavelength of Fabry-Perot etalon, and a demodulation platform was established. Sampling channels were respectively conIn order to eliminate the fiber Bragg grating demodulation error caused by the interference peak shifting of Fabry-Perot etalon, a method was proposed that multi-gratings were utilized to calibrate the wavelength of Fabry-Perot etalon, and a demodulation platform was established. Sampling channels were respectively connected with sensor gratings, Fabry-Perot etalon and reference gratings, and interference peak wavelengths with high precision were calibrated using multi-reference-gratings. Then wavelengths of sensor gratings were calculated using these wavelengths, and calibration error was reduced. The experiment demonstrates that the repeatability error of the fiber Bragg grating demodulation system is less than 1.6 pm, and the wavelength demodulated error is under than 1.8 pm..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 606003 (2016)
Error Analysis of a Fiber Optic Accelerometer Based on White Light Interference
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The model of the optical priciple error, the cross sensitivy error and the error induced by temperature were built. These errors have affected the measurement precision of a fiber optic accelerometer which can be used to measure the direct current signal of acceleration. With a purpose of obtaining the exact data, the The model of the optical priciple error, the cross sensitivy error and the error induced by temperature were built. These errors have affected the measurement precision of a fiber optic accelerometer which can be used to measure the direct current signal of acceleration. With a purpose of obtaining the exact data, the simulation and experiment were conducted. Results show that, the measurement errors of interrogation algorithm decrease with the signal-to-noise ratio increasing and the spectrum sampling interval shortening, and the measurement accury is 4.5×10－5; under the effect of one time gravitational acceleration, the cross sensitivity error is 1.8 mg; the scale factor will increase(decreas) 0.79‰ when the temperature rises (drops) 1℃..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 606004 (2016)
FPGA-based Rapid Full Field Optical Coherence Tomography
GAO Wan-rong, CHEN Yi-dan, LIU Chang, ZHANG Qiu-ting, and ZHU Yue
In order to improve the imaging speed of full-field optical coherence tomography for practical applications, a phase modulation method for rapid full-field optical coherence tomography was proposed. The Field－Programmable GateArray (FPGA) was used to build the circuits to generate accurate sinusoidal and pulse signals In order to improve the imaging speed of full-field optical coherence tomography for practical applications, a phase modulation method for rapid full-field optical coherence tomography was proposed. The Field－Programmable GateArray (FPGA) was used to build the circuits to generate accurate sinusoidal and pulse signals with adjustable frequency. The generated signals were then employed as modulation signals in four step phase shift method to obtain optical sectional images. Finally，the optical tomography images of onion cells were obtained and compared with the ones generated by traditional phase shift method and the single chip-based method. The results show that the method proposed not only can improve the image quality, but also can increase the imaging speed, the time required for reconstructing an optical tomographic image is reduced from 4 s（0.25 Hz） to 0.03～0.05 s（20 Hz～35 Hz）..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 611001 (2016)
Analysis on Imaging Uniformity of a Color Schlieren Photographer
CHEN Lei, ZHU Tao, ZHANG Qi-hua, and MA Xiao-yu
A Φ1200mm colorful schlieren system was designed by adopting an illumination system without any protecting windows. The theoretical optical model of the Φ1200mm colorful schlieren system was built up and the imaging uniformity of the system was studied under the complex working conditions as the gravity, temperature vaA Φ1200mm colorful schlieren system was designed by adopting an illumination system without any protecting windows. The theoretical optical model of the Φ1200mm colorful schlieren system was built up and the imaging uniformity of the system was studied under the complex working conditions as the gravity, temperature variation, and ambient pressure. The three typical combinations of the slit width and the cutting quantity of the knife had been considered here, which are 2mm slit width with 1/4 cutting quantity , 2mm slit width with 1/2 cutting quantity, and 0.5mm slit width with 3/4 cutting quantity. With above three combinations, the imaging uniformity of the system was analyzed under the ideal working condition and under the condition by the consideration of integral error respectively. The results show that with the consideration of integral error, the uniformity of the schlieren image is decreased compared with that of the ideal working condition. With the consideration of integral error, when the system is under relatively low sensitivity, the range of the non-uniformity is from －2.44% to 2.45%; under relatively normal sensitivity, the range of the non-uniformity is from －3.43% to 3.45%; under relatively high sensitivity, the range of the non-uniformity is from －5.76% to 5.81%..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 611002 (2016)
Improved Carré Phase Shifting Algorithm Based on White Light Interferometry
LI Hui-peng, TAN Meng-xi, ZHU Wei-wei, ZHENG Xiao, and LI Jiao
In order to reduce the error produced by using the white light interferometry while calibrating the microcosmic shape, an improved Carré phase shifting algorithm based on white light interferometry was proposed. The search path of traditional extremum algorithm was optimized, and then combined with the Carré In order to reduce the error produced by using the white light interferometry while calibrating the microcosmic shape, an improved Carré phase shifting algorithm based on white light interferometry was proposed. The search path of traditional extremum algorithm was optimized, and then combined with the Carré phase shifting algorithm to extract the phase. The proposed algorithm can eliminate the random error caused by the shot-noise of CCD, it do not need to limit the step of the phase adjustments by using the central wavelength of white light and the phase unwrapping is no longer needed, and it makes the computation efficiency improved. The central wavelength on line was modified to reduce the error caused by the characteristic of light and environment disturbance. The three-dimensional topography of standard roughness specimens was restored and the surface roughness was mesuresed by different kinds of algorithms. The experimental results show that, compared with other algorithms, the accuracy is improved and repeatability is better than 1% by using the proposed improved algorithm..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 612001 (2016)
Light Pressure Measuring Based on Device of Mach-Zehnder Interference
ZHAO Jing, LIN Hong-xiang, QIU Tang, and CHEN Jing-fang
A device of light pressure detection was designed. The device based on Mach-Zehnder interference theory, and had modulation and amplification interference optical path. The deformation (displacement) of double reflection aluminum film caused by the laser pulse with different frequency and power. The light generated by A device of light pressure detection was designed. The device based on Mach-Zehnder interference theory, and had modulation and amplification interference optical path. The deformation (displacement) of double reflection aluminum film caused by the laser pulse with different frequency and power. The light generated by HeNe laser was split to the reference light and the signal light by a semi-reflecting and semi-transmitting mirror. The optical path difference of the reference light and the signal light was changed because of the thin film shift. Therefore, it caused the movement of interference fringes. The displacement of interference fringes were recorded by CCD, and then the relationship of fringes movement and the film deformation was calculated. At last, the light pressure was obtained. The effects of pulsed laser incident angle, frequency and other parameters were discussed in detail and the thermal radiation effect is eliminated by using the method of double incidence angle. The device could measure the minimum pressure (13.42 μPa) produced by the minimum optical power of 15.0mW. The linear range is from 15mW（13.42 μPa）to 200（13.42 μPa). The device works steadily, with high sensitivity and accuracy..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 612002 (2016)
Calibration Method for Linear Array Camera of Intersection Measurement System
WU Pei, WANG Yan-jie, SUN Hong-hai, YAO Zhi-jun, and WU Zhi-guo
In order to improve the measurement accuracy of the large target intersection measurement system, the miss distance formula of target was derived by analyzing the principle of intersection measurement. According to the parameters of the formula, a mapping model between the pixel coordinate and the offset angle was estaIn order to improve the measurement accuracy of the large target intersection measurement system, the miss distance formula of target was derived by analyzing the principle of intersection measurement. According to the parameters of the formula, a mapping model between the pixel coordinate and the offset angle was established by using the geometric relationship. A calibration method for linear camera was designed by using grating scale according to the model. This method takes the whole optical system as a whole and does not need to consider the parameters of the camera, which directly calibrates the mapping relationship between the coordinates and their corresponding offset angles. The experimental results show that the average measurement error of the calibrated intersection measurement system at 1.4 m is 0.4 mm, and the maximum measurement error is better than 0.6 mm. The proposed method is simple but effective, and can improve the speed of the calibration and satisfy the accuracy requirement of the system..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 612003 (2016)
Analyzing Spectral Interferometer Fringe Using a Short Time Fourier Transform for Single Shot Complex Pulses Measurement
LI Yu, LI Ze-ren, LIU Shou-xian, LI Jan-zhong, ZHONG Sen-cheng, and CHEN Guang-hua
A single-shot measurement and analysis technique with a Fourier transform limited pulse as a reference pulse was presented, which can be used for measuring the complex picoseconds pulses. Substituting the Fourier transform with a short time Fourier transform, a time-frequency analysis of the spectral fringe was achieveA single-shot measurement and analysis technique with a Fourier transform limited pulse as a reference pulse was presented, which can be used for measuring the complex picoseconds pulses. Substituting the Fourier transform with a short time Fourier transform, a time-frequency analysis of the spectral fringe was achieved to directly extract the chirp characteristics or composition of complex pulse. Furthermore, the temporal envelope of pulse was reconstructed from the spectrogram by summing the power density S(ω,t) along the spectrum ω axis. To verify the utility of this method, this method and the traditional spectral interferometry was used to measure a linear chirped pulse and a complex pulse respectively. The results show that this method can be used to measure the characterization of complex shaped pulses in real-time, and with a temporal resolution of 70 fs..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 612004 (2016)
Frequency Linkage between the Dual Frequency Combs Based on the Polarization-Maintaining Femtosecond Fiber Laser
XU Xin, FENG Ye, LIU Yuan-shan, WU Guan-hao, WANG Yi-shan, WEI Ru-yi, and ZHAO Wei
The frequency linkage between the dual frequency combs was realized by using of the tracking feedback controlling circuit.The linkage characteristic was studied when the master frequency comb’s frquency is changed automatically and manully respectively. The results show that, the frequency of the slave frequency comb iThe frequency linkage between the dual frequency combs was realized by using of the tracking feedback controlling circuit.The linkage characteristic was studied when the master frequency comb’s frquency is changed automatically and manully respectively. The results show that, the frequency of the slave frequency comb is varied following the automatic or manual frequency scanning of the master frequency comb. The max correlation coifficient between the frequency of the dual frequency combs is up to 0.99, which demonstrates the better linkage characteristic. Finally, the linked dual frequency combs was used in the abosulate distance measurement. The measured distance is 1.332 m, the interval is 0.2 s, the standard deviation of the experimental results is 0.35 μm with 16 times, and the measurement precision is less than 1 μm..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 614001 (2016)
The 1/f Noise Correlation of Semiconductor Lasers under Low Bias Current
WU Xuan-zi, GUO Shu-xu, YANG Chao, GUAN Jian, TIAN Chao, CAO Jun-sheng, and GAO Feng-li
The electrical low-frequency noise of 976nm InGaAs quantum well high-power semiconductor lasers was measured under a current less than 1/30 of the threshold current. An approach was proposed to analyze the noise origins by using the relation between the 1/f noise correlation of time-domain signal wavelet coefficients aThe electrical low-frequency noise of 976nm InGaAs quantum well high-power semiconductor lasers was measured under a current less than 1/30 of the threshold current. An approach was proposed to analyze the noise origins by using the relation between the 1/f noise correlation of time-domain signal wavelet coefficients and the bias current. Combining the 1/f noise origin model with the characteristics of the wavelet coefficients, a series of contrast experiments were conducted to compare the results before and after adding white noise under different bias currents. The results indicate that, the low-frequency noise we measured shows typical 1/f noise characteristics. For a pure 1/f noise, the same results are obtained when to determine the noise origin by using the noise amplitude method and wavelet coefficients correlation method. However, for the 1/f noise signal containing white noise, there is a significant fluctuation on the noise amplitude and it cannot show the origin 1/f noise correctly, whereas the wavelet coefficients correlation under some scales is still a reliable criterion..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 614002 (2016)
Multi-wavelength Thulium-doped Mode-locking Fiber Laser Based on Nonlinear Polarization Rotation
LIU Peng, WANG Tian-shu, ZHANG Peng, ZHANG Yan, MA Wan-zhuo, SU Yu-wei, BI Ming-zhe, and ZHANG Jing
By using the nonlinear polarization rotation, a thulium doped mode-locked multi wavelength fiber laser was achieved. In the ring cavity, a 1 565 nm fiber laser pumps a 3 m long thulium doped fiber. Filtering is realized by the nonlinear polarization rotation effect.When the pump power is 800mW, the pulse output of the By using the nonlinear polarization rotation, a thulium doped mode-locked multi wavelength fiber laser was achieved. In the ring cavity, a 1 565 nm fiber laser pumps a 3 m long thulium doped fiber. Filtering is realized by the nonlinear polarization rotation effect.When the pump power is 800mW, the pulse output of the passively mode locked state is realized by adjusting the fiber polarization controller. The pulse repetition frequency is 3.178 MHz and the pulse width is 617 ps.Further increasing the pump power, the laser is working at a multi wavelength state. By adjusting the fiber polarization controller, a stable 1~5 wavelength laser output is obtained at a room temperature, and the edge is less than 40～60 dB..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 614003 (2016)
Cat′s Eye Echo-wave Characteristics of Staring Photoelectric Imaging System
LEI Peng, SUN Ke, ZHANG Yu-fa, LI Feng, NIE Jin-song, and SUN Xiao-quan
The echo-wave was deduced based on the Huygens-Fresnel diffraction formula. The numerical results with the two-dimensional grating as focal plane device of staring photoelectric imaging system were verified experimentally. The impact of aperture size on the correlation between the echo image and the modulation of focalThe echo-wave was deduced based on the Huygens-Fresnel diffraction formula. The numerical results with the two-dimensional grating as focal plane device of staring photoelectric imaging system were verified experimentally. The impact of aperture size on the correlation between the echo image and the modulation of focal plane device was analyzed, and the influence of the cut-off frequency on the echo-wave was also discussed. With the size of aperture decreasing, the information of echo wave decreases, and the correlation also decreases. What′s more, with the aperture size increasing, more and more diffraction spots from the grating appear in the echo-wave image which shows complex pattern because of the interference between the spots. The spatial frequency of the pattern reflects the overlapping of the diffraction spot. The study of echo characteristics has practical application value for laser active detection on photoelectric reconnaissance equipment..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 614004 (2016)
Electronic Structures and Optical Properties of β-PTCDA Based on the First-Principles Investigation
WANG Xue-yan, ZHENG Jian-bang, LI Xiao-jiang, and CAO Chong-de
Electronic band structure, Partial Density of States (PDOS) and optical properties of β-phase 3,4,9,10-perylenetetracarboxylic dianhydride (β-PTCDA) molecular crystal were systematically investigated by first-principles calculations based on Density Functional Theory (DFT). The contribution of different type of atoms eElectronic band structure, Partial Density of States (PDOS) and optical properties of β-phase 3,4,9,10-perylenetetracarboxylic dianhydride (β-PTCDA) molecular crystal were systematically investigated by first-principles calculations based on Density Functional Theory (DFT). The contribution of different type of atoms electronic states to different electronic levels was analyzed, and the frequency dependent optical functions such as the dielectric function, absorption coefficient, refractive index and energy loss function of β-PTCDA molecular crystal that changed with optical frequency were analyzed and obtained. The results showed that β-PTCDA is a direct narrow band gap semiconductor, and the electron orbit making larger contribution to the Fermi level is the O 2p electronic state and C 2p electronic state that come from the perylene core, which are also the top of valence band; what makes larger contribution to the bottom of the conduction band is also the C 2p and O 2p electronic states, including anhydride C atoms; in the photon energy range of 2 to 10 eV, the strong light absorption and obvious biaxial anisotropy can be observed. In the optical frequency range with the real part of dielectric function ε1(ω)<0, β-PTCDA molecular crystal has an anisotropic conductivity, which is consistent with the energy loss function..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 616001 (2016)
Synthesis and Properties of Eu3+, Sm3+-doped TiO2 Down-conversion Photoanode for Dye-sensitized Solar Cells
QIN Yi-ying, HU Zhi-qiang, ZHANG Pu-tao, HAO Hong-shun, and LIU Gui-shan
Eu，Sm-codoped TiO2 nanocrystals were synthesized by the sol-gel method, and the down-conversion photoanode were prepared with the matrix of P25 doped with the as-prepared Eu，Sm-codoped TiO2 powders, which was introduced into the dye-sensitized solar cell. The photoelectric properties were enhanced due to the down-conveEu，Sm-codoped TiO2 nanocrystals were synthesized by the sol-gel method, and the down-conversion photoanode were prepared with the matrix of P25 doped with the as-prepared Eu，Sm-codoped TiO2 powders, which was introduced into the dye-sensitized solar cell. The photoelectric properties were enhanced due to the down-conversion feature of Eu，Sm-codoped TiO2. The luminescent properties of powders were characterized by the fluorescence spectroscopy. Fluorescence spectroscopy results indicate that the Eu，Sm-codoped TiO2 powders possess down-conversion feature of converting ultraviolet light to 550~700 nm visible light exposed to 463nm ultraviolet light. The short circuit current density of the dye-sensitized solar cell with a photoanode doped with 1 mol% Eu3+ and 0.5 mol% Sm3+ reaches to 14.08 mA/cm2, which is 32.08% higher than that with Eu3+ doped TiO2 photoanode, and the efficiency is also reached to 5.29 %..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 616002 (2016)
Design of Large Zoom Ratio Liquid Lens System
WANG Hong-he, LI Xiang-ning, PAN Wen-qiang, and HUANG Hao
The optical properties of the electro-wetting liquid zoom lens and the theory of zoom lens design were analyzed. Make the focal length of each element be variable and list the equations of the liquid lens zoom system. An initial liquid zoom lens structure by utilizing PSO and balance aberrations was studied by using opThe optical properties of the electro-wetting liquid zoom lens and the theory of zoom lens design were analyzed. Make the focal length of each element be variable and list the equations of the liquid lens zoom system. An initial liquid zoom lens structure by utilizing PSO and balance aberrations was studied by using optical design software. A 6×(20~120mm) zoom ratio liquid lens zoom system with four pieces of liquid lens was designed. The MTF at 66 lp/mm of this system at each focal length are greater than 0.3, and distortion is less than 2%, which meets the design requirements..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 622001 (2016)
Structure Design of a Fast Adjustment Mechanism in the Image Spin Compensation System
YAN Yong-yao, LIU Wei, FU Jin-jiang, and YUAN Ting
Regarding the image rotation happened on the rotation direction of large astronomical cameras, a system of fast adjustment mechanism was designed with the flexible hinge shafting which was characterized by zero friction, non-abrasion, free of lubrication, easy maintenance and high resolution. This system could directlyRegarding the image rotation happened on the rotation direction of large astronomical cameras, a system of fast adjustment mechanism was designed with the flexible hinge shafting which was characterized by zero friction, non-abrasion, free of lubrication, easy maintenance and high resolution. This system could directly drive the camera for a mechanically despun. The flexible shafting was composed of 8 flexible units which were rounded off and evenly distributed. According to the structure of each flexible unit, a theoretical model was also set up for the system guided by applied mechanics theories, by which we analyzed the relationship between the rigidity and the structural parameters, carried out the finite element simulation and made experiments for test. The results showed: The maxim error between the finite element simulation and the theoretical analysis was 3.215%. The maxim error between the testing result and the theoretical analysis was 4.875%. It verified that the theoretical formula is correct and reliable. The mathematical model was built up according to theoretical formula, so that we could define the optimized structural parameters efficiently for the fast adjustment mechanism, and realize the design goal to meet the technical requests and minimize the working moment..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 622002 (2016)
Target Detection of Quantum Illumination Based on M&M′ State
XU Shi-long, HU Yi-hua, ZHAO Nan-xiang, LI Le, and GUO Li-ren
NOON states and M&M′ states are both typical path-entangled Fock state. M&M′ state is a new class of path-entangled photon Fock states which possesses photons in both path, and has been confirmed with a good performance in loss environment. In this paper, the detecting error-probability bound of quantum illuminNOON states and M&M′ states are both typical path-entangled Fock state. M&M′ state is a new class of path-entangled photon Fock states which possesses photons in both path, and has been confirmed with a good performance in loss environment. In this paper, the detecting error-probability bound of quantum illumination based on M&M′ state was derived under the assumption that the target echo photons are pure states， which was also compared with the error-bounds of Fock state and NOON state. The simulation results show that the error bounds of M&M′ states are no longer limited by the total photon number, but influenced by the proportion of photon number between the signal path and the unused path. Therefore, the quantum illumination system with M&M′ states can offer an enhanced performance over Fock state in a larger dynamic range of signal to noise ratio(at least double time of NOON states)..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 627001 (2016)
Monitoring Method for Filter Film Thickness Based on the Combination of Photoelectric Extreme Value and Quartz Crystal Oscillation
ZHANG Xue-dian, QIAN Yan-hua, CHANG Min, and JIANG Min-shan
According to the disadvantages of both photoelectric extreme value and quartz crystal oscillation methods, a combination method based on photoelectric and quartz control were presented. To evaluate the performance of the combination method, the films with coating thickness of 905 nm narrow band filter (quarter wave coaAccording to the disadvantages of both photoelectric extreme value and quartz crystal oscillation methods, a combination method based on photoelectric and quartz control were presented. To evaluate the performance of the combination method, the films with coating thickness of 905 nm narrow band filter (quarter wave coatings) and 830nm cutoff filter (non-quarter wave coatings) were monitored using the combination method and individual method respectively under the same process. The combination method shows better performance, compared to the case of using an indiviual method. From the spectral transmittance curves of filters, the average transmittance values in the pass bands increase by 3%～6% by using the combination method. Meanwhile, the transmittance curve achieved by the combination method consists well with the theoretical spectral curve. The results show that this method can not only monitors quarter wave coatings and non-quarter wave coatings, but also effectively reduce the monitoring error and improve the spectral characteristics..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 631001 (2016)
Protected-Silver Coating for Telescope Primary Mirrors Prepared by Downward Thermal Evaporation
XU Xu, LIU Hong-xiang, LI Bin-cheng, and PEI Wen-jun
By using a high-vacuum resistive heating evaporation coating machine with the materials evaporated downwards, the research of downward thermal evaporation for large-aperture optics was implemented. The silver coating was prepared at a high deposition rate by resistive heating tungsten filaments without splashing. The aBy using a high-vacuum resistive heating evaporation coating machine with the materials evaporated downwards, the research of downward thermal evaporation for large-aperture optics was implemented. The silver coating was prepared at a high deposition rate by resistive heating tungsten filaments without splashing. The adhesion layer and protective layer were also thermally evaporated downwards with specially designed evaporation boats with Cr or CrNx as the adhesion layer and SiOx or SiOxNy as the protective layer. To evaluate the performance of the protected-silver coating, three kinds of protected-silver coatings were prepared and researched in details. The reflectance, cross-section morphology and environmental stability of the prepared coating samples were characterized. The results show that the coating with 3nmCr/120nmAg/0.6nmCrNx/150nmSiOxNy structure has good performances on environmental stability and spectral characteristics. Especially,it has an average reflectance of 97.8% in the 400~1800 nm spectral range , and passed the tests of 24-hour humidity (50℃/98% RH) and salt folg..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 631002 (2016)
Characteristics of All-optical Switch in Photochromic Films Containing Spirooxazines
NING Xiao-dan, FU Shen-cheng, ZHENG Mei-ling, and XIE Xin
The different matrices films containing the photochromic molecules of spirooxazine were prepared by the spin-coating method and the drop-coating method, which were further applied to all-optical switch. The photochromic characteristics of spriooxazine doped polymethyl methacrylate and silicon dioxide films were investiThe different matrices films containing the photochromic molecules of spirooxazine were prepared by the spin-coating method and the drop-coating method, which were further applied to all-optical switch. The photochromic characteristics of spriooxazine doped polymethyl methacrylate and silicon dioxide films were investigated, and their absorption spectra were compared with each other. The results show that the intensity of the transmitted signal for the spriooxazine doped polymethyl methacrylate film obviously decays after multiple switching cycles, and the intensity of transmission signal for the spriooxazine doped silicon dioxide film keeps constant. Therefore, the latter one has a relatively higher optical-reversibility and is more suitable for all-optical switch. For the spirooxazine doped silicon dioxide film, photo-erasure and thermal-erasure were applied to the experiment of holographic optical switch. Then, the decay kinetics of the output optical signal was investigated. It is found that a shorter response time is obtained in photo-erasure. Based on photo-erasure, the optical switching characteristics of 5 mW, 10 mW and 25 mW were studied. The results show that the optimized power appears at 10 mW, in which the contrast of grating, the first order diffraction light intensity and the contrast radio are all the highest..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 631003 (2016)
Total Reflection Amorphous Carbon Mirrors in EUV and Soft X-ray Range
TAN Mo-yan, JIANG Li, and WANG Zhan-shan
The samples were fabricated using high vacuum direct current magnetron sputtering system. The layer thicknesses, roughness and densities of samples were measured by X-ray grazing incidence reflection equipment. Surface roughness were measured by AFM (Atomic Force Microscope ). The reflectivity properties of total refleThe samples were fabricated using high vacuum direct current magnetron sputtering system. The layer thicknesses, roughness and densities of samples were measured by X-ray grazing incidence reflection equipment. Surface roughness were measured by AFM (Atomic Force Microscope ). The reflectivity properties of total reflection amorphous carbon mirrors fabricated under different working pressures were characterized using synchrotron radiation. The measured results show that the properties of total reflection amorphous carbon mirrors fabricated under 0.40 Pa working pressures are superior to that fabricated under 0.67 Pa working pressures. At grazing angle 4.5°, total reflection amorphous carbon mirrors show high flat reflection beyond wavelength of 5nm while reflection sharply decrease within 5nm wavelength. Fitting results indicate that the densities of fabricated total reflection amorphous carbon mirrors is the reason which causes the actual reflection lower than designed reflection..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 45, Issue 6, 631004 (2016)
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