Journals >Chinese Optics Letters
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2006
Volume: 4 Issue 2
19 Article(s)
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Fiber Optics and Optical Communications
Optical and mechanical properties of hollow-core fibers with cobweb cladding structure
Mingyang Chen, Rongjin Yu, Zhenguo Tian, and Xiangzhong Bai
This paper explores the possibility of realizing a hollow-core optical fiber, whose cladding is composed of cylindrical alternating layers of air and high-index material with supporting structure. The optical properties and the design criteria of the proposed fiber are evaluated by the compact two-dimensional (2D) finiThis paper explores the possibility of realizing a hollow-core optical fiber, whose cladding is composed of cylindrical alternating layers of air and high-index material with supporting structure. The optical properties and the design criteria of the proposed fiber are evaluated by the compact two-dimensional (2D) finite-difference time-domain (FDTD) method. In particular, the influence of the number and width of supporting strips on the leakage loss of the fiber is investigated. Furthermore, the mechanical performances of the fiber are estimated by finite-element method, confirming that hollow-core fibers with a reasonable size and number of supporting strips are reliable..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0263 (2006)
S+C band optical amplification in Er3+-Tm3+ co-doped fiber
Jun Chang, Qingpu Wang, Xingyu Zhang, Zejin Liu, Zhaojun Liu, and Gangding Peng
A new type of optical amplifier based on co-doping erbium in thulium doped fiber is proposed to realize S+C band gain by dual-wavelength (800+1410 nm) pumping scheme which is obtainable from laser diode. A novel model is established for the co-doped fiber considering the Er3+ to Tm3+ energy transfer process. Using apprA new type of optical amplifier based on co-doping erbium in thulium doped fiber is proposed to realize S+C band gain by dual-wavelength (800+1410 nm) pumping scheme which is obtainable from laser diode. A novel model is established for the co-doped fiber considering the Er3+ to Tm3+ energy transfer process. Using appropriate fiber parameters and energy transfer parameters, the coupled rate equations are analyzed and solved; the concentrations of Er3+ and Tm3+ and fiber length were optimized to get more uniform gain. The results predicted that the S+C band gain can be achieved at the same time by co-doping erbium in thulium doped fluoride fiber..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0266 (2006)
2*40 Gb/s OCDM using superstructure fiber Bragg gratings en/decoder
Xiaogang Chen, Dexiu Huang, Xiuhua Yuan, and Ge Xia
A 7-chip, 280 Gb/s optical code-division multiplexing (OCDM) system incorporating quaternary phase coding and decoding superstructured fiber Bragg gratings (SSFBGs) is experimentally demonstrated. Only ordinary phase masks and sub-micrometer precision are needed to fabricate the encoding and decoding SSFBGs. InterchannA 7-chip, 280 Gb/s optical code-division multiplexing (OCDM) system incorporating quaternary phase coding and decoding superstructured fiber Bragg gratings (SSFBGs) is experimentally demonstrated. Only ordinary phase masks and sub-micrometer precision are needed to fabricate the encoding and decoding SSFBGs. Interchannel interference noise is also considered and evaluated, 2-channel 40 (Gb/s)/channel (2*40 Gb/s) signal transmission is demonstrated..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0269 (2006)
Clock recovery from NRZ data at 10 Gb/s using SOA loop mirror and mode-locked fiber ring laser based on SOA
Lina Yin, Guoming Liu, Jian Wu, and Jintong Lin
All-optical clock recovery from non-return-to-zero (NRZ) data using an semiconductor optical amplifier (SOA) loop mirror and a mode-locked SOA fiber laser is firstly schematically explained and experimentally demonstrated at 10 Gb/s. Furthermore, the pulse quality of the recovered clock is effectively improved by usingAll-optical clock recovery from non-return-to-zero (NRZ) data using an semiconductor optical amplifier (SOA) loop mirror and a mode-locked SOA fiber laser is firstly schematically explained and experimentally demonstrated at 10 Gb/s. Furthermore, the pulse quality of the recovered clock is effectively improved by using a continuous-wave (CW) assist light in the gain region of SOA, through which the amplitude modulation is reduced from 57.2% to 8.47%. This scheme is a promising method for clock recovery from NRZ data in the future all-optical communication networks..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0272 (2006)
Image Processing
New region of interest image coding and its applications for remote sensing image
Libao Zhang, and Ke Wang
A new region of interest (ROI) coding called partial multiply bitplane alternating shift (PMBAShift) is presented in this paper. In PMBAShift, the partial most significant bitplanes of ROI are shifted up and no overlap with any bitplane of background (BG). The most significant bitplanes of BG and general significant biA new region of interest (ROI) coding called partial multiply bitplane alternating shift (PMBAShift) is presented in this paper. In PMBAShift, the partial most significant bitplanes of ROI are shifted up and no overlap with any bitplane of background (BG). The most significant bitplanes of BG and general significant bitplanes of ROI coefficients are shifted up by bitplane-by-bitplane alternating scaling. Finally, the least significant bitplanes of ROI and the general significant bitplanes of BG are obtained in the original position and the least significant bitplanes of BG coefficients are shifted down and no overlap with any bitplane. The new method not only retains advantages of maximum shift (Maxshift) method, but also efficiently compresses multiple ROIs according to different degrees of interest without any shape information..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0276 (2006)
Adaptively wavelet-based image denoising algorithm with edge preserving
Yihua Tan, Jinwen Tian, and Jian Liu
A new wavelet-based image denoising algorithm, which exploits the edge information hidden in the corrupted image, is presented. Firstly, a canny-like edge detector identifies the edges in each subband. Secondly, multiplying the wavelet coefficients in neighboring scales is implemented to suppress the noise while magnifA new wavelet-based image denoising algorithm, which exploits the edge information hidden in the corrupted image, is presented. Firstly, a canny-like edge detector identifies the edges in each subband. Secondly, multiplying the wavelet coefficients in neighboring scales is implemented to suppress the noise while magnifying the edge information, and the result is utilized to exclude the fake edges. The isolated edge pixel is also identified as noise. Unlike the thresholding method, after that we use local window filter in the wavelet domain to remove noise in which the variance estimation is elaborated to utilize the edge information. This method is adaptive to local image details, and can achieve better performance than the methods of state of the art..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0280 (2006)
Integrated Optics
Compact all-optical switches based on photon-induced suppression of mode interference
Longzhi Li, Yi Tang, Jianyi Yang, Minghua Wang, and Xiaoqing Jiang
An optically activated optical switch based on suppression of mode interference (SMI) is presented. The imaging properties of multi-mode interference (MMI) section in the switch with Y-branch can be modified by a controlling light injection. The switch was simulated by finite difference beam propagation method (FD-BPM)An optically activated optical switch based on suppression of mode interference (SMI) is presented. The imaging properties of multi-mode interference (MMI) section in the switch with Y-branch can be modified by a controlling light injection. The switch was simulated by finite difference beam propagation method (FD-BPM) and fabricated on GaAlAs/GaAs epitaxial materials. At the wavelength of 1.31 um, the primary experiment showed an extinction ratio of about 8 dB with controlling light power density of 73.5 W/mm2..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0293 (2006)
Lasers and Laser Optics
All-solid-state quasi-continuous-wave high power dispersion cavity tunable Ti:sapphire laser
Xin Ding, Yue Zou, Lei Zou, Hongmei Ma, Wuqi Wen, Yizhong Yu, Ying Lu, Peng Wang, and Jianquan Yao
An all-solid-state quasi-continuous-wave dispersion cavity tunable Ti:sapphire laser pumped by a laser diode pumped frequency-doubled Nd:YAG laser is reported. Using a dense flint glass prism as the dispersion element, a tuning range from 730 to 880 nm with the linewidth of 3 nm and the pulse width of 17.2 ns was obtaiAn all-solid-state quasi-continuous-wave dispersion cavity tunable Ti:sapphire laser pumped by a laser diode pumped frequency-doubled Nd:YAG laser is reported. Using a dense flint glass prism as the dispersion element, a tuning range from 730 to 880 nm with the linewidth of 3 nm and the pulse width of 17.2 ns was obtained. The maximum output power of this laser system was 5.6 W at 786.3 nm corresponding to an optical-to-optical conversion efficiency of 25.5% under the pump power of 22 W..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0296 (2006)
Coupling coefficient for TEA CO2 laser propulsion with variable pulse repetition rate
Yijun Zheng, Rongqing Tan, Donglei Wang, Guang Zheng, Changjun Ke, Kuohai Zhang, Chongyi Wan, and Jin Wu
Because pulse repetition rate affected directly the momentum coupling coefficient of transversely excited atmospheric (TEA) CO2 laser propulsion, a double pulse trigger, controlling high voltage switch of laser excitation circuit, was designed. The pulse interval ranged between 5 and 100 ms. The momentum coupling coeffBecause pulse repetition rate affected directly the momentum coupling coefficient of transversely excited atmospheric (TEA) CO2 laser propulsion, a double pulse trigger, controlling high voltage switch of laser excitation circuit, was designed. The pulse interval ranged between 5 and 100 ms. The momentum coupling coefficient for air-breathing mode laser propulsion was studied experimentally. It was found that the momentum coupling coefficient decreased with the pulse repetition rate increasing..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0299 (2006)
Medical Optics and Biotechnology
Study on the interaction of anticancer drug mitoxantrone with DNA by fluorescence and Raman spectroscopies
Lingjuan Tang, Zhenrong Sun, Jianyu Guo, and Zugeng Wang
Mitoxantrone, a clinically useful antitumour antibiotic for leukaemia and breast cancer, has received more attentions. In this paper, the interaction between mitoxantrone and calf thymus DNA is investigated by Raman and fluorescence spectroscopies, and the binding site of mitoxantrone to calf thymus DNA is explored. ThMitoxantrone, a clinically useful antitumour antibiotic for leukaemia and breast cancer, has received more attentions. In this paper, the interaction between mitoxantrone and calf thymus DNA is investigated by Raman and fluorescence spectroscopies, and the binding site of mitoxantrone to calf thymus DNA is explored. The results showed that mitoxantrone interacts with calf thymus DNA bases by the intercalation of anthracycline into the base pair plane of adenine (A) and thymine (T), and it results in the disruption of the hydrogen bonds between calf thymus DNA bases, and thus the calf thymus DNA double-strand can be disrupted into the B-form DNA double-strand segments..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 02101 (2006)
Influence of high-order optical parameters of tissue on spatially resolved reflectance in the region close to the source
Huijuan Tian, Ying Liu, Lijun Wang, Xiaojuan Zhang, and Zonghui Gao
Influences of the scattering phase functions on spatially resolved diffuse reflectance from a homogenous semi-infinite medium close to source are studied with Monte Carlo simulation. It is shown that the influences of optical parameters higher than the second order on the diffuse reflectance are quite weak in the regioInfluences of the scattering phase functions on spatially resolved diffuse reflectance from a homogenous semi-infinite medium close to source are studied with Monte Carlo simulation. It is shown that the influences of optical parameters higher than the second order on the diffuse reflectance are quite weak in the region from 0.3 to several transport mean free pathes when Henyey-Greenstein phase function or a combined phase function of two parameters are used. But this influence may be substantial if the double Henyey-Greenstein function is used to describe the scattering property of tissue..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 02105 (2006)
Nonlinear Optics
Modulation instability of broad optical beams in nonlinear media with general nonlinearity
Hongcheng Wang, and Weilong She
The modulation instability of quasi-plane-wave optical beams is investigated in the frame of generalized Schrodinger equation with the nonlinear term of a general form. General expressions are derived for the dispersion relation, the critical transverse spatial frequency, as well as the instability growth rate. The anaThe modulation instability of quasi-plane-wave optical beams is investigated in the frame of generalized Schrodinger equation with the nonlinear term of a general form. General expressions are derived for the dispersion relation, the critical transverse spatial frequency, as well as the instability growth rate. The analysis generalizes the known results reported previously. A detailed discussion on the modulation instability in biased centrosymmetric photorefractive media is also given..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 02108 (2006)
Optical Devices
Phase retarder in chemical oxygen-iodine laser at 45-deg. incidence
Fang Wang, Jianbing Huang, Yingjian Wang, and Zhengxiu Fan
A phase retarder used in chemical oxygen-iodine laser (COIL) system has been fabricated by ion beam sputtering (IBS). When the incident angle is 45 deg. the reflectivity is about 99.9% from 1290 to 1340 nm and about 83.8% at 632.8 nm, and the phase retardance between the parallel and perpendicular polarization componenA phase retarder used in chemical oxygen-iodine laser (COIL) system has been fabricated by ion beam sputtering (IBS). When the incident angle is 45 deg. the reflectivity is about 99.9% from 1290 to 1340 nm and about 83.8% at 632.8 nm, and the phase retardance between the parallel and perpendicular polarization components is -92.8 deg. at 1315 nm. In order to get the influence of temperature on the phase retarder, six samples have been annealed from 523 to 648 K at interval of 25 K in air respectively, and the results show good temperature performance. With increasing temperature, phase retardance becomes smaller, and the variation is within 4 deg. at 1315 nm. At the same time, the variation maintains within +- 10 deg. for the incidence from 44 to 49 deg...
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 02114 (2006)
Instrumentation, Measurement, and Metrology
Coarse error analysis and correction of a two-dimensional triangulation range finder
Huaqiao Gui, Liang Lv, Wei Huang, Jun Xu, Deyong He, Huanqin Wang, Jianping Xie, Tianpeng Zhao, and Hai Ming
A real-time two-dimensional (2D) triangulation range finder is presented, which is composed of two linear complementary metal oxidation semiconductor (CMOS) chips, two camera lenses, and four light emitting diodes (LEDs). The high order distortion in image aberrations is the main factor responsible for the coarse errorA real-time two-dimensional (2D) triangulation range finder is presented, which is composed of two linear complementary metal oxidation semiconductor (CMOS) chips, two camera lenses, and four light emitting diodes (LEDs). The high order distortion in image aberrations is the main factor responsible for the coarse errors. The theoretical prediction is in good agreement with experiments and the correction equation is used to obtain more reliable results with the unique distortion coefficient in the whole working region..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0284 (2006)
Optimized design of laser range finding system using the self-mixing effect in a single-mode VCSEL
Huanqin Wang, Tianpeng Zhao, Jun Xu, Deyong He, Liang Lv, Huaqiao Gui, Wei Huang, Hai Ming, and Jianping Xie
An optimized design of laser range finding system using the self-mixing effect in a single-mode vertical-cavity surface-emitting laser (VCSEL) is proposed. In order to improve the ranging accuracy and expand dynamic measurement range, we apply difference frequency analog phase-locked loop (PLL) instead of fast Fourier An optimized design of laser range finding system using the self-mixing effect in a single-mode vertical-cavity surface-emitting laser (VCSEL) is proposed. In order to improve the ranging accuracy and expand dynamic measurement range, we apply difference frequency analog phase-locked loop (PLL) instead of fast Fourier transform (FFT) to process signal, and choose the optimum triangular wave frequency fm = 500 Hz and small modulation current 'Delta'I(p-p) = 0.28 mA to modulate single-mode VCSEL. The experiment results show that, without controlling the laser's temperature, the ranging accuracy is better than 2 mm and the measurement dynamic range is as large as 50-500 mm when the sampling time is 0.1 s and the room temperature is 0-55 Celsius degree..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0287 (2006)
Research of measurement errors caused by salt solution temperature drift in surface plasmon resonance sensors
Yingcai Wu, Zhengtian Gu, and Yifang Yuan
Influence of temperature on measurement of surface plasmon resonance (SPR) sensor was investigated. Samples with various concentrations of NaCl were tested at different temperatures. It was shown that if the affection of temperature could be neglected, measurement precision of salt solution was 0.028 wt.-%. But measureInfluence of temperature on measurement of surface plasmon resonance (SPR) sensor was investigated. Samples with various concentrations of NaCl were tested at different temperatures. It was shown that if the affection of temperature could be neglected, measurement precision of salt solution was 0.028 wt.-%. But measurement error of salinity caused by temperature was 0.53 wt.-% in average when the temperature drift was 1 Celsius degree. To reduce the error, a double-cell SPR sensor with salt solution and distilled water flowing respectively and at the same temperature was implemented..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 0291 (2006)
OPTICAL DATA STORAGE
Three-dimensional multilevel memory based on laser-polarization-dependence birefringence
Guanghua Cheng, Qing Liu, Yishan Wang, Wei Zhao, and Guofu Chen
The femtosecond laser-modified region in isotropic glass medium shows a big optical birefringence. Transmission of the birefringent regions between two crossed polarizers depends on phase retardation and the orientation angle of the birefringent optical axes. Based on this effect, three-dimensional (3D) multilevel memoThe femtosecond laser-modified region in isotropic glass medium shows a big optical birefringence. Transmission of the birefringent regions between two crossed polarizers depends on phase retardation and the orientation angle of the birefringent optical axes. Based on this effect, three-dimensional (3D) multilevel memory was proposed and demonstrated for nonvolatile memory up to eight levels, in contrast to the standard two-level technology. Eight-level writing and reading are distinguishable in fused silica with a near-infrared femtosecond laser. The retention of this memory is characterized for nonvolatile applications..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 02111 (2006)
Spectroscopy
Large scale gas leakage monitoring with tunable diode laser absorption spectroscopy
Ruifeng Kan, Wenqing Liu, Yujun Zhang, Jianguo Liu, Min Wang, Dong Chen, Jiuying Chen, and Yiben Cui
Tunable diode laser absorption spectroscopy (TDLAS) has been widely employed in atmospheric trace gases detecting and industrial control due to its high sensitivity, selectivity, and rapidity of response. An open path TDLAS system is developed for monitoring large scale methane leakage around the oil refinery. The tunaTunable diode laser absorption spectroscopy (TDLAS) has been widely employed in atmospheric trace gases detecting and industrial control due to its high sensitivity, selectivity, and rapidity of response. An open path TDLAS system is developed for monitoring large scale methane leakage around the oil refinery. The tunable distributed feedback (DFB) diode laser emits at 1.65 um. In order to enhance the sensitivity, a system combining long open path and second harmonic detection technique is developed. The test results show that the time resolution is less than 0.1 second and the detection limit is lower than 3.6 ppmv. This system is adapted for monitoring a large scale methane concentration changing trend instead of measuring its absolute concentration..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 02116 (2006)
Ultrafast Optics
Dynamics of Coulomb explosion of hydrogen clusters in a high-intensity femtosecond laser pulse
Xuhong Cai, Peiqing Zhang, Yue Jiang, and Shaohui Li
Using Bethe model, the dynamics of the ionization and Coulomb explosion of hydrogen clusters (0.5-5 nm) in high-intensity (10^(15)-10^(17) W/cm2) femtosecond laser pulses have been studied theoretically, and the dependence of energy of protons emitted from exploding clusters on cluster size and laser intensity has beenUsing Bethe model, the dynamics of the ionization and Coulomb explosion of hydrogen clusters (0.5-5 nm) in high-intensity (10^(15)-10^(17) W/cm2) femtosecond laser pulses have been studied theoretically, and the dependence of energy of protons emitted from exploding clusters on cluster size and laser intensity has been investigated. It is found that the maximum proton energy increases exponentially with the cluster size, and the exponent is mainly determined by the laser intensity. For a given cluster size, the maximum proton energy increases with increasing laser intensity and gets saturation gradually. The calculation results are in agreement with the recent experimental observation..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 4, Issue 2, 02122 (2006)
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