Journals >Chinese Optics Letters
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2011
Volume: 9 Issue 6
29 Article(s)
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Vision, Color, and Visual
Spectral-based color separation method for a multi-ink printer
Binyu Wang, Haisong Xu, M. Ronnier Luo, and Jinyi Guo
A spectral-based 8-ink characterization model is developed to accurately predict the recipe for a multi-ink printer. The 8-ink color separation method is a union of five 3-ink and six 4-ink combinations based on the cellular Yule-Nielsen spectral Neugebauer model with a recipe selection strategy. The performance levelsA spectral-based 8-ink characterization model is developed to accurately predict the recipe for a multi-ink printer. The 8-ink color separation method is a union of five 3-ink and six 4-ink combinations based on the cellular Yule-Nielsen spectral Neugebauer model with a recipe selection strategy. The performance levels of the forward and backward models are evaluated for individual ink combinations using printed testing samples. Furthermore, the spectral-based method performs better compared with the XYZ-based approach. On the basis of the backward model performance, a novel fast recipe selection strategy is proposed and estimated..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 063301 (2011)
Holography
Improvement of speckle noise suppression in digital holography by rotating linear polarization state
Wen Xiao, Jing Zhang, Lu Rong, Feng Pan... and Aga He|Show fewer author(s)
An improved polarization recording approach to reduce speckle noise in digital holography is proposed. Multiple off-axis holograms are obtained by rotating the linear polarization state of both illumination and reference wave simultaneously. By averaging the intensity fields, the speckle noise in the reconstructed imagAn improved polarization recording approach to reduce speckle noise in digital holography is proposed. Multiple off-axis holograms are obtained by rotating the linear polarization state of both illumination and reference wave simultaneously. By averaging the intensity fields, the speckle noise in the reconstructed images is well suppressed. Statistical evaluation of the experimental results shows the effectiveness and improvement of the proposed method..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 060901 (2011)
Instrumentation, Measurement, and Metrology
Modified adaptive algebraic tomographic reconstruction of gas distribution from incomplete projection by a two-wavelength absorption scheme
Ning Li, and Chunsheng Weng (翁春生)
A modified adaptive algebraic reconstruction technique (MAART) with an auto-adjustment relaxation parameter and smoothness regularization is developed to reveal the tomographic reconstruction of H2O distribution in combustion from incomplete projections. Determinations of relaxation parameter and regularization factor A modified adaptive algebraic reconstruction technique (MAART) with an auto-adjustment relaxation parameter and smoothness regularization is developed to reveal the tomographic reconstruction of H2O distribution in combustion from incomplete projections. Determinations of relaxation parameter and regularization factor are discussed with regard to the consideration of improvement in reconstruction and reduction of computational burden. A two-wavelength scheme from tunable diode laser absorption measurement, 7444.36 and 7185.59 cm ?1, is used to simplify the nonlinear solution problem for obtaining the tomographic distributions of concentration and temperature simultaneously. Results of calculations demonstrate that MAART can perform the reconstruction results more efficiently with little complex modification and much lower iterations as compared with the traditional algebraic reconstruction technique (ART) or simultaneous iterative reconstruction technique (SIRT) methods. The stability of the algorithm is studied by reconstruction from projections with random noise at different levels to demonstrate the dependence of reconstruction results on precise line-of-sight measurements..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 061201 (2011)
Optimization of computer-generated holograms for dynamic optical manipulation with uniform structured light spots
Jing Bu, Guanghui Yuan, Yuyang Sun, Siwei Zhu, and Xiaocong Yuan
An optimized iterative technique combining the merits of conventional Gerchber-Saxton (G-S) and adaptive-additive (A-A) algorithms to design multilevel computer-generated holograms for the creation of a desirable structured intensity pattern for multiple optical manipulation is theoretically adopted. Optical trap arrayAn optimized iterative technique combining the merits of conventional Gerchber-Saxton (G-S) and adaptive-additive (A-A) algorithms to design multilevel computer-generated holograms for the creation of a desirable structured intensity pattern for multiple optical manipulation is theoretically adopted. Optical trap arrays are demonstrated with the help of liquid crystal spatial light modulator and a microscopic optical tweezer system. Additionally, continuous locked-in transport and deflection of microparticles with the generated optical lattice is proven experimentally. The proposed method possesses apparent high efficiency, high uniformity, and dynamic and reconfigurable advantages..
Chinese Optics Letters
- Publication Date: May. 06, 2011
- Vol. 9, Issue 6, 061202 (2011)
Lasers and Laser Optics
Frequency-narrowed external-cavity broad-area-diode for rubidium laser pumping
Zining Yang, Yuandong Li, Hongyan Wang, Qisheng Lu, and Xiaojun Xu
Using an external cavity with holographic grating, we demonstrate the spectral narrowing of a high power broad-area-diode with a single emitter. The spectral bandwidth of less than 15 GHz is obtained with output power exceeding 10 W and external cavity efficiency exceeding 60%. Absorption of 98% of the laser radiation Using an external cavity with holographic grating, we demonstrate the spectral narrowing of a high power broad-area-diode with a single emitter. The spectral bandwidth of less than 15 GHz is obtained with output power exceeding 10 W and external cavity efficiency exceeding 60%. Absorption of 98% of the laser radiation by a 25-mm rubidium vapor cell filled with 600-torr ethane at a temperature of 368 K is acquired, which demonstrates the availability of this pump source for efficient rubidium laser pumping..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 061401 (2011)
Dynamic behavior and complexity of modulated optical micro ring resonator
Lei Yang, Wei Pan, Bin Luo, ShuiYing Xiang, and Ning Jiang
The dynamic behavior of an optical micro ring resonator (OMRR) with an amplitude modulator positioned in the micro ring is investigated quantitatively by adopting a recently introduced quantifier, the permutation entropy (PE). The effects of modulation depth are focused on, and the roles of input power are considered. The dynamic behavior of an optical micro ring resonator (OMRR) with an amplitude modulator positioned in the micro ring is investigated quantitatively by adopting a recently introduced quantifier, the permutation entropy (PE). The effects of modulation depth are focused on, and the roles of input power are considered. The two-dimensional (2D) maps of PE showing dependence on both modulation depth and input power are presented as well. PE values nearly increase with modulation depth. On the other hand, the optimal value of input power is achieved when the PE reaches its maximum. Thus, PE can successfully quantify the dynamics of modulated OMRR. Selecting the parameters in the region with high PE values would contribute to the complexity-enhanced OMRR-based chaotic communication systems..
Chinese Optics Letters
- Publication Date: May. 06, 2011
- Vol. 9, Issue 6, 061402 (2011)
Mid-infrared optical parametric oscillator based on ZnGeP2 pumped by 2- \mum laser
Yuefeng Peng, Xingbin Wei, and Weimin Wang
We present a 3~5 \mum optical parametric oscillator (OPO) based on ZGP pumped by KTP OPO 2.1-\mum laser. The tuning curves of ZGP OPO are calculated. The 8 \times 6 \times 18 (mm) ZGP crystal, whose end faces are antireflection coated at 2.1 and 3.7~4.6 \mum, is cut as \theta =53.5o, \phi =0o. When the pump power of 2.We present a 3~5 \mum optical parametric oscillator (OPO) based on ZGP pumped by KTP OPO 2.1-\mum laser. The tuning curves of ZGP OPO are calculated. The 8 \times 6 \times 18 (mm) ZGP crystal, whose end faces are antireflection coated at 2.1 and 3.7~4.6 \mum, is cut as \theta =53.5o, \phi =0o. When the pump power of 2.1-\mu m polarized laser is 15 W at 8 kHz, 5.7-W output power and 46.6% slope efficiency are obtained with a ZGPtype I phase match. Central wavelengths of the signal and idler lasers are 4.10 and 4.32 μm, respectively. Pulse duration is about 27 ns. Beam quality factor M2 is better than 1.8. The tunability of 3~5 \mu m can be achieved by changing the angle of the ZGP crystal..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 061403 (2011)
Single-mode surface-emitting distributed feedback quantum-cascade lasers based on hybrid waveguide structure
Wanhong Guo, Junqi Liu, Jianyan Chen, Lu Li... and Zhanguo Wang|Show fewer author(s)
Surface-emitting distributed feedback quantum-cascade lasers operating at \lambda \approx 7.8 \mu m are demonstrated. The metal-covered second-order grating is shallow-etched into the surface of a thin InGaAs contact and cladding layer. This forms a hybrid waveguide and used to achieve relatively low waveguide losses aSurface-emitting distributed feedback quantum-cascade lasers operating at \lambda \approx 7.8 \mu m are demonstrated. The metal-covered second-order grating is shallow-etched into the surface of a thin InGaAs contact and cladding layer. This forms a hybrid waveguide and used to achieve relatively low waveguide losses and high coupling strengths. The devices exhibit stable single-mode operation from 90 to 130 K with a side mode suppression ratio above 20 dB. A slope efficiency of 194 mW/A is obtained at 90 K, which is twice higher than that of the Fabry-Perot counterpart..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 061404 (2011)
Localized CO2 laser treatment and post-heating process to reduce the growth coef f icient of fused silica surface damage
Shizhen Xu, Xiaotao Zu, and Xiaodong Yuan
The lifetime of optical components in high-fluence ultraviolet (UV) laser applications is typically limited by laser-initiated damage and its subsequent growth. Using 10.6-μm CO2 laser pulses, we successfully mitigate 355-nm laser induced damage sites on fused silica surface with dimensions less than 200 \mu m. The damThe lifetime of optical components in high-fluence ultraviolet (UV) laser applications is typically limited by laser-initiated damage and its subsequent growth. Using 10.6-μm CO2 laser pulses, we successfully mitigate 355-nm laser induced damage sites on fused silica surface with dimensions less than 200 \mu m. The damage threshold increases and the damage growth mitigates. However, the growth coefficients of new damage on the CO2 laser processed area are higher than those of the original sample. The damage grows with crack propagation for residual stress after CO2 laser irradiation. Furthermore, post-heating is beneficial to the release of residual stress and slows down the damage growth..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 061405 (2011)
Effects of processing parameters on fatigue properties of LY2 Al alloy subjected to laser shock processing
Lei Zhang, Jinzhong Lu, Yongkang Zhang, Kaiyu Luo... and Junwei Zhong|Show fewer author(s)
We address the effects of processing parameters on residual stresses and fatigue properties of LY2 Al alloy by laser shock processing (LSP). Results show that compressive residual stresses are generated near the surface of samples due to LSP. The maximum compressive residual stress at the surface by two LSP impacts on We address the effects of processing parameters on residual stresses and fatigue properties of LY2 Al alloy by laser shock processing (LSP). Results show that compressive residual stresses are generated near the surface of samples due to LSP. The maximum compressive residual stress at the surface by two LSP impacts on one side is higher than that by one LSP impact. The maximum value of tensile residual stress is found at the mid-plane of samples subjected to two-sided LSP. Compared with fatigue lives of samples treated by single-sided LSP, lives of those treated by two-sided LSP are lower. However, these are higher than untreated ones..
Chinese Optics Letters
- Publication Date: May. 12, 2011
- Vol. 9, Issue 6, 061406 (2011)
Multi-wavelength erbium-doped fiber laser using four-wave mixing effect in doped fiber
N. S. Shahabuddin, Z. Yusoff, H. Ahmad, and S. W. Harun
We demonstrate a multi-wavelength erbium-doped fiber laser (EDFL) using erbium gain and four-wave mixing (FWM) effect in a piece of erbium-doped fiber (EDF) with high erbium ion concentration. The EDF has a pump absorption rate of 24.6 dB/m at 979 nm and is bi-directionally pumped by 980-nm laser diodes. FWM effect redWe demonstrate a multi-wavelength erbium-doped fiber laser (EDFL) using erbium gain and four-wave mixing (FWM) effect in a piece of erbium-doped fiber (EDF) with high erbium ion concentration. The EDF has a pump absorption rate of 24.6 dB/m at 979 nm and is bi-directionally pumped by 980-nm laser diodes. FWM effect redistributes the energy of different oscillating lines and causes multi-wavelength operation. The laser generates more than 22 lines of optical comb with a line spacing of approximately 0.10 nm at the 1569-nm region using only 1.5-m-long EDF..
Chinese Optics Letters
- Publication Date: May. 12, 2011
- Vol. 9, Issue 6, 061407 (2011)
Diffraction and Gratings
Reflex optical sensor based on dual metal gratings with high angular sensitivity
Ji Xu, Chen Cheng, Qiang Bai, Jing Chen, and Jianping Ding
An interesting reflection phenomenon in a dual metal grating (DMG) structure is studied, which is related to the competition between Fabry-Perot (F-P) resonance effect and evanescent-field coupling effect inside the gap between the two composing single metal gratings. This competition leads to high angular sensitivity An interesting reflection phenomenon in a dual metal grating (DMG) structure is studied, which is related to the competition between Fabry-Perot (F-P) resonance effect and evanescent-field coupling effect inside the gap between the two composing single metal gratings. This competition leads to high angular sensitivity in response to the refractive index variation of the sample solution in the gap. A reflex optical sensor with high sensitivity based on DMG for detecting the change in refractive index is proposed and its performance theoretically is discussed..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 060501 (2011)
Fiber Optics and Optical Communications
Radiation-induced effects in polarization-maintaining optical fibers for interferometric gyroscope
Xueqin Wang, Chunxi Zhang, Jing Jin, and Ningfang Song
Radiation-induced attenuation (RIA) in four types of polarization-maintaining optical fibers for interferometric fiberoptic gyroscope (IFOG) at 1310 nm is measured. The measurements are conducted during and after steady-state γ-ray irradiation using a 60Co source in order to observe significantly different RIA behaviorRadiation-induced attenuation (RIA) in four types of polarization-maintaining optical fibers for interferometric fiberoptic gyroscope (IFOG) at 1310 nm is measured. The measurements are conducted during and after steady-state γ-ray irradiation using a 60Co source in order to observe significantly different RIA behavior and recovery kinetics. Mechanisms involving dopants and manufacturing process are introduced to analyze the RIA discrepancy as well as to guide the choice and hardening of optical fibers during the design of IFOG. Medium-accuracy IFOG using Ge–F-codoped fiber and pure silica core fiber can survive in the space radiation environment..
Chinese Optics Letters
- Publication Date: May. 06, 2011
- Vol. 9, Issue 6, 060601 (2011)
Analysis of IPACT network performance considering channel switch latency for WDM-EPON
Zhao Zhou, Shilin Xiao, Min Zhu, and Meihua Bi
In wavelength-division multiplexing (WDM) ethernet passive optical networks (EPONs), to realize the statistical multiplexing of upstream wavelength resources, some optical tunable components are introduced in the optical network units. However, the switch latency (SL) of these tunable components constrains the performaIn wavelength-division multiplexing (WDM) ethernet passive optical networks (EPONs), to realize the statistical multiplexing of upstream wavelength resources, some optical tunable components are introduced in the optical network units. However, the switch latency (SL) of these tunable components constrains the performance of WDM-EPON. In this letter, we extend the mathematical model of the WDM interleaved polling with adaptive cycle time (IPACT) scheme by additionally considering the SL conditions. We also investigate the effect of channel SL on network performance. The simulation results show that the performance of WDM-IPACT-SL deteriorates as the SL increases..
Chinese Optics Letters
- Publication Date: May. 06, 2011
- Vol. 9, Issue 6, 060602 (2011)
Improved large-mode-area Bragg fiber
Peiguang Yan, Jian Zhao, Shuangchen Ruan, Junqing Zhao... and Shengping Chen|Show fewer author(s)
A novel large-mode-area Bragg fiber (BF) is proposed for selectively suppressing the amplified spontaneous emission (ASE) of Yb. Confinement loss can be effectively lowered by adding a layer of F-doped glass near the core of this fiber. The BF can achieve effective suppression of ASE of Yb when the bend radius is 0.15 A novel large-mode-area Bragg fiber (BF) is proposed for selectively suppressing the amplified spontaneous emission (ASE) of Yb. Confinement loss can be effectively lowered by adding a layer of F-doped glass near the core of this fiber. The BF can achieve effective suppression of ASE of Yb when the bend radius is 0.15 m at wavelength lower than 1.13 \mu m in theory, and eliminate LP11 mode in mode competition in wavelength range of 1.15-1.2 \mu m..
Chinese Optics Letters
- Publication Date: May. 06, 2011
- Vol. 9, Issue 6, 060603 (2011)
Optimized optical phase conjugation configuration for fiber nonlinearity compensation in CO-OFDM systems
Lujiao Li, Yaojun Qiao, and Yuefeng Ji
The optimized optical phase conjugation (OPC) configuration is proposed for the 40-Gb/s CO-OFDM system. The proposed configuration for nonlinear cancellation is systematically depicted in transmission links with lumped amplification. Numerical simulations are performed to demonstrate effectiveness. Simulation results sThe optimized optical phase conjugation (OPC) configuration is proposed for the 40-Gb/s CO-OFDM system. The proposed configuration for nonlinear cancellation is systematically depicted in transmission links with lumped amplification. Numerical simulations are performed to demonstrate effectiveness. Simulation results show that mid-span spectral inversion (MSSI) can partially compensate for nonlinear distortions. Moreover, its optimized configuration can further improve system performances and increase nonlinear compensation effectiveness. Compared with MSSI, the maximal Q factor, nonlinear threshold, and transmission distance of optimized OPC configuration increase by over 1.6 dB, 2 dB, and 2 times, respectively..
Chinese Optics Letters
- Publication Date: May. 12, 2011
- Vol. 9, Issue 6, 060604 (2011)
Imaging Systems
Investigations of range accuracy for long-range three-dimensional active imaging
Xiuda Zhang, Huimin Yan, and Qin Zhou
Distance resolutions and noises are analyzed experimentally for long-range three-dimensional (3D) active imaging systems that have signal-to-noise ratios (SNRs) more optimal than 30:1. Findings indicate that the photon shot noise primarily determines the SNR. However, the active imaging method, which has a relatively lDistance resolutions and noises are analyzed experimentally for long-range three-dimensional (3D) active imaging systems that have signal-to-noise ratios (SNRs) more optimal than 30:1. Findings indicate that the photon shot noise primarily determines the SNR. However, the active imaging method, which has a relatively low SNR, generates a relatively high distance resolution. To explain this phenomenon, a theory in which the distance resolution of 3D active imaging systems is determined by both the photon shot noise and the subinterval width is developed. Theoretical and experimental results differ by less than 4%..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 061101 (2011)
Optics in Computing
All-optical prefix tree adder with the help of terahertz optical asymmetric demultiplexer
Dilip Kumar Gayen, Tanay Chattopadhyay, Rajat Kumar Pal, and Jitendra Nath Roy
We propose and describe an all-optical prefix tree adder with the help of a terahertz optical asymmetric demultiplexer (TOAD) using a set of optical switches. The prefix tree adder is useful in compound adder implementation. It is preferred over the ripple carry adder and the carry lookahead adder. We also describe theWe propose and describe an all-optical prefix tree adder with the help of a terahertz optical asymmetric demultiplexer (TOAD) using a set of optical switches. The prefix tree adder is useful in compound adder implementation. It is preferred over the ripple carry adder and the carry lookahead adder. We also describe the principle and possibilities of the all-optical prefix tree adder. The theoretical model is presented and verified through numerical simulation. The new method promises higher processing speed and accuracy. The model can be extended for studying more complex all-optical circuits of enhanced functionality in which the prefix tree adder is the basic building block..
Chinese Optics Letters
- Publication Date: May. 06, 2011
- Vol. 9, Issue 6, 062001 (2011)
Image Processing
KW-SIFT descriptor for remote-sensing image registration
Xiangzeng Liu, Zheng Tian, Weidong Yan, and Xifa Duan
A technique to construct an affine invariant descriptor for remote-sensing image registration based on the scale invariant features transform (SIFT) in a kernel space is proposed. Affine invariant SIFT descriptor is first developed in an elliptical region determined by the Hessian matrix of the feature points. ThereaftA technique to construct an affine invariant descriptor for remote-sensing image registration based on the scale invariant features transform (SIFT) in a kernel space is proposed. Affine invariant SIFT descriptor is first developed in an elliptical region determined by the Hessian matrix of the feature points. Thereafter, the descriptor is mapped to a feature space induced by a kernel, and a new descriptor is constructed by whitening the mapped descriptor in the feature space, with the transform called KW-SIFT. In a final step, the new descriptor is used to register remote-sensing images. Experimental results for remote-sensing image registration indicate that the proposed method improves the registration performance as compared with other related methods..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 061001 (2011)
Photoacoustic image reconstruction based on Bayesian compressive sensing algorithm
Mingjian Sun, Naizhang Feng, Yi Shen, Jiangang Li... and Zhenghua Wu|Show fewer author(s)
The photoacoustic tomography (PAT) method, based on compressive sensing (CS) theory, requires that, for the CS reconstruction, the desired image should have a sparse representation in a known transform domain. However, the sparsity of photoacoustic signals is destroyed because noises always exist. Therefore, the originThe photoacoustic tomography (PAT) method, based on compressive sensing (CS) theory, requires that, for the CS reconstruction, the desired image should have a sparse representation in a known transform domain. However, the sparsity of photoacoustic signals is destroyed because noises always exist. Therefore, the original sparse signal cannot be effectively recovered using the general reconstruction algorithm. In this study, Bayesian compressive sensing (BCS) is employed to obtain highly sparse representations of photoacoustic images based on a set of noisy CS measurements. Results of simulation demonstrate that the BCS-reconstructed image can achieve superior performance than other state-of-the-art CS-reconstruction algorithms..
Chinese Optics Letters
- Publication Date: May. 06, 2011
- Vol. 9, Issue 6, 061002 (2011)
Detectors
X-ray photon-counting detector based on a micro-channel plate for pulsar navigation
Baomei Chen, Baosheng Zhao, Huijun Hu, Qiurong Yan, and Lizhi Sheng
The pulse time of arrival (TOA) is a determining parameter for accurate timing and positioning in X-ray pulsar navigation. The pulse TOA can be calculated by comparing the measured arrival time with the predicted arrival time of the X-ray pulse for pulsar. In this study, in order to research the measurement of pulse arThe pulse time of arrival (TOA) is a determining parameter for accurate timing and positioning in X-ray pulsar navigation. The pulse TOA can be calculated by comparing the measured arrival time with the predicted arrival time of the X-ray pulse for pulsar. In this study, in order to research the measurement of pulse arrival time, an experimental system is set up. The experimental system comprises a simulator of the X-ray pulsar, an X-ray detector, a time-measurement system, and a data-processing system. An X-ray detector base is proposed on the basis of the micro-channel plate (MCP), which is sensitive to soft X-ray in the 1–10 keV band. The MCP-based detector, the structure and principle of the experimental system, and results of the pulse profile are described in detail. In addition, a discussion of the effects of different X-ray pulse periods and the quantum efficiency of the detector on pulse-profile signal-to-noise ratio (SNR) is presented. Experimental results reveal that the SNR of the measured pulse profile becomes enhanced as the quantum efficiency of the detector increases. The SNR of the pulse profile is higher when the period of the pulse is smaller at the same integral..
Chinese Optics Letters
- Publication Date: May. 12, 2011
- Vol. 9, Issue 6, 060401 (2011)
Remote Sensing and Sensors
Experimental research of temperature sensor based on twin-core fiber
Ruifeng Zhao, Li Pei, Zhuoxuan Li, Tigang Ning... and Weiwei Jiang|Show fewer author(s)
A low-cost, compact, and lossless temperature sensor based on a twin-core fiber (TCF) is demonstrated and manufactured by splicing two single-mode fibers to the ends of a TCF. The extinction ratio of the comb transmission spectrum is bigger than 15 dB, and the temperature sensitivity of the coupling angle is –0.02 rad/A low-cost, compact, and lossless temperature sensor based on a twin-core fiber (TCF) is demonstrated and manufactured by splicing two single-mode fibers to the ends of a TCF. The extinction ratio of the comb transmission spectrum is bigger than 15 dB, and the temperature sensitivity of the coupling angle is –0.02 rad/(oC.m) at –30–90 oC and –0.032 rad/(oC.m) at 90–175 oC. Finite element method is used to calculate the supermodes of the TCF, and the result agrees well with the experiment..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 062801 (2011)
Novel system for modulated lidar parameter optimization
Bo Zhou, Yong Ma, Kun Liang, Zhiqiang Tu, and Hongyuan Wang
We present a novel system for parameter design and optimization of modulated lidar. The system is realized by combining software simulation with hardware circuit. This method is more reliable and flexible for lidar parameter optimization compared with theoretical computation or fiber-simulated system. Experiments confiWe present a novel system for parameter design and optimization of modulated lidar. The system is realized by combining software simulation with hardware circuit. This method is more reliable and flexible for lidar parameter optimization compared with theoretical computation or fiber-simulated system. Experiments confirm that the system is capable of optimizing parameters for modulated lidar. Key parameters are analyzed as well. The optimal filter bandwidth is 200 MHz and the optimal modulation depth is 0.5 under typical application environment..
Chinese Optics Letters
- Publication Date: May. 12, 2011
- Vol. 9, Issue 6, 062802 (2011)
Scattering
Light transmission in porous silicon dioxide filled with liquids of different refractive indices
Jun Li, Xinzheng Zhang, Fan Shi, Yan Xu... and Jingjun Xu|Show fewer author(s)
Optical transmission at 532 nm from nonabsorbing disordered porous silicon dioxide has been studied experimentally. The transmission behaviors can be adjusted by filling the pores with liquids of different refractive indics, which are analyzed based on the theory of diffusion in a weak scattering regime. In our experimOptical transmission at 532 nm from nonabsorbing disordered porous silicon dioxide has been studied experimentally. The transmission behaviors can be adjusted by filling the pores with liquids of different refractive indics, which are analyzed based on the theory of diffusion in a weak scattering regime. In our experiment, the transmission coefficient changes from a value less than 1% to one that is greater than 75%, that is, the opaque sample becomes transparent, which means that the transport mean free path of light within the material has been effectively adjusted. In addition, this method is a useful nondestructive method to derive the refractive index of an unknown bulk porous material..
Chinese Optics Letters
- Publication Date: May. 06, 2011
- Vol. 9, Issue 6, 062901 (2011)
Spectroscopy
Spectroscopic characterization of fluorine atoms in atmospheric pressure He/SF6 plasmas
Huiliang Jin, Bo Wang, and Feihu Zhang
We investigate reactive fluorine atom spectroscopic characterization in atmospheric pressure of He/SF6 plasma using atomic emission spectrometry. As input radio frequency (RF) power levels are raised from 140 to 220 W, the emission spectra of 685.60 (3p4D-3s4P transition) and 739.87 nm (3p4P-3s4P transition) increase sWe investigate reactive fluorine atom spectroscopic characterization in atmospheric pressure of He/SF6 plasma using atomic emission spectrometry. As input radio frequency (RF) power levels are raised from 140 to 220 W, the emission spectra of 685.60 (3p4D-3s4P transition) and 739.87 nm (3p4P-3s4P transition) increase significantly. Moreover, an optimal value of SF6 volume concentration in the production of fluorine radicals, which is 0.8% is achieved. Addition of certain amounts of O2 into He/SF6 plasma results in the promotion of SF6 dissociation. Emission intensities of fluorine atoms show the maximum at the O2/SF6 ratio of 0.4..
Chinese Optics Letters
- Publication Date: May. 06, 2011
- Vol. 9, Issue 6, 063001 (2011)
Ultrafast Optics
Manifestation of attosecond XUV fields temporal structures in attosecond streaking spectrogram
Guanglong Chen, Yunjiu Cao, and Dong Eon Kim
The features of an attosecond extreme ultraviolet (XUV) field are encoded in the attosecond XUV spectrogram. We investigate the effect of the temporal structures of attosecond XUV fields on the attosecond streaking spectrogram. Factors such as the number of attosecond XUV pulses and the temporal chirp of attosecond XUVThe features of an attosecond extreme ultraviolet (XUV) field are encoded in the attosecond XUV spectrogram. We investigate the effect of the temporal structures of attosecond XUV fields on the attosecond streaking spectrogram. Factors such as the number of attosecond XUV pulses and the temporal chirp of attosecond XUV pulses are considered. Results indicate that unlike the attosecond streaking spectrogram for an attosecond XUV field with two pulses of a half-cycle separation of streaking field, the spectrogram for the attosecond XUV field with three pulses demonstrates fine spectral fringes in separated traces..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 063201 (2011)
Research on electrical pulse of 20-kV/30-Hz GaAs photoconductive switches
Hong Liu, Jingli Wang, Lin Zhang, Binjie Xin... and Wei Shi|Show fewer author(s)
Photoconductive semiconductor switches (PCSSs) are widely used in high power ultra-wideband source applications and precise synchronization control due to their high power low-jitter high-repetition-frequency. In this letter, a 14-mm gap semi-insulating GaAs PCSS biased under 20 kV is triggered by a 1064-nm laser with Photoconductive semiconductor switches (PCSSs) are widely used in high power ultra-wideband source applications and precise synchronization control due to their high power low-jitter high-repetition-frequency. In this letter, a 14-mm gap semi-insulating GaAs PCSS biased under 20 kV is triggered by a 1064-nm laser with a repetition frequency of 30 Hz. Although the trigger condition is greater than the threshold of the lock-on effect, the high gain mode is not observed. The results indicate that the high gain mode of the PCSS is quenched by decreasing the remnant voltage of pulsed energy storage capacitor..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 063202 (2011)
Atmospheric and Oceanic Optics
Method of sensitivity improving in the non-dispersive infrared gas analysis system
Youwen Sun, Wenqing Liu, Shimei Wang, Shuhua Huang, and Xiaoman Yu
A method of interference correction for improving the sensitivity of non-dispersive infrared (NDIR) gas analysis system is demonstrated. Based on the proposed method, the interference due to water vapor and carbon dioxide in the NDIR NO analyzer is corrected. After interference correction, the absorbance signal at the A method of interference correction for improving the sensitivity of non-dispersive infrared (NDIR) gas analysis system is demonstrated. Based on the proposed method, the interference due to water vapor and carbon dioxide in the NDIR NO analyzer is corrected. After interference correction, the absorbance signal at the NO filter channel is only controlled by the absorption of NO, and the sensitivity of the analyzer is improved greatly. In the field experiment for pollution source emission monitoring, the concentration trend of NO monitored by NDIR analyzer is in good agreement with the differential optical absorption spectroscopy NO analyzer. Small variations of NO concentration can also be resolved, and the measuring correlation coefficient of the two analyzers is 94.28%..
Chinese Optics Letters
- Publication Date: Jul. 09, 2021
- Vol. 9, Issue 6, 060101 (2011)
Direct inversion of shallow-water bathymetry from EO-1 hyperspectral remote sensing data
Zhishen Liu, and Yan Zhou
Using the US National Aeronautics and space Administration (NASA) Earth Observing-1 Mission (EO-1) hyperion hyperspectral remote sensing data, we study the shallow-water bathymetry inversion in Smith Island Bay. The fast line-of-sight atmospheric analysis of spectral hypercubes module is applied for atmo-spheric correcUsing the US National Aeronautics and space Administration (NASA) Earth Observing-1 Mission (EO-1) hyperion hyperspectral remote sensing data, we study the shallow-water bathymetry inversion in Smith Island Bay. The fast line-of-sight atmospheric analysis of spectral hypercubes module is applied for atmo-spheric correction, and principal component analysis method combined with scatter diagram and maximum likelihood classification is used for seabed classification. The diffuse attenuation coefficient Kd is derived using quasi-analytical algorithm (QAA), which performs well in optically deep water. Kd obtained from QAA requires correction, particularly those derived in some coastal areas with optically shallow water and calculated by direct inversion based on radiative transfer theory to obtain the bathymetry. The direct inversion method derives the water depth quickly, and matches the results from optimized algorithm..
Chinese Optics Letters
- Publication Date: May. 12, 2011
- Vol. 9, Issue 6, 060102 (2011)
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