Journals >Chinese Optics Letters
Contents
2009
Volume: 7 Issue 11
27 Article(s)
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Research Article
Theoretical analysis on the efficiency of optical-optical double-color double-resonance multiphoton ionization
Guiyin Zhang, and Yidong Jin
Analytic formula of the efficiency of optical-optical double-color double-resonance multi-photon ionization (OODR-MPI) is derived from the dynamic rate equation about the interaction of photon and material. Based on this formula, the influence of characteristic of the pump and probe laser on the ionization efficiency oAnalytic formula of the efficiency of optical-optical double-color double-resonance multi-photon ionization (OODR-MPI) is derived from the dynamic rate equation about the interaction of photon and material. Based on this formula, the influence of characteristic of the pump and probe laser on the ionization efficiency of (1+2+1) OODR-MPI process is simulated theoretically. It is shown that the pump laser will affect the ionization efficiency by the number control of the molecules excited to the first resonance state. The ionization efficiency is decided by the probe laser directly. Both of the excited molecules and ionization efficiency increase with the intensity and pulse duration of the laser until saturation. It is also found that the longer the delay time of the probe laser to the pump one is, the lower the ionization efficiency would be. The delay time ought to be smaller than the lifetime of the excited molecule in the practical use of the OODR-MPI technique..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 971 (2009)
High-efficiency spatial color separation method based on fractional Talbot ef fect
Qiaofeng Tan, Yan Zhang, and Guofan Jin
Based on fractional Talbot effect, Talbot grating is adopted to realize spatial color separation with high light efficiency. For red and green colors, a two-step Talbot grating is optimized and the light efficiency reaches over 95%. The two-step Talbot grating is fabricated and tested. Experimental results show that thBased on fractional Talbot effect, Talbot grating is adopted to realize spatial color separation with high light efficiency. For red and green colors, a two-step Talbot grating is optimized and the light efficiency reaches over 95%. The two-step Talbot grating is fabricated and tested. Experimental results show that the Talbot grating indeed has the good ability of spatial color separation..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 975 (2009)
Wavelength pre-assignment collision schedule for wavelength-routed optical networks
Yiqiang Hua, Yueming Lu, Tong Zhao, Yuefeng Ji, and Baoquan Rao
A novel wavelength assignment scheme called the wavelength pre-assignment collision schedule (WPCS) is proposed for wavelength-routed networks. The WPCS pre-assigns the wavelength at the forward detection phase, and schedules the potential collision by priority. The potential collision is scheduled at the forward detecA novel wavelength assignment scheme called the wavelength pre-assignment collision schedule (WPCS) is proposed for wavelength-routed networks. The WPCS pre-assigns the wavelength at the forward detection phase, and schedules the potential collision by priority. The potential collision is scheduled at the forward detection phase and the blocking of the wavelength assignment is reduced. Simulation is conducted with several other existing schemes. The numerical results show thatWPCS performs better than other schemes in blocking probability under various traffic conditions..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 978 (2009)
Research on performance of multicasting in optical packet switched networks
Xin Liu, Yuefeng Ji, Lin Bai, Hongxiang Wang, and Yongmei Sun
Different multicasting schemes in optical packet switched networks are discussed, including the parallel mode, serial mode, and hybrid mode multicasting schemes. Simulated modeling technique is applied to compare the network-level performance of the three multicasting schemes. A conclusion can be drawn from the resultsDifferent multicasting schemes in optical packet switched networks are discussed, including the parallel mode, serial mode, and hybrid mode multicasting schemes. Simulated modeling technique is applied to compare the network-level performance of the three multicasting schemes. A conclusion can be drawn from the results that since the hybrid-mode multicasting scheme can increase the multicast success ratio and reduce the packet retransmission times compared with the other two schemes, it is the best choice for delivering multicasting sessions in the optical packet switched networks..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 983 (2009)
Ef fect of the third-order filter term on soliton interactions in soliton transmission systems with filters
Yingji He, Li Luo, Weiling Zhu, and Hezhou Wang
The effect of the third-order filter term on soliton interactions in optical fibers with guiding filters is theoretically analyzed. We find that this term causes a significant difference to the interaction of solitons through filters among the regimes of without sliding, with up- and down-sliding frequencies of filtersThe effect of the third-order filter term on soliton interactions in optical fibers with guiding filters is theoretically analyzed. We find that this term causes a significant difference to the interaction of solitons through filters among the regimes of without sliding, with up- and down-sliding frequencies of filters. It is shown that the interaction between solitons can be more effectively suppressed by up-sliding filters than that by down-sliding filters in the presence of the third-order filter term. Moreover, the third-order filter term is found to play a positive role in suppressing soliton interactions in the case of non-sliding..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 986 (2009)
UWB monocycle pulse generation based on optical cross-polarization modulation
Shiguang Wang, Hongwei Chen, Minghua Chen, and Shizhong Xie
A novel all-optical method for ultra-wideband (UWB) monocycle pulses generation based on cross polarization modulation (CPM) effect in highly nonlinear photonic crystal fiber is proposed and demonstrated. Due to the CPM effect between the probe light and the pump pulse, a pair of polarity-reversed Gaussian pulses is prA novel all-optical method for ultra-wideband (UWB) monocycle pulses generation based on cross polarization modulation (CPM) effect in highly nonlinear photonic crystal fiber is proposed and demonstrated. Due to the CPM effect between the probe light and the pump pulse, a pair of polarity-reversed Gaussian pulses is produced. After proper differential delay, an UWB monocycle pulse with 84-ps width and the fractional bandwidth of 153% is generated after photodetection..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 990 (2009)
A compact single-polarization erbium-doped fiber laser by exploiting vernier effect
Xiangqiao Mao, Fengping Yan, Yongjun Fu, Lin Wang... and Shuisheng Jian|Show fewer author(s)
A compact single-polarization fiber laser with fiber Bragg gratings inscripted in a polarization-maintaining erbium-doped germanosilicate fiber is demonstrated experimentally. The single-wavelength and singlepolarization regime of our studied laser is achieved by applying a radial stress upon one of two gratings and stA compact single-polarization fiber laser with fiber Bragg gratings inscripted in a polarization-maintaining erbium-doped germanosilicate fiber is demonstrated experimentally. The single-wavelength and singlepolarization regime of our studied laser is achieved by applying a radial stress upon one of two gratings and stretching the other one axially to adjust the reflection peak match. Two single-wavelength and singlepolarization lasing lines are realized respectively with fine power stability..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 993 (2009)
Image registration based on matrix perturbation analysis using spectral graph
Chengcai Leng, Zheng Tian, Jing Li, and Mingtao Ding
We present a novel perspective on characterizing the spectral correspondence between nodes of the weighted graph with application to image registration. It is based on matrix perturbation analysis on the spectral graph. The contribution may be divided into three parts. Firstly, the perturbation matrix is obtained by peWe present a novel perspective on characterizing the spectral correspondence between nodes of the weighted graph with application to image registration. It is based on matrix perturbation analysis on the spectral graph. The contribution may be divided into three parts. Firstly, the perturbation matrix is obtained by perturbing the matrix of graph model. Secondly, an orthogonal matrix is obtained based on an optimal parameter, which can better capture correspondence features. Thirdly, the optimal matching matrix is proposed by adjusting signs of orthogonal matrix for image registration. Experiments on both synthetic images and real-world images demonstrate the effectiveness and accuracy of the proposed method..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 996 (2009)
A RNN-based objective video quality measurement
Xuan Huang, Rong Zhang, and Jianxin Pang
Technology used to automatically assess video quality plays a significant role in video processing areas. Because of the complexity of video media, there are great limitations to assess video quality with only one factor. We propose a new method using artificial random neural networks (RNNs) with motion evaluation as aTechnology used to automatically assess video quality plays a significant role in video processing areas. Because of the complexity of video media, there are great limitations to assess video quality with only one factor. We propose a new method using artificial random neural networks (RNNs) with motion evaluation as an estimation of perceived visual distortion. The results are obtained through a nonlinear fitting procedure and well correlated with human perception. Compared with other methods, the proposed method performs more adaptable and accurate predictions..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1004 (2009)
Performance of dispersed Rayleigh interferometer on the active cophasing and alignment testbed
Shanshan Wang, Qiudong Zhu, Weirui Zhao, Lin Li, and Genrui Cao
We report the laboratory experiment on a segmented mirror testbed that shows the use of a dispersed Rayleigh interferometer to phase segmented mirrors. Segment alignment of tip-tilt is fulfilled by overlapping diffraction pattern centroids of the three individual segments on the focal plane. A spherical interferometer We report the laboratory experiment on a segmented mirror testbed that shows the use of a dispersed Rayleigh interferometer to phase segmented mirrors. Segment alignment of tip-tilt is fulfilled by overlapping diffraction pattern centroids of the three individual segments on the focal plane. A spherical interferometer is introduced to evaluate the performance of piston, tip-tilt sensing, and control closed-loop, and finally a total residual root-mean-square (RMS) surface error of about 45 nm is achieved, in which a typical error of about 20 nm is contributed by piston. These results demonstrate that the dispersed Rayleigh interferometer can successfully sense the piston of segmented mirrors and be used in phasing segmented telescopes under extensive studies..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1007 (2009)
Repetition rate tunable ultra-short optical pulse generation based on electrical pattern generator
Xin Fu, Hongming Zhang, Meng Yan, and Minyu Yao
An actively mode-locked laser with tunable repetition rate is proposed and experimentally demonstrated based on a programmable electrical pattern generator. By changing the repetition rate of the electrical patterns applied on the in-cavity modulator, the repetition rate of the output optical pulse sequences changes acAn actively mode-locked laser with tunable repetition rate is proposed and experimentally demonstrated based on a programmable electrical pattern generator. By changing the repetition rate of the electrical patterns applied on the in-cavity modulator, the repetition rate of the output optical pulse sequences changes accordingly while the pulse width of the optical pulse train remains almost constant. In other words, the output ultra-short pulse train has a tunable duty cycle. In a proof-of-principle experiment, optical pulses with repetition rates of 10, 5, 2.5 and 1.25 GHz are obtained by adjusting the electrical pattern applied on the in-cavity modulator while their pulse widths remain almost unchanged..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1010 (2009)
Coaxial combination of coherent laser beams
Hongcheng Dong, Xiao Li, Chaoyang Wei, Hongbo He... and Zhengxiu Fan|Show fewer author(s)
Based on polarization state conversion, a technique for coaxially coherent combination of laser beams is introduced. Laser beams can be coaxially coupled into one beam with high combination efficiency and perfect beam quality. A polarized laser beam combination system based on master oscillator power amplifier (MOPA) cBased on polarization state conversion, a technique for coaxially coherent combination of laser beams is introduced. Laser beams can be coaxially coupled into one beam with high combination efficiency and perfect beam quality. A polarized laser beam combination system based on master oscillator power amplifier (MOPA) configuration is developed and the efficiencies of both unit combination and the whole system are investigated. In the experiment of combining four beams with single longitudinal mode, a combination efficiency of 85.3% is achieved. It can be further enhanced by improving the stability of experimental environment and the quality of optical and mechanical components..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1012 (2009)
Diode-pumped self-Q-switched Cr,Nd:YAG laser with 7-W average output power
Yuxian Shi, Sumei Wang, Qinan Li, Jing Zhang... and Shiwen Zhang|Show fewer author(s)
We report a diode-pumped self-Q-switched 1064-nm Cr,Nd:YAG laser with pulse duration in the range of 16?18 ns. The maximum average output power up to 7 W, corresponding to a slope efficiency of 33%, is obtained in a simple and compact linear cavity by using a plane-concave output coupler with a transmittance of 15%. ThWe report a diode-pumped self-Q-switched 1064-nm Cr,Nd:YAG laser with pulse duration in the range of 16?18 ns. The maximum average output power up to 7 W, corresponding to a slope efficiency of 33%, is obtained in a simple and compact linear cavity by using a plane-concave output coupler with a transmittance of 15%. The laser operates at TEM00 mode with a pump power of 14.2 W..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1015 (2009)
Coherent combining of tunable erbium-doped fiber lasers by a single-mode fiber feedback loop
Bing Lei, and Ying Feng
We experimentally demonstrate the coherent combining of two tunable erbium-doped fiber lasers by using a single-mode fiber feedback loop configuration. A single-mode fiber is arranged in the feedback loop to filter the far-field pattern, and the energy of desired in-phase mode is collected and injected into the resonatWe experimentally demonstrate the coherent combining of two tunable erbium-doped fiber lasers by using a single-mode fiber feedback loop configuration. A single-mode fiber is arranged in the feedback loop to filter the far-field pattern, and the energy of desired in-phase mode is collected and injected into the resonators of two component fiber lasers. The coherently combined laser is tunable over a wide spectrum ranging from 1536 to 1569 nm, which means that the combining scheme is compatible with wavelength tuning. The effects and necessity of whether adopting polarization controlling measures or not in component lasers are investigated in detail. The results indicate that adding polarization controlling can improve the array’s coherence, whereas it will decrease the output power and efficiency simultaneously..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1018 (2009)
A novel 852-nm tunable fiber laser
Yanlong Shen, Chun Gu, Lixin Xu, Anting Wang... and Xiaobing Wang|Show fewer author(s)
We report a novel fiber laser operating at 850-nm band by using semiconductor optical amplifier and fiber grating. The laser system is stable, compact, and the operating wavelength can be tuned continuously from about 851 to 854 nm for Cs atomic clock system by stretching the fiber grating. An output power up to 20 mW We report a novel fiber laser operating at 850-nm band by using semiconductor optical amplifier and fiber grating. The laser system is stable, compact, and the operating wavelength can be tuned continuously from about 851 to 854 nm for Cs atomic clock system by stretching the fiber grating. An output power up to 20 mW is obtained with a signal-to-background ratio beyond 30 dB..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1022 (2009)
High power doubly resonant all-intracavity deep blue laser at 447 nm based on sum-frequency-mixing technology
Yongji Yu, Guangyong Jin, Chao Wang, Xinyu Chen... and Yibo Wang|Show fewer author(s)
A high power continuous-wave deep blue laser at 447 nm is obtained by using a doubly cavity and a type critical phase matching KTP crystal for intracavity sum-frequency-mixing. With the incident pump power of 240 W for the Nd:YAP crystal and 120 W for the other Nd:YAP crystal, the deep blue laser output of 5.7 W at 447A high power continuous-wave deep blue laser at 447 nm is obtained by using a doubly cavity and a type critical phase matching KTP crystal for intracavity sum-frequency-mixing. With the incident pump power of 240 W for the Nd:YAP crystal and 120 W for the other Nd:YAP crystal, the deep blue laser output of 5.7 W at 447 nm with near fundamental mode is obtained, and the beam quality M<sup>2</sup> value equals 2.53 in both horizontal and vertical directions at the maximum output power. The power stability is better than 2% at the maximum output power during half an hour. The experimental results show that the intracavity sum-frequency mixing by doubly resonant is an effective method for high power blue laser..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1024 (2009)
Diode-pumped Yb:Lu2Si2O7 laser with tunable and ef f icient output
Jinping He, Xiaoyan Liang, Lihe Zheng, Liangbi Su... and Zhizhan Xu|Show fewer author(s)
Diode-pumped laser action of a new crystal Yb<sup>3+</sup>:<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> (LPS) is demonstrated for the first time to our knowledge. An output power of 2.22 W at 1070 nm and a slope efficiency of 34.7% were achieved with a 5 at.-% Yb: LPS sample. Diode-pumped laser action of a new crystal Yb<sup>3+</sup>:<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> (LPS) is demonstrated for the first time to our knowledge. An output power of 2.22 W at 1070 nm and a slope efficiency of 34.7% were achieved with a 5 at.-% Yb: LPS sample. The tuning can cover the range form 1034 to 1080 nm..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1028 (2009)
Theoretical model and quantif ication of reflectance photometer
Lihua Huang, Youbao Zhang, Chengke Xie, Jianfeng Qu... and Xiangzhao Wang|Show fewer author(s)
The surface morphology of lateral flow (LF) strip is examined by scanning electron microscope (SEM) and the diffuse reflection of porous strip with or without nanogold particles is investigated. Based on the scattering and absorption of nanogold particles, a reflectance photometer is developed for quantification of LF The surface morphology of lateral flow (LF) strip is examined by scanning electron microscope (SEM) and the diffuse reflection of porous strip with or without nanogold particles is investigated. Based on the scattering and absorption of nanogold particles, a reflectance photometer is developed for quantification of LF strip with nanogold particles as reporter. The integration of reflection optical density is to indicate the signals of test line and control line. As an example, serial dilutions of microalbunminuria (MAU) solution are used to calibrate the performance of the reflectance photometer. The dose response curve is fitted with a four-parameter logistic mathematical model for the determination of an unknown MAU concentration. The response curve spans a dynamic range of 5 to 200 \mu g/ml. The developed reflectance photometer can realize simple and quantitative detection of analyte on nanogold-labeled LF strip..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1031 (2009)
2-\mu m fluorescence and Raman spectra in high and low Al(PO3)3 content fluorophosphate glasses doped with Er-Tm-Ho
Meng Wang, Lixia Yi, Liyan Zhang, Guonian Wang... and Junjie Zhang|Show fewer author(s)
Thermal stability and 2-\mu m fluorescence of high and low Al(PO<sub>3</sub>)<sub>3</sub> content of fluorophosphate glasses are investigated. Thermal stability of high Al(PO<sub>3</sub>)<sub>3</sub> content of fluorophosphate glass is better than low Al(PO<sub>3<Thermal stability and 2-\mu m fluorescence of high and low Al(PO<sub>3</sub>)<sub>3</sub> content of fluorophosphate glasses are investigated. Thermal stability of high Al(PO<sub>3</sub>)<sub>3</sub> content of fluorophosphate glass is better than low Al(PO<sub>3</sub>)<sub>3</sub> content of fluorophosphate glass. However, 2.04-\mu m fluorescence intensity of high Al(PO<sub>3</sub>)<sub>3</sub> content of fluorophosphate glass is only 48.2, lower than low Al(PO<sub>3</sub>)<sub>3</sub> content of fluorophosphate glass. Raman spectroscopy is employed to investigate the difference in thermal stability and 2-\mu m fluorescence. Moreover, fluorescence peak intensity ratios of 2.04 to 1.81 \mu m and 2.04 to 1.57 \mu m are calculated, which indicate that Er-Tm-Ho doped fluorophosphate glasses are suitable materials in 2-\mu m applications..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1035 (2009)
Widely continuous-tunable 2.789 4.957 \mu m twin MgO:PPLN cascaded optical parametric oscillator
Linzhong Xia, Hong Su, and Shuangchen Ruan
An all-solid-state mid-infrared optical parametric oscillator with wide tunability by using two identical multi-grating periodically poled 5-mol.-% MgO-doped lithium niobate cascaded is reported. The pump laser is an acousto-optically Q-switched Nd:YAG laser with 150-ns pulse width at repetition rate of 10 kHz. Wide tuAn all-solid-state mid-infrared optical parametric oscillator with wide tunability by using two identical multi-grating periodically poled 5-mol.-% MgO-doped lithium niobate cascaded is reported. The pump laser is an acousto-optically Q-switched Nd:YAG laser with 150-ns pulse width at repetition rate of 10 kHz. Wide tunability from 2.789 to 4.957 \mu m at the idler wavelength is achieved by varying the temperature from 40 to 200 ℃ and translating the grating periods from 26 to 31 \mu m with a step of 0.5 \mu m. When the incident pump average power is 8.15 W, the maximum idler output average power is 2.23 W at 3.344 \mu m and the optic-optic conversion efficiency is about 27.4%..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1038 (2009)
Design and fabrication of a compact multimode interference splitter with silicon photonic nanowires
Jingtao Zhou, Huajun Shen, Huihui Zhang, and Xinyu Liu
A compact multimode interference (MMI) splitter with silicon photonic nanowires on silicon-on-insulator (SOI) substrate is designed and fabricated. The footprint of the MMI section is only approximately 3×10 (\mu m). The simulation results show that the device may have a low excess loss of 0.04 dB. The transmissioA compact multimode interference (MMI) splitter with silicon photonic nanowires on silicon-on-insulator (SOI) substrate is designed and fabricated. The footprint of the MMI section is only approximately 3×10 (\mu m). The simulation results show that the device may have a low excess loss of 0.04 dB. The transmission loss of the silicon photonics wire is measured to be 0.73±0.3 dB/mm. The compact size and low transmission loss allow the device to be used in ultra-compact photonic integrated circuits. The device exhibits a good light splitting function. In a spectral range of 1549–1560 nm, the excess loss is 1.5 dB and the average imbalance between the two channels is 0.51 dB..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1041 (2009)
Optimization of line-tapered MMI devices using a genetic algorithm
Yongsheng Xiao, Jianjiang Zhou, Shujing Li, Lizhen Huang... and Huaming Wu|Show fewer author(s)
We discuss the optimal design of line-tapered multimode interference (MMI) devices using a genetic algorithm (GA). A 1×4 MMI device is designed as a numerical example. Compared with the conventional design based on self-imaging theory, the present method demonstrates superior performance with low insertion loss anWe discuss the optimal design of line-tapered multimode interference (MMI) devices using a genetic algorithm (GA). A 1×4 MMI device is designed as a numerical example. Compared with the conventional design based on self-imaging theory, the present method demonstrates superior performance with low insertion loss and small non-uniformity..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1045 (2009)
Non-classical correlation between a single photon and the collective spin excited state of a cold atomic ensemble
Xiaosong Lu, Qunfeng Chen, Baosen Shi, and Guangcan Guo
We experimentally establish a non-classical correlation between a single Stokes photon and the collective spin excited state of a cold atomic ensemble by using a spontaneous Raman scattering process. The correlation between them can be proved by transferring the spin excited state of the atomic ensemble into an anti-StWe experimentally establish a non-classical correlation between a single Stokes photon and the collective spin excited state of a cold atomic ensemble by using a spontaneous Raman scattering process. The correlation between them can be proved by transferring the spin excited state of the atomic ensemble into an anti-Stokes photon and checking the Cauchy-Schwarz inequality between the Stokes and the anti-Stokes photons. The non-classical correlation can be kept for at least 300 ns..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1048 (2009)
Analysis of saturation signal correction of the troposphere lidar
Zhishen Liu, Zhigang Li, Bingyi Liu, and Rongzhong Li
Usually, lidar detection systems are optimized for the measurement of the low intensity signal using the photon counting technique, but this approach results in the nonlinear signal response for the higher intensity signal. The problem is successfully solved by the combination of analog-to-digital (AD) and photoncountiUsually, lidar detection systems are optimized for the measurement of the low intensity signal using the photon counting technique, but this approach results in the nonlinear signal response for the higher intensity signal. The problem is successfully solved by the combination of analog-to-digital (AD) and photoncounting (PC) detection. The optimized processing procedure of the signal combination of AD and PC is described, and the corrected result is analyzed and compared with the results by the dead-time correction method. In this way, the accuracy of wind and aerosol measurement in the nonlinear range is improved. In addition, the signal-to-noise ratios (SNRs) of the two detection methods of AD and PC are compared in the overall dynamic range of signal for the performance analysis..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1051 (2009)
Surface-enhanced Raman spectroscopy of morphine in silver colloid
Shangyuan Feng, Weiwei Chen, Wei Huang, Min Cheng... and Rong Chen|Show fewer author(s)
We report the surface-enhanced Raman (SERS) spectra of morphine in silver colloid, and study the silver colloid enhanced effects on the Raman scattering of morphine. The Raman bands of morphine are assigned to certain molecule vibrations. The broad band in the long-wavelength region of the electronic absorption spectraWe report the surface-enhanced Raman (SERS) spectra of morphine in silver colloid, and study the silver colloid enhanced effects on the Raman scattering of morphine. The Raman bands of morphine are assigned to certain molecule vibrations. The broad band in the long-wavelength region of the electronic absorption spectra of the sol with added adsorbent at certain concentrations has been explained in terms of the aggregation of the colloidal silver particles. The potential applications of SERS in quantitative measurement of the morphine samples are demonstrated. By using a proper Raman band of morphine, the detection limit of morphine in silver sol is found to be 1.5 ng/ml. The result suggests that it is of great significance to use SERS in illicit drug morphine inspection..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1055 (2009)
Identification of tartrazine and sunset yellow by fluorescence spectroscopy combined with radial basis function neural network
Jun Wang, Guoqing Chen, Tuo Zhu, Shumei Gao... and Linna Bi|Show fewer author(s)
The fluorescence spectra of synthetic food dyes of sunset yellow and tartrazine are analyzed. The fluorescence peak wavelengths of sunset yellow and tartrazine are 576 and 569 nm, respectively, while the fluorescence spectra widths are 480–750 and 500–750 nm induced by ultraviolet light between 310–400 nm. The fluorescThe fluorescence spectra of synthetic food dyes of sunset yellow and tartrazine are analyzed. The fluorescence peak wavelengths of sunset yellow and tartrazine are 576 and 569 nm, respectively, while the fluorescence spectra widths are 480–750 and 500–750 nm induced by ultraviolet light between 310–400 nm. The fluorescence spectra of sunset yellow overlap heavily with those of tartrazine, so it is difficult to distinguish them. Based on the principle of radial basis function neural network, a neural network is obtained from the training of the 14 groups of experimental data. The results show that the species of sunset yellow and tartrazine could be recognized accurately. This method has potential applications in other synthetic food dyes detection and food safety inspection..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1058 (2009)
Imaging photothermal microscopy for absorption measurements of optical coatings
Chunxian Tao, Yuanan Zhao, Hongbo He, Dawei Li... and Zhengxiu Fan|Show fewer author(s)
For absorption measurement of large-aperture optical coatings, a novel method of imaging photothermal microscopy based on image lock-in technique is presented. Detailed theoretical analysis and numerical calculation are made based on the image photothermal technique. The feasibility of this imaging method is proved thrFor absorption measurement of large-aperture optical coatings, a novel method of imaging photothermal microscopy based on image lock-in technique is presented. Detailed theoretical analysis and numerical calculation are made based on the image photothermal technique. The feasibility of this imaging method is proved through the coincidence between the theoretical results of single spot method and multi-channel method. The measuring speed of this imaging method can be increased hundreds of times compared with that of the raster scanning. This technique can expand the applications of photothermal technique..
Chinese Optics Letters
- Publication Date: Jul. 08, 2021
- Vol. 7, Issue 11, 1061 (2009)
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