Journals >Electro-Optic Technology Application
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2015
Volume: 30 Issue 6
21 Article(s)
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Research Article
[in Chinese]
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 1 (2015)
Research on a Novel All-optical Solid Framing Camera Framing Mode
YUAN Fen-fang, LIU Xi-shun, CHEN Shao-rong, LIANG Ling-liang, and GAO Gui-long
All-optical solid framing camera technology is one of the most promising areas with the best developing future in ultrafast diagnosis technology. The technology is widely paid attention due to the unique advantages of time resolution realization at picosecond and sub-picosecond level, ultra-high spatial resolution, broAll-optical solid framing camera technology is one of the most promising areas with the best developing future in ultrafast diagnosis technology. The technology is widely paid attention due to the unique advantages of time resolution realization at picosecond and sub-picosecond level, ultra-high spatial resolution, broadening the waveband range of detection signals, reliability, stability, anti-jamming and anti-radiation. Wavelength division multiplexing and polarization multiplexing technologies are applied to the all-optical solid framing camera system to the multi-framing schemeresearch. Under ensuring picosecond level time resolution, the framing schemes of acquiring several to tens of pieces of frames are explored. Four pieces of framing images with 60 lp/mm spatial resolutions are obtained through experiments. Experimental results show that time resolution of wave division framing is 1.414 ps and time resolution of polarization framing is 15 ps..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 1 (2015)
[in Chinese]
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 1 (2015)
Time-delayed Feedback Control in Single-mode Laser System
GU Xiao-hui
A control mechanism of time-delayed feedback is designed to suppress the fluctuation of a single-mode laser. Using the small time delay approximation, the analytic expression of the stationary probability distribution function of the single-mode laser filed is obtained. The mean, normalized variance and skewness of theA control mechanism of time-delayed feedback is designed to suppress the fluctuation of a single-mode laser. Using the small time delay approximation, the analytic expression of the stationary probability distribution function of the single-mode laser filed is obtained. The mean, normalized variance and skewness of the steady-state laser intensity are calculated. It is found that the time-delayed feedback control can suppress the intensity fluctuation of the laser system. Matlab is used to perform numerical simulation and the results accord with the approximate analytic results..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 5 (2015)
Research on Spectral Change and Spectral Switch of Multicolor Partial Coherent Light
LI Hong-peng
By using the fundamental theory of the partially coherent light and the general diffraction theory, the spectral changes and spectral switch phenomenon of multicolor partial coherent light through a multi-slit system are mainly researched theoretically. The spectral changes and spectral switch phenomenon near light sinBy using the fundamental theory of the partially coherent light and the general diffraction theory, the spectral changes and spectral switch phenomenon of multicolor partial coherent light through a multi-slit system are mainly researched theoretically. The spectral changes and spectral switch phenomenon near light singularity of multicolor spatial coherent light diffracted by Fresnel zone plate are discussed. And Mathcad software is used to research spectral changes and spectral switch phenomenon of different parameters. According to theory and experimental research results, the applications of spectral changes and spectral switch in information encoding and transmission are described..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 9 (2015)
Emission Spectrum Analysis of Copper Plasma Induced by Laser
SANG Tao, and HAO Xiao-jian
By using of Nd:YAG pulse laser, spectral lines of copper are experimentally studied in air atmosphere. The plasma characteristic spectral line of copper is obtained by 119.1, 154.6, 201.7 and 256.2 mJ·Pulse-1 energy. CuI 510.5 nm and 521.8 nm are selected as the research object. The relationship between spectral lBy using of Nd:YAG pulse laser, spectral lines of copper are experimentally studied in air atmosphere. The plasma characteristic spectral line of copper is obtained by 119.1, 154.6, 201.7 and 256.2 mJ·Pulse-1 energy. CuI 510.5 nm and 521.8 nm are selected as the research object. The relationship between spectral line intensity and laser energy is analyzed and it is found that the broadening line is Lorenz and Gauss respectively. The results show that different bands correspond to different spectral broadening mechanism for Cu plasma emission spectrum and with the increasement of laser energy, the spectral line intensity is increased gradually, and the full width at half maximum (FWHM) of the spectral lines also increased..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 14 (2015)
Experiment Contrast Research on Three Kind of C+L Band Erbium-doped Fiber Amplified Spontaneous Emission Light Source
LI Li, and JIA Zhen-an
Based on experimental research on three kinds of C+L band Erbium-doped fiber amplified spontaneous emission (ASE) light source including signal-stage, two-stage and three-stage structure, the characteristics are compared and the advantages and disadvantages are analyzed. Results show that C band and L band spectrum of Based on experimental research on three kinds of C+L band Erbium-doped fiber amplified spontaneous emission (ASE) light source including signal-stage, two-stage and three-stage structure, the characteristics are compared and the advantages and disadvantages are analyzed. Results show that C band and L band spectrum of C+L band Erbium-doped fiber ASE light source with single-stage and two-stage structure is difficult to realize optimal matching and flatness is not ideal. Though the three-stage two-pumping structure light source is more complicated than that of the other two structures, the flatness of output spectrum is better through optimizing light source parameters. So the application requirements from distributed fiber Bragg grating (FBG) sensing system, long range fiber communication system, fiber gyroscope and spectrum testing are better satisfied..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 18 (2015)
Air Gap on Diffraction Efficiency for Multilayer Diffractive Optical Element
GONG Hao, DI Xu, and XUE Chang-xi
Based on the expression of diffraction efficiency for multilayer diffractive optical element, the relationship between the air gap of a two-layer diffractive optical element and diffraction efficiency is derived. The influence on diffraction efficiency of the diffraction optical element in visible spectrum, infrared meBased on the expression of diffraction efficiency for multilayer diffractive optical element, the relationship between the air gap of a two-layer diffractive optical element and diffraction efficiency is derived. The influence on diffraction efficiency of the diffraction optical element in visible spectrum, infrared medium wave and infrared long wave from air gap, period and incident wave is analyzed. Taking 400~700 nm, 3~5 μm and 8~12 μm wavelength as examples, with polycarbonate (PC), poly methyl methacrylate (PMMA) as the first layer basement and the second layer basement of the two-layer diffraction optical element in visible wavelength respectively, with zinc sulfide (ZnS) and zinc selenide (ZnSe) as the first layer basement and the second layer basement of the two-layer diffraction optical element in infrared medium wave and infrared long wave. In particular period situation, the influence on diffraction efficiency of multilayer diffractive optical element from the size of air gap of two-layer diffraction optical element is determined..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 22 (2015)
Research on Effect of Typical Process Defect on Optical Waveguide Characteristic
FAN Zhe-hui, and WANG Jian
For the typical process defects of semiconductor optical waveguide in the actual fabrication process, an effective analysis method is proposed based on the finite element method. For actual incident optical fields, the optical fields in waveguide are calculated for the first time when the defects exist. The effects of For the typical process defects of semiconductor optical waveguide in the actual fabrication process, an effective analysis method is proposed based on the finite element method. For actual incident optical fields, the optical fields in waveguide are calculated for the first time when the defects exist. The effects of the defect position, size, type and wavelength of the incident light on the loss and mode coupling of semiconductor optical waveguide are analyzed. The results show that the waveguide transmission loss oscillates with defect size and light wavelength. The defect refractive index is larger, oscillation frequency is higher. When defects are moving from the core center to the edge, the oscillation of the transmission loss with waveguide structure size become monotone increasing. One part of the loss energy becomes the substrate radiation mode, and the other is coupled to high-order modes. The process defects make semiconductor optical waveguide loss increase greatly, the waveguide transmission mode is changed, and the integrated optical circuit performance is degraded significantly..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 26 (2015)
Experimental Research on All-fiber Ytterbium-doped Superfluorescent Fiber Source
YUAN Chu-jun, and LOU Shu-qin
Based on a segment of Ytterbium-doped dual-cladding fiber (YDF), an all-fiber superfluorescent fiber source (SFS) experimental system is demonstrated. The characteristics of double-ended output SFS is researched under forward pump condition. And the effects of YDF with different length on the performances of SFS are diBased on a segment of Ytterbium-doped dual-cladding fiber (YDF), an all-fiber superfluorescent fiber source (SFS) experimental system is demonstrated. The characteristics of double-ended output SFS is researched under forward pump condition. And the effects of YDF with different length on the performances of SFS are discussed. Experimental result shows that backward output SFS has higher conversion efficiency and broader bandwidth. When the length of gain fiber becomes shorter, the laser oscillation threshold is higher and thus higher output power can be obtained. With the increasing of gain fiber length, the maximum output power decreases, but the bandwidth of the output spectrum increases at the same time..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 31 (2015)
1 064 nm and 532 nm Dual-wavelength Switchable Solid State Laser
YAN Xin-jie, and LI Lei
Dual-wavelength and multi-wavelength lasers have received considerable attention recently and have been used extensively in interference rain bow holograph, fine laser spectrum, differential absorption radar, multi-photon step ionization of atom and molecular, nonlinear frequency conversion and laser medicine fields. BDual-wavelength and multi-wavelength lasers have received considerable attention recently and have been used extensively in interference rain bow holograph, fine laser spectrum, differential absorption radar, multi-photon step ionization of atom and molecular, nonlinear frequency conversion and laser medicine fields. By using the Nd:YAG crystal while adopting the methods of laser diode (LD) side-pumped, electro-optical Q-switched, multistage amplifier and the technology of polarization controlled by electricity, the switchable output of dual-wavelength of 1 064 nm and 532 nm is acquired. The single pulse energy is 750 mJ at 1 064 nm, when 1 064 nm laser with 230 mJ single pulse energy is input, single pulse energy is 106 mJ at 532 nm, corresponding to the repetition frequency of 100 Hz and the conversion efficiency of 46%. The above laser can be applied to the fields of airborne, spaceborne, shipborne laser ranging and illumination, radar and the laser environmental monitoring as its feature of stable orientation..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 37 (2015)
Experiment Research on Laser-diode-pumped Cr:YAG Passively Q-switched Intracavity SrWO4 Mode-locked Raman Laser
JIA Hai-xu
A laser-diode-pumped Cr:YAG passively Q-switched intracavity SrWO4 mode-locked Raman laser is used to obtain stable Q-switched mode-locked Raman pulse of 100% modulation depth. An average output power of 968 mW is obtained when the incident pump power is 5.2 W, the conversion efficiency of pump to Raman laser is 18.6%.A laser-diode-pumped Cr:YAG passively Q-switched intracavity SrWO4 mode-locked Raman laser is used to obtain stable Q-switched mode-locked Raman pulse of 100% modulation depth. An average output power of 968 mW is obtained when the incident pump power is 5.2 W, the conversion efficiency of pump to Raman laser is 18.6%.The Q-switched pulses with repetition rate of 51 kHz and pulse width of 7 ns is obtained. To our knowledge, this is the most efficient at present. And the forming reason of mode-locked Raman laser pulse in the experiment is analyzed. The polarization mechanism is researched and reasonable explanations are analyzed..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 40 (2015)
Research on Vibration Signal Feature Extraction on Optical Fiber Sensor
SHENG Yuan-yuan, LIU Jun-cheng, JIN Jia-ying, CHENG Peng-shen, and HU Tong
The false alert caused by environmental disturbances is the main reason for application limitation of vibration optical fiber. One of the key issues to reduce the rate of false alert is how to extract features sensitive to the type and amplitude of vibrations. The feature extraction method of vibration signals of an opThe false alert caused by environmental disturbances is the main reason for application limitation of vibration optical fiber. One of the key issues to reduce the rate of false alert is how to extract features sensitive to the type and amplitude of vibrations. The feature extraction method of vibration signals of an optical fiber sensor on time-domain and frequency-domain based on the Mach-Zehnder interferometric principle is researched. The variation rules of common vibration source time frequency feature parameters are analyzed, and the thresholds of features of common vibration source are determined through experiments. The experiments show that the types of vibration signals are identified correctly through setting multiple thresholds for time domain and frequency domain of the vibration signals, and the effectiveness and reliability of the proposed method for extracting the feature parameters are validated..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 45 (2015)
Research on Image Recognition Method Based on Projection
MA Chun-yan
According to engineering requirements, the image recognition method based on projection features is researched. Based on the actual production line without preprocessing, the image is projected to eight directions directly and image feature compression is extracted. Neural network is adopted to recognize the image and According to engineering requirements, the image recognition method based on projection features is researched. Based on the actual production line without preprocessing, the image is projected to eight directions directly and image feature compression is extracted. Neural network is adopted to recognize the image and the projection is performed normalized feature extraction. Adaptive resonance ART-1 neural network can remember template image features through learning and training, so neuron I representing template image features is chosen. When the features of the image to be identified are input, neuron I2 is represented by network choice. If neuron I and I2 are same, it is thought that the image to be identified is the same as the template image, and otherwise it is thought that the image to be identified is different from the template image. Recognition error is related with the setting of vigilance parameter ρ.And image recognition is better achieved in the way..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 51 (2015)
Analysis and Improvement on Digital Refocusing Sharpness Evaluation Function of Light Field Photography
LIANG Xin
The basic principle of digital refocusing is analyzed and different depth of field corresponds to different refocusing results. The traditional gray gradient evaluation function introduces too much gradient information in light field photography systems, which affects the sensitivity of the evaluation function. In ordeThe basic principle of digital refocusing is analyzed and different depth of field corresponds to different refocusing results. The traditional gray gradient evaluation function introduces too much gradient information in light field photography systems, which affects the sensitivity of the evaluation function. In order to solve the defect, an improved image sharpness evaluation algorithm is proposed. A local area in the image is evaluated by the method. Firstly, image gray gradient energy function named Tenengrad function is used to extract high-frequency information to assess the sharpness of the image. And then, a threshold is added to distinguish the edge and non-edge points to reduce the influence on the evaluation function from the area with low image contrast. Comparing with other traditional gradient evaluation algorithms, the advantages of this algorithm is to obtain higher recognition accuracy. Experimental results show that this algorithm has better sensitivity comparing with traditional gradient algorithm through MATLAB platform simulation..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 56 (2015)
State Dynamic Prediction Method Based on Beidou Navigator in Monitoring and Displaying
ZHAO Xiu-ying, XIONG Zhuang, XIAO Jing-xin, and XU Wen
The real-time monitoring on the aircraft is realized by feeding back flight state data at several moments to Beidou land navigation station. The states of the aircraft at present and subsequent moments are needed to be predicted. Based on the studies of prediction and estimation, the flight state of the aircraft througThe real-time monitoring on the aircraft is realized by feeding back flight state data at several moments to Beidou land navigation station. The states of the aircraft at present and subsequent moments are needed to be predicted. Based on the studies of prediction and estimation, the flight state of the aircraft through Kalman and particle filter methods, the idea that dynamic weight average of multi-point state data adopted to obtain the flight state data of the aircraft at present and subsequent is presented. And it is displayed on digital earth in real-time to realize aircraft real-time monitoring and a better effect is obtained. The average relative error is 0.03% after predicting extracted aircraft real data and performing algorithm comparison experiment..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 60 (2015)
Infrared Image Denoising Based on Wavelet Transform Threshold Shrinkage Method
XING Yong-zhen
Most of infrared image denoising methods focus only on the space domain or the frequency domain. Aiming at the shortcoming, an infrared image denoising algorithm is proposed based on wavelet transform threshold shrinkage method. The algorithm has the characteristic of analyzing time domain and space domain simultaneousMost of infrared image denoising methods focus only on the space domain or the frequency domain. Aiming at the shortcoming, an infrared image denoising algorithm is proposed based on wavelet transform threshold shrinkage method. The algorithm has the characteristic of analyzing time domain and space domain simultaneously, and wavelet transform with a concentration characteristic to the determined signal is used to make the power of a signal on a small number of coefficients in wavelet transform domain. And then, wavelet coefficient is threshold, the low amplitude noise and unexpected image information in wavelet transform domain can be removed. Experimental results show that image quality can be improved effectively by threshold shrinkage denosing algorithm based on wavelet transform. The visual effect of the image is enhanced and the expected image information is obtained accurately..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 64 (2015)
Research on Measurement Method of Variational Momentum of the Zero Position of White Light Sighting Telescope
ZHANG Cong, AN Zhi-yong, HAN Di, and ZHANG Ji-ming
According to a certain variational momentum of the zero position in a sighting telescope before and after shooting, a method for measuring the variational momentum of the zero position is introduced. Charge coupled device (CCD) is used to measure the total variational momentum of the zero position, and then an optoelecAccording to a certain variational momentum of the zero position in a sighting telescope before and after shooting, a method for measuring the variational momentum of the zero position is introduced. Charge coupled device (CCD) is used to measure the total variational momentum of the zero position, and then an optoelectronic autocollimator is used to measure the repeat installation error, the difference of these two measurements is the pure variational momentum of the zero position. Comparing to the traditional measurement method with non-eliminated repeat installation error, the advantage of the method is to measure the pure variational momentum of the zero position. Through the operation principle introduction and experiment analysis, the results show that the pure variational momentum of the zero position σ is less than 6.48″ (0.03 mil). The measured variational momentum of the zero position through the method has high accuracy and meets the requirements performance..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 67 (2015)
Circuit Design of Insensitive Electric Igniter Trigger Based on ATMEGA1281
CAI Jing-hai, and YANG Qian
An insensitive electric igniter trigger based on ATMEGA1281 is designed. The trigger can offer multiplex large current pulse to trigger insensitive electric igniters. In the design, pulse channel operation state inspection, load state inspection and pulse current inspection in real time are realized and good testabilitAn insensitive electric igniter trigger based on ATMEGA1281 is designed. The trigger can offer multiplex large current pulse to trigger insensitive electric igniters. In the design, pulse channel operation state inspection, load state inspection and pulse current inspection in real time are realized and good testability design is shown. And multiple protection circuits are designed to improve the reliability and safety of the trigger effectively..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 70 (2015)
Research on Electrically Tunable Fiber Bragg Grating Based on Thermally Poled Twin-hole Fiber
GUO Yan, REN Guo-bin, and HUANG Lin
An electrically tunable fiber Bragg grating based on thermally poled twin-hole fiber is designed. The formation of frozen-in electric field during thermal poling is analyzed based on the two-dimensional charge dynamics model. A periodically poled Bragg fiber grating is designed based on the role of ultraviolet light inAn electrically tunable fiber Bragg grating based on thermally poled twin-hole fiber is designed. The formation of frozen-in electric field during thermal poling is analyzed based on the two-dimensional charge dynamics model. A periodically poled Bragg fiber grating is designed based on the role of ultraviolet light in the second-order nonlinearity (SON) periodically erasing of thermally poled fiber and the fiber grating manufacturing. The tunability is achieved as the variation responses of refractive indices to modulating voltage in SON erased zone and SON zone are different. The influence of the initial refractive index and the length of the grating on the tunability are also investigated. The electrically tunable thermally poled fiber Bragg grating has important reference value for the application of fiber Bragg grating and thermally poled optical fiber in active optical devices..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 75 (2015)
FPGA Implementation of Infrared Image Processing Algorithm
GAO Xue-chao
For being susceptible to noise and high real-time requirements during infrared image transmission and comparing with the other two infrared image enhancement algorithms, a revised infrared image histogram projection enhancement algorithm is proposed. The algorithm not only meets real-time requirement but also implementFor being susceptible to noise and high real-time requirements during infrared image transmission and comparing with the other two infrared image enhancement algorithms, a revised infrared image histogram projection enhancement algorithm is proposed. The algorithm not only meets real-time requirement but also implements easily in hardware. Field-programmable gate array (FPGA) with plenty of internal logic resources is taken as the core processor to complete infrared image enhancement algorithm implementation in hardware. Experimental results show that the design is feasible..
Electro-Optic Technology Application
- Publication Date: Jan. 01, 1900
- Vol. 30, Issue 6, 80 (2015)
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