Journals >Opto-Electronic Engineering
Contents
2014
Volume: 41 Issue 10
16 Article(s)
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Research Article
Analysis of Gaussian Laser Jamming Effect on theInfrared Imaging Guidance System
HE Yuanxing, LI Jian, MU Baili, HUANG Jian, and LI Wei
Considering the influence of the aberration of laser system, the atmospheric turbulence, the pointing error of the tracking equipment and the jitter error of the laser axis, the parameter of the power density on the target is used to evaluate the high power laser jamming effect on the infrared imaging guidance system. Considering the influence of the aberration of laser system, the atmospheric turbulence, the pointing error of the tracking equipment and the jitter error of the laser axis, the parameter of the power density on the target is used to evaluate the high power laser jamming effect on the infrared imaging guidance system. Combined with the dazzle threshold of the detector, the method for estimating operating range of high power laser system is proposed. The infrared seeker of missile under high power CO2 laser irradiation is taken as example, and the relationship between operating range and laser transmitting power are calculated. The results show that the operating range increases along with the increasing of laser transmitting power, and its curvilinear tread becomes slower as the laser power reaches higher. Besides,the jamming effect of normal incidence of the laser is better than the non-normal incidence..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1 (2014)
Study for MNP Method in Catenary Thermal State Detection
MIN Yongzhi, WANG Hongxia, KANG Fei, and DANG Jianwu
Infrared thermal imaging technology was widely used in many fields. So infrared thermal imaging technology and image processing were combined in detection of catenary thermal state. In image processing, firstly, image preprocessing was used for infrared thermal images, and then mutual information-based image template mInfrared thermal imaging technology was widely used in many fields. So infrared thermal imaging technology and image processing were combined in detection of catenary thermal state. In image processing, firstly, image preprocessing was used for infrared thermal images, and then mutual information-based image template matching was used to detect and recognize the targets of infrared image. Mutual information was similarity measure criterion in image template matching, and Non-Parametric (NP) window method was to estimate the Joint Probability Distribution Function(JPDF) for underlying template. For weakness of NP window method was long computing time, Modified Non-Parametric (MNP) window method was used with a triangle distribution instead of uniform distribution in the original NP window. Experimental results show that accuracy in calculating the joint probability distribution of MNP method is higher and the image template matching time is shortened..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 7 (2014)
Fusion Algorithm of Infrared and Visible Images Based on Local NSST and PCNN
CHEN Guangqiu, GAO Yinhan, DUAN Jin, and LIN Jie
For enhancing fusion accuracy of infrared and visible images, an adaptive fusion algorithm of infrared and visible images based on Local Nonsubsampled Shearlet Transform (LNSST) and Pulse Coupled Neural Networks (PCNN)is proposed. First,source images are decomposed to multi-scale and multi-direction subband images by LFor enhancing fusion accuracy of infrared and visible images, an adaptive fusion algorithm of infrared and visible images based on Local Nonsubsampled Shearlet Transform (LNSST) and Pulse Coupled Neural Networks (PCNN)is proposed. First,source images are decomposed to multi-scale and multi-direction subband images by LNSST. Secondly,blocked singular value decomposition of each subband image is done to calculate the area feature energy value which is served as linking strength of each neuron in PCNN. After the processing of PCNN with the adaptive linking strength, new fire mapping images of the entire subband images are obtained, the clear objects of subband images are selected by the compare-selection operator with the fire mapping images pixel by pixel and then all of them are merged into a group of new clear subband images. Finally, fused subband images are reconstructed to image by local nonsubsampled shearlet inverse transform. Some fusion experiments on several sets of infrared and visible images are done and objective performance assessments are implemented to fusion results. The experimental results indicate that the proposed method performs better in subjective and objective assessments than a few existing typical fusion techniques in the literatures and obtains better fusion performance..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 12 (2014)
Generation of Ultra-short Pulses and Supercontinuum in the Sub-nanosecond Pulse Pumping Regime
SUN Wu
The generation of ultra-short pulses and the formation of supercontinuum in the sub-nanosecond pulse pumping regime have been simulated. First of all, we briefly introduced the generalized nonlinear Schrodinger equation,which could effectively describe laser propagation in the nonlinear medium. The choice of temporal rThe generation of ultra-short pulses and the formation of supercontinuum in the sub-nanosecond pulse pumping regime have been simulated. First of all, we briefly introduced the generalized nonlinear Schrodinger equation,which could effectively describe laser propagation in the nonlinear medium. The choice of temporal resolution and the high-accuracy adaptive change of step size were secondly studied for the split-step Fourier method. The formation of supercontinuum was finally researched by gradually increasing the peak power of incident pulse. The results showed that sub-picosecond pulses could be generated from the breakup of sub-nanosecond pulse owing to modulation instability, and the higher-order nonlinear effects of ultra-short pulses, including self-steepening, intrapulse Raman scattering, the fission of higher-order soliton, lead to the formation of supercontinuum spanning from 481 nm to1 750 nm of 30 dB bandwidth..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 21 (2014)
LED Illumination Lens Design Based on an Energy Partition Relation Mapping
CHEN Enguo, and GUO Tailiang
Based on a spatial energy partition mapping, a design method of LED illumination lens is demonstrated to realize high-efficiency and high-uniformity illumination on the target screen. This method first performs the differential of the radiation source, and then establishes a relation mapping with the prescribed lightinBased on a spatial energy partition mapping, a design method of LED illumination lens is demonstrated to realize high-efficiency and high-uniformity illumination on the target screen. This method first performs the differential of the radiation source, and then establishes a relation mapping with the prescribed lighting. Lens structure can be finally achieved by solving a group of partial differential equation. For design demonstration, a high-power LED with the emitting area of 1.2 mm×1.2 mm is applied. The designed lens could offer an effective lighting on the target with the collection efficiency over 99% and the spatial uniformity of 91.67%. Simulation results agree well with the theoretical derivation..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 27 (2014)
Correction of Schmidt Prism by Polarizing Aberration
LU Jinjun, DONG Qinpei, YANG Kai, SUN Xueping, and ZHU Weibing
In order to correct the polarization aberration of Schmidt prism and eliminate the double image and the ghost image, we derive the relationship between the factor B of the Jones matrix and the diffraction intensity. According to our derivation, the relationship between the factor B and the reflection phase shift δ on tIn order to correct the polarization aberration of Schmidt prism and eliminate the double image and the ghost image, we derive the relationship between the factor B of the Jones matrix and the diffraction intensity. According to our derivation, the relationship between the factor B and the reflection phase shift δ on the roof surface is got. And the condition to eliminate the polarization aberration is to make the reflection phase shift δ=π clear. We will coat the phase film on the roof surface and we compare the characters of reflection phase shift between the single film and multilayer film and the characteristics for eliminating the polarization aberration in the visible region are achieved. An effective technical way to correct the polarization aberration about every polarization state B=0 is proved to be true. We have coated the samples and tested the polarization aberration of every incident polarization state. The experimental results have a good agreement with the theoretical result..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 32 (2014)
Optical System Design of Ultra High Speed Optic electronic Framing Camera Used in Shlieren Experiment
LI Jian, LIU Ningwen, XIAO Zhengfei, and ZHAO Xincai
The image dividing method of ultra high speed optic-electronic framing camera using pyramid would induce the un-integrity of the final images when being used in Schlieren experiment. For resolving the problem, we designed the optical system, dividing the image into 8 integrate parts, through the 1:1 dividing prisms. WeThe image dividing method of ultra high speed optic-electronic framing camera using pyramid would induce the un-integrity of the final images when being used in Schlieren experiment. For resolving the problem, we designed the optical system, dividing the image into 8 integrate parts, through the 1:1 dividing prisms. We obtained the high-resolution Schlieren image about Φ30 μm tungsten filament explosive experiment. The ultra high speed optic-electronic framing camera has been used in the field of laser effect..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 38 (2014)
Medium Infrared (MIR) Hybrid Refractive/Diffractive Fore Zoom Optical System Design for AOTF Spectrum Camera
ZHAO Zhao, WANG Jinsong, GAO Duorui, and AN Zhiyong
Based on performance and application characteristic of acousto-optic tunable filter (AOTF) and the detector, a fore zoom optical system for AOTF spectra camera is designed which works on medium wave. The optical system adopts hybrid diffractive-refractive model and six lens to achieve a 12× continuous zoom configuBased on performance and application characteristic of acousto-optic tunable filter (AOTF) and the detector, a fore zoom optical system for AOTF spectra camera is designed which works on medium wave. The optical system adopts hybrid diffractive-refractive model and six lens to achieve a 12× continuous zoom configuration and ZEMAX software is used to optimize the optical system and assess the image quality of the system. The results show that the Modulation Transfer Function (MTF) of the system approaches to diffraction limit across the whole brand at spatial frequency16 lp/mm, encircled energy is greater than 90%. It is demonstrated that the system can apply in the field of infrared spectral imaging analysis and infrared target detection and recognition..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 42 (2014)
Design of Narrow Beam for High-power COB Light Source Based on SMS
LI Min, SHEN Weimin, HUANG Jie, WANG Le, WANG Shaolei, HE Zhihua, and TONG Fei
For integrated light source cannot be easily realized with small emitting angle, a method of designing narrow beam for high-power COB light source is proposed. According to light distribution of the source and the desired light distribution of emergent rays, an optical system with Refraction-refraction(R-R) was chosen.For integrated light source cannot be easily realized with small emitting angle, a method of designing narrow beam for high-power COB light source is proposed. According to light distribution of the source and the desired light distribution of emergent rays, an optical system with Refraction-refraction(R-R) was chosen. The source model was established based on spectral distribution and relative intensity of the chosen COB light source, and then the divergence angle of a Lambertian source was reduced to 60° by using the Compound Parabolic Concentrator(CPC). Points on profile curves of the front surface and the behind surface of the lens were obtained with the extended conservation law and the Simultaneous Multiple Surface (SMS). Profile curves were obtained by curve fitting with these points, and then the lens model was established with three-dimensional software. The optical system was simulated with ray-tracing software. The results show that the divergence angle of the system is controlled within 30° in the optical port, the angle of the half of light intensity is 11.336°, and the total luminous efficiency is up to 89.398%..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 49 (2014)
Effects of Piston, Tip-tilt and Gap Errors on Image Quality of the Segmented Telescope
WANG Jin, XIAN Hao, WANG Shengqian, ZHOU Longfeng, and LI Bin
The impact of segmented telescope piston error, tip-tilt error and gap on image quality by theoretical and numerical simulation was analyzed. Different error segmented telescope Point-spread-function (PSF) and the far-field spot Strehl Ratio (S.R) expression were derived theoretically. Then, set up simulation model aboThe impact of segmented telescope piston error, tip-tilt error and gap on image quality by theoretical and numerical simulation was analyzed. Different error segmented telescope Point-spread-function (PSF) and the far-field spot Strehl Ratio (S.R) expression were derived theoretically. Then, set up simulation model about three kinds of error effect on segmented telescope PSF and far-field spot S.R, and analyzed three kinds of error influence on imaging quality of splicing telescope. Analysis results show that: when the segmented mirror exist piston error, segmented telescope image quality with piston error standard deviation δ increasing gradually becomes poor; when δ < λ/20 segmented telescope, the far field spot RS.R >0.9;when the segmented mirror exist tip-tilt error, the segmented telescope imaging quality with the wavefront phase RMS increases gradually worse, when eRMS<0.3 rad, the far-field spot of the segmented telescope RS.R>0.9; when the segmented mirror exist gap, its imaging quality with the gap factor w increases gradually becomes poor, and when w<0.025, a segmented telescope far-field spot RS.R>0.9..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 55 (2014)
Improved Active Constellation Extension Algorithm for PAPR Reduction of CO-OFDM System
LIU Jianfei, YU Meilong, ZENG Xiangye, LU Jia, and WANG Mengjun
The high Peak-to-average Power Ratio (PAPR) problem in the Coherent Optical Orthogonal Frequency-division Multiplexing (CO-OFDM) systems can lead to serious optical fiber nonlinear effects. In order to solve this problem, an improved Active Constellation Extension (ACE) algorithm was proposed, which could obtain betterThe high Peak-to-average Power Ratio (PAPR) problem in the Coherent Optical Orthogonal Frequency-division Multiplexing (CO-OFDM) systems can lead to serious optical fiber nonlinear effects. In order to solve this problem, an improved Active Constellation Extension (ACE) algorithm was proposed, which could obtain better PAPR suppression effect. The traditional ACE algorithm was achieved combined with the projection onto convex sets method (POCS). In the proposed algorithm, Parabolic Peak Cancellation (PPC) algorithm was used to improve the peak regeneration phenomenon in the process of iteration, and the speed of convergence was improved by constellation point pre-adjustment technology. We applied the improved algorithm to a 4-QAM, and 29 Gb/s CO-OFDM system. The simulation results show that the proposed algorithm can effectively reduce the PAPR of OFDM signals by 4.41 dB and have faster convergence speed..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 63 (2014)
Realization and Testing of Auto-Coupling Control System for Planar Optical Waveguide
WANG Yike, YIN Zuoshan, QIU Jifang, DU Wentao, ZHOU Yu, WU Jian, and LIN Jintong
A method based on MATLAB instrument control technology was proposed to realize an auto-coupling system,avoiding complicated and time-consuming manual alignment. A Binary-tree Data-truncation (BTDT) algorithm and Return-traversal Search (RTS) algorithm based on a threshold were designed for single axis searching. ReturnA method based on MATLAB instrument control technology was proposed to realize an auto-coupling system,avoiding complicated and time-consuming manual alignment. A Binary-tree Data-truncation (BTDT) algorithm and Return-traversal Search (RTS) algorithm based on a threshold were designed for single axis searching. Return-traversal algorithm provides a higher accuracy which also achieves multiple kinds of accuracy and BTDT can search faster.Combined with a laser and a power meter, an auto testing system was developed with GPIB technology. The experiments show that insertion loss of tapered fiber can drop to 8~9 dB including the transmission loss of waveguide in 15 minutes while aligning manually usually takes more than 0.5 hour and system can be kept stable in 15~20 minutes. Besides, with auto testing system, scan of wavelength and power can be completed in 8 minutes for 2 200 points. Auto-coupling system has good effect, stability and practicability..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 68 (2014)
A Phase Stabilization Method for Fiber-optic Interference Fringes Using Sinusoidal Phase Modulating
BO En, DUAN Fajie, FENG Fan, Lü Changrong, and FU Xiao
Aimed at eliminating the effect of the environmental factors (especially the vibration and temperature fluctuation) for 3D profilometry measurement, a method based on the Sinusoidal Phase Modulation (SPM) is developed to stabilize the phase of fiber interference fringes. The system makes use of the Mach-Zehnder interfeAimed at eliminating the effect of the environmental factors (especially the vibration and temperature fluctuation) for 3D profilometry measurement, a method based on the Sinusoidal Phase Modulation (SPM) is developed to stabilize the phase of fiber interference fringes. The system makes use of the Mach-Zehnder interferometer structure and Young’s double pinhole interference principle to achieve the high-density interference fringe projection of cosine distribution. The Fresnel reflection on the exit faces of two interference arms is used to generate a Michelson interference signal, which is detected by the Photoelectric Detector (PD) and send into Phase Control System (PCS). We extract the phase of the Michelson interference signal, then feedback the compensation signal to the Piezoelectric Transducer (PZT)driver, and drive the PZT with sinusoidal phase modulating signal together. The phase shift brought by the environmental factors can be compensated, and a well stability of the fringe phase can be achieved. The phase shift can be reduced to 57mrad, and experiment has verified the feasibility of the proposed method..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 75 (2014)
The Design and Applications of Tunable Semiconductor Laser Gas Detection Circuit Based on FPGA
XU Xiumin, ZHANG Yujun, HE Ying, YOU Kun, WANG Liming, ZHOU Yi, GAO Yanwei, and LIU Jianguo
Tunable semiconductor laser absorption spectrum technology (TDLAS) has the characteristics such as high resolution and high sensitivity, currently widely used in trace gas detection, so portable and online debugging is the trend of its development. Because the FPGA has the obvious advantages of fast speed, small size, Tunable semiconductor laser absorption spectrum technology (TDLAS) has the characteristics such as high resolution and high sensitivity, currently widely used in trace gas detection, so portable and online debugging is the trend of its development. Because the FPGA has the obvious advantages of fast speed, small size, simple structure, strong anti-interference ability, online debugging, parallel and so on, combined with FPGA technology, TDLAS trace gas detection system will have a good application prospect. This paper mainly studies the signal generation and the signal acquisition based on FPGA. Continuous observation experiment in the open light path indicates that the signal is high precision and its frequency can be as high as 10 kHz without distortion, the acquisition is high precision, stable and reliable, optimizing the traditional TDLAS trace gas detection system. It can be seen that the FPGA implementation of signal generation and signal acquisition is feasible, which is an important step to the FPGA implementation of TDLAS trace gas detection system..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 81 (2014)
Dichromatic Interference Intensity Modulation Approach for Thin Lubricating Film Thickness Measurement
ZHAO Guolei, GUO Feng, LIU Haichao, and HONG Jenghaur
Optical interferometry is an effective way for lubricating film thickness measurement. The dichromatic interferometry can avoid artificial fringe order counting, while operates with a fair resolution and a large film thickness measurement range. However, the traditional dichromatic interferometry depends on strict caliOptical interferometry is an effective way for lubricating film thickness measurement. The dichromatic interferometry can avoid artificial fringe order counting, while operates with a fair resolution and a large film thickness measurement range. However, the traditional dichromatic interferometry depends on strict calibration processes and the observer. In this paper, a dichromatic interference intensity modulation approach is proposed for micro/nano lubricating film thickness measurement, whereby linear superposition of the intensities of the red and the green components is carried out and a modulated signal is obtained to infer the film thickness at its local maximum/minimum. Thereafter the film thickness of other points can be obtained by the interference intensity of the red or green light. To validate this approach,contact gap between a steel ball and a glass disc was measured, and the results were well correlated with the theoretical calculation. A measurement range of 2 μm can be achieved by an optimum selection of the wavelengths of the red and green lights..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 88 (2014)
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