Journals >Infrared and Laser Engineering
Contents
2018
Volume: 47 Issue 4
37 Article(s)
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[in Chinese]
Figure error measurement method of cylindrical reflection mirror for conic approximate Wolter-I X-ray type telescope
Liu Na, Shen Zhengxiang, Ma Bin, Wei Zhenbo, Xu Xudong, and Wang Zhanshan
The manufacturing technology of cylindrical mirror used in conic approximate Wolter-I X-ray focusing telescope is hot slumping glass segments, which makes the thin glass substrate replicated on the convex surface of cylindrical mandrel. The most important errors of cylindrical glass are the figure error and ripple erroThe manufacturing technology of cylindrical mirror used in conic approximate Wolter-I X-ray focusing telescope is hot slumping glass segments, which makes the thin glass substrate replicated on the convex surface of cylindrical mandrel. The most important errors of cylindrical glass are the figure error and ripple error, which are the major factors affecting the focusing performance of telescope. Therefore, the high-precision and quickly measuring low and mid spatial frequency error of concave surface and convex surface of cylindrical glass is the key technology in manufacturing process. The traditional test plate can′t meet the requirements because it can only measure specific surface with the same of radius of the test plate inefficiently and can′t measure the thin glass. The convex surface of smooth cylindrical mandrel and concave surface of thin cylindrical glass were measured by an interferometer with both computer generated hologram (CGH) and laser scanner quickly and quantitatively. Also, with the two testing methods, the power spectral density(PSD) of cylindrical glass was calculated and the point spread function (PSF)and half power diameter (HPD) were plotted by fitting slope error. It demonstrates that the two methods can characterize the influence of the low and mid spatial frequency error on the angular resolution of X-ray telescope, which benefit for improving the precision of the manufacturing mirror and the focusing performance of X-ray telescope..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 417001 (2018)
Design and verification of 2Π space all-sky polarization observation system
Ke Zibo, Li Yanfei, Wu Shuiping, Wang Hong, and Yan Lei
The sky polarization pattern is an important feature of the atmospheric effect of remote sensing observation. It describes the distribution of polarization information in all sky. The atmospheric effect on polarization observation is immense, and analysis of the method of the atmosphere acting on polarized light is theThe sky polarization pattern is an important feature of the atmospheric effect of remote sensing observation. It describes the distribution of polarization information in all sky. The atmospheric effect on polarization observation is immense, and analysis of the method of the atmosphere acting on polarized light is the basis, it can provide a new idea for reducing the impact of atmospheric effect on polarization images. Because different regions and different observation situations correspond to different sky polarization patterns, it is a prerequisite to develop instrument to research the polarization pattern of the sky. The emphasis of this paper was on the design of an all-sky polarization observation system and validating it through precision measurement. It introduced main parts of the instrument firstly, including mechanical structure, optical design and circuit control, then the instrument control accuracy was described by analyzing control strategy and control precision of the instrument. At last, by contrast experiments, the results prove the reliability of polarization observation instrument..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 417002 (2018)
An online laser-induced flaw inspection device for optical elements
Shi Yali, Tao Xian, Zhou Xinda, Zhang Jiabin, Ding Lei, and Zhang Zhengtao
The laser-induced damage experiments are very important to verify the reliability and lifespan of the optical elements. The optical elements are irradiated by the high energy laser frequently and the corresponding damage information is recorded by the researchers. A device was designed and constructed to inspect the suThe laser-induced damage experiments are very important to verify the reliability and lifespan of the optical elements. The optical elements are irradiated by the high energy laser frequently and the corresponding damage information is recorded by the researchers. A device was designed and constructed to inspect the surface flaws of the optical elements on line efficiently and automatically. The device was composed of six parts, which were automatic zoom microscopic camera, spectral confocal sensor, two dimensional scan movement axes, focus movement axis, fast reset platform and system controller. The laser irradiated area of the optical elements was scanned by the two dimensional scan movement axes according to the planned path. The work distance of the microscope was detected by the spectral confocal sensor and adjusted by the movement of the focus axis. The sub images were acquired by the microscopic camera and saved to the computer. Firstly, the main error factors that affect the image matching precision were analyzed and compensated by the image correction and so on. Then the image with large area and high resolution was obtained by stitching the corrected sub images. Lastly, the damage information was obtained after image processing. The experimental results show that the time is no more than 5 minutes to detect an area of 15 mm×15 mm. The resolution of the microscope imaging system is better than 228 lp/mm and the stitching error is better than 2 pixel..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 417003 (2018)
Research on nondestructive measurement of sea pearls using optical coherence tomography technique
Dong Junqing, and Li Qinghui
To ascertain the inner structure diversity of the two different size sea pearls, some sea pearls including south pearls of China and south sea pearls were non-destructively analyzed by a new swept-source optical coherence tomography (OCT) technique and Raman spectroscopy. The Raman spectrum analysis results indicate thTo ascertain the inner structure diversity of the two different size sea pearls, some sea pearls including south pearls of China and south sea pearls were non-destructively analyzed by a new swept-source optical coherence tomography (OCT) technique and Raman spectroscopy. The Raman spectrum analysis results indicate that the phases of the nacre of all sea pearls are aragonite. Any artificial organic dye and additive were not found. The nacre thicknesses were speedily and effectively determinated based on the measuring function and graph manipulation function of this OCT technique. On the basis of the nacre thickness data, these sea pearls can be classified into five grades. The thickness and the diameter of the pearls were comparatively studied. The thicknesses of most of sea pearls have weak positive correlation with the diameters except several ones. In addition, according to the texture characteristics of OCT 2D images, the quality uniformity of nacre, transition layer and nucleus were classified and evaluated. The OCT technique could provide significant evidence for grade classification for nacre thickness and quality uniformity of pearls..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 417004 (2018)
On-orbit absolute radiometric calibration of high resolution satellite optical sensor based on gray-scale targets
Xu Weiwei, Zhang Liming, Li Xin, Yang Baoyun, and Wang Jixiang
Radiometric calibration in-flight is one of critical techniques for information quantification of optical satellite sensor. A calibration approach based on gray-scale targets has been presented. It substitutes the measured ratio of diffusion to global irradiance and atmospheric optical depth to the assumption of aerosoRadiometric calibration in-flight is one of critical techniques for information quantification of optical satellite sensor. A calibration approach based on gray-scale targets has been presented. It substitutes the measured ratio of diffusion to global irradiance and atmospheric optical depth to the assumption of aerosol scatter. And the method could isolate the DN signal created by the targets from the response produced by background radiance sources, which simplify the calibration process. It can break the time and locale conditions limit of radiometric sites and achieve high precision, high frequency and normalizable calibration application for high spatial resolution multi-spectral sensor with full dynamic range. The results show that the calibration approach′s uncertainty is less than 3.5%. And the difference of calibration coefficient is less than 5% compared with the reflectance-based method. Simultaneously, this approach can also satisfy the application to the complex environment..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 417005 (2018)
Measuring method for large size planar parts based on edge restoration
Li Xiaojie, Wang Jia, Geng Lei, and Ye Kun
Aiming at the problem that the imaging accuracy of the planar part was decreased due to pseudo edges in the illumination of the backlight, a measurement method for recovering the accurate edge from the pseudo edges of the measured object was proposed. Firstly, pseudo sub-pixel edges of planar parts were extracted by CaAiming at the problem that the imaging accuracy of the planar part was decreased due to pseudo edges in the illumination of the backlight, a measurement method for recovering the accurate edge from the pseudo edges of the measured object was proposed. Firstly, pseudo sub-pixel edges of planar parts were extracted by Canny algorithm and surface fitting algorithm. Secondly, upper and lower edge points distinguishing method based on direction angle difference was proposed and the upper edges were restored by the method of mean Euclidean distance. Finally, the upper edges were converted to the measurement plane by the similar triangular method, and dimension of planar parts could be calculated by using the camera calibration parameters. The results show that the absolute error is less than 0.08 mm and the relative error is less than 0.05% in the range of 1 200 mm×800 mm..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 417006 (2018)
Generation of Orbital Angular Momentum superpositions and its test
Ke Xizheng, and Xue Pu
The beam with helical phase distribution has Orbital Angular Momentum(OAM), whose helical phase depends on the topological charge of OAM state. The phase distribution and the light field distribution of the superposition vortex beams were analyzed theoretically, and then the phase distribution pattern was loaded onto tThe beam with helical phase distribution has Orbital Angular Momentum(OAM), whose helical phase depends on the topological charge of OAM state. The phase distribution and the light field distribution of the superposition vortex beams were analyzed theoretically, and then the phase distribution pattern was loaded onto the spatial light modulator to generate the superposition vortex beams. The light of the field diffraction pattern with different topological charges superposition was discussed. The experimental results show that the optical field diffraction pattern of the superposition state varies regularly with the positive and negative values of the superposition of the beam topological charge and the numerical value, namely when the superposition of two optical topological charges is different symbol, the number of diffraction spots is the sum of the absolute values of the two optical topological charges; when the superposition of two optical topological charges is same symbol, the number of diffraction spots is the absolute value of the difference between the two optical topological charges. By this property, the topological charge of the vortex beam can be detected, which provides a new method for the topological charge detection of the superposed vortex beams in the free space optical communication system..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 417007 (2018)
Line-of-sight angle estimation method of strapdown munition based on ideal trajectory
Liu Zhenya, Gao Min, and Xu Lutie
Aiming at the problem that inertial measurement unit can not meet the operation requirement of the low cost guidance munition, a line-of-sight (LOS) angle estimation method of strapdown semi-active laser-guided munition based on ideal trajectory was proposed. According to the relative motion model between ammunition anAiming at the problem that inertial measurement unit can not meet the operation requirement of the low cost guidance munition, a line-of-sight (LOS) angle estimation method of strapdown semi-active laser-guided munition based on ideal trajectory was proposed. According to the relative motion model between ammunition and target and the seeker measurement model, the nonlinear filter system was built. Aiming at the features that the ballistic parameters varied in the small range, this algorithm took the ideal trajectory parameters as filter parameters by analyzing the impact from projectile motion parameters on the system uncertainty; the LOS angel was estimated by using the measurement information from laser semiactive seeker and the cubature Kalman filter (CKF). The digital simulation results showed that under the condition of small disturbance, the root mean square errors (RMSE) of LOS inclination and declination are 0.182°and 1.668°, the max estimation errors of them are 0.259° and 2.913°. The algorithm has better estimation precision and robust property..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 417008 (2018)
[in Chinese]
Study of wide spectrum superluminescent diode at 1 550 nm
Zi Hui, Xue Zhengqun, Wang Linghua, Lin Zhongxi, and Su Hui
Superluminescent diode had important applications in OCT or light processing technology because of its wide and low ripple spectrum as well as incoherent light output. To satisfy the demand of wide and low ripple spectrum, the 1 550 nm AlGaInAs multi-quantum-well superluminescent diode was designed and manufactured. InSuperluminescent diode had important applications in OCT or light processing technology because of its wide and low ripple spectrum as well as incoherent light output. To satisfy the demand of wide and low ripple spectrum, the 1 550 nm AlGaInAs multi-quantum-well superluminescent diode was designed and manufactured. In this paper, tilt waveguide(12°) structure and isolation area were further adopted. Combined with the anti-reflect film, broad spectrum and low ripple superluminescent diode was obtained. Also, the influences of the isolation area on the device properties were compared. The experimental results show that the 3 dB spectral bandwidth of the superluminescent diode can reach around 83 nm with ripple as small as 0.1 dB, at the current of 200 mA, the output power is above 1.5 mW..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 420001 (2018)
Antidepressant effect of bright white LED combined with classical music
Wang Danni, Dai Yuhuan, Cheng Jing, Zhang Dawei, Wang Cheng, and Zhuang Songlin
The treatment of bright white LED combined with classical music was proposed by laboratory mice. Mice suffered from chronic mild stress were divided randomly into three groups and exposed to 12:12 h bright light:dark (350 lx) conditions. The control group (C) received no treatment. The classical music group (M) was treThe treatment of bright white LED combined with classical music was proposed by laboratory mice. Mice suffered from chronic mild stress were divided randomly into three groups and exposed to 12:12 h bright light:dark (350 lx) conditions. The control group (C) received no treatment. The classical music group (M) was treated with classical music of 2 h per day. The classical music + bright light group (M+B) was treated daily with classical music of 2 h and 5 000 lx white LED light. Thirty days later, depression-like behaviors were assessed using saccharin solution preferences and forced swim tests. Mice in M and M+B demonstrated signi cantly shorter immobility times and longer climbing times and swimming times compared to those in C(p<0.001). It was observed that M+B experienced shorter immobility times (52.3±25.18 s) than M (78.9±14.82 s), and there was significant difference between two groups(t(9)=3.414, p=0.008<0.05). The combination therapy of bright white LED and classical music raised the vitality of mice and possessed antidepressant effect..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 420002 (2018)
Regulation of bismuth germanate electro-optic crystal′s half-wave voltage
Xie Nan, Qiu Xinmao, Xu Qifeng, Tan Qiao, and Ma Jing
To increase the measurement range of optical voltage sensor, a method for regulating and increasing the half-wave voltage of bismuth germanate crystal by varying the cutting direction was proposed. With the electro-optic wave coupling theory, the dependence of half-wave voltage on crystal cutting direction was investigTo increase the measurement range of optical voltage sensor, a method for regulating and increasing the half-wave voltage of bismuth germanate crystal by varying the cutting direction was proposed. With the electro-optic wave coupling theory, the dependence of half-wave voltage on crystal cutting direction was investigated. The light propagation direction and the electrical field direction of bismuth germanate crystal were determined by the crystal cutting directions. The results demonstrate that the half-wave voltage is increased to 5 times when crystal is cut along direction[-2-0.5, 2-0.5, 0] and [0.219, 0.219, 0.951]. And the half-wave voltage is increased to 12 times when crystal is cut along direction [0.140, 0.275, 0.951] and [2-0.5, 2-0.5, 0]. The influence of light propagation direction on half-wave voltage was also discussed. When bismuth germanate crystal is cut along the standard direction, the variation of half wave voltage is less than 0.06% with angle error of light propagation in the range of ±0.05π. This method of half-wave voltage regulation is also suitable for other electro-optic crystals..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 420003 (2018)
[in Chinese]
Full-duplex radio over fiber system for tunnel communication
Wang Houjun, Yan Lianshan, Ye Jia, Pan Wei, Zou Xihua, Luo Bin, and Li Peixuan
Due to the poor wireless transmission in the long tunnels, conventional communication technique cannot meet the high-quality communication demands of the passengers. A ROF (Radio over Fiber) distributed tunnel communication system employing WDM-PON (Wavelength Division Multiplex-Passive Optical Network) was proposed. BDue to the poor wireless transmission in the long tunnels, conventional communication technique cannot meet the high-quality communication demands of the passengers. A ROF (Radio over Fiber) distributed tunnel communication system employing WDM-PON (Wavelength Division Multiplex-Passive Optical Network) was proposed. By combining the WDM and DAS (Distributed Antenna System) techniques, a wireless access network can be achieved to provide different wireless services through optical channels. Moreover, the transmission bandwidth can be increased by using this proposed scheme which can also suppress the signal degradation under the scenario of tunnel transmission. A full-duplex ROF platform was experimentally demonstrated. The optical generation and transmission of electrical 16/64QAM vector signals at 24 GHz were achieved. And the feasibility of the scheme was verified by measuring the EVM value of the uplink and downlink..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 422001 (2018)
Mine wind speed sensor using fiber Bragg grating based on differential pressure principle
Li Zhen, Wang Jiqiang, Zhao Lin, Zhang Huawen, and Liu Tongyu
A design of mine wind speed sensor using fiber Bragg grating (FBG) was reported, which was based on differential pressure principle and differential sensitive architecture was adopted which was composed of a bellows, an equal-strength beam and two FBGs. Furthermore, an algorithm was introduced for temperature compensatA design of mine wind speed sensor using fiber Bragg grating (FBG) was reported, which was based on differential pressure principle and differential sensitive architecture was adopted which was composed of a bellows, an equal-strength beam and two FBGs. Furthermore, an algorithm was introduced for temperature compensation. Through these methods the cross sensitivity of temperature was effectively eliminated and a high strain sensitivity was achieved. The relation between the central wavelength variation of the two FBGs and the wind speed was derived. Meanwhile, the hydraulic simulation test of sensitive architecture was carried out and the sensitivity of 0.703 pm/Pa was given, which agreed well with the theoretical value. The wind speed sensor was tested by wind tunnel and the results show that the measurement error of the sensor is within ±0.3 m/s in the range of 0.2-20 m/s, and the wind speed sensor has good linearity..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 422002 (2018)
Design of integrated digital temperature sensor for liquid nitrogen temperature
Zhang Changfeng, Mao Wenbiao, Zhang Jiqing, Guo Qiang, Zhong Shengyou, and Yao Libin
The temperature sensor is one of the most important components of the cooled infrared detector assembly which measures and controls the operating temperature of the detector. Its working temperate directly affects the performance of the detector, such as SNR, detectivity and blind pixel rate. Considering that traditionThe temperature sensor is one of the most important components of the cooled infrared detector assembly which measures and controls the operating temperature of the detector. Its working temperate directly affects the performance of the detector, such as SNR, detectivity and blind pixel rate. Considering that traditional PN junction temperature sensor requires complex analog signal processing and is easily affected by electromagnetic interference, a CMOS integrated digital temperature sensor was proposed. Fabricated in a 0.35 μm CMOS process, the chip area of the sensor is 380 μm×500 μm(without PAD), the proposed sensor reached the conversion speed of 6.1 times/s and consumed 300 μW when the working voltage is 2.5 V. The resolution of the sensor was 0.061 6 K and RMS noise is 0.148 K@77 K. The mesurement results prove that the proposed integrated digital temperature sensor is suitable for cooled infrared detector temperature measurement..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 422003 (2018)
[in Chinese]
Comparison of laser phased array and microwave phased array radar transmitting antenna
Ci Mingru, Liu Jingjiao, Jiang Dongsheng, Han Long, and Liu Jinsheng
For the development and application of detecting laser phased array radar based on technology of microwave phased array radar, the basic knowledge of microwave phased array radar antenna was simulated and learned at first. And partial content, which can be compared between microwave phased array radar antenna and opticFor the development and application of detecting laser phased array radar based on technology of microwave phased array radar, the basic knowledge of microwave phased array radar antenna was simulated and learned at first. And partial content, which can be compared between microwave phased array radar antenna and optical fiber laser phased array radar, was compacted. Then, technical essential and potential ability of optical fiber laser phased array antenna was analyzed, its system function and scale were calculated based on the existing research and development level. Finally, the technical features and main questions of optical fiber laser phased array and microwave phased array antenna were tried to discuss. The system configuration of each other was put forward, which not only helped to improve the microwave phased array radar in complex electromagnetic environment of high-speed, short-range stealth and multi target detection, recognition and localization ability, but also may be appropriate to reduce the pressure on paint with the laser phased array searching a wide range regional target..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 406001 (2018)
Influence of performances of APD detector on CO2 concentration error retrieved by lidar measurement
Zuo Weikang, Zhu Yadan, Qiu Min, Liu Jiqiao, and Chen Weibiao
Space-borne integrated path differential absorption(IPDA) lidar has been regarded as an efficient method to measure the concentration of the global atmospheric CO2 column concentration all day long. As a key part of the lidar receiver, the performance of the photodetector has a significant influence in the overall lidaSpace-borne integrated path differential absorption(IPDA) lidar has been regarded as an efficient method to measure the concentration of the global atmospheric CO2 column concentration all day long. As a key part of the lidar receiver, the performance of the photodetector has a significant influence in the overall lidar system. Avalanche photodiode(APD) is widely used in space-borne lidar because of its large dynamic range and high responsivity. The basic theories of the APD detector and the IPDA lidar were briefly introduced. And taking the actual working conditions of the space -borne IPDA lidar into account, the actual performances of an APD detector such as the detector′s responsivity, dynamic range, linearity and the signal to noise ratio under different optical powers were tested. Then based on the experiment result, the influence caused by the performances of the detector on concentration inversion was analyzed. The result shows that, when the CO2 concentration is 400 ppm, and the on-line wavelength output voltage of the APD detector is between 280 mV and 980 mV, the CO2 concentration error caused by the non-linearity and noise of the APD detector is less than 0.8 ppm..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 406002 (2018)
Design and simulation of a panoramic laser imaging fuze
Liu Bohu, Song Chengtian, and Duan Yabo
Laser imaging detection is an important direction of fuze technology development. The panoramic imaging detection technology can effectively improve the detection capability of the fuze system. In this paper, a simple panoramic laser imaging fuze principle and structure were firstly proposed that can realize 360° Laser imaging detection is an important direction of fuze technology development. The panoramic imaging detection technology can effectively improve the detection capability of the fuze system. In this paper, a simple panoramic laser imaging fuze principle and structure were firstly proposed that can realize 360° panoramic detection and create a target image in the process of missile-target encounter. Secondly, the model of missile-target encounter and the 3D model of target were established. The process of aerial and ground target imaging detection was simulated, and the images of the target were generated. Finally, the simulation software of panoramic laser imaging fuze was designed to generate the simulation data of imaging fuze under various missile-target encounter conditions, including target gray image, binary image, echo signal and so on. It is great favourable for the design of image recognition circuit and the panoramic laser imaging fuze′s final engineering realization..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 406003 (2018)
Temperature characteristics of absorber for large-energy long pulse laser energy meter
Li Nan, Qiao Chunhong, Fan Chengyu, and Yang Gaochao
For requirement of accurate measurement of large-energy long pulse laser energy, the temperature characteristics of absorber for laser energy meter are numerically analyzed and researched. The results show that, the temperature of absorber inwall rises with periodic oscillation. As the wall deep increasing, the oscillaFor requirement of accurate measurement of large-energy long pulse laser energy, the temperature characteristics of absorber for laser energy meter are numerically analyzed and researched. The results show that, the temperature of absorber inwall rises with periodic oscillation. As the wall deep increasing, the oscillation amplitude decreases rapidly. The temperature of absorber outerwall is without periodism, and it rises gradually with time. Meanwhile, the factors to affect the temperature rise are single pulse energy, pulse width and repetition frequency. When the single pulse energy is same, the shorter the pulse width, the higher the temperature rise of absorber inwall. And also the higher the pulse repetition frequency, the higher the temperature rise of absorber inwall. But when the total energy is same, the higher the repetition frequency, the lower the temperature rise of absorber inwall. By the optimization design of absorber structure, the total energy of long pulse laser sequence can be measured. As well as the energy of every pulse for low repetition frequency pulse sequence can be obtained, when the repetition frequency of long pulse laser sequence is less than 10 Hz. The work provides important references for the design and application of large-energy long pulse laser energy meter..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 406004 (2018)
Effects of LSPwC on microstructure and properties of GH3044 turbine case
Xie Mengyun, Wang Cheng, Zhang Peiyu, Ming Jiqing, and Chen Hui
Aiming at the problem of covering absorption and protection coatings on turbine case parts during laser shock processing, a compound technology was put forward, which used water sand paper to polish out the ablative layer after laser shock processing without coating(LSPwC). The effects of LSPwC on microstructure and meAiming at the problem of covering absorption and protection coatings on turbine case parts during laser shock processing, a compound technology was put forward, which used water sand paper to polish out the ablative layer after laser shock processing without coating(LSPwC). The effects of LSPwC on microstructure and mechanical properties of GH3044 alloy were researched, the feasibility of the compound technology was verified. Energy disperse spectroscopy (EDS) was used to analyze element composition, the surface microstructure of samples was observed by means of scanning electron microscope (SEM) and metallographic microscope, mechanical properties were studied through residual stress and high cycle fatigue life test. The results show that LSPwC generates an ablative layer on sample surface, which thick 10-15 μm range. Carbon and oxygen are rich in the layer, while the residual and tensile compressive stress alternately exist. The grain and carbide under the ablative layer are even-distributed and refined to different degree; Compared to original samples, LSPwC nearly improves the fatigue life of GH3044 alloy. After polishing out the ablative layer by water sand paper, a residual compressive stress, which is about 510 MPa, is generated on surface and the affected depth is about 1 mm. Besides, the fatigue life is improved to be about 3 times compared to original samples..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 406005 (2018)
Detection of internal thread for spacecraft with gas turbulence laser Doppler
Wang Tao, Zan Zhanhua, Zhang Cuiting, Yao Jianquan, Ma Junjie, Cai Jun, and Li Yuxiang
To solve the problem of the automatic inspection of the internal threads of a rotating sleeve operated by an aerospace vehicle, especially when the surface of the internal thread has oil pollution and rust, simply using optical image detection method was difficult to solve. The flat gas was blew inward internal thread To solve the problem of the automatic inspection of the internal threads of a rotating sleeve operated by an aerospace vehicle, especially when the surface of the internal thread has oil pollution and rust, simply using optical image detection method was difficult to solve. The flat gas was blew inward internal thread to form the turbulence output mapping the appearance of the internal thread, and then the turbulence characteristics of internal thread was detected by Doppler laser. The data characteristics were investigated in the stretching process and compression process of internal thread gas turbulence. The gas turbulence data was dealt with box line chart method. A standard template database of the box line chart of internal thread turbulent was established. The detection data was compared with the standard template. The result shows that when the threshold value of outliers is set to be 7%, the detection accuracy is 99.3%. Gas turbulent laser Doppler method for detecting internal threads is feasible, and overcomes the surface oil pollution and other difficulties, meets test requirements totally..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 406006 (2018)
Optical design of compact infrared imaging spectrometer
Yuan Liyin, Xie Jianan, Hou Jia, Lv Gang, and He Zhiping
To reduce the burden of the working platform, optimize the optical structure and promote the thermal adaption of the imaging spectrometer, an optical design of a compact infrared imaging spectrometer was presented. Due to compactness and aberration correction, the extended polynomial surfaces were utilized in the opticTo reduce the burden of the working platform, optimize the optical structure and promote the thermal adaption of the imaging spectrometer, an optical design of a compact infrared imaging spectrometer was presented. Due to compactness and aberration correction, the extended polynomial surfaces were utilized in the optical design of the infrared imaging spectrometer with spectral region between 1 μm to 3.4 μm, optical speed of F/2.86, and spectral sampling of 7.5 nm. The optical system was comprised of a free form three mirror telescope and a plane grating based free form spectrometer. The telescope was semi telecentric for pupil matching with the telecentric spectrometer, free of distortion and able to provide enough imaging space for other modules. The good imaging quality of spectrometer, and spectral distortion correction were achieved, and the tilt of image plane for detector arrangement was improved. The system is analyzed from the diffraction efficiency of the grating, the supressed stray light, as well as the opto-mechanical design of the integrated mirrors, which show it has high engineering feasibility..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 418001 (2018)
Design and mechanical experiment analysis of support structure for X-ray focusing telescope
Xie Wenliang, Shen Zhengxiang, Yu Jun, Wang Zhanshan, Huang Fan, Chen Changya, and Fan Feng
The design of the support frame structure of grazing incidence X-ray telescope is one of the key technologies in the development of telescope. The low energy focusing telescope of XTP satellite was planned, which adopted the X-ray focusing telescope based on the ultrathin glass. According to the rigorous optical and meThe design of the support frame structure of grazing incidence X-ray telescope is one of the key technologies in the development of telescope. The low energy focusing telescope of XTP satellite was planned, which adopted the X-ray focusing telescope based on the ultrathin glass. According to the rigorous optical and mechanical performance requirements for telescope prototypes, a hexagon barrel type telescope support structure was designed after structure selection and optimization. The modal analysis and frequency response analysis of the support structure were carried out by using the finite element software, and the results were compared with the mechanical experimental results. The results show that the support structure has a large structural rigidity, and the structure of the telescope will not be destroyed when it is launched, which can meet the requirements of mechanical properties. The support frame has the advantages of simple structure, high assembling precision and good manufacturability as well. It provides a reference for telescope development..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 418002 (2018)
Investigation on correction method of aero-optical transmission effects imaging deviation based on BOS technique
Ding Haolin, Yi Shihe, Wu Yuyang, Zhang Feng, and He Lin
When high-speed imaging guidance missile was flying in the atmosphere, which was affected by aero-optical effect, and then the imaging target position was different from the actual position. It was difficult for aero-optical imaging deviation to be corrected, due to the very strong random and nonlinear characteristic. When high-speed imaging guidance missile was flying in the atmosphere, which was affected by aero-optical effect, and then the imaging target position was different from the actual position. It was difficult for aero-optical imaging deviation to be corrected, due to the very strong random and nonlinear characteristic. The deviation of light rays passing through a variable refractive index field was measured based on Background Oriented Schlieren (BOS), the control points between the distortion image and reference image (undistorted image) were built, local weighted mean fitting method was adopted to construct the mapping function for the image correction, and bi-cubic convolution method was used to resample the image gray value, the distortion images were corrected at last. The imaging deviations caused by the stationary phase (lens) and the jet Mach number 3.0 supersonic film were corrected partly, and the validity of the correction method is confirmed by the experimental results..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 418003 (2018)
Fore optical system design for remote laser Raman spectrum detection system
Wang Shuai, Xia Jiabin, Yao Qifeng, Dong Mingli, and Zhu Lianqing
In order to realize the Raman spectrum detection of high spatial resolution of remote material, a fore optical system of the common aperture remote laser Raman detection system was designed. The common aperture structure was applied in the optical system to realize the common aperture and common optical axis of the lasIn order to realize the Raman spectrum detection of high spatial resolution of remote material, a fore optical system of the common aperture remote laser Raman detection system was designed. The common aperture structure was applied in the optical system to realize the common aperture and common optical axis of the laser emission system, the Raman light collection system and the micro area imaging system. The designed optical system can focus the laser to reduce the size of the laser spot, so that the system has a better spatial resolution than the 0.125 mrad. The effective aperture of the Raman light collecting lens is 50 mm, Raman scattering light image height in coupling lens focal plane was less than 25 ?滋m, space optical coupling can be directed to spectrometer with the slit width of 50 ?滋m, optical fiber of 50 ?滋m core diameter can also be employed for coupling this optical system and spectrometer. The system can be used for laser focusing, Raman detection and micro region imaging of long distance materials..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 418004 (2018)
Experimental study on precision molding of small dual aspherical chalcogenide glass lens
Tang Kun, Kong Minghui, Zhu Yongjian, Chen Fengjun, Mao Cong, and Zhang Mingjun
In order to realize the precision molding of small dual aspherical chalcogenide glass lenses, the influence of the relevant process parameters on the quality of molded lenses was studied by orthogonal molding experiment. Firstly, the molding process and the PFLF7-60A multi-station molding machine were introduced, the tIn order to realize the precision molding of small dual aspherical chalcogenide glass lenses, the influence of the relevant process parameters on the quality of molded lenses was studied by orthogonal molding experiment. Firstly, the molding process and the PFLF7-60A multi-station molding machine were introduced, the target lens was designed according to the aspheric curve formula. Secondly, an environmentally friendly chalcogenide glass IRG205 was selected, and the relationship between the viscosity and temperature of the glass was fitted by the VFT equation, then the molding temperature was determined, and the experimental parameters of each station were also established. Finally, the orthogonal molding experiments were conducted with no-coated mold and spherical preform, the regular influence of molding process parameters such as molding temperature, pressing load and maintenance force on the lenses′ molding quality(form accuracy PV, surface roughness Ra and profile deviation) were analyzed, and the optimized molding process parameters were obtained. The results have demonstrated that the values of PV for ASP1 and ASP2 are 129.2 nm and 174.8 nm, the values of Ra are 19.6 nm and 25.6 nm, and the values of profile deviation are 0.614 μm and 2.682 μm, respectively. The results can satisfy the requirements for high-precision applications of lenses, and provide reference and basis for the high-precision mass production of small dual aspheric chalcogenide glass lenses..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 418006 (2018)
Super-resolution in telescope imaging system by two-dimensional polynomial phase pupil filter
Liu Xianzhu, Wang Chao, Jiang Lun, Liu Zhuang, Yang Jinhua, and Jiang Huilin
In order to realize the transverse super-resolution imaging with a telescope optical system, a two-dimensional polynomial function phase pupil filter with a high strehl ratio was designed, and its improvement for the light distribution around the focal point of the optical imaging system was demonstrated. The result ofIn order to realize the transverse super-resolution imaging with a telescope optical system, a two-dimensional polynomial function phase pupil filter with a high strehl ratio was designed, and its improvement for the light distribution around the focal point of the optical imaging system was demonstrated. The result of the theory analysis shows that, when the filter is added into the system, the system transverse optical resolution is increased 1.33 times, and the Strehl ratio is 0.75 time as much as that of the system without this pupil filter. The performance of two-dimensional polynomial filter was compared with the other typical phase pupil filters, including the three-zone, the four-zone and the one-dimensional polynomial phase filter. The comparison results show that the Strehl ratio of the two-dimensional polynomial filter is the highest in these filters, and the transverse super-resolution ratio of this filter is next only to that of the four-zone filter. But the Strehl ratio of the four-zone filter is too low to be applied into the telescope. The influence of the incident field angle on the imaging results of the telescope optical system was also be studied, and it was found that the super-resolution effect of the system is better when the field-of-view is no more than ±4°..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 418007 (2018)
[in Chinese]
One class support vector machine used for blind pixel detection
Zhang Dongge, and Fu Yutian
One class support vector machine(OCSVM) was applied to classify the pixels of the infrared detectors, and it can detect the blind pixels by the random scenes. The blind pixel detection algorithms were reviewed in the beginning, and the imbalance distribution of the normal pixels and blind pixel was discussed in the folOne class support vector machine(OCSVM) was applied to classify the pixels of the infrared detectors, and it can detect the blind pixels by the random scenes. The blind pixel detection algorithms were reviewed in the beginning, and the imbalance distribution of the normal pixels and blind pixel was discussed in the following. The infrared image sequence was used to set up the OCSVM models and calculate the super sphere parameters, when the support vectors were represented by the Lagrangian coefficients. The OCSVM was an unsupervised method to cluster the pixels by the changing gray level and the random scenes. The super sphere model built by OCSVM would be refreshed by the updating image sequence, while the Lagrangian coefficients of the support vectors were recorded, so the blind pixels could be eventually classified by the statistic results of the preceding coefficients series. The mid-wave infrared 320×256 image sequence was taken as an example to illustrate the proposed method, and it got the same results as the black body calibration. It could conclude that the OCSVM used for the online modeling of the blind pixel detection of the infrared detectors is adaptive and self-refreshing, and it could improve the efficiency of the infrared system test.中国科学院上海技术物理研究所创新基金(2014-CX25).
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 404001 (2018)
Reseach on calibration method of double-channel thermal-infrared standard radiometer
Xie Chenyu, Li Jianjun, Pang Weiwei, Xia Maopeng, and Zheng Xiaobing
Blackbody radiation source as a primary standard, its measurement accuracy determines the uncertainty level of the whole traceability link. To improve the measurement accuracy of blackbodies′ radiance, a double-channel thermal-infrared standard radiometer was developed. According to the principle of the instrument, calBlackbody radiation source as a primary standard, its measurement accuracy determines the uncertainty level of the whole traceability link. To improve the measurement accuracy of blackbodies′ radiance, a double-channel thermal-infrared standard radiometer was developed. According to the principle of the instrument, calibration coefficients of the standard radiometer were obtained by using a high accuracy water-bath blackbody. Experimental results suggest that the radiometer′s instability is less than 0.3% within one hour, uncertainty of fitting coefficient is less than 1.23%, and combined uncertainty is less than 0.39%, 1.3% in 5 μm and 10 μm channel respectively. This radiometer provides new means for tracing blackbody radiance directly to radiant standard in lab..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 404002 (2018)
Fiber laser pumped multi-wavelength mid-infrared optical parametric oscillator
Yu Guangqi, Wang Peng, Song Wei, and Liu Kuiyong
A fiber laser pumped three-wavelength mid-infrared optical parametric oscillator was demonstrated. The pump source had three wavelengths which were 1 060 nm, 1 065 nm and 1 080 nm and the maximum pump power was 70.7 W. 8.7 W mid-infrared idler output was achieved under the maximum pump power, indicating a 16% slope effA fiber laser pumped three-wavelength mid-infrared optical parametric oscillator was demonstrated. The pump source had three wavelengths which were 1 060 nm, 1 065 nm and 1 080 nm and the maximum pump power was 70.7 W. 8.7 W mid-infrared idler output was achieved under the maximum pump power, indicating a 16% slope efficiency. The idler wave had three wavelengths which were 3 132 nm, 3 170 nm and 3 310 nm but the signal wave just had one wavelength locating at 1 604 nm. The experiment result was analyzed in both theory and experiment, and came to a conclusion that in the optical resonator, the optical parametric oscillation happened to the 1 060 nm pump wave and the difference frequency generation happened between the 1 604 nm signal wave and the 1 065 nm, 1 080 nm pump waves separately. The intensity difference between idler waves generated by the difference frequency generation of 1 065 nm and 1 080 nm was also analyzed using the conversion efficiency theory of difference frequency generation..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 404003 (2018)
A long-distance detection/ identification continuous zoom thermal imager based on MW MCT detector
Chen Jinjin, Su Junhong, Jin Ning, Pu Enchang, Zhang Hao, Su Junbo, Zhou Ligang, Ming Jingqian, Xu Man, Yang Kaiyu, and Song Zhihang
Large zooming ratio thermal imager based on medium-wave(MW) 640 pixel×512 pixel(15 ?滋m) MCT staring focal plane detector has been achieved. The thermal imager has wide field of 35°×28°capacitating wide area surveillance by 35× continuous zoom optical lens and the instantaneous field of view (IFLarge zooming ratio thermal imager based on medium-wave(MW) 640 pixel×512 pixel(15 ?滋m) MCT staring focal plane detector has been achieved. The thermal imager has wide field of 35°×28°capacitating wide area surveillance by 35× continuous zoom optical lens and the instantaneous field of view (IFOV) is 0.027 mrad/pixel. In the standard atmospheric conditions, this thermal imager can detect 4 m× 3 m×2.3 m vehicles target at 55 km and can identify the same target at 15 km (identification probability of 50%). This high performance has met the needs of the modern long-distance photoelectric weapons system. There are four key techniques during the design of the high performance imager including zoom optical system design of smooth change roots compensation curve, the single rail/double slider zoom structure technology, adaptive servo control technology and infrared image enhancement technology. The image is always clear and has no breakpoint in the continuous zoom process of the whole large variable ratio. The excellent Minimum Resolvable Temperature Difference (MRTD) of this imager has been achieved at Nyquist frequency(18 cyc/mrad). Performance data and imager photos have been presented. Test results show that the thermal imager has good performance and the above four key techniques of the thermal imager have been achieved from the theory design to the machine system engineering research..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 404004 (2018)
Design and experiment of mid-infrared differential CO detector
Li Guolin, Ji Wenhai, and Wang Yiding
CO molecules have the strongest absorption peak at 4.6 μm, which was selected as the central wavelength of the gas absorption. Combined with the luminescence characteristics of light source EMS200, spherical mirror chamber open was designed. A mid-infrared differential CO detection system was developed using the doubleCO molecules have the strongest absorption peak at 4.6 μm, which was selected as the central wavelength of the gas absorption. Combined with the luminescence characteristics of light source EMS200, spherical mirror chamber open was designed. A mid-infrared differential CO detection system was developed using the double pass structure of single detector. The performance of the instrument was studied by using the standard gas concentration of carbon monoxide in the mixed gas station. The research results reveal that, the resolution of the instrument is 20 ppm, and the limit of detection (LOD) is 18 ppm. The relative error was not more than 8.5% within the low concentration range of 30-1 500 ppm. Compared with the CO detection systems utilizing laser spectroscopy technology, pulsed infrared thermal source used in this system, its performance-cost ratio was high; with open spherical mirror chamber, the light path was simple and easy to implement. So the proposed detector shows potential applications in CO detection under the circumstances of coal-mine, environmental protection and petrochemical industry..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 404005 (2018)
Research method of the temperature characteristic of infrared thin-films
Wang Duoshu, Li Youlu, Li Kaipeng, Wang Jizhou, and Dong Maojin
Optical elements closed to photodetector always work in low temperature in infrared optical system, and the transmitted spectrum of the system would be shifted by the low temperature condition. This shift can affect the image quality of the system seriously. Some study have found that the reasons of the spectral shift Optical elements closed to photodetector always work in low temperature in infrared optical system, and the transmitted spectrum of the system would be shifted by the low temperature condition. This shift can affect the image quality of the system seriously. Some study have found that the reasons of the spectral shift are the change of the refractive index of the infrared thin-films in the system. In the paper, temperature characteristics of the infrared thin-films were studied. Based on the theory of optical thin film and analysis of several kinds of wavelength dispersion model, a new research on the temperature characteristic method of infrared thin film was put forward. With the method, the refractive index of infrared thin film at different temperature can be measured by spectral inversion according to the transmission spectra, and then, a formula for calculating refractive index of infrared thin film can be deduced based on the Cauchy dispersion model through data fitting analysis. The temperature characteristics of two kinds of infrared typical film materials(PbTe and Ge) were studied with the method, and the results verify the validity of the method..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 404006 (2018)
Multi-band infrared detector assemblies and performances for 2nd-generation GEO meteorological satellite
Liu Dafu, Xu Qinfei, Wang Yang, Jia Jia, and Yuan Honghui
The second-generation geostationary orbit (GEO) quantitative remote sensing meteorological satellite had been developed by China. Channels of the satellite′s scanning radiometer are increased from four of 1st generation Fengyun-2 to fourteen, with eight infrared channels covering the infrared band from short band to veThe second-generation geostationary orbit (GEO) quantitative remote sensing meteorological satellite had been developed by China. Channels of the satellite′s scanning radiometer are increased from four of 1st generation Fengyun-2 to fourteen, with eight infrared channels covering the infrared band from short band to very long band. The eight infrared bands are implemented by three assemblies, known as shortwave dual channel assembly (MS-IR), water vapor dual channel assembly (WV-IR) and long wave four-channel assembly (LW-IR). The MS-IR contains two 8 × 1 PV MCT detector chips, corresponding to two CMOS low-temperature amplifiers, to achieve the photoelectric voltage signal conversion and amplification. The WV-IR contains two 4×1 MCT detector chips. LW-IR contains two 4 ×1 and one 4×2 MCT detector chip. These assemblies have good electrical and optical properties, such as MS-IR D* is up to 1×1012 cm·Hz1/2·W-1. WV-IR D* is better than 8×1010 cm·Hz1/2·W-1. The response spectra of these eight bands are quantitatively controlled, and the response spectrum is limited to the inner and outer limits. The small spot scanning system test results show that there was no obvious optical crosstalk inside the assembly. The registration accuracies between the two bands were better than 0.01 mm. In this paper, these assemblies are described, as well as performance, such as electrical performance, chip registration, optical crosstalk and relative spectral response..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 404007 (2018)
Research on cooperative location and tracking approach of infrared guided munition
Zang Luyao, Lin Defu, Yang Zhe, and Wang Wugang
Aiming at the problem that infrared guided missile cannot measure guidance information such as the relative distance, line of sight(LOS) rate and target acceleration directly, the observability of a single missile was less, and the target location error was large, considering the measurement characteristics of infraredAiming at the problem that infrared guided missile cannot measure guidance information such as the relative distance, line of sight(LOS) rate and target acceleration directly, the observability of a single missile was less, and the target location error was large, considering the measurement characteristics of infrared seeker, geometrical relationship among multiple missiles and the target was used to locate the target cooperatively. Multiple missiles cooperative tracking the target model was established. The distance between missiles and the target was estimated by calculating the relative motion between missiles, and it was used as pseudo quantity measurement. The new measurement equation was constructed combined with the angle measurement information of seeker. The relative distance and LOS rate was estimated by Kalman filtering algorithm. Aiming at the maneuvering target, an interactive multiple model filtering cooperative tracking method was studied. The maneuvering model of real target was estimated by weighted fusion of multiple target maneuvering models. Simulation results show that the proposed method can effectively improve the estimation accuracy of the stationary/maneuvering target..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 404008 (2018)
[in Chinese]
Parameters design and simulation of Raman laser optical phase-locked loop
Li Ding, Ma Huijuan, Ru Ning, and Wang Yu
The optical phase-locked loop(OPLL) technology is an effective-method to realize the phase coherent of laser beam. In consideration of the loop filter influence on OPLL, a new method was presented to obtain the optimized parameters of a second order passive loop filter. Firstly, a formula was deduced to design the paraThe optical phase-locked loop(OPLL) technology is an effective-method to realize the phase coherent of laser beam. In consideration of the loop filter influence on OPLL, a new method was presented to obtain the optimized parameters of a second order passive loop filter. Firstly, a formula was deduced to design the parameters according to the definition of phase angle margin and mathematical model of open-loop transfer function. Based on MATLAB software, a parameter optimization algorithm was formulated. Secondly, in order to calculate the parameters of Raman laser optical phase-locked loop precisely, a experiment of Doppler-free absorption spectrum was designed to get the accurate gain parameter from the piezoelectric ceramic to feedback the laser. The overshoot and regulation time of unit step response were about 6.53% and 0.584 ?滋s, respectively, in the systematic performance simulation of closed-loop optical phase-locked system. Finally, by using Simulink tools to establish models and simulating the optical phase-locked loop system module, the lasers′ phase was locked at a high speed with 2 ?滋s. Therefore, the method of OPLL parameters optimization has turned out reasonable. In addition, certain guidelines can be given for the circuit devise of the optical phase-locked loop in engineering applications..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 406007 (2018)
Progress in holographic printing technique
Huang Yingqing, Su Jian, Chen Yibei, Yan Xingpeng, and Jiang Xiaoyu
Holographic printing technique can achieve a true three-dimensional display of the scene well. Based on different sources and different recording methods of interference patterns, holographic printing techniques can be classified as synthetic holographic stereogram printing, computer-generated hologram printing, and waHolographic printing technique can achieve a true three-dimensional display of the scene well. Based on different sources and different recording methods of interference patterns, holographic printing techniques can be classified as synthetic holographic stereogram printing, computer-generated hologram printing, and wavefront printing. Synthetic holographic stereogram printing can′t record the depth information of the three-dimensional scene accurately, so there occurs the vergence-accommodation conflicts during the reconstruction of the hologram. Computer-generated hologram printing can record and reconstruct the depth information of the scene accurately, and solve the vergence-accommodation conflicts. However, the hologram is only a thin transmission hologram which can′t be reconstructed by white light. Wavefront printing can not only solve the vergence-accommodation conflicts, but also achieve a thick reflection hologram for white-light reconstruction with good observation effect. Principles of different holographic printing techniques were introduced, then research status of each technique was analyzed. Finally, the advantages and disadvantages of them were discussed to illustrate their own properties..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 406008 (2018)
[in Chinese]
Quality characteristics and nondestructive test and evaluation technology for laser additive manufacturing alloy steel components (invited)
Xu Binshi, Dong Shiyun, Men Ping, and Yan Shixing
Nondestructive test(NDT) technology is the important technical support for laser additive manufacturing alloy steel components, the key technology to ensure laser additive manufacturing production quality and in-service safety and the important technical composition to the production safety guarantee through life cycleNondestructive test(NDT) technology is the important technical support for laser additive manufacturing alloy steel components, the key technology to ensure laser additive manufacturing production quality and in-service safety and the important technical composition to the production safety guarantee through life cycle. The formation, texture and mechanics properties of alloy steel components made by laser additive manufacturing are different from those made by traditional technologies, so NDT technology faces many challenges. The forming quality characteristics of laser additive manufacturing alloy steel were summarized, including forming flaws and mechanics properties; Based on the development of NDT technologies, the applications of NDT technologies in laser additive manufacturing were reviewed, especially in applications of material mechanics properties and flaws; Based on ultrasonic and micro-magnetic techniques, micro-magnetic sensor design scheme, calibration method and principles of evaluating the material mechanics properties were outlined; Finally, the challenges and prospects of NDT in laser additive manufacturing alloy steel components were discussed.北京市科技计划(Z161100001516007).
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 4, 401001 (2018)
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