Journals >Infrared and Laser Engineering
Contents
2017
Volume: 46 Issue 4
42 Article(s)
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Large-area micro-channel plate photomultiplier tube
Sun Jianning, Ren Ling, Cong Xiaoqing, Huang Guorui, Jin Muchun, Li Dong, Liu Hulin, Qiao Fangjian, Qian Sen, Si Shuguang, Tian Jinshou, Wang Xingchao, Wang Yifang, Wei Yonglin, Xin Liwei, Zhang Haoda, and Zhao Tianchi
According to the requirement of detector in high energy physics and nuclear physics national scientific equipment, the large-area micro-channel plate photomultiplier(MCP-PMT) different from dynode PMT was researched. The large-area MCP-PMT had low-background glass and microchannel plate multiplier. Using Sb-K-Cs as phoAccording to the requirement of detector in high energy physics and nuclear physics national scientific equipment, the large-area micro-channel plate photomultiplier(MCP-PMT) different from dynode PMT was researched. The large-area MCP-PMT had low-background glass and microchannel plate multiplier. Using Sb-K-Cs as photocathode, MCP-PMT enjoyed very high quantum efficiency at 350-450 nm. With double MCPs as electron amplifier, the gain could reach 107. The detection efficiency and single photon detection of large-area PMT was improved. Compared with conventional dynode PMT, this MCP-PMT is a completely new design in structure and has better ratio of spectrum peak to valley, high gain, better anode uniformity, fast response time in single photoelectron detection..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 402001 (2017)
[in Chinese]
Aerosol classification method based on high spectral resolution lidar
Liu Bingyi, Zhuang Quanfeng, Qin Shengguang, Wu Songhua, and Liu Jintao
Aerosols play a key role in climate change and air quality. The quantitative analysis of aerosol′s contribution relies on accurate measurements of aerosol optical properties and their vertical profiles. The High Spectral Resolution Lidar(HSRL) has the capability of spectrally discriminating molecular backscatter from aAerosols play a key role in climate change and air quality. The quantitative analysis of aerosol′s contribution relies on accurate measurements of aerosol optical properties and their vertical profiles. The High Spectral Resolution Lidar(HSRL) has the capability of spectrally discriminating molecular backscatter from aerosol backscatter by a narrow-band optical filter. Therefore aerosol extinction coefficient and aerosol backscatter coefficient can be retrieved independently without assumption of the aerosol lidar ratio.The research on aerosol classification method was conducted based on HSRL technique in this paper. According to published results of aerosol classification, a classification method based on aerosol optical properties was given and an aerosol classification look-up table was provided accordingly. Aerosol extinction coefficient, aerosol backscatter coefficient and depolarization ratio measured by HSRL in Qingdao during the spring of 2015 were used to classify aerosol types referring to the established aerosol classification look-up table. The results are consistent with the trajectory model HYSPLIT and aerosol analysis system NAAPS. Results of case studies demonstrate the method in this paper is capable to identify different aerosol types properly..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 411001 (2017)
Effective absorption for Black Carbon-NaCl internal mixed aerosols
Yin Kaixin, Wang Haitao, and Fan Chengyu
Effective absorption of internal mixed aerosol has severe negative effects on laser transmission in atmosphere. The effective absorption coefficients of homogeneous sphere model, BC-core model and NaCl-core model aerosols, with the same density and specific heat of particle, were discussed by Mie theory. Results show tEffective absorption of internal mixed aerosol has severe negative effects on laser transmission in atmosphere. The effective absorption coefficients of homogeneous sphere model, BC-core model and NaCl-core model aerosols, with the same density and specific heat of particle, were discussed by Mie theory. Results show that effective absorption is associated with comprising method. The BC-core sphere particles mainly show superior effective absorption at short wavelength as visible light and infrared light, homogeneous sphere particles mainly super at mid-infrared wavelength and far-infrared wavelength after 100 μs, while NaCl-core particles mainly show larger effective absorption coefficient at far-infrared wavelength at beginning of heating procedure..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 411002 (2017)
Experimental study of atmospheric dispersion at Xinglong observatory
Xiang E, Wang Huijuan, Xu Kefeng, and Jiang Xiaojun
Atmospheric dispersion affects the observation quality of high-resolution imaging, photometry and spectrometry. It obtained atmospheric dispersion of four bands including 360-440 nm, 360-550 nm, 360-640 nm and 360-790 nm, according five zenith angles including 59.8°, 57.6°, 48.1°, 47.8° and 36.4Atmospheric dispersion affects the observation quality of high-resolution imaging, photometry and spectrometry. It obtained atmospheric dispersion of four bands including 360-440 nm, 360-550 nm, 360-640 nm and 360-790 nm, according five zenith angles including 59.8°, 57.6°, 48.1°, 47.8° and 36.4°, with an 80 cm telescope at Xinglong Observatory. Four main sources of error were discussed in detail, and the accuracy of the measurement was about 0.6″. Based on the zenith angle, the temperature, the humidity and the atmospheric pressure during observation, the theoretical value of atmospheric dispersion was calculated. The results of the calculation and measurement are consistent well with each other. In addition, it discussed the influence factors of atmospheric dispersion and their effect on high precision astronomical observation, and offered solutions for decreasing atmospheric dispersion for large telescope. The calculation and measured results show that: the observation method can achieve adequate precise result; and the effect of atmospheric dispersion is obvious for high-accuracy astronomical observation with large telescope, and corresponding auxiliary equipment is needed to decrease or correct atmospheric dispersion for different observation..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 411003 (2017)
[in Chinese]
Decoding techniques of single-ring absolute photoelectric shaft encoder
Su Xiaogang, Hu Xiaodong, Xiao Maosen, and Zhang Xiaodong
In comparison with incremental and traditional absolute encoder, the single-ring absolute encoder processes more advantage. And the research of decoding system and algorithm are essential to the single-ring absolute encoder. In order to improve single-ring absolute photoelectric encoder′s circuit integration, response In comparison with incremental and traditional absolute encoder, the single-ring absolute encoder processes more advantage. And the research of decoding system and algorithm are essential to the single-ring absolute encoder. In order to improve single-ring absolute photoelectric encoder′s circuit integration, response speed and accuracy, a decoding system was designed in this paper. Linear CCD was used in this system as the disc image receiving and photoelectric conversion device which also provided the basement of subdivision algorithm. And FPGA was used to achieve circuit control and decoding algorithm. A new decoding algorithm was also proposed in this paper. On the one hand, the coding information was achieved by counting high electrical level of the binaryzation signal of CCD′s output. Coding information was obtained by recognition of the disc image and combination of 12-bits coding number. On the other hand, precise value was obtained by calculating the shifting between the centroid of image and virtual center. The centroid of stripe was calculated based on CCD centroid location algorithm. Finally, the value of angle was precisely received from combination of these two values. A prototype of theodolite was developed based on this single-ring absolute encoder decoding system and can reach the accuracy of 2"..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 411007 (2017)
High-precision measurement method and device on diffraction efficiency of Acousto-Optic Tunable Filter based on double-optical-path and cross-references
Qin Xiage, Ji Zhongpeng, Xu Yingyu, and Shu Rong
To adapt to the further requirement of measurement accuracy of slight photo electric signal in the field of modern photoelectric detection technology, high-precision measurement method of diffraction efficiency of Acousto-Optic Tunable Filter (AOTF) was proposed and verified. Light path switchable devices was used to aTo adapt to the further requirement of measurement accuracy of slight photo electric signal in the field of modern photoelectric detection technology, high-precision measurement method of diffraction efficiency of Acousto-Optic Tunable Filter (AOTF) was proposed and verified. Light path switchable devices was used to achieve cross-reference detection, reducing the effect of light source instability, non-uniform response of the detector and photoelectric-jamming, which improved the accuracy of measurement effectively. Firstly, the principle of high-precision measurement of diffraction efficiency of AOTF based on double-optical-path and cross-references was introduced concretely in this paper. Experiments were performed to testify the accuracy of this method. Experimental results indicate that the diffraction efficiency measurement accuracy is improved 50 percent averagely by using cross-references approach. The proposed method has a significance to reduce the influence of source instability and response difference in detectors, and improve high-precision measuring. Finally, the range of application and referential meaning of this method were also discussed and analyzed..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 417001 (2017)
Accurate optical parameters measurement of different optical path in the terahertz range
Ji Beibei, Li Zhaoxin, Zhou Wei, Song Binbin, Guo Xiangshuai, and Li Dehua
In the past two decades, with the rapid development of the terahertz science and technology, the interaction between terahertz pulse and material has attracted much more scientific interest. In this paper, an accurate optical parameters extracting method was theoretically derived and experimentally demonstrated, a HDPEIn the past two decades, with the rapid development of the terahertz science and technology, the interaction between terahertz pulse and material has attracted much more scientific interest. In this paper, an accurate optical parameters extracting method was theoretically derived and experimentally demonstrated, a HDPE sample was measured by two similarly experimental scheme with terahertz time-domain spectroscopy. To compare the results of the regular method and the different optical path (DOP) method, the refractive index and the absorption coefficient from 0.5-2.5 THz were obtained, respectively, and the results show that the refractive index and the absorption coefficient of measured sample are quite different. The refractive indexes obtained by regular method and DOP method are 1.505 and 1.483 respectively. The absorption coefficient measured by the regular method has a peak in 1.465 THz, while DOP method′s absorption coefficient has two peaks both in 1.166 THz and 2.431 THz. The different optical path method can reveal the absorption peak of the materials which can′t be revealed by the regular method, and provide a more precious measurement of material optical parameters..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 417002 (2017)
EKF-based scaling factor identification for strap-down seeker
Wang Wei, Ji Yi, Shi Zhongjiao, Lin Defu, and Lin Shiyao
Based on extended Kalman filter(EKF), a scaling factor(SF) identification method for strap-down seeker(SS) was proposed. First, a nonlinear model for SS system was set up under proportional guidance(PNG) law. Then, the extended Kalman equations were deduced on this nonlinear model, and it should be linearized at the vaBased on extended Kalman filter(EKF), a scaling factor(SF) identification method for strap-down seeker(SS) was proposed. First, a nonlinear model for SS system was set up under proportional guidance(PNG) law. Then, the extended Kalman equations were deduced on this nonlinear model, and it should be linearized at the value of EKF estimated based on Taylor expansion. At last, actions of this method on how to keep guidance system stability were studied under above conditions. According to mathematic simulation results, in this way, the SSSF could be estimated accurately and quickly, and the tolerable SSSF error scope of guidance system stability is extended, the robustness of system is promoted..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 417003 (2017)
Binary spatiotemporal encoded method used for uneven fringes phase unwrapping
Ji Hongbin, Zhang Huibo, Dai Shijie, and Wang Zhiping
A binary spatiotemporal encoded method for uneven fringes phase unwrapping was proposed to remove the limitation of the existing non - uniform striped phase unwrapping method. From the standard non-uniform stripes cut off the phase reverse to cut off the phase line, the boundary line for binary coding and decoding.By uA binary spatiotemporal encoded method for uneven fringes phase unwrapping was proposed to remove the limitation of the existing non - uniform striped phase unwrapping method. From the standard non-uniform stripes cut off the phase reverse to cut off the phase line, the boundary line for binary coding and decoding.By using four step phase shifting method, the absolute phase of deformed uneven fringes can be obtained with three pieces of aided coding patterns. The nonholonomic system was established, and the relationship between the absolute phase and the depth of the object was fitted by quadratic polynomial. Compared with existing methods in simulation environment, the improved amount of average and standard deviation of all symmetric points height difference of arch object are 65% and 51% respectively. The improved amount of average and standard deviation for arch cuboid are 95% and 90% respectively. At the same time, the method is used to measure the surface of the rectangular object, which average error is only 0.64%, compared with the measurement results of the Coordinate Measuring Machine(CMM). The experimental results show that the method can improve the quality of uneven fringes phase unwrapping, and improve the measurement accuracy under the condition that the number of aided coding pattern is not increase..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 417004 (2017)
Novel approach for high-precision measurement of micre refractive index difference of two transparent mediums
Wu Ting, Zou Yan, Li Zhitong, Hui Yongling, and Li Qiang
A novel method to measure the refractive index distribution of two transparent mediums was proposed in this paper after analyzing measure methods of refractive indexes in existence. The basic principle and interferometry method of the measurement of micro refractive index change between two transparent mediums were desA novel method to measure the refractive index distribution of two transparent mediums was proposed in this paper after analyzing measure methods of refractive indexes in existence. The basic principle and interferometry method of the measurement of micro refractive index change between two transparent mediums were described, and the theoretical feasibility of this measurement method was studied by using Zemax optical simulation software. Firstly, in this experiment, a composite plate from two transparent mediums to be measured was prepared by adhere-free bonding technology. Secondly, the optical path difference caused by the refractive index difference in the bonding interface was measured with the help of interferometer, under the different splitting angles of the composite plate. And then, the relational expression between the refractive index distribution and the optical path difference was deduced by using the law of refraction in geometrical optics. At last, the micro difference value of the optical path difference for normal incidence was obtained by conic approach technique in dealing with measuring data, and thus the final result of refractive index difference between two transparent mediums was obtained according to the conversion expression. The measured value of refractive index difference of a 1 at. % Yb3+: YAG/YAG bonded sample was also gotten and the value was 5.41×10-5, thus the accuracy of measurement system was up to 10-7 magnitude. The experiment result shows that the measurement method is simple, easy operation and has high precision..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 417005 (2017)
Extracting scattering characteristic from photoelectric/IR reconnaissance satellites targets
Gong Junbin, and Ding Fan
Satellites targets scattering characteristics is the basis of the monitoring, identification and striking for the military objectives, the scattering characteristic controlling is also the important part of system design for satellites. Firstly, the boundary conditions of photoelectric reconnaissance satellites configuSatellites targets scattering characteristics is the basis of the monitoring, identification and striking for the military objectives, the scattering characteristic controlling is also the important part of system design for satellites. Firstly, the boundary conditions of photoelectric reconnaissance satellites configuration was determined, based on the threat of satellites facing and the load characteristics of satellites loading, the composition and character of the complicated satellites′ scattering construction were analyzed. The scattering characteristic of typical satellites target was simulated by SBR method, PO method and EEC method on different frequency and angle. The Defense Support Program was taken as an example to build the structure mesh model, electromagnetic simulation model. Based on the scattering simulation conclusion of DSP model for frequency, polarity and incidence angle, the scattering characteristic of photoelectric/IR reconnaissance satellites targets was extracted. The scattering highlights and stealth improvement suggestions were given, which could be used to guide the target detection and stealth design for satellites targets..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 417006 (2017)
[in Chinese]
Development of high precision temperature control device for large aperture frequency doubling crystal
Liu Baolin, Zhang Peng, Sun Fuzhong, Zhang Qingchun, and Lu Lihua
In noncritical phase matching condition, it is necessary to precisely control the stability and uniformity of the crystal temperature in full aperture. A device using resistive heater to control the temperature of the large aperture crystal was introduced. Taking full account of the low thermal conductivity and large aIn noncritical phase matching condition, it is necessary to precisely control the stability and uniformity of the crystal temperature in full aperture. A device using resistive heater to control the temperature of the large aperture crystal was introduced. Taking full account of the low thermal conductivity and large aperture of the crystal, it was heated by thermal conduction and the natural convection of the inner air, which was heated up at the same time for temperature balancing. The characteristics of temperature distribution of the device were studied. Through experiments and simulations analysis, it was found that the crystal temperature of steady state and the necessary heating time varied with the heating length and the thermal conductivity of the crystal material. The result shows the practicability of the thermal control of the crystal with the aperture of Φ80 mm. The temperature difference of the crystal, in steady state, could be controlled within ±0.15°C..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 420001 (2017)
Study on connected defective elements in focal plane array identification by response and crosstalk
Hou Zhijin, Fu Li, Wang Wei, Lv Yanqiu, Lu Zhengxiong, and Wang Jinchun
The connected defective elements in Focal Plane Array (FPA) were tested by optical microscopy and FPA test-bench. The reasons of forming connected defective elements in FPA were studied. Results show that it is difficult to identify connected defective elements by optical microscopy. And it is also difficult to identifThe connected defective elements in Focal Plane Array (FPA) were tested by optical microscopy and FPA test-bench. The reasons of forming connected defective elements in FPA were studied. Results show that it is difficult to identify connected defective elements by optical microscopy. And it is also difficult to identify connected defective elements by FPA response testing bench because the response voltage of connected defective elements is basically the same as that of normal elements. The connected defective elements can be identified effectively by FPA crosstalk testing bench because the crosstalk between connected defective elements is 100%, which is obviously different from that of the normal elements. At this point, the response voltage of connected defective elements is average of that of the normal elements. The tables with connecting or the electrodes with connecting caused by the process of photolithography and eroding result in the generation of the connected defective elements. As well as the indium bump with connecting caused by the process of photolithography and lift-off also leads to the generation of the connected defective elements. Fabrication process such as photolithography, eroding and lift-off was optimized to reduce connected defective elements..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 420002 (2017)
Terahertz refractive index sensing of microfluid based on metamaterials
Zheng Wei, Fan Fei, Chen Meng, Bai Jinjun, and Chang Shengjiang
A metamaterial device was designed and fabricated for microfluidic sensing in the terahertz regime, its transmission, resonance and sensing properties were numerically simulated in terms of the Finite Difference Time Domain(FDTD). The influence of polarization direction on the sensitivity of sensor was experimentally iA metamaterial device was designed and fabricated for microfluidic sensing in the terahertz regime, its transmission, resonance and sensing properties were numerically simulated in terms of the Finite Difference Time Domain(FDTD). The influence of polarization direction on the sensitivity of sensor was experimentally investigated by terahertz time-domain spectroscopy system. The experimental result shows that when the resonant metamaterial ring opening direction is parallel and perpendicular with the direction of polarization of the incident THz wave, the refractive index sensing sensitivity can reach 39.29 GHz/RIU and 74.43 GHz/RIU, respectively. The transmission and resonance characteristics of the metamaterials are analyzed by the equivalent circuit model to further clarify the sensing mechanism. This THz metamaterial device has the potential applications in sensing chemical and biological component because it is capable of realizing the refractive index sensing of microliquid (5 μl/mm2) with a high sensitivity..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 420003 (2017)
Development of 0.1 THz finline fundamental single-balanced mixer circuit
Yang Dabao, Wang Junlong, Zhang Lisen, Xing Dong, Liang Shixiong, Zhao Xiangyang, and Feng Zhihong
This design, fabrication and test of a 0.1 THz fundamental finline single-balanced mixer circuit on a single quartz substrate was presented. The local oscillator(LO) input signal was feeded from WR10 waveguide to a suspended microstrip line, the radio frequency(RF) input signal was also feeded from WR10 waveguide to a This design, fabrication and test of a 0.1 THz fundamental finline single-balanced mixer circuit on a single quartz substrate was presented. The local oscillator(LO) input signal was feeded from WR10 waveguide to a suspended microstrip line, the radio frequency(RF) input signal was also feeded from WR10 waveguide to a finline, and the intermediate frequency(IF) signal was taken to the output port through a LO-IF duplexer. This novel mixer circuit can omit a complex W-band filter compared to traditional mode. The circuit features simple design and easy assemblage. A pair of flip-chipped diodes rested on the 75 μm thick quartz substrate, which could improve the size precision of circuit, constitute the basic balanced mixing circuit. After the mixer circuit is fabricated, it owns a 90-110 GHz operating frequency, and its single side band conversion loss is better than 9 dB when the IF is fixed at 50 MHz..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 420004 (2017)
Imaging simulation and error analysis of large field of view airborne infrared scanner
Ye Sirong, Jiang Wanshou, Li Jinlong, and Liu Xiaobo
To analyze the effect of the system error on a large field of view infrared multispectral scanner, and provide the basis for determining calibration program, airborne infrared scanner imaging simulation was completed by using strict imaging model. For the un-coincidence of camera projection center and the rotation centTo analyze the effect of the system error on a large field of view infrared multispectral scanner, and provide the basis for determining calibration program, airborne infrared scanner imaging simulation was completed by using strict imaging model. For the un-coincidence of camera projection center and the rotation center of stable platform, the relationship between camera placement errors and POS system placement errors was focused on. Simulation results show that the effect of camera placement errors and POS system placement errors on the positioning accuracy are basically the same, there is a strong correlation between the two but it decreases with the sweep angle increases; when the sweep amplitude is less than 20°, the camera placement error can be incorporated into the POS system placement errors. This conclusion can provide reference for later calibration program design..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 420005 (2017)
[in Chinese]
Method of preprocessing and phase correction for photo-elastic modulated interferograms
Zhang Minjuan, Bi Manqing, Hao Qian, Wang Zhibin, and Li Shan
Interferograms in the photo-elastic modulator Fourier transform spectrometers（PEM-FTS)has high modulation frequency, and its modulated optical path difference is continuous nonlinear. In order to improve the accuracy and stability of the rebuilt spectrums whose interferograms is sampled by the equal time intervals, it Interferograms in the photo-elastic modulator Fourier transform spectrometers（PEM-FTS)has high modulation frequency, and its modulated optical path difference is continuous nonlinear. In order to improve the accuracy and stability of the rebuilt spectrums whose interferograms is sampled by the equal time intervals, it is necessary to study the technology of pretreatment and phase correction of photo-elastic modulated interferograms. In the paper, the characteristic that the amplitude of the zero optical path difference was maximum in a interferogram were used to derive these data of a interferogram. Simultaneously, the method which combined the improved Mertz method and the accelerated nonuniform fast Fourier transform algorithm (NUFFT) was put forward to resolve the asymmetric and to improve the velocity and precision of the rebuilt spectrum. In the experiment, the asymmetrical photo-elastic modulated interferograms of 300 K infared blackbody were generated by simulation, the data processing algorithm was applied to enhance the accuracy of the rebuild spectrum, and the atmosphere spectral curve was rebuilt and gas components were qualitative analyzed with the atmosphere window as the measured object..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 423001 (2017)
[in Chinese]
Analysis of the effect of light spot size and ray axis deflection on heterodyne efficiency of space optical hybrid
Nan Hang, Zhang Peng, Tong Shoufeng, Ma Tingting, Tong Guangheng, Cao Haishuai, and Fan Xuebing
Effect of light spot size and optical axis deflection on heterodyne efficiency of space optical hybrid was focused on in this paper. With deduction of the heterodyne efficiency expression based on Gaussian model, the result shows that when the proportion of the light spot size and target plane equals 0.64, the heterodyEffect of light spot size and optical axis deflection on heterodyne efficiency of space optical hybrid was focused on in this paper. With deduction of the heterodyne efficiency expression based on Gaussian model, the result shows that when the proportion of the light spot size and target plane equals 0.64, the heterodyne efficiency reaches optimal. Then by calculating and simulating the expressions which included spot size deviation and optical axis deflection, the curve of relation between heterodyne efficiency and spot size deviation and optical axis deflection was obtained. By these works several results can be shown: Firstly, the scope of spot size deviation is between -42 μm and 250 μm and the scope of axis deflection is 203 μrad when heterodyne efficiency is 10%. Besides, by calculating the spot size deviation and comprehensive optical axis deflection error, negative influence of heterodyne caused by axis error can be improved with modulating the light spot size deviation. In order to test the theoretical result, an experimental platform of influence factor of spatial optical hybrid was built up and an experiment of deflection angle of optical axis with choosing three light spot sizes was implemented. The result is consistent with that of the simulation. The curves of actual measurement are slightly less than the theoretical value because of the influence of insertion loss caused by experiment components. These influence obtained may provide technical reference for the design, adjustment and process of spatial optical hybrid..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 422001 (2017)
Single multi-mode fiber digital scanning imaging method
Liu Guodong, Yin Zhe, Liu Bingguo, Lu Binghui, Wei Fupeng, Zhuang Zhitao, Gan Yu, Chen Fengdong, and Zhang Daquan
For the problem of large computation and slow speed to generate the focused spots in the multimode fiber digital scanning imaging method, the digital scanning imaging method with a single multi-mode fiber (MMF) was proposed based on adaptive parallel coordinate(APC) algorithm. By controlling the input field of the MMF,For the problem of large computation and slow speed to generate the focused spots in the multimode fiber digital scanning imaging method, the digital scanning imaging method with a single multi-mode fiber (MMF) was proposed based on adaptive parallel coordinate(APC) algorithm. By controlling the input field of the MMF, the focused spots were formed. The theoretical imaging model of single MMF digital scanning was established. APC algorithm was adopted to optimize the phase on the spatial light modulator(SLM), which can effectively reduce the time to form focused spots and improve the imaging speed. 30×30 focused spots were formed to sample the resolution target in 50 μm×50 μm region. The experiment demonstrates that the object on the sample plane 60 μm far from the MMF output end can be reconstructed. The resolution is 2.46 μm..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 422002 (2017)
Study of pattern recognition based on SVM algorithm for φ-OTDR distributed optical fiber disturbance sensing system
Zhang Junnan, Lou Shuqin, and Liang Sheng
Currently, phase sensitive optical time-domain reflectometer (φ-OTDR) distributed optical fiber sensing system is difficult to accurately determine current position of disturbance and distinguish the model of disturbance effectively. A method was proposed based on support vector machine (SVM) which can accurately distiCurrently, phase sensitive optical time-domain reflectometer (φ-OTDR) distributed optical fiber sensing system is difficult to accurately determine current position of disturbance and distinguish the model of disturbance effectively. A method was proposed based on support vector machine (SVM) which can accurately distinguish disturbance and the model of disturbance. With the technique of the binary tree, a categorizer based on SVM was set up by extracting the various signal characteristics of the mean, the variance, the mean square deviation and energy of the time- domain and frequency-domain. Thus the disturbance and disturbance mode can be distinguished. In terms of the sensing signal feature, the categorizer I was determined if the sensing signals was disturbance signals or not firstly. Then, mode of disturbance can be recognized by the following categorizers. Experiments were carried out to validate the proposed method by 600 groups of data. The correct discrimination rate is better than 96%. The rate of missing report and the rate of false positives is less than 4%. The rate of correct pattern recognition is greater than 94%..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 422003 (2017)
Monte Carlo simulation on channel characteristics of underwater laser communications
Huang Aiping, Zhang Yingluo, and Tao Linwei
The channel characteristics were investigated for underwater laser communications based on Monte Carlo simulation method. Using the blue-green laser with wavelength 532 nm, the impulse response of link was discussed both in theorem and simulation. Also the channel parameters such as the water type, attenuation length, The channel characteristics were investigated for underwater laser communications based on Monte Carlo simulation method. Using the blue-green laser with wavelength 532 nm, the impulse response of link was discussed both in theorem and simulation. Also the channel parameters such as the water type, attenuation length, divergence angle, beam width, received field-of-view(FOV), received aperture were taken into account. Monte Carlo simulation experiment was verified. Simulation results suggest that in clear water, the channel can effectively be considered as non ISI when working distance less than 40 m. Therefore, it practically did not need to perform computationally complex signal processing at the received end. However, in harbor water, the channel delay spread enlarged with larger received FOV or divergence angle, and the data transmission efficiency was reduced. When the attenuation length was smaller than the diffused length, the received intensity decreased with received aperture enlarged. In contrast, the received intensity enhances with larger received aperture at the small FOV, however, they trend to similar regardless of the apertures at large FOV. Therefore, the results give us some insight in terms of what constitutes an accurate underwater laser communication channel..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 422004 (2017)
[in Chinese]
Real-time correction of dynamic thermal differential of supersonic conformal optical system
Li Yanzhang, Huang Changchun, Zhang Yunqiang, Niu Yajun, Song Dalin, and Chang Jun
With the development of science and technology, there are more and more high requirements of imaging quality for high speed aircraft. The effect of friction heating on imaging quality of supersonic speed system with a conformal dome was studied. An conformal optical system with a conformal dome which had a length-to-diWith the development of science and technology, there are more and more high requirements of imaging quality for high speed aircraft. The effect of friction heating on imaging quality of supersonic speed system with a conformal dome was studied. An conformal optical system with a conformal dome which had a length-to-diameter ratio of 1 was designed. The system had two wedge mirrors for field scanning, which provided a instantaneous FOV of 4° and a scanning FOV of 60°. A conformal fairing aerodynamic simulation experiment with the speed of Mach 3 and attack angle of 0° was finished. The surface temperature distribution of conformal dome in supersonic speed was obtained. Through the fluid-solid interaction, surface variation of different periods was calculated. The thermal surface variation was fitted into Zernike coefficients and applied to conformal optical system. The analysis results showed that the dynamic aberration introduced by high speed flight affected the imaging quality of optical system. In order to guarantee the system precision, a Spatial Light Modulator (SLM) was used to correct the aberration of different periods. After correction, system imaging quality was close to the diffraction limit, which had realized thermal aberration correction of conformal dome in supersonic speed flight. This study has certain significance to the development of high precision aircraft..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 418001 (2017)
[in Chinese]
Antireflective silicon based microstructures for the mid- and long-wavelength infrared
Wu Qihua, Xiong Min, Huang Yong, Zhang Baoshun, and Bai Yu
Si based micro-pillar arrays and micro-cone arrays were fabricated using micro processing technology, the reflection performance of the micro structures was studied in the long wave infrared wavelengths (2.5-9 μm) reflection performance of different polarized light. Micro-fabrication combined with modeling analysis of Si based micro-pillar arrays and micro-cone arrays were fabricated using micro processing technology, the reflection performance of the micro structures was studied in the long wave infrared wavelengths (2.5-9 μm) reflection performance of different polarized light. Micro-fabrication combined with modeling analysis of silicon based micro-pillar and micro-cone arrays have been performed to study the effects of structural parameters on the reflectivity of infrared light from 2.5-9 μm. Simulation results using rigorous coupled wave analysis (RCWA) method is in line with the test results from a Fourier transform infrared spectrometer (FTIR). It is found that the antireflection characteristics can be obtained for both transverse electric(TE) and transverse magnetic(TM) polarizations, and the micro-cone arrays have lower reflectivity than the micro-pillar arrays. Moreover, the optimized micro-cone arrays show a reflectivity of only 2% or lower from 2.5-6.5 μm under TM polarization, with wide-spectrum and omnidirectional antireflection characteristics..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 404001 (2017)
Calculation method of shrouded radar target surface temperature field
Chen Shan, Ma Junchun, Liu Chaohui, and Wang Zhong
A method of shrouded radar target surface temperature field calculation was proposed in this paper, in allusion to the important strategic position of radar target during military attack. Firstly, the structural characteristic of radar target was analyzed, based on which radar target was simplified into spheroid. SeconA method of shrouded radar target surface temperature field calculation was proposed in this paper, in allusion to the important strategic position of radar target during military attack. Firstly, the structural characteristic of radar target was analyzed, based on which radar target was simplified into spheroid. Secondly, radar target three-dimensional temperature field model was established, including building heat balance equation in spherical coordinates, analyzing boundary conditions, establishing thermal equilibrium model. Finally, through simplifying the surface temperature field model and the boundary condition of the radar target, target surface temperature field was obtained by solving the temperature field model, and a method based on reduced dimension finite difference iterative was proposed. The experimental results show that the calculated distribution of temperature field and the generated infrared simulation images accorded with actual situation, and temperature variation was consistent with the actual, so the temperature field model established and solution method were feasible, which provided basic parameters and theoretical basis for further study on the target infrared radiation characteristics..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 404002 (2017)
Circuit and optical system design for high frame rate DMD infrared scene simulation equipment
Zhang Yingxin, Wang Yunping, and Hou Junyan
To improve the application question of the timing synchronization, high frame rate display and optical match caused by infrared scene simulation equipment based on DMD in the hardware-in-the-loop simulation test, a novel infrared scene simulation equipment based on DMD which can match application with several kinds of To improve the application question of the timing synchronization, high frame rate display and optical match caused by infrared scene simulation equipment based on DMD in the hardware-in-the-loop simulation test, a novel infrared scene simulation equipment based on DMD which can match application with several kinds of common infrared staring imaging system was designed and constructed. Firstly, the scheme of synchronization delay driving and the scheme of display control were proposed. The synchronization signal processing circuit and the driving circuit were designed and developed, the timing synchronization and high frame rate display were realized. Then, according to parameters of optical system of several kinds of common infrared staring imaging system which will be tested, the lighting optical system and the projection optical system were designed, developed and simulated, optical match with several kinds of common infrared staring imaging system was realized. Test results indicate that the equipment can realize timing synchronization and optical match between the equipment and several kinds of common infrared imaging system, the frame rate of the simulation image is 300 Hz, the maximum simulation temperature of the simulation image is 160 ℃, the minimum simulation temperature of the simulation image is 0.03 ℃, the maximum contrast of the simulation image is 0.7, the nonuniformity of the simulation image is 1%, the equipment play a key role in a large number of hardware-in-the-loop simulation tests..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 404003 (2017)
Non-uniformity correction in polarization imaging obtained with integrated microgrid polarimeters
Peng Yong, Feng Bin, Shi Zelin, Xu Baoshu, and Hui Bin
Traditional non-uniformity correction algorithm cannot correct the non-uniformity of polarization images, therefore a matrix correction algorithm was proposed. Firstly, the mechanism and imaging performance of non-uniformity in integrated microgrid polarimeters were presented. Then the difference of non-uniformity betwTraditional non-uniformity correction algorithm cannot correct the non-uniformity of polarization images, therefore a matrix correction algorithm was proposed. Firstly, the mechanism and imaging performance of non-uniformity in integrated microgrid polarimeters were presented. Then the difference of non-uniformity between the polarization image and traditional image was illustrated and the reasons for the failure of traditional methods were analyzed. By constructing a model of polarization imaging system in response to the incident polarized light source, the matrix correction algorithm was further proposed. After that, experiments gave the correction effects of polarization flatfiled images and scene images containing rich details. A quantitative analysis of experimental results proves that our matrix correction algorithm reduces the non-uniformity of flatfiled images to about 10%..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 404004 (2017)
Experimental investigation of infrared suppressing characteristics of different nozzles
Zhang Bo, Li Jinjing, Yuan Shuai, and Ji Honghu
Three different convergent nozzles(axis symmetrical, rectangular, and S -curved)with the same inlet, outlet areas and lengths, the radiation characteristics in different detecting planes of which were experimentally investigated. The results show that in the horizontal plane, the thermal radiation intensity of three noThree different convergent nozzles(axis symmetrical, rectangular, and S -curved)with the same inlet, outlet areas and lengths, the radiation characteristics in different detecting planes of which were experimentally investigated. The results show that in the horizontal plane, the thermal radiation intensity of three nozzles all decreased with the increase of detecting angle, the S-curved nozzle has the best infrared suppressing characteristics; in the vertical plane, the S-curved nozzle also has the best infrared suppressing characteristics. While being detected from upwards, the intensity of S-curved nozzle increased first then decreased with the increase of angle, and the largest radiation magnitude appeared in the detecting angle 10°. Compared with the axis nozzle, the thermal radiation intensity of rectangular and S-curved nozzles decreased in turn. In the direction of right behind the nozzles, the thermal radiation of rectangular and S-curved nozzles decreased by 33.2% and 80.2% separately, compared with the axis nozzle..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 404005 (2017)
[in Chinese]
Design of steady-state magnetic field and effect of current intensity on microstructure of Fe55 alloy coating by laser cladding
Liu Hongxi, Liu Zifeng, Zhang Xiaowei, Shi Hai, and Jiang Yehua
Using self-designed steady-state magnetic field device, combined with laser cladding process, by adjusting current intensity to obtain corresponding steady-state magnetic field and put the magnetic field on laser molten pool, Fe55 alloy coatings was fabricated on 45 substrate steel surface. The microstructure, chemicalUsing self-designed steady-state magnetic field device, combined with laser cladding process, by adjusting current intensity to obtain corresponding steady-state magnetic field and put the magnetic field on laser molten pool, Fe55 alloy coatings was fabricated on 45 substrate steel surface. The microstructure, chemical composition and phase characteristics of the cladding coatings were characterized by scanning electron microscope(SEM), energy disperse spectroscopy(EDS) and X-ray diffraction (XRD). The results show that Fe55 alloy coating is mainly composed of γ-(Fe, Cr) solid solution, (Fe, Ni) solid solution, (Cr, Fe)23C6 carbide and a small amount of Cr9.1Si0.9. The interdendritic Cr element content in laser cladding Fe55 alloy coating with steady-state magnetic field is higher than that of the laser cladding without magnetic field, and dendrite internal Fe element content also increased. To a certain extent, the steady-state magnetic field can promote the mass transfer process in laser melten pool, which is beneficial to the diffusion of Fe, Cr elements and the formation of (Fe, Cr) solid solution. When the current intensity is 4.0 A, steady-state magnetic field greatly reduces the temperature gradient of solid-liquid interface in laser molten pool, and increases the nucleation rate in liquid metal molten pool. A large number of columnar dendrites and dendritic crystals are changed into directions different equiaxed grains in coating, and the microstructure of Fe55 alloy coating has been significantly optimized..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 406001 (2017)
Effect of subsurface impurities of fused silica on laser induced damage probability
Gao Xiang, Qiu Rong, Zhou Guorui, Yao Ke, Jiang Yong, and Zhou Qiang
Based on Mie theory and heat equation, combined with the measurement of the main components for impurities on the subsurface of fused silica by ICP-OES, a model for calculating laser-induced damage probability on the surface of optical components by absorbing impurities was presented. Based on this theoretical model, tBased on Mie theory and heat equation, combined with the measurement of the main components for impurities on the subsurface of fused silica by ICP-OES, a model for calculating laser-induced damage probability on the surface of optical components by absorbing impurities was presented. Based on this theoretical model, the critical fluence required to initiate damage by various impurities as a function of particle radius and the damage probability on the surface of fused silica induced by the impurities with different distribution were investigated. The damage probability on the surface of fused silica was measured under the irradiation of 355 nm laser with different beam sizes. Comparison of the calculated and experimental results was conducted. The contribution to laser-induced damage probability for these three impurities was analyzed (Cu>Al>CeO2) with same particle distribution parameters. Through the model, the effect of various potential absorbing impurities embedded in the subsurface of optical substrates or films on damage probability can be analyzed..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 406002 (2017)
Study on thermal effect and compensation technology of 0.53 μm all-solid-state laser
Wang Lei, Nie Jinsong, Ye Qing, and Hu Yuze
Based on the application prospect of 0.53 μm and 1.06 μm dual-wavelength composite output technology in military affairs, the thermal effect of all-solid-state dual-wavelength composite output laser was studied. Using Poisson heat conduction theory with more accurate boundary conditions, the formation process of thermaBased on the application prospect of 0.53 μm and 1.06 μm dual-wavelength composite output technology in military affairs, the thermal effect of all-solid-state dual-wavelength composite output laser was studied. Using Poisson heat conduction theory with more accurate boundary conditions, the formation process of thermal lens effect and thermal induced phase-mismatch was simulated and analyzed under the conditions of three LD side-pumping and intracavity frequency-doubling. Effectiveness and general regularity of the plano-convex cavity compensation were then analyzed. Through the experiment, the influence of thermal effect on the beam quality of dual-wavelength laser was explored. Compensation effect of plano-convex cavity on thermal effect was verified. It shows that the quality of composite laser beam improves with larger fundamental mode volume and lower higher-order mode gain in plano-convex cavity. The thermal effect compensation will be enhanced with the decrease of the curvature radius of the plano-convex lens compensation..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 406003 (2017)
Highly stable compact intra-cavity continuous-wave optical parametric oscillator
Li Yuxin, Li Shifeng, Ju Panpan, Zhao Gang, Lv Xinjie, and Qin Yiqiang
An Intra-cavity Continuous-Wave Optical Parametric Oscillator(IC-OPO) was developed in order to resolve problems inherent in IC-OPO such as instability of output power, long-lived bursts of relaxation-oscillations, etc. First, compensative design of thermal lens effect was devised to improve pattern matching. Second, aAn Intra-cavity Continuous-Wave Optical Parametric Oscillator(IC-OPO) was developed in order to resolve problems inherent in IC-OPO such as instability of output power, long-lived bursts of relaxation-oscillations, etc. First, compensative design of thermal lens effect was devised to improve pattern matching. Second, an aperture slot was used to suppress the oscillations of high-order transverse mode. Finally, by placing a KTP crystal in the cavity for the purpose of SHG, the relaxation oscillation was suppressed by nonlinear loss. After these improvements, the compact tunable infrared to mid-infrared(2.2-4.2 μm) continuous source with high-stability was obtained. The amplitude stability of output power is 0.52%(RMS) and peak-to-peak amplitude stability is less than ±1.8%. The beam quality M2 is 1.72. Especially, a series of observations show that the relaxation-oscillation is suppressed effectively. Without KTP crystal, the threshold (808 nm) is as low as 1.5 W..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 406004 (2017)
Laser fuze anti-surf based on two-wavelength detection
Xie Shaoyu, Zhao Yiqiang, Wang Jinhua, and Jia Xiaodong
Two-wavelength laser fuze detection principle was expounded and a new technical approach was invented for laser fuze anti-surf and target-recognition by the character of echo between infrared and blue-green laser was different observably when two-wavelength laser exposured sea and the character of echo between infraredTwo-wavelength laser fuze detection principle was expounded and a new technical approach was invented for laser fuze anti-surf and target-recognition by the character of echo between infrared and blue-green laser was different observably when two-wavelength laser exposured sea and the character of echo between infrared and blue-green laser was similar when two-wavelength laser exposured the target. Laser transmitter system of two-wavelength laser fuze transmitted two kinds band laser of infrared and blue-green at same time, receiving system received echo signal of two kinds band by two detectors, information processing system acquisited echo signal with high-speeds and realtime to acquire the range, pulse width and laser echo ratio and so on, using this information to distinguish sea and target. The prototype of two-wavelength laser fuze was designed, and the different objectives test in the sea by the prototype was done. The result of test show that the effect of two-wavelength laser fuze anti-surf is favourable..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 406005 (2017)
Properties of laser-induced acoustic signals transmission in liquid
Li Shengyong, Wu Ronghua, Wang Xiaoyu, Wang Jiang′an, and Zong Siguang
In order to understand the transmission properties of laser-induced acoustic in liquid, the transmission properties of laser-induced acoustic were analyzed theoretically, and the experimental research on the laser-induced acoustic was carried out by using high speed camera and fiber MEMS hydrophone. Wavelet transform wIn order to understand the transmission properties of laser-induced acoustic in liquid, the transmission properties of laser-induced acoustic were analyzed theoretically, and the experimental research on the laser-induced acoustic was carried out by using high speed camera and fiber MEMS hydrophone. Wavelet transform was used to analyze the spectrum characteristics of the laser-induced acoustic signals at different locations. The results show that the laser-induced acoustic is a pulsating source, amplitude and distance are inversely proportional in the process of laser acoustic signal transmission; laser acoustic analysis of band memory has obvious dominant frequency, with peak frequency stability of 3.1 kHz and bandwidth stability of 3 kHz; low frequency signal energy accounted for more than 70% of the total energy, high frequency part is mainly noise; from the power spectrum waveform analysis, low frequency signal amplitude with time and distance attenuation is slower, and high frequency noise with time and distance transform decays faster..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 406006 (2017)
Laser jamming experiment of varifocal colour CCD imaging system
Tang Wei, Wang Rui, Wang Tingfeng, and Guo Jin
Out-field laser jamming experiment of varifocal colour CCD imaging system irradiated by semiconductor laser was done. Laser jamming effects of colour CCD imaging system with different focal lengths were measured. Laser jamming model was set-up, and theoretical proving and analysis on experimental results were completedOut-field laser jamming experiment of varifocal colour CCD imaging system irradiated by semiconductor laser was done. Laser jamming effects of colour CCD imaging system with different focal lengths were measured. Laser jamming model was set-up, and theoretical proving and analysis on experimental results were completed. Theorical and experimental results show that laser jamming effect of colour CCD imaging system irradiated by 750 nm laser is obvious, and CCD surface appears obvious light saturation and crosstalk phenomena. In the same initial laser irradiating conduction, laser power truncated by the aperture gradually decreases with increase of focal length f, and light saturation area on the CCD surface gradually increases. When focal length f of colour CCD imaging system is 17 mm, light saturation area on the CCD surface is 0.33 mm×0.29 mm. While focal length f of colour CCD imaging system increases to 120 mm, light saturation area on the CCD surface is 1.8 mm×1.2 mm. Simulation results are coincident with experimental results, and it proves laser jamming model is correct. The conclusions have a reference value for colour CCD in the practical application..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 406007 (2017)
Laser truing and sharpening of bronze-bond diamond grinding wheel
Cai Song, Xiong Biao, Chen Genyu, and Wu Jiping
A heat transfer model for pulse laser ablation of a bronze-bond diamond grinding wheel was built by considering the effects of evaporation, plasma shielding, and energy accumulation under the pulse interval. The model was applied for numerical simulation of the heat transfer characteristics in the pulse laser ablation A heat transfer model for pulse laser ablation of a bronze-bond diamond grinding wheel was built by considering the effects of evaporation, plasma shielding, and energy accumulation under the pulse interval. The model was applied for numerical simulation of the heat transfer characteristics in the pulse laser ablation of bronze and diamond. According to the results of numerical simulation, experiments were conducted for pulse laser ablation of a bronze wheel and bronze-bonded diamond grinding wheel. The theoretical analysis and experimental results showed that under the indicated conditions, the laser of 2.10×108 W/cm2 could only perform dressing on a bronze-bonded diamond grinding wheel; the laser of 2.10×108 W/cm2-2.52×108 W/cm2 merged the truing and dressing of the grinding wheel; and the laser of greater than 2.52×108 W/cm2 realized great-depth dressing but seriously affected the projection height of grits from the bond and their grinding performance. These researches provide theoretical guidance for optimizing the process parameters associated with laser ablation of a bronze-bonded diamond grinding wheel and the experimental data is in good agreement with the numerical solution to the model, thus verifying the correctness and feasibility of the heat transfer model..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 406008 (2017)
[in Chinese]
Motion-blurred image deblurring of fast moving target
Zhang Yuye, Zhou Shengming, Zhao Yuliang, and Wang Chunxin
In the process of a single motion-blurred image restoration, it is difficult to estimate point spread function(PSF) and the ill-posed deconvolution will affect restoration result. Considering that several different PSFs can get joint invertibility to make deblurring well-posed, it was proposed that the motion-blurred iIn the process of a single motion-blurred image restoration, it is difficult to estimate point spread function(PSF) and the ill-posed deconvolution will affect restoration result. Considering that several different PSFs can get joint invertibility to make deblurring well-posed, it was proposed that the motion-blurred images of different PSFs could be obtained by multiple cameras with same parameters to shoot continuously at high speed moving target in one field of view. The images had the same brightness, different exposure time, and different motion blur. The PSFs were easy to be estimated by consecutive frames. According to the motion-blurred character of the target and background imaging pixels, complete convolution blurred images of the target could be extracted from the observation images respectively. Finally, the target image was recovered by iterative restoration in the spatial domain by multiple images joint solution. Experiments show that the method only needs common hardware, and the obtained images can help more exact image restoration by joint PSFs solution. And the restoration results maintain details well and have lower signal noise ratio (SNR)..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 428001 (2017)
Terrain following based on forward-looking image sequences for unmanned air vehicles
Wei Donghui, Chen Wanchun, and Cheng Jin
According to the problem of autonomous terrain following in unknown environment for UAVs, a novel terrain following method was introduced based on the skyline of the forward-looking image sequences. And the guidance law of adaptive angle method was designed in detail, where the forward terrain information was detected According to the problem of autonomous terrain following in unknown environment for UAVs, a novel terrain following method was introduced based on the skyline of the forward-looking image sequences. And the guidance law of adaptive angle method was designed in detail, where the forward terrain information was detected by the passive images in real time, so the digital map and the high precision navigation requirement were reduced. The 6DOF simulation results demonstrate that the method is better than the traditional method based on digital map, the average terrain following height from the ground can be reduced by over thirty-five percent, so the method can improve the penetration performance significantly..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 428002 (2017)
[in Chinese]
Breast cancer oxyhemoglobin surface enhanced Raman spectroscopy
Zhang Ming, Zhu Shaoling, Gao Fei, and Luo Guo
Based on the repeatability and good biological compatibility two-dimensional nano silver membrane as oxyhemoglobin near infrared surface enhanced Raman scattering(SERS), a study on oxyhemoglobin used SERS spectra was carried out by using near infrared laser with good match as excitation light source, which caused resonBased on the repeatability and good biological compatibility two-dimensional nano silver membrane as oxyhemoglobin near infrared surface enhanced Raman scattering(SERS), a study on oxyhemoglobin used SERS spectra was carried out by using near infrared laser with good match as excitation light source, which caused resonance Raman effect respectively of healthy women and women with breast cancer. The study found that obvious differences existed between healthy women and female breast cancer patients′ oxyhemoglobin. By using the method of principal component analysis(PCA) and independent variable T test statistical analysis through SPSS, an extremely significant difference was found between the two spectra in 659, 813 and 1122 cm-1 Raman shift spectrum peak. By attribution analysis on the principal component, a significant reduction was found, compared with the healthy women, in the female breast cancer patients′ oxygenated hemoglobin molecules, pyrrole ring vibration, and symmetric deformation of antisymmetric deformation and pyrrole ring breathing vibration intensity, which resulted in an obvious difference in the graph spectral peaks. In addition, SERS technique can be combined with SPSS statistical analysis method to distinguish the oxygenated hemoglobin between healthy women and patients with breast cancer, which is expected to develop into a new type of clinical diagnosis technology for breast cancer..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 433001 (2017)
[in Chinese]
3D scanning measurement system based on double-line projection and the line-plane constraint
Wang Peng, Shi Ruize, Zhong Xiaofeng, and Sun Changku
A system about 3D scanning measurement towards large objects without rails was developed in this paper, which combined binocular sensor with structured-light sensor together and achieved the unity of their coordinate systems through calibration. The double-line projection model was presented, through which the system cA system about 3D scanning measurement towards large objects without rails was developed in this paper, which combined binocular sensor with structured-light sensor together and achieved the unity of their coordinate systems through calibration. The double-line projection model was presented, through which the system can complete the stereo matching of the mark points in the binocular sensor and get mark points′ 3D coordinates. Based on the double-line projection model, a structured-light model named line-plane constraint was designed to get the modulated information of the light strips on the objects′ surface. In order to build the relationship between the sensor coordinate system and the global coordinate system, the property of the space geometrical invariability of the mark points was used. In this way, the entire system of the sensor can convert the 3D points cloud data measured at different locations to the global system in real time. Thus, the entire sensor system can complete the 3D scanning measurement of the object, the measurement precision was better than 0.08 mm within the working distance..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 427001 (2017)
Radially polarized beam restructuring based on Stokes-vector measurement and interferometry
Zhan Xiangkong, Li Zhengyong, Zhang Yi, Wang Mingyu, Wang Haiyang, and Wu Chongqing
With rapid development of optical manipulation technology, it became urgent to measure and reconstruct the radially polarized beam (RPB). Utilizing a set of quartz rotators, the RPB was prepared firstly. In consideration of optical quality assessment, due to the direct connection with longitudinal component at the focaWith rapid development of optical manipulation technology, it became urgent to measure and reconstruct the radially polarized beam (RPB). Utilizing a set of quartz rotators, the RPB was prepared firstly. In consideration of optical quality assessment, due to the direct connection with longitudinal component at the focal region, the parameter of polarization orientation and power deviation have been brought up and measured. A method to reconstruct the vector-structure of RPB was designed and implemented. Results show that the normalized amplitude deviation was 0.054 8 and polarization deviation is 0.004 4. Furthermore, by the interferometer, the phase distribution of the RPB has been achieved, and the average phase difference was 1.471 between neighboring sections. Finally, by processing the data of polarization and phase information, the vector-field of the RPB have been successfully reconstructed, the topological charge was 3, which paves the way for accurate quantum manipulation and measurement..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 427002 (2017)
Position and orientation measurement system based on monocular vision and fixed target
Wang Tianyu, Dong Wenbo, and Wang Zhenyu
The position and orientation measurement system based on computer vision is extensively applied on robotics, motion control and precision detection systems. Using the minimum hardware resource, a localization system based on mono-vision and manual planar target was designed and the method of image matching and positionThe position and orientation measurement system based on computer vision is extensively applied on robotics, motion control and precision detection systems. Using the minimum hardware resource, a localization system based on mono-vision and manual planar target was designed and the method of image matching and position resolving was also studied. Firstly, the object detection based on image matching was used to get the coordinate of the planar target in image. The matching was based on SIFT features and projection estimation to detect the target in image, and then the accurate coordinate of the target′s center was calculated by some inherent shape information. A number of image samples were used to validate the accuracy and robustness of the image matching algorithm. Secondly, a new method to solve the PnP problem based on the rectangular distribution was proposed. The method uses the locations of target control points in the image coordinate system and the object coordinate system was used to get the relative position and orientation between the moving object and the camera. The experiment was conducted on the 5D precision displacement stage and results show that the system can achieve the accuracy level of mm in the range of 800 mm, which meets the project requirement..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 427003 (2017)
[in Chinese]
Development of beam combining of high power high brightness diode lasers
Wang Lijun, Peng Hangyu, Zhang Jun, Qin Li, and Tong Cunzhu
Diode lasers have advantages of high efficiency and compact structure. The low power and poor beam quality of diode lasers limits its application fields. The new developments of diode lasers in power and beam quality were introduced. The new combining techniques and the experimental results of diode lasers were summariDiode lasers have advantages of high efficiency and compact structure. The low power and poor beam quality of diode lasers limits its application fields. The new developments of diode lasers in power and beam quality were introduced. The new combining techniques and the experimental results of diode lasers were summarized. The high brightness diode laser achievements acquired by CIOMP were also presented..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 4, 401001 (2017)
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