Journals >Infrared and Laser Engineering
Contents
2020
Volume: 49 Issue 6
36 Article(s)
Export citation format
Laser & Laser Optics
Propagation characteristics of non-uniformly Sinc-correlated blue-green laser beam through oceanic turbulence
Wang Mingjun, Zhang Jialin, and Wang Jiao
The propagation model of non-uniformly Sinc-correlated blue-green laser beam in oceanic turbulence was developed according to generalized Huygens-Fresnel principles. Based on the cross-spectral density, intensity variations in different propagation distances were discussed. When the oceanic turbulence parameters were vThe propagation model of non-uniformly Sinc-correlated blue-green laser beam in oceanic turbulence was developed according to generalized Huygens-Fresnel principles. Based on the cross-spectral density, intensity variations in different propagation distances were discussed. When the oceanic turbulence parameters were varied, intensity and lateral shifted intensity maximum were numerically simulated. The results show that the propagation distance and ocean turbulence parameters have a certain influence on the intensity self-focusing effect of the non-uniformly Sinc-correlated blue-green laser beam. When the propagation distance is certain, the effect of the rate of dissipation of mean-square temperature on the intensity self-focusing is greater than the rate of dissipation of kinetic energy and the relative strength of temperature and salinity fluctuations..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190370 (2020)
Yb-doped all-fiber laser based on fiber saturable absorber
Jiaqi Zu, Shuai Wu, Haitao Zhang, Dongxian Geng, and Xu Lu
An Yb-doped all-fiber Q-switched laser based on fiber saturable absorber was reported. In order to obtain laser pulses output with a higher peak power and a narrower pulse width, the saturable absorption effect of Ytterbium-doped fiber was used with laser. The 20/130 μm large mode double cladding Yb-doped fiber was useAn Yb-doped all-fiber Q-switched laser based on fiber saturable absorber was reported. In order to obtain laser pulses output with a higher peak power and a narrower pulse width, the saturable absorption effect of Ytterbium-doped fiber was used with laser. The 20/130 μm large mode double cladding Yb-doped fiber was used as the gain fiber. The 10/130 μm single mode double cladding Yb-doped fiber was used as saturable absorber. The laser adopted a all fiber-optic structure, and a relatively stable pulse output was obtained at a relatively low cost. The maximum average power was 3 W, the slope efficiency was 30%, the repetition rate was 10–100 kHz, and the minimum pulse duration was 344 ns with the spectral width of 0.05 nm and the central wavelength of 1 064 nm..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20190382 (2020)
Design of semiconductor laser driver circuit and analysis of loop noise -suppression
Wu Tao, Pang Tao, Tang Yuquan, Sun Pengshuai, Zhang Zhirong, and Xu Qiming
In order to prevent the fluctuation of driving current from affecting the laser excitation wavelength and luminous power, a sinusoidal modulation driving circuit of semiconductor laser with strong anti-interference ability was designed. The driving circuit takes the deep negative feedback architecture as the core, and In order to prevent the fluctuation of driving current from affecting the laser excitation wavelength and luminous power, a sinusoidal modulation driving circuit of semiconductor laser with strong anti-interference ability was designed. The driving circuit takes the deep negative feedback architecture as the core, and sends control instructions by serial port. Through STM32 controller, the magnitude of dc signal in the setting voltage as well as the frequency and amplitude of sinusoidal signal were adjusted. First-order manual analysis of the whole loop was carried out, and a noise suppression network with automatically adjustable parameters was introduced by Tina-TI simulation.Experimental results show that the current driving circuit of the laser can suppress the loop noise of more than 10 times the target frequency by more than 20 dB.The maximum deviation between the output value of the frequency and the set value is 0.001 Hz, and the control linearity is 0.999 9. The short-term stability of the 2 hour driving current under dc bias is better than 0.005 6%, and the long-term stability is up to 0.011% at 63 hours. The control linearity of the laser power is 0.999 4, and the standard error is 0.092 87..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190386 (2020)
Comparison on detection performance of FMCW and pulsed lidar in aerosol environment
Chen Peng, Zhao Jiguang, Song Yishuo, and Wang Shen
The detection performance of frequency modulated continuous wave (FMCW) and pulsed laser detection systems under aerosol interference were investigated, and the detection performance comparison between the two systems was proposed. Based on Monte Carlo method, the target detection model under aerosol interference was eThe detection performance of frequency modulated continuous wave (FMCW) and pulsed laser detection systems under aerosol interference were investigated, and the detection performance comparison between the two systems was proposed. Based on Monte Carlo method, the target detection model under aerosol interference was established. The detection results of different distance targets were studied. The feasibility of comparing the two systems of FMCW and pulse system was demonstrated, and the quantitative comparison of the detection performance of the two systems was carried out. Taking the phosphorus smoke aerosol as an example, the simulation and the distance measurement experiment in the fog chamber were carried out. The results show that the FMCW laser detection system can improve the detection performance by increasing the modulation frequency. In an aerosol environment, FMCW laser detection has a higher signal-to-clutter ratio (SCR) than the pulse system, which means better detection performance and stronger resistance to backscattering interference. Under the condition of low aerosol visibility and the same range resolution, the detection performance of the FMCW system with 400 MHz initial modulation frequency is about 8-10 dB higher than that of the pulse system..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190399 (2020)
Design and application of electromagnetic shielding of optical detection system
Hongyan Zhuo, Zhiqiang Liu, Wen Peng, Peng Ye, and Zhihui Liu
IR optical detector system can work at strong radiation and electromagnetic interference caused by the operation of high power microwave(HPM) system. The strong electromagnetic pulse generated by HPM will enter the inner circuit system through the front-end optical lens of the detector with the back-door coupling, resuIR optical detector system can work at strong radiation and electromagnetic interference caused by the operation of high power microwave(HPM) system. The strong electromagnetic pulse generated by HPM will enter the inner circuit system through the front-end optical lens of the detector with the back-door coupling, resulting in the phenomenon of instant black screen, image jitter, electronic device destruction and so on. The optical window was developed by using embedding metal lines into optical materials. These metal lines were made to be a net and to be implanted in the middle of optical glass. The performance of electrical shielding was up to 65 dB in 2.4 GHz±100 MHz frequency band. It can meet the requirement of the optical window transmittance of the detection target. The application shows that the image of the optical detection system loaded with the electromagnetic shielding optical window is stable and undisturbed when the HPM is working..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20190412 (2020)
Backscattering echo characteristics of haze detected by ultraviolet laser
Zhao Taifei, Wang Shiqi, Liu Kun, and Li Xingshan
In order to study the backscattering characteristics of the haze by ultraviolet laser (UV laser), the UV laser backscattering model was established to simulate the backscattering process of UV laser under the haze conditions, based on Mie scattering theory and Monte Carlo method. The peak power, peak delay and full widIn order to study the backscattering characteristics of the haze by ultraviolet laser (UV laser), the UV laser backscattering model was established to simulate the backscattering process of UV laser under the haze conditions, based on Mie scattering theory and Monte Carlo method. The peak power, peak delay and full width at half maximum of the backscattered echoes of ultraviolet laser pulses with different widths were analyzed. The results show that, within the certain range of haze concentration, the lower haze concentration and the narrower the emission pulse width are, the more obvious the distortion of the laser echo waveform is. As the width of the emission pulse increases, when the emission pulse width is larger than 10 ns, the laser echo is approximately Gaussian distribution; Under the same emission pulse width condition, the peak power and echo peak delay of the laser echo increase with the increase of the haze concentration, and the full width at half maximum of the echo decreases with the increase of the haze concentration, When the emission pulse width is larger than 32 ns, the peak echo power tends to be flat. The results of this paper can provide a theoretical basis for UV laser detection of haze concentration and analyzing the echo characteristics of haze backscattered laser..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190414 (2020)
Comparison of mid-infrared laser generated by optical parametric oscillation of BaGa4Se7 and KTiAsO4
Kong Hui, Bian Jintian, Ye Qing, Yao Jiyong, Wu Chang, and Sun Xiaoquan
Both BaGa4Se7 (BGSe) and KTiAsO4 (KTA) can generate mid-infrared lasers pumped by 1.06 μm laser. Firstly, the phase matching curves of two kinds of non-linear crystals were simulated and calculated. The results show that BGSe with cutting angles of (56.3°, 0°) and KTA with cutting angle of (90°, 0°)Both BaGa4Se7 (BGSe) and KTiAsO4 (KTA) can generate mid-infrared lasers pumped by 1.06 μm laser. Firstly, the phase matching curves of two kinds of non-linear crystals were simulated and calculated. The results show that BGSe with cutting angles of (56.3°, 0°) and KTA with cutting angle of (90°, 0°) can generate idle frequency light of ~3.5 micron under phase matching conditions of type I and type II-A, respectively. Then through theoretical calculation, the effective non-linear coefficients of BGSe (56.3°, 0°, type-I) is ?11.9 pm/V, and that of KTA (90°, 0°, type II-A) is ?3.2 pm/V. The OPO oscillation threshold of 15 mm long BGSe (56.3°, 0°, type-I) is 35.11% of that of 20 mm long KTA (90°, 0°, type II-A). Then, the experimental results show that the oscillation threshold of BGSe-OPO (56.3°, 0°, type-I, 15 mm) is smaller than that of KTA-OPO (90°, 0°, type-II-A, 20 mm). The output energy of BGSe (56.3°, 0°, type-I) is larger than that of KTA (90°, 0°, type II-A). Therefore, BGSe is a promising mid-infrared non-linear crystal..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190423 (2020)
Terahertz vertical transition structure based on coupling cavity
Wang Xudong, Lv Xin, and Cheng Gong
The paper proposed a cavity-coupled vertical transition structure working at 110 GHz. Two modetransition units were fabricated at ends of a vertical metal cavity symmetrically, acting as two excitation ports of a waveguide. The proposed mode-transition unit was realized on a 50-μm thick quartz-substrate with via holes The paper proposed a cavity-coupled vertical transition structure working at 110 GHz. Two modetransition units were fabricated at ends of a vertical metal cavity symmetrically, acting as two excitation ports of a waveguide. The proposed mode-transition unit was realized on a 50-μm thick quartz-substrate with via holes and double-side patterned. In this way, the vertical transition structure presented a low insertion loss at terahertz frequency. Good agreement between simulated and measured results was obtained. The simulated S21 of the mode-transition unit was ?0.7 dB, the measured S21 was less than ?1.3 dB. The bandwidth from 105 GHz to 116 GHz was obtained for reflection level lower than ?10 dB..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190566 (2020)
Effect of droplet filling position on dynamic behavior of molten pool in laser welding
Jin Peng, Xingxing Wang, Hongqiao Xu, Jiajia Yang, and Furong Zhang
With the three-dimensional transient thermal flow coupled finite element model of laser welding, the three-dimensional keyhole morphology and metal flow characteristics of the molten pool during the process of the droplet entering the molten pool at different droplet filling positions were studied. Numerical simulationWith the three-dimensional transient thermal flow coupled finite element model of laser welding, the three-dimensional keyhole morphology and metal flow characteristics of the molten pool during the process of the droplet entering the molten pool at different droplet filling positions were studied. Numerical simulation results show that the droplet filling position had a significant effect on the three-dimensional morphology of keyhole and the flow behavior of molten pool during laser welding. When the droplet filling position was increased from 0.5 mm to 1.8 mm, the influence on the three-dimensional shape change of keyhole was weakened. The flow trend that the front and rear walls of the keyhole was squeezed inside the molten pool to drive the keyhole to close was weakened, while the flow tendency of maintaining the keyhole wall opening was enhanced, and the fluctuation amplitude of liquid metal flow velocity at the bottom of keyhole was weakened..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20200025 (2020)
Study on time jitter and trigger synchronization characteristics of ns pulsed laser diode
Rujun Liu, Cheng Ma, Wei Shi, Zhaoyu Hui, and Yuhua Hang
The time jitter of nanosecond semiconductor laser (LD) and the time synchronization of multiple LD parallel triggers are important parameters in various ultra-fast photoelectric processes and applications. In this paper, the time jitter characteristics of nanosecond pulse LD (with driving circuits) and the synchronizatThe time jitter of nanosecond semiconductor laser (LD) and the time synchronization of multiple LD parallel triggers are important parameters in various ultra-fast photoelectric processes and applications. In this paper, the time jitter characteristics of nanosecond pulse LD (with driving circuits) and the synchronization of two nanosecond LD triggers were studied. The results show that the time jitter of nanosecond LD (with driving circuits) is related to the voltage of driving circuits and is in the range of sub-nanoseconds. The time jitter of a single nanosecond LD is 72 ps, when a driving power supply simultaneously triggers two nanoseconds LD in parallel, the time jitter of each nanosecond LD increases to about 200 ps, and the time synchronization of two parallel nanosecond LD is about 300 ps..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20200147 (2020)
Optical Design
Material selection and design of beryllium-aluminum alloy mirror assembly for large-diameter space infrared camera
Zhai Yan, Jiang Huilin, Mei Gui, and Jiang Fan
In order to ensure that the space infrared camera obtained a light and reliable sweeping head, and the mirrors had good surface accuracy and a high first-order natural frequency for the space sweeping camera system, the structure of sweeping part was studied in a targeted manner. The beryllium-aluminum alloy material wIn order to ensure that the space infrared camera obtained a light and reliable sweeping head, and the mirrors had good surface accuracy and a high first-order natural frequency for the space sweeping camera system, the structure of sweeping part was studied in a targeted manner. The beryllium-aluminum alloy material was selected as the Φ750 mm diameter main mirror material, the flexible support structure of the titanium alloy material was selected as the support structure, and installed in the main mirror chamber of the beryllium-aluminum alloy material. It included a secondary mirror assembly, a secondary mirror support part and a light-shielding cylinder. The total weight of the entire swinging part was 17.5 kg. The finite element method was used to simulate the mirror assembly under the condition of force and heat coupling. The results show that the maximum surface error RMS of the mirror is 27.04 nm, which is no less than λ/20 (λ=632.8 nm) in the full aperture range requirements. The first-order resonant frequency of the oscillating portion is 122 Hz, which reserves a large bandwidth for the control system. The mechanical test results of the solid model are close to those of the finite element analysis, indicating that the overall design requirements for the sweeping part are met..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190390 (2020)
Design of infrared optical lens with large field of view
Jianfa Chen, Zhifeng Pan, and Helong Wang
The ultra large field of view infrared optical lens was mainly used to warn the incoming target militarily. Compared with the conventional infrared optical system, its design had many different characteristics. Combined with practical engineering applications, the characteristics of the design of the infrared field sysThe ultra large field of view infrared optical lens was mainly used to warn the incoming target militarily. Compared with the conventional infrared optical system, its design had many different characteristics. Combined with practical engineering applications, the characteristics of the design of the infrared field system of the large field of view were analyzed in terms of projection mode, optical configuration, image plane illumination, field of view, non-thermalization, evaluation mode and so on. A concrete design example was given. The detector adopted 1 024×1 024@ 15 μm cooled medium wave infrared detector. The operating band of the optical system was 3.7-4.95 μm, the focal length was 9.6 mm, the field of view was 116°, and only 4 lenses were used to realize optical non-thermalization without diffraction surfaces, the working temperature covered a range of -55-70 ℃, the lens structure was compact, and the total length was less than 70 mm. The results of image quality evaluation showed that the angular resolution uniformity of a single pixel in the full field of view was more than 95%, the energy concentration of a single pixel was more than 75%, and the illuminance of the optical system edge field of view was more than 90% of the central field of view..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20190443 (2020)
Several ways to realize multi-band common aperture optical imaging system(Invited)
Jian Deng, Rui Qu, and Jianbing Huang
By using differential method, the inter-band chromatic aberration and intra-band chromatic aberration conditions in optical system were introduced, and the extended complex chromatic aberration theory was established. By comparing the refractive vs chromatic coefficients of each band and the whole band, the material waBy using differential method, the inter-band chromatic aberration and intra-band chromatic aberration conditions in optical system were introduced, and the extended complex chromatic aberration theory was established. By comparing the refractive vs chromatic coefficients of each band and the whole band, the material was matched and iteratively optimized to correct all kinds of aberrations. Several ways of realizing the multi-band common aperture (MCA) optical system were discussed, including the medium-wave (MW)/near-infrared (NIR) secondary imaging system with transmission structure, which was introduced into the respective detectors by the dichroic beam splitter in convergent optical path; the MW/long-wave (LW) infrared secondary imaging system with transmission structure, which adopted the co-focal surface design of the co-optical road; and the AN/AAQ-33 “Sniper XR” pod’s main optical system, which adopted MW/NIR co-aperture transmission fore telescope system; the AN/ASQ-228 ATFLIR pod’s main optical system, which adopted the MCA off-axis three-mirror anastigmatic (TMA) fore telescope system; the AN/AAS-52 MTS-B pod’s main optical system, which adopted the MCA coaxial bias field of view (FOV) TMA fore telescope system; the EKV’s main optical system, which adopted the MCA coaxial four mirror secondary imaging system. And correspondingly, some coaxial mirror-lens fore telescope systems were introduced, and the last, some typical missile borne MCA imaging optical structures were introduced..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20201017 (2020)
Photoelectric Measurement
Study on calibration method of sky radiometer and aerosol optical properties in Xi''''an region
Jingjing Liu, Guoying Wang, Zixiang Xu, Yun Liu, Jun Wang, Qing Yan, and Dengxin Hua
On the base of Langley method, a more reliable instrument calibration coefficient was obtained after the expected average and fitting average method were used, and the spatiotemporal characteristics of aerosol optical depth(AOD) and ?ngstr?m wavelength exponent were analyzed using observations of sky radiometer at Xi&#On the base of Langley method, a more reliable instrument calibration coefficient was obtained after the expected average and fitting average method were used, and the spatiotemporal characteristics of aerosol optical depth(AOD) and ?ngstr?m wavelength exponent were analyzed using observations of sky radiometer at Xi''an University of Technology from 2015 to 2018. Results revealed that: (1) Only the Langley method is used to calibrate the instrument. The error is large. After the introduction of the expected average method and the fitted average method, the instrument calibration value obtained is more reasonable, effectively solving the problem of large fluctuations in the legal value of the Langley legal calibration value; (2) the diurnal variation of aerosol optical depth has 5 types: flat type, ascending type, descending type, convex type, and concave type, respectively. The frequency of flat type is lowest, 3.55%, and concave type is highest, 34.25%; (3) the seasonal variation of aerosol optical depth at 550 nm wavelength showed spring and summer are lower, and autumn and winter are higher, with the average values: 0.60±0.36, 0.59±0.33, 0.62±0.40, 0.68±0.36, respectively. Moreover, ?ngstr?m wavelength exponent have a highest value in summer (1.06±0.33), and have a lowest value in spring (0.81±0.32).espectively. Moreover, ?ngstr?m wavelength exponent have a highest value in summer (1.06±0.33), and have a lowest value in spring (0.81±0.32).al variation of aerosol optical depth at 550 nm wavelength showed spring and summer are lower, and autumn and winter are higher, with the average values: 0.60±0.36, 0.59±0.33, 0.62±0.40, 0.68±0.36, respectively. Moreover, ?ngstr?m wavelength exponent have a highest value in summer (1.06±0.33), and have a lowest value in spring (0.81±0.32)..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20190404 (2020)
Remote measuring system of road surface temperature based on dual window infrared detector
Cheng Yin, Liu Jianguo, Gui Huaqiao, Lu Yihuai, and Wei Xiuli
In the environment of out-field application, the temperature of the infrared remote measuring system of road surface temperature would change greatly, and the changes of the internal stray radiation thereby caused can lead to great systematic measurement error. So, infrared remote measuring system of road surface tempeIn the environment of out-field application, the temperature of the infrared remote measuring system of road surface temperature would change greatly, and the changes of the internal stray radiation thereby caused can lead to great systematic measurement error. So, infrared remote measuring system of road surface temperature based on dual window infrared detector was designed to measure the target object radiation and the internal stray radiation in real-time; meanwhile, based on the temperature effect of the detector, road surface temperature calculation model was established by eliminating the influences of internal stray radiation. The results of the calibration test show that when the working temperature of the detector and the measured target temperature are within -10-40 ℃, -10-60 ℃ respectively, the temperature effect and the radiometric calibration function can be processed linearly, showing linear superposition effect, which verifies the rationality of the road surface temperature calculation model. After calibration, out-field comparison test was conducted on infrared remote measuring system of road surface temperature and Pt100 contact temperature sensor, and it was obtained that the correlation between the measurement system and the measured data of Pt100 contact temperature sensor was up to 98.7%, among which the measurement error at night was lower than 2.78%, suggesting that the proposed system can measure the road surface temperature under out-field condition with changing environmental temperature..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190455 (2020)
Closed-loop control method of optical fiber positioning of center-opening four-quadrant detector
Linzheng Wang, Hua Zou, Shuo Huang, Hang Zhang, and Shiyu Zhao
Optical fiber positioning technology is a key technology in multi-target optical fiber spectroscopes. The accuracy of optical fiber positioning is an important factor affecting the observation efficiency of telescopes. With the development of the spectral survey project, the requirements for the optical fiber positioniOptical fiber positioning technology is a key technology in multi-target optical fiber spectroscopes. The accuracy of optical fiber positioning is an important factor affecting the observation efficiency of telescopes. With the development of the spectral survey project, the requirements for the optical fiber positioning unit to be miniaturized, high density, integrated and high precision positioning have become a general trend, which poses higher technical requirements and challenges for optical fiber positioning systems. Optical fiber positioning technology was also expected to achieve a high-precision real-time monitoring and feedback system, forming an effective closed-loop control. Based on the requirements, a center-opening four-quadrant（4-Q） detector fiber positioning technology was proposed, and a two-dimensional Gaussian model was used to design the center-opening four-quadrant detector positioning algorithm. The algorithm performs a single calibration of the unit beam spot waist, can achieve high precision multiple real-time spot position determination and fiber position adjustment. The performance of the device and algorithm was simulated with the experiment set up based on the principle of the optical fiber spectroscope telescope. With this closed-loop control method, the absolute positioning error was obtained when the four-quadrant detector had a zero offset diameter of 40 mm and a fiber cross-sectional area of 1 000 μm2. It can be controlled within 6 μm, and the relative error can be controlled within 0.15% ,which meets the requirements of the optical fiber spectroscope telescope fiber positioning technology. This device can be applied as an optical fiber positioning system..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20190466 (2020)
Compact multi-measurement mode interferometer for on-machine testing
Wang Daodang, Xiang Chao, Zhu Qixing, Kong Ming, and Xu Xinke
With the advantages of high precision, full field and non-contact testing, the interferometers have been widely applied in the testing of optical elements. To meet the need of on-machine testing of optical elements in the machining stage, a compact interferometer with multiple working modes was proposed to achieve tranWith the advantages of high precision, full field and non-contact testing, the interferometers have been widely applied in the testing of optical elements. To meet the need of on-machine testing of optical elements in the machining stage, a compact interferometer with multiple working modes was proposed to achieve transient testing. The proposed system can work in modes including single-wavelength laser interferometer, multi-wavelength interferometer and LED interferometric microscope, enabling the testing of surface figure with large dynamic range, surface roughness microscopic structures. A polarization camera was utilized to realize the simultaneous phase-shifting measurement with a single shot, by which the effect environmental disturbance can be minimized. To demonstrate the feasibility of the proposed interferometer, the on-machine testing in various working modes have been carried out on diamond turning machine, as well as the control experiment with Zygo laser interferometer and Zygo optical profiler; Besides, the freeform surface testing has also been achieved with the proposed interferometer. High measurement accuracy and large dynamic range has been achieved in experiments. It was compact in system with dimensions of 195 mm×160 mm×65 mm, making it extremely suitable for installing and testing on machining equipment. Besides, the transient wavefront testing makes the proposed system insensitive to environmental disturbance, and it has a great prospect for application in on-machine testing of alignment tool and various optical elements in machining stage..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190472 (2020)
Mainstream NDIR breathing CO2 monitoring system based on new light chamber structure
Tao Xiong, Ming Gao, Gibson Des, and Hutson David
Aiming at the problem of low sensitivity and low signal-to-noise ratio of mainstream non-dispersive infrared (NDIR) breathing CO2 monitoring systems, the method using a compound parabolic concentrator (CPC) to improve the performance of the monitoring system was proposed. ZEMAX was utilized to simulate optical chambersAiming at the problem of low sensitivity and low signal-to-noise ratio of mainstream non-dispersive infrared (NDIR) breathing CO2 monitoring systems, the method using a compound parabolic concentrator (CPC) to improve the performance of the monitoring system was proposed. ZEMAX was utilized to simulate optical chambers, optimize CPC and commonly used straight cylinder concentrator and cone concentrator. The mainstream integrated method of single source and double light path was used to design the chamber of the monitoring system. STM32F100 was selected as the main control chip to control the hardware system. CO2 concentration calibration and real-time human breathing detection experiments were performed on monitoring systems with different optical chamber structures, and the corresponding relationship between CO2 concentration and system output signals and CO2 waveform diagrams were obtained. The results show that the CPC optical chamber has a simulated optical efficiency of 4.3%, which can be up to 89.77 times higher than commonly used concentrators; the monitoring system equipped with CPC has a sensitivity and signal-to-noise ratio of 8.940 7 and 24.65, which can increase the sensitivity by up to 3.811 times and the signal-to-noise ratio by 1.926 times compared to systems equipped with common concentrators; And the system installed with CPC runs stably, responds quickly, and can display the capnogram of the subject in real time..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20190575 (2020)
Design of polarization-independent reflective metalens in near infrared waveband
Zhang Yuhui, Yang Bowei, Li Yiting, Zhao Yuanzhi, and Fu Yuegang
Metalens has received extensive concern in recent years. Design of a polarization-independent reflective metalens was proposed baesd on Au in infrared waveband. MgF2was chosen as the dielectric spacer of the metalens. All simulations were carried out by using the finite-difference time-domain(FDTD) software. Results shMetalens has received extensive concern in recent years. Design of a polarization-independent reflective metalens was proposed baesd on Au in infrared waveband. MgF2was chosen as the dielectric spacer of the metalens. All simulations were carried out by using the finite-difference time-domain(FDTD) software. Results show that the proposed metalens has the same effect on different polarized light and can work well in the range of 700 - 850 nm and one-focus works best in the range of 750 - 800 nm. When the incidence wavelength is chosen as 800 nm, the proposed metalens can also work well for one-focus and multi-focus. At that time, the focal length of one focus, dual focus and three focus are 9.6, 6.6 and 4.7 μm, respectively. Different focus requirements can be realized according to the characteristics of the metalens..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20200048 (2020)
Application research of new photoelectric detection technology on precision guided weapons(Invited)
Chuang Song, Peng Jiang, Lei Duan, Jianfeng Sun, and Zhiguo Fan
Precision guided weapon is the main weapon in modern warfare. The precision guided weapon with photoelectric guidance has the advantages of strong resolution and high accuracy. It is widely used in the fields of sea-to-sea, air defense, anti-missile, space attack and defense. As optoelectronic guided weapons play an inPrecision guided weapon is the main weapon in modern warfare. The precision guided weapon with photoelectric guidance has the advantages of strong resolution and high accuracy. It is widely used in the fields of sea-to-sea, air defense, anti-missile, space attack and defense. As optoelectronic guided weapons play an increasingly prominent role in modern warfare, their corresponding countermeasures are also constantly developing, which makes the combat environment more complex and requires them to continuously enhance adaptability to the increasingly complex battlefield environment. Based on the summary of the application of existing optical detection technologies such as infrared, visible light and laser semi-active in guided weapons, the shortcomings of the current technology in complex combat environments are analyzed, such as harsh natural weather, complex background and human interference. In view of the current development of multi-spectral detection, polarization imaging, laser three-dimensional imaging, quantum detection and other new technologies, the current research progress and results are introduced. It mainly includes multi-spectral multi-segment segmentation against true and false target camouflage recognition, polarization imaging against rain and fog, bad natural weather, laser three-dimensional imaging in the application of anti-complex background and penetration shielding and other research advantages and research progress. Finally, the problems in the application of the new detection technology and the key technologies that need to be broken through are systematically analyzed, and it is suggested that the guidance application of the new detection technology should be promoted through the joint attack of the basic technology and the application technology..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20201015 (2020)
Study on aero-optical effect of the imaging detection system of high speed flight vehicle(Invited)
Zhang Liqin, and Fei Jindong
With the increasing dependence on the accuracy and effectiveness of information acquired during flight, the photoelectric image detection and hyper-speed flight technology have become the development trend of the future flight vehicles. However, when the flight vehicles equipped with optical imaging detection and guidaWith the increasing dependence on the accuracy and effectiveness of information acquired during flight, the photoelectric image detection and hyper-speed flight technology have become the development trend of the future flight vehicles. However, when the flight vehicles equipped with optical imaging detection and guidance system fly at high speed in the dense atmosphere, the optical dome and incoming flow generate a complex flow filed because of intense interaction. The complex thermal response generated in optical windows brings aerodynamic thermal noise for the optical imaging detection system in the optical dome, and causes deviation, jitter, blur of the target, which is called aero-optical effect. From three levels——mechanism, project and application, research ideas and further works were put forward for aero-optical effect faced by the imaging detection system of high speed fight vehicle, aiming at providing reference ideas for study on aero-optical effect..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20201016 (2020)
Special Issue-Optical 3D Imaging and Sensing
Target recognition method based on single-pixel imaging system and deep learning in the noisy environment
Feng Shi, Tongxi Lu, Shuning Yang, Zhuang Miao, Ye Yang, Wenwen Zhang, and Ruiqing He
Single-pixel imaging system attracts a lot of attentions because of its special imaging method, but its target recognition method in noisy environment has not been studied deeply. Aiming at this problem, the signal sequences obtained by the bucket detector and the corresponding formed two-dimensional images were used aSingle-pixel imaging system attracts a lot of attentions because of its special imaging method, but its target recognition method in noisy environment has not been studied deeply. Aiming at this problem, the signal sequences obtained by the bucket detector and the corresponding formed two-dimensional images were used as the training samples for deep learning to identify targets in noisy environments. By comparing the recognition results of these two methods, it was found that when the sampling rate was low, the former one could obtain a higher recognition rate even in a strong noise environment; while for the latter one, although the recognition rate was relatively stable, its preprocessing time was high, so the former one was more suitable for target recognition in high-speed imaging. In addition, for the method using only the bucket detector signal as the training samples, the effect of target sparsity on its recognition accuracy was also analyzed. It was found that when the external noise and sampling rate were fixed, the higher the sparsity of the target, the higher the recognition accuracy was. This paper can be used as the reference for the selection of single pixel system recognition methods in noisy environments..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20200010 (2020)
Speckle projection profilometry with deep learning
Zhong Jinxin, Yin Wei, Feng Shijie, Chen Qian, and Zuo Chao
Traditional single speckle pattern matching algorithms always suffer from the low measurement accuracy and cannot be used to measure complex surface objects. A speckle projection profilometry with deep learning was proposed to realize the pixel-by-pixel matching. The siamese convolutional neural network structure was aTraditional single speckle pattern matching algorithms always suffer from the low measurement accuracy and cannot be used to measure complex surface objects. A speckle projection profilometry with deep learning was proposed to realize the pixel-by-pixel matching. The siamese convolutional neural network structure was applied and extended where the main speckle pattern and the auxiliary speckle pattern were fed into the neural network patch by patch. It was expected that the feature from the speckle pattern patches could be extracted by the convolution operation. In this way, the features were fused and the matching coefficient between the two patches was obtained, which could be further used to formulate the disparity data and then the three-dimensional (3D) object was reconstructed. The experiment results demonstrate that with the proposed method 3D measurement with an accuracy of about 290 μm could be achieved through a single speckle pattern..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20200011 (2020)
Multi-stage deep learning based single-frame fringe projection 3D measurement method
Zhao Zhang, Bowen Han, Haotian Yu, Yi Zhang, Dongliang Zheng, and Jing Han
The application of deep learning has simplified the process of 3D measurement of digital fringe projection. In the process of fringe projection, phase calculation, phase unwrapping, and phase-depth mapping of traditional digital fringe projection 3D measurement technology, researchers have successfully demonstrated theThe application of deep learning has simplified the process of 3D measurement of digital fringe projection. In the process of fringe projection, phase calculation, phase unwrapping, and phase-depth mapping of traditional digital fringe projection 3D measurement technology, researchers have successfully demonstrated the feasibility of combining the first three stages and the entire process with deep neural networks. Based on deep learning, the Phase to Depth Network (PDNet) was proposed to achieve the map from absolute phase to depth. Combined with multi-stage deep learning based single-frame fringe projection 3D measurement method, the absolute phase and depth information of the object were obtained by deep learning in stages. The experimental results show that the PDNet can measure the depth information of the object comparatively accurately, and the application of deep learning is feasible in the phase-height mapping stage. And compared with the single-stage deep learning based single-frame fringe projection 3D measurement method that directly maps from the fringe image to the three-dimensional topography information, multi-stage deep learning based single-frame fringe projection 3D measurement method can significantly improve the measurement accuracy, which only require a single fringe input to obtain millimeter-level measurement accuracy, and it can adapt to 3D measurement of objects with complex surfaces..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20200023 (2020)
Single-shot 3D measurement using grayscale expanded composited grating
Li Hongmei, Cao Yiping, Wang Yapin, Wang Lu, Li Chengmeng, An Haihua, and Xu Cai
A single-shot 3D shape measurement using orthogonal composited grating based on grayscale expanding (OCGGE) was proposed. In the traditional orthogonal composited grating (OCG) profilometry, the modulated gratings in the orthogonal composited grating must share the same grayscale level since the maximal grayscale dynamA single-shot 3D shape measurement using orthogonal composited grating based on grayscale expanding (OCGGE) was proposed. In the traditional orthogonal composited grating (OCG) profilometry, the modulated gratings in the orthogonal composited grating must share the same grayscale level since the maximal grayscale dynamic range of commercial Digital Light Processing (DLP) is limited in 256, that results in some phenomenon increasing the measuring error, including the weakened contrast of the modulated grating, the compressed phase information and the broken phase during the process of phase unwrapping. Based on the principle of time division multiplexing, one orthogonal composited grating was designed with 766 gray level and was spited into three different fringe patterns with 256 grayscales, then loaded these patterns in sequence to edit a video. When this video was played and projected onto the measured object continuously, by setting the exposure time as an integer times of the 3 times of the frame refresh cycle of the video for a 10bit CCD, a deformed pattern with 766 grayscales could be obtained. After the filtering and grayscale calibration, the object could be reconstructed accurately and completely. Both simulation and experiment results prove that the proposed method can break the limit of 256 grayscale projection and increase the dynamic range of the phase-shifting deformed patterns efficiently. And it can also enrich the detailed information of the measured object and avoid the incomplete surface reconstruction caused by phase break..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20200034 (2020)
Wide-angle lenses distortion calibration using phase demodulation of phase-shifting fringe-patterns
Weishuai Zhou, Jiawen Weng, Junzheng Peng, and Jingang Zhong
A distortion calibration method for wide-angle lens was proposed based on fringe-pattern phase analysis. Firstly, four standard cosine fringe-patterns with phase shift step of π/2, which were used as calibration templates, were shown on a large-size Liquid Crystal Display screen, and captured by the camera with wide-anA distortion calibration method for wide-angle lens was proposed based on fringe-pattern phase analysis. Firstly, four standard cosine fringe-patterns with phase shift step of π/2, which were used as calibration templates, were shown on a large-size Liquid Crystal Display screen, and captured by the camera with wide-angle lens to obtain four distorted fringe-patterns. A four-step phase-shifting method was employed to obtain the phase distribution of the radial distorted fringe-pattern. There was no distortion within the central region of the image captured by the wide-angle lens, so the phase distribution of radial undistorted fringe-pattern, as a benchmark for computing radial distorted phase, could be acquired by performing numerical fitting by the central undistorted phase value of the distorted image. It means that the radial distorted phase distribution was computed by subtracting the phase distribution of radial distorted fringe-pattern from the phase distribution of radial undistorted fringe-pattern. Finally, the distorted phase was transformed into the actual distorted variables. There was no need to establish any kind of image distortion model by lots of characteristic points or lines. Furthermore, the radial distortion variable at each point of the distorted image can be determined by the proposed method. Experimental results show that the proposed method is simple, effective, and has wide application value..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20200039 (2020)
Modified dual-frequency geometric constraint fringe projection for 3D shape measurement
Yuwei Wang, Xiangcheng Chen, and Yajun Wang
Dual-frequency fringe projection methods have been widely used in three-dimensional (3D) shape measurement, but the phase unwrapping is very sensitive to random noises. A modified dual-frequency geometric constraint fringe was presented. The robustness of phase unwrapping can be effectively enhanced by improving the frDual-frequency fringe projection methods have been widely used in three-dimensional (3D) shape measurement, but the phase unwrapping is very sensitive to random noises. A modified dual-frequency geometric constraint fringe was presented. The robustness of phase unwrapping can be effectively enhanced by improving the frequency of low-frequency phase. During the 3D shape measurement, firstly, the five-step phase-shifting algorithm was used to extract two wrapped phases. Secondly, the low-frequency phase was unwrapped based on the geometric constraint method. Finally, the dual-frequency algorithm was used to unwrap the high-frequency phase, and then the 3D shape could be reconstructed. Both simulations and experiments demonstrate that the modified dual-frequency fringe is more robust and applicable than the traditional one..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20200049 (2020)
Euclidean 3D reconstruction based on structure from motion of matching adjacent images
Kan Wang, Jun Gong, Jinghe Wei, Ce Zhu, and Kai Liu
Traditional incremental structure from motion is susceptible to scale change, and the reconstructed point cloud is hierarchical and has no units. A new Euclidean 3D reconstruction method was proposed by improving the reconstruction topology and the scaling iterative closest point algorithm. First, a new reconstruction Traditional incremental structure from motion is susceptible to scale change, and the reconstructed point cloud is hierarchical and has no units. A new Euclidean 3D reconstruction method was proposed by improving the reconstruction topology and the scaling iterative closest point algorithm. First, a new reconstruction topology, reconstructing a point cloud from two adjacent pictures and then merging it into the main point cloud, was presented; then, corresponding tables were established aiming to find the corresponding 3D point pairs of a world point between the newly created point cloud and the main point cloud; subsequently, combining Geman-McClure norm, an anti-noise scaling iterative closest point method was proposed; finally, ground control points were set up to introduce scale for the reconstructed point cloud. Experiment results show that the point cloud reconstructed by proposed method is more accurate than that reconstructed by traditional incremental structure from motion, and the absolute error of length for the point cloud is about 1%-2%. The proposed method is suitable for precise Euclidean reconstruction of objects in close scene..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20200078 (2020)
Fast measurement of human body posture based on three-dimensional optical information
Limei Song, Haozhen Huang, Yang Chen, Xinjun Zhu, Yangang Yang, and Qinghua Guo
The three-dimensional measurement of human body posture is of great significance to the comfort evaluation of car seat design. In order to acquire the 3D data of the human body in the car quickly and accurately, a method of 3D data acquisition based on binocular vision was adopted, which combined the structured light wThe three-dimensional measurement of human body posture is of great significance to the comfort evaluation of car seat design. In order to acquire the 3D data of the human body in the car quickly and accurately, a method of 3D data acquisition based on binocular vision was adopted, which combined the structured light with the marked points, and realized the rapid reconstruction of 3D point cloud of the human body and the automatic and rapid measurement of 3D attitude (distance and angle). The experimental results show that when the distance is more than 2 m and the measuring range is 1.5 m × 2 m, the measurement accuracy of human body posture can reach 0.03 mm, which meets the demand of high-precision three-dimensional data acquisition of automobile human body posture. Compared with traditional three-dimensional measurement method, the three-dimensional automatic measurement method used in this paper not only has a high degree of automation, but also has the advantages of high accuracy, fast speed and strong robustness..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20200079 (2020)
Segmentation in multi-objects scene based on disparity and fringe modulation analysis
Xiaohan Li, Lu Chen, and Xiang Zhou
Noise is an important problem that affects image segmentation. A novel scheme was proposed that could accurately extract multiple objects in a noisy real-world scene. The phase map and disparity map were obtained by using the binocular structured light system based on sinusoidal fringe projection. Firstly, a disparity Noise is an important problem that affects image segmentation. A novel scheme was proposed that could accurately extract multiple objects in a noisy real-world scene. The phase map and disparity map were obtained by using the binocular structured light system based on sinusoidal fringe projection. Firstly, a disparity map was transformed into the corresponding U-disparity map. Then, according to the different projection characteristics of object and noise regions in the disparity map, the preliminary segmentation regions were obtained by using the closed region detection algorithm. In addition, the fringe modulation analysis method was used to remove the noise in the shadow region, and the accurate segmentation results were finally obtained. Experimental results and objective evaluation data indicate that the proposed segmentation algorithm in this paper is not only robust to noise but also can effectively separate the object from the horizontal support surface. It has the advantages of low computational complexity and strong anti-interference ability in different scenarios. The average segmentation accuracy is above 90%, and the best accuracy can achieve 99.2%. The average running time is almost 27 ms..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20200085 (2020)
Special Issue-Polarization Detection and Imaging
Research on coating materials detection and recognition based on infrared spectral polarization degree contrast
Weili Chen, Wenbin Xu, Shuhua Wang, Yan Chen, Yazhou Zhang, Junwei Li, and Rong Deng
In order to reduce the accuracy of material infrared recognition, a common method was presented to change the emissivity of material surface by coating the material surface. Firstly, the influence of the surface emissivity of the target material on the infrared characteristics of the target material was deduced and anaIn order to reduce the accuracy of material infrared recognition, a common method was presented to change the emissivity of material surface by coating the material surface. Firstly, the influence of the surface emissivity of the target material on the infrared characteristics of the target material was deduced and analyzed through the Stokes expression of the infrared radiation polarization transmission model of the target material based on the micro-plane element theory. The theoretical analysis results show that the change of the surface emissivity of the target material does not affect the infrared polarization of the surface. Secondly, in view of the irrelevance between the material surface emissivity and infrared polarization characteristics, this method of coating material was proposed based on the spectral degree of polarization contrast. And the infrared hyperspectral polarization imaging characteristics of coating materials with different surface emissivities on the same substrate and coating materials with the same emissivity on different substrates were verified and analyzed. The results show that the change of the surface emissivity of the coated material does not affect the polarization degree of the infrared spectrum. And even if the target material is coated with the same emissivity coating, the characteristic of spectral polarization degree is more obviously different than that of spectral radiation brightness. The research results can provide a new method for infrared camouflage material detection and recognition..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20190445 (2020)
Multiband submarine photoelectric polarization imaging detection simulation study based on water surface characteristics ripple
Hengze Wu, [in Chinese], Weiqi Jin, Su Qiu, Fuduo Xue, and Jie Yang
Submarine detection is a key technology of coastline defense, the direct and indirect imaging to detect submarines both involves solving the problem of detecting the water surface ripple. 3D surface measurement method based on polarization detection can effectively detect the water corrugated surface, in which the deteSubmarine detection is a key technology of coastline defense, the direct and indirect imaging to detect submarines both involves solving the problem of detecting the water surface ripple. 3D surface measurement method based on polarization detection can effectively detect the water corrugated surface, in which the detection and calculation of surface polarization characteristics is an important part of surface reconstruction. The model of water surface polarization was established. Visible and infrared waveband of the water polarization characteristic under different water temperature, different meteorological conditions were simulated and analyzed. The results show that the surface polarization is s polarization in the visible waveband and p polarization in the middle and long infrared waveband, degree of polarization first increases with the increase of incident angle and then decreases, moreover the degree of water surface polarization increases with the rising of temperature. The degree of water surface polarization in visible, middle infrared and long infrared waveband was measured by polarization measurement system based on Stokes vector. The results of the simulation were consistent with the measured results, which proved the accuracy of the polarization model used. The characteristics of polarization imaging detection in common wavebands were analyzed, which can provide theoretical simulation and experimental methods for the analysis and calculation of polarization characteristics of water surface..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20190547 (2020)
Review of underwater polarization clear imaging methods
Zhao Yongqiang, Dai Huimin, Shen Linghao, and Zhang Jingcheng
Underwater images often suffer from many typical problems: in a complex optical environment, the quality of underwater images drops sharply, and features such as color and brightness are often attenuated seriously, which makes it difficult to improve the quality of underwater images. Polarization imaging can effectivelUnderwater images often suffer from many typical problems: in a complex optical environment, the quality of underwater images drops sharply, and features such as color and brightness are often attenuated seriously, which makes it difficult to improve the quality of underwater images. Polarization imaging can effectively suppress underwater scattering. In the underwater imaging environment, according to the polarization characteristics of the signal, backscatter and forwardscatter light, the impact of different components on the image is solved. Based on the underwater physical imaging model and the principle of polarization imaging, the principle of underwater polarization imaging is described in detail, and several classic underwater polarization imaging methods are emphasized. The current underwater imaging technology based on polarization characteristics is summarized, and according to their actual effect, these methods are evaluated and analyzed. What''s more, based on the advantages and disadvantages of the existing underwater polarization imaging technology and their actual results, the future development of the underwater polarization imaging technology is summarized..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20190574 (2020)
Study on UV polarization reflection characteristics of sweat latent fingerprints(Invited)
Wang Feng, Jia Rong, Liu Xiao, Zhai Hao, Wang Sunchen, and Wu Yunzhi
Sweat latent fingerprint was the most common type of fingerprint on crime scenes, featuring features that disappeared quickly and were not easily detected. According to its characteristics, the UV polarization imaging detection technology was used for target detection. Compared with the traditional intensity image, theSweat latent fingerprint was the most common type of fingerprint on crime scenes, featuring features that disappeared quickly and were not easily detected. According to its characteristics, the UV polarization imaging detection technology was used for target detection. Compared with the traditional intensity image, the polarization parameter image could improve the target contrast and help to distinguish the targets in different backgrounds. However, the UV polarization imaging detection technology was sensitive to angles, bands and guest materials. Therefore, through the design of reasonable experiments, the characteristics of the UV polarization reflection characteristics of the sweat latent fingerprints with angle, band and guest materials were analyzed. The results show that the sweat latent fingerprints exhibited regular polarization characteristics at different angles; among the four spectral polarization channels provided by the system, the near-ultraviolet bands are well reproducible and distinguishable; the polarization characteristics of different guest materials varied greatly. The UV-polarized reflection characteristics of the comparative analysis samples effectively improved the detection and recognition performance of latent fingerprints, and provided a basis for the UV-polarized imaging detection technology of sweat latent fingerprints..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20201011 (2020)
Rapid identification of metal debris in complicated scenes by using polarization imaging(Invited)
Xiong Zhihang, Liao Ran, Zeng Yaguang, Liu Jin, and Ma Hui
Crimes associated to explosives always kill the lives of people, destroy the facilities, and threaten the public security. Rapid identifying the medal debris from the residuals of the explosives in criminal scenes is the key to speed up the detection of these criminal cases. Responding to these applications, in the papCrimes associated to explosives always kill the lives of people, destroy the facilities, and threaten the public security. Rapid identifying the medal debris from the residuals of the explosives in criminal scenes is the key to speed up the detection of these criminal cases. Responding to these applications, in the paper, a method was proposed based on polarization imaging to rapidly identify the medal debris from the complicated scenes. Two setups were built, which can respectively capture polarization images with multiple colors and in a simultaneous imaging manner. Experiments of the medal and non-medal debris and their mixtures show that polarization imaging can effectively identify the medal debris if the incident angle polarization, and wavelength of the illuminating light are appropriately set. Simulations based on Fresnel formula show how the polarization degrees and angles change with the incident angle, polarization, and wavelength of the illumination light. And the results suggest that polarization imaging can identify the types of the medal debris, which is proved by the additional experiments. In summary, it is indicated that polarization imaging has the potential to rapidly identify the medal debris from the complicated scenes which would help for the physical evidence in criminal detections..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 49, Issue 6, 20201012 (2020)
Advances on theory and application of polarization information propagation(Invited)
Zhongyi Guo, Xinyang Wang, Dekui Li, Pengfei Wang, Ning Zhang, Tianwei Hu, Man Zhang, and Jun Gao
The polarization state of light is the basic attribute of electromagnetic wave. Polarization information is an engineering science and applying technology, which uses the polarization states of light as the information representation, requiring proper characterizing methods to be described. Due to the scattering characThe polarization state of light is the basic attribute of electromagnetic wave. Polarization information is an engineering science and applying technology, which uses the polarization states of light as the information representation, requiring proper characterizing methods to be described. Due to the scattering characteristics of atmosphere, light has a special polarization distribution pattern on the earth surface, which can be used for autonomous navigation in near-earth space. At the same time, the transmissions of different polarization states in various scattering media also have some specific transmission characteristics. Therefore, the investigations on the transmission characteristics of polarization information in different dispersive media have important values for its wide applications in modern military, aviation, marine and other fields. Meanwhile, in recent years, the optical polarization imaging has been widely applied for achieving clear imaging in haze, underwater and other scattering media systems, in which many excellent research results have been obtained. In this paper, various presentation forms of the polarization states of light, transmission characteristics of polarization information in different dispersion media systems, polarization information recovery algorithm, and application of polarization dehazing technology were mainly introduced. Lastly, the future-development trends for the applications of polarization information was prospected..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2020
- Vol. 49, Issue 6, 20201013 (2020)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20