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2021
Volume: 41 Issue 21
29 Article(s)
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Atomic and Molecular Physics
Long-Distance Transmission of Cold Atomic Beams Based on Red-Detuned Gaussian Beams
Qian Liu, Yu Xie, Lin Li, Ang’ang Liang, Wenwen Li, Henan Cheng, Su Fang, Liang Liu, Bin Wang, and Desheng Lü
This paper presents a scheme for the long-distance transmission of cold atomic beams by two-dimensional magneto-optical traps based on the optical dipole force of red-detuned Gaussian beams. The scattering force equation of two-level atoms is used to analyze the forces on 87Rb atoms in a two-dimensional magneto-opticalThis paper presents a scheme for the long-distance transmission of cold atomic beams by two-dimensional magneto-optical traps based on the optical dipole force of red-detuned Gaussian beams. The scattering force equation of two-level atoms is used to analyze the forces on 87Rb atoms in a two-dimensional magneto-optical trap with an optical dipole trap (2D-ODT MOT). In consideration of collisions of atoms with the background gas, the equations of atomic motion are solved by the fourth-order Runge-Kutta method and the trajectories of the atoms are obtained. The number of atoms entering the differential pumping range at different detunings of Gaussian beams and different powers is counted. Finally, the loading of cold atoms in magneto-optical traps of the science chamber is experimentally verified for four operating states in which the red-detuned Gaussian beam and the push light of atomic beams are combined. The theoretical and experimental results show that the 2D-ODT MOT based on the red-detuned Gaussian beam is effective in transmitting cold atomic beams over long distances. Both the loading efficiency and the number of atoms loaded in the science chamber are increased significantly..
Acta Optica Sinica
- Publication Date: Nov. 08, 2021
- Vol. 41, Issue 21, 2102001 (2021)
Detectors
Small Target Detection of Infrared Linear Array Image Based on Complemented Gradient Enhancement
Chenfeng Lou, Yong Zhang, and Ya Liu
Aiming at the problem that the detection of weak and small infrared targets could be affected by false alarm, according to the noise characteristics of infrared line array sensor and the gradient symmetry of small target, a method of constructing multi-scale stacked enhanced re-integrated image (MSERI) in image gradienAiming at the problem that the detection of weak and small infrared targets could be affected by false alarm, according to the noise characteristics of infrared line array sensor and the gradient symmetry of small target, a method of constructing multi-scale stacked enhanced re-integrated image (MSERI) in image gradient space is proposed to detect small infrared target. First, different sizes of small targets are estimated, and the unidirectional gradient images of the original image are calculated from multiple directions. Then, the complementary gradient of the gradient values in the unidirectional gradient image are found to enhance the gradient image. Then, the enhanced gradient image is integrated to restore the image, and the integrated images in different directions are stacked as a image. And, the maximum enhanced value is taken from the stacked images with different estimated sizes as the enhanced result. Finally, according to the peak to peak value of clutter in the neighborhood of pixels from enhanced result, the adaptive threshold is calculated to segment small infrared targets. The experimental results show that the method has better detection ability and lower false alarm rate in various scenarios, and the running speed is better than algorithms with similar performance..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 21, 2104001 (2021)
Research on Detection Capability of Low-Orbit Infrared Satellite to HTV-2-Like Hypersonic Vehicle
Hailong Chen, Ao Zhang, Xuemei Liu, Jing Li, and Shaoguang Li
Due to the advantages of high speed, low altitude and strong maneuverability, it is difficult to effectively detect near space hypersonic vehicles by the early warning and detection system consisted of land/sea-based radars and high orbit infrared satellites in whole process. Therefore, according to the technical charaDue to the advantages of high speed, low altitude and strong maneuverability, it is difficult to effectively detect near space hypersonic vehicles by the early warning and detection system consisted of land/sea-based radars and high orbit infrared satellites in whole process. Therefore, according to the technical characteristics of hypersonic vehicles, the detection capability and global coverage of low-orbit infrared satellites are researched. Firstly, based on the aerodynamic shape of HTV-2-like lift body, the surface temperature distribution of the aircraft under typical operating parameters is simulated. Then, the detection model of low-orbit infrared satellite is established. Combined with the typical parameters of infrared detector, the relationship among signal-to-noise ratio of detector, observation angle, and working band at different orbital altitudes is given, and the effective detection half cone angles of infrared satellites at orbital altitudes of 550 km and 1600 km are obtained. Finally, the configuration and main parameters of low-orbit infrared satellite constellation with global detection capability are given..
Acta Optica Sinica
- Publication Date: Nov. 08, 2021
- Vol. 41, Issue 21, 2104002 (2021)
Diffraction and Gratings
Structure Design and Simulation Analysis Based on Electrically Driven Nanograting
Zhouqiang Zhang, Ling Zhou, Zhongchao Guo, Qianwei Huang, and Xiaofei Li
Aiming at the problems of traditional mechanical gratings, such as unadjustable period, low detection accuracy and inability to realize continuous spectral scanning, a low-voltage direct current driven tunable nanograting based on composite material made of graphene (GNP) and polydimethylsiloxane (PDMS) is proposed, anAim
ing at the problems of traditional mechanical gratings, such as unadjustable period, low detection accuracy and inability to realize continuous spectral scanning, a low-voltage direct current driven tunable nanograting based on composite material made of graphene (GNP) and polydimethylsiloxane (PDMS) is proposed, and the overall structure of grating is designed. The effects of grating structure size and driving voltage on grating period and film temperature are studied by using COMSOL Multiphysics software. The analysis results show that the maximum temperature change of film is about 160 ℃ and the maximum tuning amount of grating period is 160 nm within 5 s under low-voltage driving. Moreover, the changing laws of grating period and film temperature are similar under different driving voltages, which meets the different detection requirements for industrial gases.
.Acta Optica Sinica
- Publication Date: Nov. 08, 2021
- Vol. 41, Issue 21, 2105001 (2021)
Fiber Optics and Optical Communications
Ni-MOF-74-Derived Co/NiO for High-Sensitivity Fiber-Optic CO Sensor
Juncheng Zhou, Wenlin Feng, Xiaozhan Yang, and Lian Wang
A fiber-optic CO sensor based on the Ni-MOF-74 is proposed in this paper. Part of the Ni ions in the Ni-MOF-74 are replaced with Co ions by the doping method of ion replacement to generate Co/Ni-MOF-74. Co/NiO is then obtained by calcination. It has multiple active sites and a specific adsorption capacity for CO molecuA fiber-optic CO sensor based on the Ni-MOF-74 is proposed in this paper. Part of the Ni ions in the Ni-MOF-74 are replaced with Co ions by the doping method of ion replacement to generate Co/Ni-MOF-74. Co/NiO is then obtained by calcination. It has multiple active sites and a specific adsorption capacity for CO molecules. When the CO volume fraction is within 0--60×10 -6, the sensitivity of the fiber-optic sensing system integrating the Co/NiO can reach 60.58 pm/10 -6 and the detection limit is 179.76×10 -9. In addition, the sensor, with a high concentration-wavelength linear goodness-of-fit (fitting coefficient R2=0.97176) and favorable selectivity and temporal stability, has huge application potential for detecting CO at a low volume fraction..
Acta Optica Sinica
- Publication Date: Nov. 01, 2021
- Vol. 41, Issue 21, 2106001 (2021)
Influence of Polarization-Maintaining Fibers on Azimuth Transmission Under Variable Temperature and Electric Field
Zhiyong Yang, Junchen Song, Wei Cai, and Gaoxiang Lu
Given the azimuth transmission errors caused by temperature and electric fields in the non-line-of-sight azimuth transmission system based on polarization-maintaining fibers, we derive azimuth calculation models for polarization-maintaining fibers under the action of a variable temperature and electric field, respectivGiven the azimuth transmission errors caused by temperature and electric fields in the non-line-of-sight azimuth transmission system based on polarization-maintaining fibers, we derive azimuth calculation models for polarization-maintaining fibers under the action of a variable temperature and electric field, respectively, from the perspective of the working principle of the non-line-of-sight azimuth transmission system. We also simulate and analyze the influences of the length and thermal expansion coefficient of the polarization-maintaining fibers and the electric field amplitude on the azimuth transmission accuracy. The experimental results show that when the temperature is 20 ℃, the azimuth solution error is not sensitive to temperature, whereas when the temperature is higher than 20 ℃, it is significantly affected by temperature and the length of the polarization-maintaining fibers. The azimuth transmission error can be controlled by adjusting the thermal expansion coefficient and Poisson’s ratio of the polarization-maintaining fibers. The azimuth solution error is affected by both the electric field magnitude and the length of the polarization-maintaining fibers within the electric field. When the action angle is 45°, the electric field amplitude will not produce an azimuth solution error. The conclusion of the study is of guiding significance for studying the environmental adaptability and improving the system measurement accuracy of non-line-of-sight azimuth transmission systems based on polarization-maintaining fibers..
Acta Optica Sinica
- Publication Date: Nov. 01, 2021
- Vol. 41, Issue 21, 2106002 (2021)
Design of 4-LP Few-Mode Fiber with Low-Differential Mode Delay
Yong Dai, Feng Tian, Yongjun Wang, and Yu Gu
In this study, the structure of 4-LP few-mode fiber with low-differential mode delay is designed based on a dense air hole. The influence of different structural parameters on the differential mode delay is analyzed using the COMSOL software. The simulation results show that the differential mode delay of optical fiberIn this study, the structure of 4-LP few-mode fiber with low-differential mode delay is designed based on a dense air hole. The influence of different structural parameters on the differential mode delay is analyzed using the COMSOL software. The simulation results show that the differential mode delay of optical fiber is below 25 ps/km at a wavelength of C+ L. Therefore, the proposed structure of few-mode fiber with low-differential mode delay can improve the system performance and reduce the complexity and power consumption of the receiver..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 21, 2106003 (2021)
Strain Sensing Performance of Material Packaged Fiber Bragg Grating in Wide Temperature Range
Dequan Feng, Xiaodong Luo, Wei Fan, Baohui Zhu, and Xueguang Qiao
Aiming at the issue of strain of elastic packaging materials for fiber Bragg grating (FBG) sensors used in high-temperature oil and gas wells in a wide temperature range, austenitic stainless steel and trial-produced niobium-based constant-elastic alloys are designed and manufactured into elastic strain elements, and tAim
ing at the issue of strain of elastic packaging materials for fiber Bragg grating (FBG) sensors used in high-temperature oil and gas wells in a wide temperature range, austenitic stainless steel and trial-produced niobium-based constant-elastic alloys are designed and manufactured into elastic strain elements, and the FBGs are pasted on them for packaging to make tension sensors respectively. The strain sensing performance of the two materials at 30--250 ℃ is investigated and compared by applying tension to the sensors at different temperatures. The results show that linearity of the tensile response of the two alloy materials at different temperatures is better than 0.999; however, as temperature increases, the tensile response sensitivity decreases, repeatability decreases, and hysteresis increases. Temperature affects the strain sensing performance of the elastic material; in the temperature range of 30--250 ℃, the sensor packaged using the trial-produced niobium-based constant-elastic alloy is superior than the sensor packaged using the austenitic stainless steel material in terms of repeatability, hysteresis, linearity, and sensitivity stability. Thus, the trail-produced niobium-based constant-elastic alloy can be used as an elastic packaging material for FBG sensors in a wide temperature range.
.Acta Optica Sinica
- Publication Date: Nov. 01, 2021
- Vol. 41, Issue 21, 2106004 (2021)
Fourier Optics and Signal Processing
Analysis and Optimization of Instantaneous Frequency Measurement System Based on Polarization Time Delay Interference
Wei Zhu, Jing Li, Li Pei, Tigang Ning, Jingjing Zheng, and Jianshuai Wang
An instantaneous frequency measurement (IFM) system based on polarization time delay interference is proposed. The amplitude comparison function (ACF) is established by detecting the optical power of the two orthogonal polarization signals. The calculation results show that ACF is only related to the frequency of microAn instantaneous frequency measurement (IFM) system based on polarization time delay interference is proposed. The amplitude comparison function (ACF) is established by detecting the optical power of the two orthogonal polarization signals. The calculation results show that ACF is only related to the frequency of microwave signal to be measured and the time delay difference introduced by birefringence effect of polarization maintaining fiber (PMF), and the tunability of ACF measurement range and accuracy can be realized by adjusting the time delay difference. The simulation results show that the absolute error tolerance of the IFM system is 300 MHz in the frequency range from 0 to 25 GHz. Moreover, the effects of laser wavelength drift, radio frequency signal intensity, bias voltage shift of Mach-Zehnder modulator (MZM), MZM extinction ratio and polarization angle drift of polarization controller 2 (PC2) on the measurement frequency of the system are discussed. Compared with similar methods, the proposed scheme adopts the integrated structure of PMF and polarization beam splitting, which not only realizes the adjustable frequency range, but also simplifies the system structure and reduces the cost..
Acta Optica Sinica
- Publication Date: Nov. 08, 2021
- Vol. 41, Issue 21, 2107001 (2021)
Image Processing
Infrared Target Imaging Liquid Level Detection Method Based on Deep Learning
Xiao Liang, Jiawei Li, Xiaolong Zhao, Junbin Zang, Zhidong Zhang, and Chenyang Xue
The detection of container liquid level is an important link in the process of industrial production, storage and transportation of chemical raw materials. Aiming at the problems that the sensor layout in the existing liquid level detection technology is easily limited by space and the short service life of the sensor The detection of container liquid level is an important link in the process of industrial production, storage and transportation of chemical raw materials. Aiming at the problems that the sensor layout in the existing liquid level detection technology is easily limited by space and the short service life of the sensor in special environments such as high temperature, high pressure, dust and humidity, a method of infrared target imaging liquid level detection based on deep learning is proposed in this paper. Through the optimization training of the infrared image annotation data set of the tank liquid level, the model that can accurately identify the percentage content of liquid in the container is obtained. First, construct a standard data set of tank liquid level and build an image detection framework based on Pytorch's deep learning. Then, enhance the data on the image at the input end, adjust the width and depth of the model, and optimize and train the detection model. Finally, the feature pyramid network and path aggregation network structure are used to fuse the feature information of different size feature maps, the complete intersection over union is used to calculate the regression loss of the bounding box, and the weighted non maximum suppression method is introduced in the post-processing process. The experimental results show that the model has good robustness and recognition effect, the mean average precision is up to 0.804 when intersection over union is 0.5..
Acta Optica Sinica
- Publication Date: Nov. 17, 2021
- Vol. 41, Issue 21, 2110001 (2021)
Stripe Binary Encoding Method Using Genetic Algorithms to Optimize Kernel Parameters of Error Diffusion
Changhui Zhu, Pei Zhou, Jiangping Zhu, Di You, and Shiyong An
Binary fringe projection image is widely used in high speed and high precision 3D surface measurement, and improving the sinusoidal properties of binary coded fringe is of positive significance for improving the accuracy of 3D surface measurement. The traditional and improved error diffusion kernel mostly uses universaBinary fringe projection image is widely used in high speed and high precision 3D surface measurement, and improving the sinusoidal properties of binary coded fringe is of positive significance for improving the accuracy of 3D surface measurement. The traditional and improved error diffusion kernel mostly uses universal diffusion to check fringe image for binary coding, while the influence of image features and projective defocus degree on phase extraction accuracy is less considered. First, the genetic algorithm is used to find the better error diffusion kernel coefficient. Second, the optimization objective function related to defocus degree and sinusoidal fringe period is constructed by linear fitting. Finally, the sinusoidal error diffusion kernel of the optimized binary coded fringe is obtained. Simulation and experimental analysis show that the error diffusion nuclei with minimum phase error are different in different periods under different fuzzy degrees, which confirms the binary value of diffusion check image coding quality is related to image features. Experiment further proves that the phase error of the proposed algorithm can be reduced by 43.86%, 64.37% and 50.10%, respectively, compared with the universal Floyd-Steinberg diffusion method, under three defocus degrees. Compared with the improved Floyd-Steinberg diffusion method, the phase error of the proposed algorithm can be reduced by 13.51%, 18.48% and 17.65%, respectively..
Acta Optica Sinica
- Publication Date: Nov. 21, 2021
- Vol. 41, Issue 21, 2110002 (2021)
Imaging Systems
Study of Multi-Resolution Microscopic Correlation Imaging Based on Optimized Hadamard Matrix
Yueshu Feng, Cheng Zhou, Xuan Liu, Xiaohan Liu, and Lijun Song
A multi-resolution microscopic correlation imaging method based on a digital micromirror device was proposed to meet the diverse needs of microscopic imaging and resolve the contradiction between imaging quality and imaging time in practical applications. In this method, an LED was used as the background illumination sA multi-resolution microscopic correlation imaging method based on a digital micromirror device was proposed to meet the diverse needs of microscopic imaging and resolve the contradiction between imaging quality and imaging time in practical applications. In this method, an LED was used as the background illumination source, and the original optical path of a research-grade upright fluorescence microscope was modified to be an optical path of correlation imaging. The multi-resolution optimized Hadamard matrix was adopted as the preset pattern of the digital micromirror device. Continuous multi-resolution microscopic imaging of biological tissue samples was achieved by this system. The experimental results demonstrate that the resolution of the multi-resolution microscopic correlation imaging system reaches 218 nm. Eight groups of images in different resolutions can be output simultaneously after a single measurement. Therefore, different resolutions can be selected according to particular image quality requirements in practical applications. By reducing the imaging time and storage space needed, this system greatly improves the flexibility of microscopic imaging. The proposed multi-resolution microscopic correlation imaging method can be extended to fields such as cell screening and real-time cell imaging. It is expected to promote the application of correlation imaging in microscopic imaging of cells and biological tissues..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 21, 2111001 (2021)
Instrumentation, Measurement and Metrology
Effect of Assembly Stress Symmetry of Interference Optical Path on Shupe Error
Yunqiang Fan, Jixun Huang, and Jing Li
Shupe error is one of the major technical bottlenecks affecting the application of high-precision fiber-optic gyroscopes (FOGs). To address the problem that the temperature performance of high-precision FOGs deteriorates after the assembly and packaging of the optical path, this paper analyzed the temperature error of Shupe error is one of the major technical bottlenecks affecting the application of high-precision fiber-optic gyroscopes (FOGs). To address the problem that the temperature performance of high-precision FOGs deteriorates after the assembly and packaging of the optical path, this paper analyzed the temperature error of the FOG optical path and revealed the effect of the assembly stress of the interference optical path on Shupe error. Temperature errors caused by the assembly stress under different conditions were tested. Three initially installed FOGs with a full-temperature zero-bias range of 0.11 (°)/h were chosen and the tail fibers of their fiber coils and Y-waveguides were bonded in different fashions for different assembly stress symmetry. When the bonding length of the tail fibers was 30 cm, the zero-bias ranges of the two FOGs with poor assembly stress symmetry became 0.24 (°)/h and 0.43 (°)/h, signifying significant deterioration of FOG temperature performance. In contrast, the one with better assembly stress symmetry became 0.13 (°)/h, indicating no significant deterioration of FOG temperature performance. The results show that poor assembly stress symmetry of the interference optical path could lead to distinctive deterioration of FOG temperature performance. In addition, the deterioration degree is directly related to the symmetry of assembly stress. More precisely, better assembly stress symmetry results in smaller deterioration..
Acta Optica Sinica
- Publication Date: Nov. 23, 2021
- Vol. 41, Issue 21, 2112002 (2021)
Lasers and Laser Optics
Broadband Chaos Signal Generation Based on Dual-mode DFB Laser with Optical Feedback
Yiteng Zhang, Zhiwei Jia, Qingtian Li, Longsheng Wang, and Anbang Wang
We proposed and numerically verified a method of generating broadband chaotic signals using a dual-mode distributed feedback (DM-DFB) semiconductor laser with optical feedback. A theoretical model of the laser was established according to the dual-longitudinal-mode Lang-Kobayashi equation. It was determined that the geWe proposed and numerically verified a method of generating broadband chaotic signals using a dual-mode distributed feedback (DM-DFB) semiconductor laser with optical feedback. A theoretical model of the laser was established according to the dual-longitudinal-mode Lang-Kobayashi equation. It was determined that the generation mechanism of the broadband chaotic signals was the mode beat effect. The influences of mode interval, bias current, and feedback coefficient on the chaotic signal bandwidth were numerically investigated. Subsequently, a dual-mode laser was designed by simulation. In the mirror feedback system, a chaotic signal with a bandwidth of 38.6 GHz was generated under a high bias current and strong feedback intensity. The structure provides a new idea for broadband integrated chaotic sources..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 21, 2114001 (2021)
Chaotic Characteristics of Erbium-Doped Fiber Laser with Optical Injection
Jingfeng Ren, Lingzhen Yang, Wanghua Zhu, Linlin Fan, Weijie Ding, and Juanfen Wang
The output characteristics of a chaotic fiber laser with optical injection were studied experimentally. After a chaotic fiber laser with a ring cavity was built, the nonlinear Kerr effect of the fibers was employed for generation of chaotic laser. The chaotic laser generated by the master laser was injected into a chaoThe output characteristics of a chaotic fiber laser with optical injection were studied experimentally. After a chaotic fiber laser with a ring cavity was built, the nonlinear Kerr effect of the fibers was employed for generation of chaotic laser. The chaotic laser generated by the master laser was injected into a chaotic erbium-doped fiber laser via an optical isolator and a fiber coupler to achieve external optical injection. The time series, spectra, autocorrelations, stabilities, and complexities of the chaotic signals generated by the slave laser were studied after chaotic signals of different power were injected from the master laser to the slave laser. The results show that the time series of chaotic signals after optical injection are random and the amplitude frequency distributions fit Gaussian distribution. The spectra have no obvious periodic characteristics, and the autocorrelations are excellent. The chaotic output of an erbium-doped fiber laser with optical injection ensures a complex and more stable chaotic source..
Acta Optica Sinica
- Publication Date: Nov. 24, 2021
- Vol. 41, Issue 21, 2114002 (2021)
Letters
Development of Mid-Wave Infrared Image Sensor with Frame Rate of 1 MHz
Jiqing Zhang, Gongrong Deng, Wenbiao Mao, Shengyou Zhong, Nan Chen, Haosen Chen, and Libin Yao
A 64×64 ultra-high-speed digital readout integrated circuit (DROIC) with an on-chip integrated memory is designed for infrared focal plane signal readout. By bonding the DROIC with a mid-wave infrared focal plane array detector, an ultra-high-speed mid-wave infrared image sensor is developed. Experimental results A 64×64 ultra-high-speed digital readout integrated circuit (DROIC) with an on-chip integrated memory is designed for infrared focal plane signal readout. By bonding the DROIC with a mid-wave infrared focal plane array detector, an ultra-high-speed mid-wave infrared image sensor is developed. Experimental results demonstrate that the developed infrared image sensor achieves a frame rate of 1 MHz and a record length of 100 frame, with approximately linear response to blackbody temperature and a temperature resolution better than 3.6 K..
Acta Optica Sinica
- Publication Date: Nov. 20, 2021
- Vol. 41, Issue 21, 2136001 (2021)
Optical Design and Fabrication
Stability of Air Floating Optical Platform Based on Optimal Tuned Liquid Column Damper
Wenhui Cui, Jianqiang Zhu, Yuanqi He, Zhigang Liu, Quantang Fan, Weiheng Lin, and Ziming Dong
In order to solve the problem of ultra-low frequency vibration reduction of air-floating optical platform in horizontal direction and improve the output quality of ultra-precision experiments, the fluid-structure coupling theory of air-floating optical platform based on tuned liquid column damper (TLCD) is proposed to In order to solve the problem of ultra-low frequency vibration reduction of air-floating optical platform in horizontal direction and improve the output quality of ultra-precision experiments, the fluid-structure coupling theory of air-floating optical platform based on tuned liquid column damper (TLCD) is proposed to achieve optimal tuning control and improve experimental accuracy. First, the principle of TLCD is analyzed and the design range of natural frequency is deduced. Second, the fluid-structure coupling system of TLCD air floating optical platform is modeled and deduced. Then, the response characteristics and parameter optimization of the convection-solid coupling system are analyzed. Finally, the time-domain response and optical experiments are verified and analyzed. The results show that when the natural frequency ratio is constant, there is an optimal damping ratio which can make the maximum vibration reduction efficiency, and the vibration reduction efficiency at the resonance peak reaches 66.76%. At the same time, the TLCD damping system can be suitable for broadband excitation by adjusting the keyhole plate, and the effective control of the dynamic response of the air floating optical platform is beneficial to improve the experimental accuracy, which provides an effective control means for the improvement of the quality of ultra-precision experiment..
Acta Optica Sinica
- Publication Date: Nov. 17, 2021
- Vol. 41, Issue 21, 2122001 (2021)
Optical Devices
Effect of Bow Tie Type Silver Metal Array Structure on Light Extraction Efficiency of GaN-Based Light Emitting Diodes
Hua Tang, Qiang Li, Qifan Zhang, Mingyin Zhang, Shengnan Zhang, Peng Hu, Xuzheng Wang, Ye Zhang, and Feng Yun
In order to improve the luminous efficiency of GaN-based light-emitting diodes (Light Emitting Diode, LED), a bow tie type silver metal array with a simple process and low cost is designed, and the structure is integrated on the surface of the GaN-based light-emitting diode. Without damaging the epitaxial structure, thIn order to improve the luminous efficiency of GaN-based light-emitting diodes (Light Emitting Diode, LED), a bow tie type silver metal array with a simple process and low cost is designed, and the structure is integrated on the surface of the GaN-based light-emitting diode. Without damaging the epitaxial structure, the light extraction efficiency of light-emitting diodes in different wavelength bands can be improved by exciting the local surface plasmon effect. The finite-difference time-domain method is used to systematically simulate and calculate the influence of bow tie type silver metal arrays on the light extraction efficiency of GaN based light-emitting diodes at different incident wavelengths. The results show that the photoluminescence peak intensity of the LED with the central wavelength of 370, 425 and 525 nm is increased by 71.1%, 148.2% and 105.9%, respectively, compared with that of the LED without surface structure..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 21, 2123001 (2021)
Structural Design of Near Ultraviolet Nadir Imaging Spectrometer
Jianyu Yang, Xuan Yang, and Jianhua Zheng
According to the requirement of atmospheric environment monitoring and forecasting, a kind of near ultraviolet nadir imaging spectrometer which meets the requirements of optical system is designed. First, according to the given optical system, the overall configuration of the device is designed, and the primary mirror According to the requirement of atmospheric environment monitoring and forecasting, a kind of near ultraviolet nadir imaging spectrometer which meets the requirements of optical system is designed. First, according to the given optical system, the overall configuration of the device is designed, and the primary mirror and secondary mirror are optimized by variable density topology, and the layout function of each module is designed. Then, the finite element simulation analysis is carried out for the scheme, and the optical, mechanical, and thermal integration analysis is carried out for the equipment system. Finally, the experimental verification is carried out. The experimental results show that the first order frequency of the device is greater than 100 Hz; the largest magnification of sine vibration test is 1.04; maximum error of random vibration test results is 4.72%; the spectral characteristics of the equipment are consistent before and after the mechanical experiment. Experimental results show that the proposed structural design meets the technical requirements, and provides a new reference for the structural design of near ultraviolet nadir imaging spectrometer in the future..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 21, 2123002 (2021)
OPTOELECTRONICS
Near-Infrared Integrated Photodetector Based on PdSe2Nanowires Film/Si Heterojunction
Yanan Lin, Yadong Wu, Haiyang Cheng, Yang Lu, Chao Xie, and Linbao Luo
In this study, a PdSe2 nanowires (NWs) film/Si heterojunction-based near-infrared (NIR) integrated photodetector is presented. The large-area PdSe2 NWs are synthesized via thermal-assisted selenization of pregrown Pd NWs, and the integrated photodetector with 8×8 device units is obtained by assembly and transfer oIn this study, a PdSe2 nanowires (NWs) film/Si heterojunction-based near-infrared (NIR) integrated photodetector is presented. The large-area PdSe2 NWs are synthesized via thermal-assisted selenization of pregrown Pd NWs, and the integrated photodetector with 8×8 device units is obtained by assembly and transfer of the NWs. According to optoelectrical characterization, the as-fabricated device shows visible photoresponse over a broad wavelength range of 200-1300 nm with a peak response at approximately 810 nm. The device exhibits a responsivity (R) of 166 mA·W-1 under 810-nm light irradiation at zero bias, which increases to 3.24 A·W-1 when applying a -2 V bias voltage. Furthermore, the integrated device exhibits excellent uniformity, and all 64 devices have a current On/Off ratio of approximately 60. Because of its high-performance uniformity, the integrated photodetector can be used as an optical image sensor to accurately record a "LASDOP" pattern projected by NIR light, indicating a promising future use..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 21, 2125001 (2021)
Physical Optics
Properties of Optical Vortex Lattice Generated via Multiple Plane Wave Interference
Xueyun Qin, Liuhao Zhu, Yuping Tai, Jie Tang, and Xinzhong Li
Multiple plane wave interference (MPWI) is a typical method to produce an optical vortex lattice (OVL). In this letter, via defining the wave vector space coordinate system, a modulating method of OVL with MPWI is proposed, the OVLs generated by four plane wave and five plane wave interference are simulated, the gradieMultiple plane wave interference (MPWI) is a typical method to produce an optical vortex lattice (OVL). In this letter, via defining the wave vector space coordinate system, a modulating method of OVL with MPWI is proposed, the OVLs generated by four plane wave and five plane wave interference are simulated, the gradient force and energy flow of the OVL are calculated, and its application in the field of particle manipulation is analyzed. Accordingly, a more flexible and richer optical field distribution is obtained via adjusting the size of the partial wave vector and the angle of the rotation wave vector. Finally, by analyzing the gradient force and energy flow, it is found that the light field with a specific purpose can be generated by this method when manipulating particles. This study enriches the diversity of modes of OVL generated by MPWI and provides a novel idea for the study of OVL based on MPWI..
Acta Optica Sinica
- Publication Date: Nov. 23, 2021
- Vol. 41, Issue 21, 2126001 (2021)
Continuous Rotation of Airy-Hermite-Gaussian Beams with a Cross Phase Propagating Through Uniaxial Crystals
Kaicheng Zhu, Zihao Wu, Huiqin Tang, and Jie Zhu
According to the beam transmission theory in uniaxial crystal, the analytical expression of Airy-Hermite-Gaussian beam (AiHGB) with a cross phase propagating in uniaxial crystal is obtained. The numerical simulation results show that AiHGB with initial cross phase is still linearly polarized, but not necessarily transmAccording to the beam transmission theory in uniaxial crystal, the analytical expression of Airy-Hermite-Gaussian beam (AiHGB) with a cross phase propagating in uniaxial crystal is obtained. The numerical simulation results show that AiHGB with initial cross phase is still linearly polarized, but not necessarily transmission invariant. Specifically, depending on the cross phase coefficient, beam parameters, and crystal material parameters, the initial cross phase will cause AiHGB spot to rotate continuously, and the total rotation angle is 90° in the whole transmission process from near field to far field. When the cross phase coefficient is large enough, the AiHGB spot only rotates; When the cross phase coefficient is appropriate small, the AiHGB spot not only rotates in orientation, but also changes in spot shape.These results show that by properly selecting the crystal material (i.e. refractive index) and the coefficient of additional cross phase factor, the orientation and structure of beam pattern shape can be accurately adjusted, and the refractive index of crystal material can be determined or the coefficient of cross phase factor can be measured..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 21, 2126002 (2021)
Misalignment Effect on Far-Field Spatio-Temporal Characteristics in Off-Axis Gregorian System
Bilong Hu, Wei Li, Xiao Wang, Yanlei Zuo, Jie Mu, Xiaodong Wang, Zhaohui Wu, Zhaoli Li, Xiaoming Zeng, and Jingqin Su
Beam expander is an essential part of ultrahigh peak power laser system. The reflective beam expander can solve the problem of dispersion, chromatic aberration, and pulse front distortion, which can be produced by transmission beam expander. The reflective beam expansion and focusing process based on ray tracing methodBeam expander is an essential part of ultrahigh peak power laser system. The reflective beam expander can solve the problem of dispersion, chromatic aberration, and pulse front distortion, which can be produced by transmission beam expander. The reflective beam expansion and focusing process based on ray tracing method and Huygens-Fresnel principle is analyzed. The influence of the off-axis parabolic mirror misalignment on the spatio-temporal characteristics of the laser pulse are calculated, when the parameters of the reflective beam expander system are different, and the error tolerance range of Strehl ratio and peak intensity is given..
Acta Optica Sinica
- Publication Date: Nov. 17, 2021
- Vol. 41, Issue 21, 2126003 (2021)
Quantum Optics
Coherent Optical Transmission Characteristics Based on Magneto-Optical Force System
Baocheng Hou, and Huajun Chen
A magneto-optical force system including magnon-phonon-photon interaction is proposed, which comprises of a magnon (YIG sphere) and an optical resonator. In this system, the magnons are characterized by the collective motion of the majority of spins in macroscopic ferrimagnet, and coupled with photons via magnetic dipoA magneto-optical force system including magnon-phonon-photon interaction is proposed, which comprises of a magnon (YIG sphere) and an optical resonator. In this system, the magnons are characterized by the collective motion of the majority of spins in macroscopic ferrimagnet, and coupled with photons via magnetic dipole interaction and with phonons via magneto-strictive interaction, respectively. Based on the rigorous theories of quantum optics and input-output relationship, the coherent optical transmission properties in the proposed system are studied. By controlling the parameters of the system, the output field can be controlled effectively, which provides a promising platform for the study of macroscopic quantum phenomena..
Acta Optica Sinica
- Publication Date: Nov. 17, 2021
- Vol. 41, Issue 21, 2127001 (2021)
Reviews
Development of Microlens Arrays: From Fabrication to Photonic Applications
Jianjun Li, Chunyan Chu, Weitong Lu, Pingping Zhang, Gaoling Yang, Haizheng Zhong, and Yuejin Zhao
Microlens array is a multi-functional micro-optical element that can modulate incident light to realize beam expansion, beam shaping, light splitting, and optical focusing, and further to achieve large viewing angle, low aberration, small distortion, high time resolution, and infinite depth of field. Microlens array haMicrolens array is a multi-functional micro-optical element that can modulate incident light to realize beam expansion, beam shaping, light splitting, and optical focusing, and further to achieve large viewing angle, low aberration, small distortion, high time resolution, and infinite depth of field. Microlens array has important application potential in miniaturization, intelligence and integration of optoelectronic devices and optical systems. This review article first describes the design principle and development history of microlens arrays. Then the recent progress on the fabrication of microlens arrays including inkjet printing, laser direct writing, screen printing, photolithography, photopolymerization, thermal reflow, and chemical vapor deposition is reviewed. In addition, the applications of microlens arrays in the fields of imaging sensors, lighting, display, and solar cells are summarized. Finally, the future development directions are prospected, and the development trend and future challenges of curved microlens, superimposed compound eye system and the combination of microlens with new optoelectronic materials are discussed..
Acta Optica Sinica
- Publication Date: Oct. 28, 2021
- Vol. 41, Issue 21, 2100001 (2021)
Scattering
Dimension Measurement of Nanorods Based on Depolarized-Polarized Image-Based Dynamic Light Scattering
Zeqi Liu, Xiaoshu Cai, Briard Paul, and Wu Zhou
Brownian motion of 2D nanorods can be described by translational diffusion and rotational diffusion. In this paper, a method called depolarized-polarized image-based dynamic light scattering (DIDLS) is proposed, which is used for measuring the size and size distribution of nanorods by analyzing the vertical-vertical anBrownian motion of 2D nanorods can be described by translational diffusion and rotational diffusion. In this paper, a method called depolarized-polarized image-based dynamic light scattering (DIDLS) is proposed, which is used for measuring the size and size distribution of nanorods by analyzing the vertical-vertical and vertical-horizontal polarized dynamic light scattering signals induced by the translational and rotational diffusions of nanorods with Brownian movement under polarized laser. Firstly, the correlation degree function between consecutive polarized dynamic images is studied, and the average values of the translational and rotational diffusion coefficients can be estimated. Then, the length as well as ratio of length to diameter of nanorods are calculated through two inversions, and the two-dimensional distribution of particles is obtained. The influence of laser wavelength on measurement results is analyzed, and the baseline value is suggested as a criterion for judging the signal and noise ratio (SNR). The measurements for gold nanorods with diameter of 20 nm and length of 300 nm under 650,780,and 905 nm laser wavelengths are conducted, and the average size and size distribution of gold nanorods are obtained..
Acta Optica Sinica
- Publication Date: Nov. 17, 2021
- Vol. 41, Issue 21, 2129001 (2021)
Spectroscopy
Spatial Characteristics of Spectral Intensity of Laser Induced Plasma
Chenwei Sun, Yang Bu, Yuanhang Wang, Fang Wu, Yachao Cai, and Xiangzhao Wang
Laser wavelength and incident angle are important factors that influence the spatial distribution and spectral intensity of laser-induced plasma. Based on the fluid dynamics and SAHA equation, this paper simulates the two-dimensional spatial distribution of laser-induced plasma, calculates the spatial distribution of rLaser wavelength and incident angle are important factors that influence the spatial distribution and spectral intensity of laser-induced plasma. Based on the fluid dynamics and SAHA equation, this paper simulates the two-dimensional spatial distribution of laser-induced plasma, calculates the spatial distribution of radiation spectrum of the excited plasma, and studies the influences of laser incident angle, wavelength and other parameters on the spatial distribution characteristics of plasma characteristic spectral lines. The research results show that that 0° is the best incident angle for 1064 nm laser with different delay conditions. When the incident angle is 0°, the excited plasma radiation has stronger spectral signals at different detection angles. Moreover, the optimal detection angles are ±41°, ±11° and ±12° at 100 ns, 500 ns and 1000 ns delay conditions, respectively. For different wavelengths, when the delay time is 100 ns or 500 ns and the laser is incident at 0°, the intensity of plasma spectrum excited by 1064 nm laser at each detection angle is stronger compared that by a short wavelength laser. When the time delay is 100 ns, the intensity of the plasma spectrum excited by the 1064 nm laser at the optimal detection angle is approximately twice that by 532 nm or 266 nm laser at each optimal detection angle. With the decrease of the absolute value of the detection angle, the spectral intensity of the plasma radiation first increases and then decreases at the optimal detection angle. The simulation results are verified by the laser induced breakdown spectroscopy experimental results with incident wavelengths of 532 nm and 1064 nm, respectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 21, 2130001 (2021)
Ultrafast Optics
Study on Field Curvature Characteristics of Pulse-Dilation Framing Tube
Yunfei Lei, Jinyuan Liu, Houzhi Cai, Junkun Huang, Yong Wang, and Pokun Deng
In this paper, a pulse-dilation framing tube is developed, and the field curvature characteristics and off-axis spatial resolution of this tube are analyzed. Multiple short magnetic lenses are used in this tube to image the photoelectrons from the cathode onto the receiving surface of the microchannel plate. The field In this paper, a pulse-dilation framing tube is developed, and the field curvature characteristics and off-axis spatial resolution of this tube are analyzed. Multiple short magnetic lenses are used in this tube to image the photoelectrons from the cathode onto the receiving surface of the microchannel plate. The field curvature characteristics of lenses number imaging are studied by simulations and verified by experiments. The simulation results show that the field curvature of the imaging system can be reduced by multiple lenses and the spatial resolution is improved. When the imaging ratio is 1∶1, the axial deviations of simple lens, bilens, triplet lens, and four lenses from Gaussian image plane are 13 cm, 4.7 cm, 2.5 cm, and 1.7 cm, respectively. The experimental results show that the off-axis modulation of the four lenses system is 40% higher than that of the single lens..
Acta Optica Sinica
- Publication Date: Nov. 17, 2021
- Vol. 41, Issue 21, 2132001 (2021)
Vision, Color, and Visual Optics
Orthogonal Color Transfer with Depth Feature Fusion for True-Color EMCCD
Ke Ding, Wenqu Zhao, Yi Cai, Fang Dai, Jie Xu, Jiandong Xu, and Lingxue Wang
The red (R), green (G), and blue (B) filtering that has high transmittance in the near-infrared (NIR) band (i.e., R+NIR, G+NIR, and B+NIR, respectively) is a common way for an electron-multiplying charge-coupled device (EMCCD) to achieve true-color imaging and maintain high imaging sensitivity under low illumination. HThe red (R), green (G), and blue (B) filtering that has high transmittance in the near-infrared (NIR) band (i.e., R+NIR, G+NIR, and B+NIR, respectively) is a common way for an electron-multiplying charge-coupled device (EMCCD) to achieve true-color imaging and maintain high imaging sensitivity under low illumination. However, the introduction of NIR components can cause color distortion and color distribution compression. An orthogonal color transfer model was built under the constraint that a pair of pixel-registered source and reference images shared the same coordinate representation in the standard orthogonal color space. A feature dimension was introduced into the model through the convolution neural network to alleviate the one-to-many mapping problem caused by color deviation and color distribution compression. An end-to-end color transfer network was created. It consisted of two parts: a pre-trained front-end network that clustered pixels into different feature channels according to the texture and semantic meaning of an EMCCD image and a trainable back-end network that performed the color transfer of each cluster based on the coding statistics characteristics of pixels of each feature image. The proposed model, tested by real-world images, proved to have wide applicability and be able to achieve natural color in different scenes under different illuminances. Experiments show that the peak signal-to-noise ratio of a true-color image transferred by the proposed method is increased by 75.78% on average compared with that of a color-distorted image. The structural similarity index measurement is increased by 103.74%, and the chromatic aberration is decreased by 67.48%..
Acta Optica Sinica
- Publication Date: Nov. 21, 2021
- Vol. 41, Issue 21, 2133001 (2021)
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