2024
2024
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Record 349 of
Title:Design of Optical-mechanical System of Catadioptric Aerial Mapping Camera Based on Secondary Mirror Image Motion Compensation
Author Full Names:Zhang, Hongwei(1); Qu, Rui(1); Chen, Weining(1); Yang, Hongtao(1)Source Title:Guangzi Xuebao/Acta Photonica SinicaLanguage:ChineseDocument Type:Journal article (JA)Abstract:Aerial surveying and mapping is an important technical means of civil/military surveying and mapping，which can quickly obtain large-scale and high-precision scale mapping of the target area in a short period of time，and accurately obtain coordinate information of the target plane and elevation information on the map. The acquired information plays an important supporting role in digital city construction，land resources survey，military strategic planning，etc. With the development of aerial surveying and mapping technology，the requirements for aerial mapping cameras have been further improved. It is required that aerial mapping cameras can achieve wide width，high precision and large scale mapping. In order to meet the above requirements，the aerial mapping camera adopts scan imaging mode，but this imaging mechanism will introduce forward/scan image motion，which will affect the image quality. In order to satisfy the image stabilization accuracy of the aerial mapping camera，it is necessary to compensate the image motions. Therefore，a catadioptric aerial mapping camera based on secondary mirror image motion compensation is designed in this paper. Aiming at the dynamic image motion problem of the aerial mapping camera in the process of ground swing imaging，the vector aberration theory for a two-mirror telescopic systems is adopted. The secondary mirror is used as the image motion compensation element， and the comprehensive image motion compensation of the aerial mapping camera is realized through the secondary mirror multi-dimensional motion. However，in the process of compensating the image motion，the secondary mirror will be eccentric and inclined，which will cause the secondary mirror to be off-axis and affect the image quality. Therefore，a misalignment optical system model is established to study the relationship between the deviation vector of the secondary mirror field and the misalignment of the secondary mirror field，and the influence of the secondary mirror motion on the image quality is analyzed. Meanwhile，a design example of the optical-mechanical system of the catadioptric aerial mapping camera based on the secondary mirror image motion compensation is given. The effective focal length of the optical system is 450 mm，and the working spectrum is 435~900 nm. The field of view of the optical system is 4.17×3.13，and the F-number is 4.2. In the design process，the optical-mechanical system of aerial mapping camera adopts non-thermal design to adapt to the working environment of ?40 ℃~60 ℃. In order to verify the image motion compensation ability of multi-dimensional motion of the optical element，an experimental platform is built to conduct laboratory imaging tests and field imaging tests on the aerial mapping camera. The laboratory imaging test results show that the dynamic resolution of the aerial mapping camera using the image motion compensation technology can reach 74 lp/mm，and the image motion compensation accuracy is better than 0.5 pixels，which meets the design expectation. In addition，the field imaging test results show that compared with disable image motion compensation function，the aerial survey camera with enable image motion compensation function can acquire sharp edges，clear images，and image quality can meet the expected requirements. Therefore，the camera has the advantages of high accuracy of image motion compensation，compact volume and high reliability，which lays a theoretical foundation for the direction of light and small，high precision and large scale mapping. ? 2024 Chinese Optical Society. All rights reserved.Affiliations:(1) Aircraft Optical Imaging and Monitoring and Measurement Technology Laboratory, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, ChinaPublication Year:2024Volume:53Issue:2Article Number:0222001DOI Link:10.3788/gzxb20245302.0222001數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240715561717 -
Record 350 of
Title:Optimization Design of Large Aperture Curved Prism Bonding Based on Finite Element Analysis
Author Full Names:Feng, Jun(1,2); Li, Siyuan(1); Wang, Feicheng(1,2); Chen, Wencong(1,2); Tian, Feifei(1,2); Jia, Xinyin(1)Source Title:Guangzi Xuebao/Acta Photonica SinicaLanguage:ChineseDocument Type:Journal article (JA)Abstract:Aiming at the working conditions and performance requirements of large-diameter curved prisms with high face shape precision，an optimized design approach is proposed for bonding such prisms while considering the adhesive curing shrinkage stress. Based on this approach，the bonding process for large-diameter curved prisms is successfully optimized. Firstly，the finite element differential equation for the shrinkage stress during glue curing is derived based on the non-free curing model of the glue. Secondly，by applying the principles of support structure design and flexible structure design theory，a meticulously devised circular flexible bonding structure was created. The topology of the frame structure was optimized with flexibility as the primary objective while adhering to structural weight constraints，resulting in an impressive lightweight rate of 55.79%. Subsequently，a simulation and analysis model was developed to investigate the impact of adhesive curing shrinkage on mirror surface shape using the temperature loading method. The response surface model for the colloid parameters' equivalent gel contraction force was established，achieving a goodness of fit of 97.56%. It was found that the equivalent gel contraction force increased with the increase of colloid contraction rate and thickness. Additionally，the equivalent gel contraction force and the area of colloid spot exhibited different monotonous increasing and decreasing trends under varying gel contraction rates. The degree of influence of colloid contraction rate on the equivalent gel contraction force was found to be the largest，while the area of colloid spot had the least influence on the equivalent gel contraction force. The optimized parameters for the colloid were determined to be 9 mm×23 mm×0.1 mm. The study investigated the influence of adhesive type，gel parameters，and bonding quantity on the surface shape of curved prism components. The results obtained from the surface shape simulation analysis of curved prisms using three kinds of epoxy adhesives（3M-2216，Milbond，and GHJ-01）under the same conditions were compared in terms of relevant properties of adhesive materials. The influence of surface shapes before and after curing was also examined to compare the performance of the adhesives. It was determined that the 3M-2216 adhesive exhibited optimum performance among the three kinds of adhesives. With the increase in the number of bonds，the deformation value of the front and rear mirrors shows a trend of decreasing and then increasing. The maximum stress value shows a fluctuating downward trend，while the average stress value shows a trend of decreasing and then slowly increasing. When bonded with 6 glue dots，the deformation of the upper and lower dome positions can be precisely restrained，so that the maximum deformation is concentrated in the center of the mirror. The deformation value and stress value are smaller. In summary，an optimized solution for high face shape accuracy is obtained by choosing 3m-2216 epoxy adhesive，designing arc-shaped glue spots and their flexible bonding structure. Under these conditions，with 6 glue spots on each side and a homogeneous distribution of gluing，it was found that the PV value for face shape accuracy of the curved prism's front mirror face is 2.78 nm with an RMS value of 0.53 nm；for its back mirror face，it is 1.58 nm with an RMS value of 0.31 nm which is 98% lower than that of the initial structure. Compared to the initial structure，wavefront error caused by adhesive curing has been reduced by 98.89%. Additionally，environmental adaptability was analyzed using the finite element method： Z-direction self-weight significantly impacts curved prism assembly followed by X-direction；Y-direction has the least effect. The maximum deformation observed in the assembly is at its upper surface center（67.6 nm），while the maximum stress value（0.18 MPa）is found on the bonding surface of the bonding ring. For front mirror surface shape accuracy：X-direction self-weight plays a major influence with PV value being 16.3 nm and RMS value of 3.61 nm；whereas for rear mirror surface，Z-direction self-weight plays a dominant role with PV value of 29.3 nm and RMS value of 5.34 nm. The thermal deformation and thermal stress reach their maximum values when subjected to a uniform temperature rise of 4 ℃ on gel material. As the temperature gradient increases，both thermal deformation and thermal stress initially decrease before increasing again. Among different temperature gradients tested，a rise in temperature gradient by 3 ℃ shows minimal impact on curved prism assembly，which validates its structural design's rationality. After implementing an optimized gluing scheme，the face shape accuracy for curved prism mirrors is less than 0.059λ in terms of PV value，and less than 0.012λ in terms of RMS value. This proposed gluing optimization scheme considers shrinkage stress during the curing process，meeting high-precision optical system requirements. The findings from this study can serve as a reference for optimizing high-face shape precision gluing schemes and support structure designs for large-diameter curved prisms. ? 2024 Chinese Optical Society. All rights reserved.Affiliations:(1) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:53Issue:11Article Number:1122002DOI Link:10.3788/gzxb20245311.1122002數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20245117558554 -
Record 351 of
Title:Fourier ptychographic reconstruction with denoising diffusion probabilistic models
Author Full Names:Wu, Kai(1,2); Pan, An(1); Gao, Wei(1)Source Title:Optics and Laser TechnologyLanguage:EnglishDocument Type:Journal article (JA)Abstract:Fourier ptychographic microscopy (FPM) is a promising computational imaging technique that can bypass the diffraction limit of the objective lens and achieve high-resolution, wide field-of-view imaging. The FPM setups firstly capture a series of low-resolution (LR) intensity images by angle-varied illumination and then reconstruction algorithms recover the high-resolution (HR) complex-valued object from the LR measurements. The image acquisition process commonly introduces noise, ultimately leading to degradation in the quality of the reconstruction results. In this paper, we report a noise-robust Fourier ptychographic reconstruction method that generates the HR complex-valued object estimation using the image priors specified by denoising diffusion probabilistic models (DDPM). First, the initial estimation of the HR complex-valued object is matched with an intermediate state in the Markov chain defined by DDPM. Then, the noisy initial solution is iteratively updated to a high-quality reconstruction result in the reverse process of DDPM and gradient descent correction is incorporated to enforce data consistency with the LR measurements. The proposed method integrates DDPM specified image priors and gradient descent correction, achieving solutions with less noise-related artifacts and high fidelity for HR complex-valued object estimation in Fourier ptychographic reconstruction. We apply the proposed method on both synthetic and real captured data. The experimental results show that our method can efficiently suppress the impact of noise and improve reconstruction results quality. ? 2024 Elsevier LtdAffiliations:(1) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:176Article Number:111016DOI Link:10.1016/j.optlastec.2024.111016數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20241715963426 -
Record 352 of
Title:Temperature Measurement Method for Small Target Medium-Wave Infrared Spectral Radiation Based on Distance Correction
Author Full Names:Li, Wen-Kai(1,2); Zhou, Liang(1); Liu, Zhao-Hui(1); Gui, Kai(1); Liu, Kai(1); Li, Zhi-Guo(1); Xie, Mei-Lin(1)Source Title:Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral AnalysisLanguage:ChineseDocument Type:Journal article (JA)Abstract:For long-distance space targets moving at high speeds, temperature is one of the important parameters to characterize their working state and performance. Accurately obtaining the temperature of the target has an important reference value for judging its motion state and predicting its situation development. At present, the commonly used processing method of surface target or point target is no longer applicable to the measurement of the radiation characteristics of small targets. At the same time, spectral detection increases the distinguishable information of the target in the wavelength dimension, which can accurately obtain the distribution of the target energy with wavelength, providing a possibility for the inversion of the target temperature, and has great application potential. The slitless spectrometer can reduce the requirements for tracking and stabilization accuracy of space targets, has the characteristics of simple structure, high frame rate and fast response speed, and has high application value in astronomical observation and spacecraft observation. In this paper, we analyzed the spectral calibration model of target infrared radiation characteristic measurement and determined the main parameters in the linear response model of infrared detector pixels. In order to reduce the influence of imaging distance on temperature measurement accuracy, we proposed a target temperature inversion model based on distance correction. The improved temperature measurement accuracy meets the accuracy requirements in practical engineering applications and greatly affects infrared radiation spectrum temperature measurement. Certain guiding significance. ? 2024 Science Press. All rights reserved.Affiliations:(1) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:44Issue:4Start Page:1158-1164DOI Link:10.3964/j.issn.1000-0593(2024)04-1158-07數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20241515866101 -
Record 353 of
Title:Laser Center Extraction Method of Circular Linear Structure Profile Measurement Based on Cluster Segmentation
Author Full Names:Yan, Xingxu(1); Du, Hubing(1); Feng, Leijie(1); Li, Yanjie(1); Jia, Jinge(2); Zhang, Gaopeng(3)Source Title:Guangzi Xuebao/Acta Photonica SinicaLanguage:ChineseDocument Type:Journal article (JA)Abstract:Hole parts, such as bearings, cylinders, hydraulic cylinders, and artillery body tubes, are important to the field of aviation, spaceflight, auto, machine tool and heavy equipment manufacture industry. However, the inspection of inner surface quality of this kind of parts, especially deep hole inner surface, remains a difficult problem in the manufacturing field. More specifically, the difficulty of inspection system mainly lies in two aspects:firstly, the workspace is narrow, making it difficult to effectively use the existing inspection technologies;secondly, due to the limitations of the non-open space of the inner surface, it is easy to form blind zone during the task of measurement. To satisfied with the increasing requirements of quality inspection in above fields, some scholars have applied the optical method into the measurement system of hole parts because of its advantage of high accuracy, high robustness, rapid speed, non-contact, and low cost. However, when measuring inner surface of hole parts, the optical method often presents the problem of a limited or occluded field of view for the characteristics of hole parts. Due to the problem of occlusion, the well-known fringe projection profilometry cannot projected the fringe pattern to the inner surface and the desired deformed fringe pattern cannot be captured by a camera accordingly. So, circular structured light 3D measurement technology has been extensively employed to inspect accuracy of the hole parts, which is an active vision measurement technology based on the laser triangulation principle. Many works have been done to enhance the performance of circular structured light technique. However, occlusions are problematic because the light source and camera are placed on the same side of the measured object in the exiting technique. Additionally, the technique may be disturbed by speckle noise when metal surface is measured. Consequently, for structured light measurement technology, it is necessary to develop an efficient preprocess method to eliminate the disturbance to the most extent because the performance of the technology largely depends on high quality images. But this problem remains unsolved so far to our knowledge. In the work, the circular linear structure profile measurement method is proposed to inspect the quality of internal surfaces of hole parts. In our method, the light source and the image sensor are arranged on either side of the object to be measured to get a clear view during data acquisition. However, the proposed circular structure profile measurement technique is seriously affected by the quality of the extraction of the center of the laser center when a metal surface is measured. Concerned that removing the image of the light source used in the setup and laser speckle effect is vital to center extraction of circular structured light, in this paper, a clustered segmentation-based center extraction method is developed. The process of our method is as follows:The maximum inter class variance(OTSU)method is firstly used to adaptively segment the captured laser image into two parts:background and target image;then, the clustering method is used to separate the laser light source image and the laser speckle in the captured laser image;finally, sub-pixel laser center extraction is realized with help of the well-known Steger algorithm. Both simulation and experiment validate the correctness of the proposed method. The experimental results show that the proposed method can well suppress the influence of the laser light source image and the laser speckle during the extraction of the center of the laser center when compared with the typical filtering methods, such as median filtering. In addition, the proposed method can fulfil the task of center extraction efficiently, stably, and reliably. Therefore, it provides an effective way of extraction of laser center for three-dimensional contour measurement of deep hole parts. In the future work, we will focus on the development of accurate calibration method to convert 2D light stripes information into 3D coordinate information. ? 2024 Chinese Optical Society. All rights reserved.Affiliations:(1) School of Mechanical and Electrical Engineering, Xi'an University of Technology, Xi'an; 710021, China; (2) Xi'an Future Intelligent Manufacturing Digital Technology Co., Ltd., Xi'an; 710000, China; (3) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, ChinaPublication Year:2024Volume:53Issue:11Article Number:1112004DOI Link:10.3788/gzxb20245311.1112004數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20245117548489 -
Record 354 of
Title:Blind deep-learning based preprocessing method for Fourier ptychographic microscopy
Author Full Names:Wu, Kai(1,2); Pan, An(1); Sun, Zhonghan(1); Shi, Yinxia(1,2); Gao, Wei(1)Source Title:Optics and Laser TechnologyLanguage:EnglishDocument Type:Journal article (JA)Abstract:Fourier ptychographic microscopy (FPM) is a technique for tackling the trade-off between the resolution and the imaging field of view by combining the techniques from aperture synthesis and phase retrieval to estimate the complex object from a series of low-resolution intensity images captured under angle-varied illumination. The captured images are commonly corrupted by multiple noise, leading to the degradation of the reconstructed image quality. Typically speaking, the noise model and noise level of the experimental images are unknown, and the traditional image denoising methods have limited effect. In this paper we model the FPM forward imaging process corrupted by noise and divide the noise in the captured images into two parts: the signal-dependent part and the signal-independent part. Based on the noise model we propose a novel blind deep-learning based Fourier ptychographic microscopy preprocessing method, termed BDFP, for removing these two components of noise. First, from a portion of the captured low-resolution images, a set of blocks corresponding to the smooth area of the object are extracted to model signal-independent noise. Second, under the assumption that the signal-dependent noise follows a Poisson distribution, we add Poisson noise and signal-independent noise blocks to clean images to form a paired training dataset, which is then used for training a deep convolutional neural network (CNN) model to reduce both signal-dependent noise and signal-independent noise. The proposed blind preprocessing method, combining with typical FPM reconstruction algorithms, is tested on simulated data and experimental images. Experimental results show that our preprocessing method can significantly reduce the noise in the captured images and bring about effective improvements in reconstructed image quality. ? 2023 Elsevier LtdAffiliations:(1) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:169Article Number:110140DOI Link:10.1016/j.optlastec.2023.110140數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20234014830596 -
Record 355 of
Title:Dual Optical Target Recognition Method for Collimated Images Based on BLOB Region and Edge Feature Analysis
Author Full Names:He, Wenxuan(1,2); Wang, Zhengzhou(1); Wei, Jitong(1); Wang, Li(1); Yi, Dongchi(1)Source Title:Guangzi Xuebao/Acta Photonica SinicaLanguage:ChineseDocument Type:Journal article (JA)Abstract:In order to solve the problem that the collimated target recognition algorithm of optical path docking cannot distinguish the adhesive state of double targets，a new method of collimated image dual optical target recognition based on Binary Large Object（BLOB）region feature analysis is proposed. There are two optical targets in the optical alignment image，that is，the simulated optical target and the main laser target. In the initial beam control stage，the positions of the two optical targets are random and uncertain，and there is a possibility of the two optical targets sticking together，which causes great difficulties in beam control. Therefore，optical path alignment needs to solve the image recognition problem in two cases：1）In the initial beam control stage，when the main laser beam and the analog beam are just introduced，the adhesion recognition algorithm needs to be used to identify the adhesion state of the two optical targets. If the two optical targets are in the adhesion state，the two targets need to be completely separated by adjusting the 2D frame BM6XY motor；2） In the case of two optical targets completely separated，it is necessary to distinguish between the analog light target and main laser target in the two optical targets. Firstly，the binary image is processed by digital morphology to calculate the area，center Cxy，axis length lenxy and region Reginxy，of each BLOB region in the whole image. Secondly，the number of valid BLOB regions vblobcount is counted，and the distance between the two maximum connected domains dir is calculated. When vblobcount>1 and dir>100，the collimation image is the completely separated double target image，otherwise it is the adhered image. Then，for the completely separated dual-target image，the number of BLOBs located in the two largest BLOB regions with the center of each BLOB region is counted. The small number of candidate BLOB regions is the main laser target，and the large number of candidate BLOB regions is the analog light target. Finally，for the adhered image，when dir ? 2024 Chinese Optical Society. All rights reserved.Affiliations:(1) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100039, ChinaPublication Year:2024Volume:53Issue:2Article Number:0210001DOI Link:10.3788/gzxb20245302.0210001數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240715561765 -
Record 356 of
Title:A design of compact plasmonic lens consisting of high index dielectric gratings and metal nano-film
Author Full Names:Jia, Sen(1); Wang, Xianhua(1); Zhou, Libing(2)Source Title:Optics CommunicationsLanguage:EnglishDocument Type:Journal article (JA)Abstract:In this paper, a hybrid ultra-thin planar subwavelength focusing structure consisting of a high refractive index dielectric grating and a nano metal film was designed. The thickness of this structure is only 200 nm. Surface plasmon polaritons (SPPs) were excited from the nano metal film, propagated along the metal-air interface, and were then converted into a radiation field by the dielectric grating, forming a focused spot in free space. By adjusting the grating position and width parameters, the shape of the focused optical field could be controlled. The simulation results showed that, under 532 nm light irradiation, the lens could produce a 270 nm (full width at half-maximum, FWHM) spot size at a focal length of 2.46λ. Moreover, under the illumination of 633 nm and 780 nm light, the designed lenses were found to produce focal spot sizes of 304 nm (0.48λ) and 364 nm (0.47λ), respectively, which were smaller than the diffraction limit. The simplicity of this plasmonic lens design, coupled with its reduced thickness and minimal absorption loss, offered significant advantages in terms of cost-effectiveness and ease of fabrication. ? 2024 Elsevier B.V.Affiliations:(1) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (2) School of Physics and Information, Shaanxi University of Science and Technology, Xi'an; 710021, ChinaPublication Year:2024Volume:570Article Number:130928DOI Link:10.1016/j.optcom.2024.130928數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20243216819587 -
Record 357 of
Title:Tracking control of flexible link manipulator with joint space constraints
Author Full Names:Jing, Feng(1,2); Ma, Caiwen(1,2); Cao, Yu(1); Xie, Meilin(1); Wang, Fan(1); Liu, Peng(1); Fan, Xiao(1)Source Title:Journal of Physics: Conference SeriesLanguage:EnglishDocument Type:Conference article (CA)Conference Title:2024 7th International Conference on Intelligent Manufacturing and Automation, IMA 2024Conference Date:January 12, 2024 - January 14, 2024Conference Location:Virtual, Online, ChinaAbstract:A controller design with system uncertainties, external disturbances, and joint space constraints for a flexible link manipulator (FLM) is presented in this paper. To overcome the lumped disturbance and ensure that the joint space constraints are not violated, a finite-time extended state observer (ESO) and a barrier Lyapunov function are constructed. Using Lyapunov's theory, the error of the system is proved to be semi-globally ultimately uniformly bounded without violating the constraints. Finally, the rationality of the proposed methodology is verified by numerical simulation. ? Published under licence by IOP Publishing Ltd.Affiliations:(1) Xi'An Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:2787Issue:1Article Number:012043DOI Link:10.1088/1742-6596/2787/1/012043數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20242816660786 -
Record 358 of
Title:Splitting rules of the channeled modulation polarization imaging technology for different polarization detection requirements
Author Full Names:Zhang, Ning(1); Zhang, Yunyao(2); Li, Siyaun(1)Source Title:Proceedings of SPIE - The International Society for Optical EngineeringLanguage:EnglishDocument Type:Conference article (CA)Conference Title:2024 Conference on Spectral Technology and Applications, CSTA 2024Conference Date:May 9, 2024 - May 11, 2024Conference Location:Dalian, ChinaConference Sponsor:Chinese Society for Optical EngineeringAbstract:Channeled modulation polarization imaging technology can obtain full polarization information of targets through a single frame of image, with advantages such as compact, low cost, and without electric rotating accessories. It has important application value in remote sensing, biomedical, national defense, and so on. The key point of channeled modulation polarization imaging technology is to modulate the four Stokes parameters that characterize polarization to different carried frequencies through amplitude modulation, and then use the frequency domain to separate the four two-dimensional Stokes parameters. Different channels are intercepted by a bandpass filter and subjected to inverse Fourier transform, which can achieve four two-dimensional distribution pictures of the Stokes parameters. Interference is the core of this technology, which is achieved through birefringent crystals or spectroscopic interferometers. After splitting, interference occurs in the focal plane, generating carrier frequency. However, a serious problem has been troubling researchers in this field, which is how to design birefringent crystals to achieve amplitude modulation of Stokes parameters. The amplitude of the interference fringes of the beams needs to be divided corresponds one-to-one with the Stokes parameter after interference. The current spectroscopic design mainly relies on experience and luck, lacking unified standards, which will affect the efficiency of system design. To solve this problem, relying on the representation of the electric field vector of light, the mathematical expression of Stokes parameters and the corresponding relationship with the spectral results are analyzed in reverse. Then, based on the physical meaning of Stokes parameters, phase modulation is used to achieve the representation of certain parameters for the sum of light intensities and the representation of certain parameters for the difference in light intensities. Ultimately, a correspondence is formed between different spectroscopic results and the detected polarization parameters and proposed modulation criteria for channeled modulation by linking the physical meaning and mathematical model of Stokes parameters. On the one hand, this study is beneficial for the targeted design of channeled modulation polarization imaging technology in different application scenarios for different parameter detection requirements, and on the other hand, it can guide the design of optical systems for different spectral requirements in birefringent crystal design, making the design of this technology more standardized. ? 2024 SPIE.Affiliations:(1) Key Laboratory of Spectral Imaging Technology, Xi'an Institute of Optics and Precision Mechanics of Cas, Xi'an; 710119, China; (2) College of Information Science and Technology, Northwest University, Xi'an; 710126, ChinaPublication Year:2024Volume:13283Article Number:1328325DOI Link:10.1117/12.3036652數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20245217584034 -
Record 359 of
Title:Observation of Superoscillation Superlattices
Author Full Names:Ma, Xin(1); Zhang, Hao(1); Wei, Wenjun(1); Tai, Yuping(1); Li, Xinzhong(1,2,3); Shen, Yijie(4,5)Source Title:arXivLanguage:EnglishDocument Type:Preprint (PP)Abstract:Superoscillation (SO) wavefunctions, that locally oscillate much faster than its fastest Fourier component, in light waves have enhanced optical technologies beyond diffraction limits, but never been controlled into 2D periodic lattices. Here, we report the 2D superoscillation lattices (SOL) with controlled symmetries, where the local wavevector can be ~700 times larger than the global maximal wavevector (k0) in a localized region ~100 times smaller than the global minimal wavelength (λ0). We also demonstrate the superoscillation superlattices (SOSL) as twisted bilayer Moirépatterns of two SOL, akin to the magic angle tuning in advanced twistronics, we can continually tune the on-demand SO with local maximal wavevector in a range of 450k0–700k0 and with ~ λ0/100–λ0/1000. The twistronic SOSL will advance optical imaging and metrology into extreme higher-dimensional superresolution.MSC Codes 78 Copyright ? 2024, The Authors. All rights reserved.Affiliations:(1) School of Chemistry and Chemical Engineering, School of Physics and Engineering, Henan University of Science and Technology, Luoyang; 471023, China; (2) State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'An; 710119, China; (3) Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology, Luoyang; 471023, China; (4) Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences, The Photonics Institute, Nanyang Technological University, Singapore; 637371, Singapore; (5) School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore; 639798, SingaporePublication Year:2024DOI Link:10.48550/arXiv.2409.19565數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240426023 -
Record 360 of
Title:High Modulation Depth Terahertz Modulator Based on Side-polished Terahertz Fiber
Author Full Names:Luo, Zhenyang(1); Tian, Ziping(1); Zhang, Zilong(1); Wei, Longxiang(1); Xie, Manyan(1); Chen, Bingyu(1); Wang, Xingfu(2); Peng, Gangding(3); Kong, Depeng(4); Wei, Yuming(5); Yang, Tiefeng(5); Lu, Huihui(5); Guan, Heyuan(5)Source Title:Journal of Lightwave TechnologyLanguage:EnglishDocument Type:Article in PressAbstract:High modulation depth fiber-based modulators working at terahertz (THz) wavelength are of paramount importance for the application of THz communication technology by taking advantages of the low loss, high interference resistance and strong adaptability THz fiber network. Here, we demonstrate a THz modulator based on side-polished THz fiber combined with GaAs film/Au-nanoparticles (Au-Nps). The Au-Nps and the remaining thickness of the side-polishing are careful designed to achieve target resonance wavelengths. The side-polishing region of fiber provides a flat platform for integrating nanostructures to enhanced light-material interactions which greatly enhances the modulation performance. The experimental results show that this new fiber modulator can achieve the THz wave amplitude modulation under a relatively low irradiation of an external 808 nm laser, with a tunable frequency range of 0.366-1.093 THz and a maximum modulation depth of 99.24%. Besides, resonance frequency can be adjusted by changing the remaining thickness of the device. Moreover, the area of this modulator is only 9 mm2 which can be easily integrated into THz systems. Therefore, we believe our work will contribute to the developments of high-performance fiber-based THz modulator for applications in THz communication system. ? 1983-2012 IEEE.Affiliations:(1) Jinan University, Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Guangzhou; 510632, China; (2) South China Normal University, Guangdong Engineering Research Center of Optoelectronic Functional Materials and Devices, School of Semiconductor Science and Technology, Foshan; 528225, China; (3) University of New South Wales, School of Electrical Engineering and Telecommunications, Sydney; NSW; 2052, Australia; (4) Chinese Academy of Sciences, Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Shaanxi, Xi'an; 710119, China; (5) Jinan University, Key Laboratory of Optoelectronic Information, Sensing Technologies of Guangdong Higher Education Institutes, Guangzhou; 510632, ChinaPublication Year:2024DOI Link:10.1109/JLT.2024.3509575數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20245017522377