{"title":"Self-focusing of partially coherent beams based on complex screen and split-step Fourier transform methods","authors":"Fanglun Yang, Guowen Zhang, Xiaoqi Zhang, Yanli Zhang, Ruifeng Wang, Jianqiang Zhu","doi":"10.3788/col202321.071901","DOIUrl":"https://doi.org/10.3788/col202321.071901","url":null,"abstract":"The self-focusing phenomenon of partially coherent beams (PCBs) was simulated using the complex screen method com-bined with the split-step Fourier method to solve the nonlinear Schrödinger equation. Considering the propagation of Gaussian Schell-model beams in a nonlinear medium as an example, the suppression effects of intensity, propagation distance, and spatial coherence on small-scale self-focusing were demonstrated. Simulations of overall and small-scale self-focusing using this method were compared with the existing literature to demonstrate the validity of the method. This method can numerically analyze the degree of self-focusing in PCBs and advance the study of their nonlinearity","PeriodicalId":10293,"journal":{"name":"Chinese Optics Letters","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73733168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Water track laser Doppler velocimeter [Invited]","authors":"è�£ 黄, ç�¦ 王, 志毅 å�‘, 晓明 è�‚, å�¥ 周, æ™– ç½—","doi":"10.3788/col202321.090005","DOIUrl":"https://doi.org/10.3788/col202321.090005","url":null,"abstract":"A water track laser Doppler velocimeter (LDV) is developed with advantages of high update rate, high real-time performance, high concealment, light weight, and small dimensions. The water track LDV measures the advance velocity of the under-water vehicle with respect to the surrounding water. The experimental results show that the water track LDV has an accuracy of 96.4% when the moving velocity of the vehicle with respect to the ground exceeds 0.25 m/s. Thus, the water track LDV is promising in the application of underwater navigation to aid the strapdown inertial navigation system.","PeriodicalId":10293,"journal":{"name":"Chinese Optics Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135600661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liang Chen, Huiyi Guo, Zekun Shi, Wenzhe Chang, Boyu Chen, Zhi Wang, Yan-ge Liu
{"title":"Low-loss, high-purity, and ultrabroadband all-fiber LP41 mode converter employing a mode-selective photonic lantern [Invited]","authors":"Liang Chen, Huiyi Guo, Zekun Shi, Wenzhe Chang, Boyu Chen, Zhi Wang, Yan-ge Liu","doi":"10.3788/col202321.110008","DOIUrl":"https://doi.org/10.3788/col202321.110008","url":null,"abstract":"Broadband mode converters are essential devices for space-division and wavelength-division multiplexing systems. There are great challenges in the generation of higher-order modes above the third order with low loss and high mode purity employing all-fiber devices. In this paper, an all-fiber LP41 mode converter is proposed and fabricated by tapering a nine-core single-mode fiber bundle. Experimental results indicate that this all-fiber LP41 mode converter is low-loss, high-purity, and ultrabroadband. The insertion loss is less than 0.4 dB. The purity of odd LP41 at 1310 nm is 95.09%, and the operating bandwidth exceeds 280 nm.","PeriodicalId":10293,"journal":{"name":"Chinese Optics Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135612365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ultrabroadband chiral metasurface for linear polarization conversion and asymmetric transmission based on enhanced interference theory","authors":"Jingcheng Zhao, Nan Li, Yongzhi Cheng","doi":"10.3788/col202321.113602","DOIUrl":"https://doi.org/10.3788/col202321.113602","url":null,"abstract":"In this paper, we propose an ultrabroadband chiral metasurface (CMS) composed of S-shaped resonator structures situated between two twisted subwavelength gratings and dielectric substrate. This innovative structure enables ultrabroadband and high-efficiency linear polarization (LP) conversion, as well as asymmetric transmission (AT) effect in the microwave region. The enhanced interference effect of the Fabry–Perot-like resonance cavity greatly expands the bandwidth and efficiency of LP conversion and AT effect. Through numerical simulations, it has been revealed that the cross-polarization transmission coefficients for normal forward (-z) and backward (+z) incidence exceed 0.8 in the frequency range of 4.13 to 17.34 GHz, accompanied by a polarization conversion ratio of over 99%. Furthermore, our microwave experimental results validate the consistency among simulation, theory, and measurement. Additionally, we elucidate the distinct characteristics of ultrabroadband LP conversion and significant AT effect through analysis of polarization azimuth rotation and ellipticity angles, total transmittance, AT coefficient, and electric field distribution. The proposed CMS structure shows excellent polarization conversion properties via AT effect and has potential applications in areas such as radar, remote sensing, and satellite communication.","PeriodicalId":10293,"journal":{"name":"Chinese Optics Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135612369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jilian Xu, Zhiyuan Yue, Peiyao Lu, Rui Wu, Kun Jiang, Xiquan Jiang, Shuyun Teng
{"title":"Wavelength and polarization dual-multiplexed imaging based on holographic metasurfaces","authors":"Jilian Xu, Zhiyuan Yue, Peiyao Lu, Rui Wu, Kun Jiang, Xiquan Jiang, Shuyun Teng","doi":"10.3788/col202321.100501","DOIUrl":"https://doi.org/10.3788/col202321.100501","url":null,"abstract":"In light of the powerful light manipulation ability of holographic metasurfaces, optical imaging with wavelength multiplexing and polarization multiplexing is performed in this paper. The metasurface is composed of identical rectangular nanoholes etched in silver film. Three imaging effects, including the in-plane color imaging, three-dimensional wavelength-encrypted imaging, and polarization-multiplexing wavelength-encrypted imaging, are realized. The designed metasurface has compact structure, and the obtained image has lower noise. The simulation and experiment results give the verification. Multiple images, including spatial multiplexing, wavelength multiplexing, and polarization multiplexing, exhibit immense potentialities of metasurfaces, and this work is helpful for expanding the applications of metasurfaces.","PeriodicalId":10293,"journal":{"name":"Chinese Optics Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136054153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-Q resonances in terahertz all-silicon metasurface with imperforated air-hole array","authors":"Qing Wang, Pengfei Wang, Jianjun Liu, Fangzhou Shu, Guiming Pan, Zhongwei Jin, Xufeng Jing, Zhi Hong","doi":"10.3788/col202321.113601","DOIUrl":"https://doi.org/10.3788/col202321.113601","url":null,"abstract":"We propose and experimentally demonstrate a high quality (Q)-factor all-silicon bound state in the continuum (BIC) metasurface with an imperforated air-hole array. The metasurface supports two polarization-insensitive BICs originated from guided mode resonances (GMRs) in the frequency range of 0.4 to 0.6 THz, and the measured Q-factors of the two GMRs are as high as 334 and 152, respectively. In addition, the influence of the thickness of the silicon substrate on the two resonances is analyzed in detail. The proposed all-silicon THz metasurface has great potential in the design and application of high-Q metasurfaces.","PeriodicalId":10293,"journal":{"name":"Chinese Optics Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135448093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhen-bao Dong, Bo Yuan, Yonglei Liu, Fei Wang, Y. Cai, Yahong Chen
{"title":"Stokes scintillations for vector beams in turbulence","authors":"Zhen-bao Dong, Bo Yuan, Yonglei Liu, Fei Wang, Y. Cai, Yahong Chen","doi":"10.3788/col202321.100101","DOIUrl":"https://doi.org/10.3788/col202321.100101","url":null,"abstract":"We introduce the Stokes scintillation indices and the corresponding overall Stokes scintillations for quantitatively studying the fluctuations of both the intensity and polarization of an optical vector beam transmitting through the atmospheric turbulence. With the aid of multiple-phase-screen method, we examine the Stokes fluctuations of a radially polarized beam in Kolmogorov turbulence numerically. The results show that the overall scintillation for the intensity distribution is always larger than the overall scintillations for the polarization-dependent Stokes parameters, which indicates that the polarization state of a vector beam is more stable than its intensity distribution in the turbulence. We interpret the results with the depolarization effect of the vector beam in turbulence. The findings in this work may be useful in free-space optical communications utilizing the vector beams.","PeriodicalId":10293,"journal":{"name":"Chinese Optics Letters","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86506058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}