Free-space optical (FSO) communication technology is widely utilized in uncrewed aerial vehicle (UAV) communication because it provides larger communication bandwidth than radio frequency technology. However, the system performance of FSO-based UAV communication systems is severely affected by several adverse factors, such as atmospheric turbulence, fog-induced absorption, and pointing errors, all of which result in performance deterioration drastically. This study proposes a multi-UAV optical communication system to suppress the influence of the foggy channel and pointing error impairments under atmospheric turbulence with a Málaga distribution, with both amplify-and-forward (AF) and decode-and-forward (DF) protocols, respectively. Specifically, some critical statistical expressions, such as probability and cumulative density functions, were derived, which were employed to assess the performance metrics, including outage probability, average bit error rate, and ergodic capacity. Additionally, these performance metrics obtained through theoretical analysis in the presence of atmospheric turbulence, fog absorption, and pointing errors were corroborated by Monte Carlo simulations. Finally, the performance indicators under AF and DF relay protocols were compared.
自由空间光学(FSO)通信技术因其比射频技术提供更大的通信带宽而被广泛应用于无人驾驶飞行器(UAV)通信中。然而,基于 FSO 的无人机通信系统的系统性能会受到一些不利因素的严重影响,如大气湍流、雾气吸收和指向误差等,这些因素都会导致性能急剧下降。本研究提出了一种多无人机光通信系统,在马拉加分布的大气湍流条件下,分别采用放大-前向(AF)和解码-前向(DF)协议来抑制雾信道和指向误差损伤的影响。具体而言,推导出了一些关键的统计表达式,如概率和累积密度函数,并利用这些表达式来评估性能指标,包括中断概率、平均误码率和遍历容量。此外,在存在大气湍流、雾气吸收和指向误差的情况下,通过理论分析获得的这些性能指标还得到了蒙特卡罗模拟的证实。最后,比较了 AF 和 DF 中继协议下的性能指标。
{"title":"Performance Analysis of Multi-UAV Optical Communication Systems Over Foggy Channel Under Málaga Turbulence and Pointing Error Impairments","authors":"Guanjun Xu;Xiaozong Yu;Jialin Wang;Zhaohui Song;Qinyu Zhang","doi":"10.1109/JPHOT.2024.3487261","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3487261","url":null,"abstract":"Free-space optical (FSO) communication technology is widely utilized in uncrewed aerial vehicle (UAV) communication because it provides larger communication bandwidth than radio frequency technology. However, the system performance of FSO-based UAV communication systems is severely affected by several adverse factors, such as atmospheric turbulence, fog-induced absorption, and pointing errors, all of which result in performance deterioration drastically. This study proposes a multi-UAV optical communication system to suppress the influence of the foggy channel and pointing error impairments under atmospheric turbulence with a Málaga distribution, with both amplify-and-forward (AF) and decode-and-forward (DF) protocols, respectively. Specifically, some critical statistical expressions, such as probability and cumulative density functions, were derived, which were employed to assess the performance metrics, including outage probability, average bit error rate, and ergodic capacity. Additionally, these performance metrics obtained through theoretical analysis in the presence of atmospheric turbulence, fog absorption, and pointing errors were corroborated by Monte Carlo simulations. Finally, the performance indicators under AF and DF relay protocols were compared.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 6","pages":"1-16"},"PeriodicalIF":2.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10737147","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1109/JPHOT.2024.3486223
Peiqi Yang;Mingju Xin;Yaopeng Wei;Chuanxin Teng;Ming Chen;Yu Cheng;Jun Yin;Libo Yuan;Shijie Deng
A compact single-pixel spectral measurement system based on semiconductor diodes is described in this work. There are no optical components in the system configuration, which contribute to reducing the size of the equipment. Incident spectra can be reconstructed by using the photocurrent of semiconductor diode and spectral response functions. After data collection, data analysis, algorithm processing and other steps.The existing equipment can accurately reconstruct the spectra of narrowband monochromatic light at 508–556 nm and broadband light sources in the 478–598 nm wavelength range, achieving high resolution of 6 nm broadband spectra. The peak signal-to-noise ratio (PSNR) of the reconstructed spectra can reach up to 33.44 dB.
{"title":"A Compact Single-Pixel Spectral Measurement System","authors":"Peiqi Yang;Mingju Xin;Yaopeng Wei;Chuanxin Teng;Ming Chen;Yu Cheng;Jun Yin;Libo Yuan;Shijie Deng","doi":"10.1109/JPHOT.2024.3486223","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3486223","url":null,"abstract":"A compact single-pixel spectral measurement system based on semiconductor diodes is described in this work. There are no optical components in the system configuration, which contribute to reducing the size of the equipment. Incident spectra can be reconstructed by using the photocurrent of semiconductor diode and spectral response functions. After data collection, data analysis, algorithm processing and other steps.The existing equipment can accurately reconstruct the spectra of narrowband monochromatic light at 508–556 nm and broadband light sources in the 478–598 nm wavelength range, achieving high resolution of 6 nm broadband spectra. The peak signal-to-noise ratio (PSNR) of the reconstructed spectra can reach up to 33.44 dB.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 6","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10734238","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose and fabricate an unconventional photonic lantern that is not only able to achieve mode multiplexing and demultiplexing, but also has the functionality of mode-dependent loss equalization. In the process of fusion splicing between the tail fiber of photonic lantern and the few-mode fiber, by controlling the fusion splicing parameters, a refractive index (RI) modified waveguide is formed at the fusion splicing region, through which the fundamental mode will have higher attenuation than the higher-order modes, which enables us to control the attenuation of different modes, so that we can customize the unconventional photonic lantern with different differential mode attenuation (DMA). Simulation has been carried out to investigate the dependence of DMA on the structure of the RI modified waveguide, and experiments have been implemented to investigate the dependence of DMA on discharge parameters, which matches well with the simulated tendency. In addition, CCD measurements of all three output ports have been performed on the fabricated devices, well-defined mode field patterns and high mode purity at the C-band can be observed. The proposed novel unconventional photonic lanterns open a new way to obtain simultaneous mode multiplexing / demultiplexing and mode-dependent loss equalization function, which will be greatly beneficial in the few-mode fiber transmission system.
我们提出并制造了一种非常规的光子灯笼,它不仅能够实现模式复用和解复用,还具有模式相关损耗均衡功能。在光子灯笼尾纤与少模光纤熔接的过程中,通过控制熔接参数,在熔接区域形成折射率(RI)修正波导,通过该波导,基模将比高阶模具有更高的衰减,这使我们能够控制不同模式的衰减,从而定制具有不同差模衰减(DMA)的非常规光子灯笼。我们通过仿真研究了 DMA 与 RI 改进波导结构的关系,并通过实验研究了 DMA 与放电参数的关系,结果与仿真趋势吻合。此外,还对制作的器件的三个输出端口进行了 CCD 测量,可以观察到清晰的模场模式和 C 波段的高模式纯度。所提出的新型非传统光子灯笼为同时获得模式复用/解复用和模式相关损耗均衡功能开辟了一条新途径,这将大大有利于少模光纤传输系统。
{"title":"Mode-Dependent Loss Equalized Few-Mode Fiber Photonic Lantern","authors":"Yingxuan Li;Senyu Zhang;Zhiyong Zhao;Jing Liu;Zhuyixiao Liu;Ming Tang","doi":"10.1109/JPHOT.2024.3485689","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3485689","url":null,"abstract":"We propose and fabricate an unconventional photonic lantern that is not only able to achieve mode multiplexing and demultiplexing, but also has the functionality of mode-dependent loss equalization. In the process of fusion splicing between the tail fiber of photonic lantern and the few-mode fiber, by controlling the fusion splicing parameters, a refractive index (RI) modified waveguide is formed at the fusion splicing region, through which the fundamental mode will have higher attenuation than the higher-order modes, which enables us to control the attenuation of different modes, so that we can customize the unconventional photonic lantern with different differential mode attenuation (DMA). Simulation has been carried out to investigate the dependence of DMA on the structure of the RI modified waveguide, and experiments have been implemented to investigate the dependence of DMA on discharge parameters, which matches well with the simulated tendency. In addition, CCD measurements of all three output ports have been performed on the fabricated devices, well-defined mode field patterns and high mode purity at the C-band can be observed. The proposed novel unconventional photonic lanterns open a new way to obtain simultaneous mode multiplexing / demultiplexing and mode-dependent loss equalization function, which will be greatly beneficial in the few-mode fiber transmission system.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 6","pages":"1-6"},"PeriodicalIF":2.1,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10733746","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-17DOI: 10.1109/JPHOT.2024.3483209
Xin Jiang;Weilong Zhou;Wen Dong;Zhu Wang;Yifei Xie;Xinyue Tang;Zichun Le
Laser speckle caused by high coherence severely affects the image quality. The traditional optical approaches cannot effectively suppress speckles without compromising the coherence of the laser in the optical path. In this study, we develop a method in which a novel polymer-stabilized liquid crystal screen (PSLCS) was used to display images for efficient speckle suppression while preserving the coherence and high brightness of lasers. The scattering-induced fluctuations in the intensity of the light reflected from the PSLCS are evaluated to reveal decorrelation variation. The optimal parameters for suppressing speckles and obtaining a clear and high-resolution image via both laser projection and AR imaging are identified by adjusting the driving parameters. A speckle suppression efficiency of 67.34%, which exceeds that achieved by other similar methods, was achieved without using any additional optical elements. An experiment was implemented for verifying the performance of multi-plane AR imaging by a PSLCS, which, to our knowledge, is the first study to investigate the image quality and speckle suppression effect in AR imaging. The proposed cost-effective laser speckle suppression method enables high quality imaging, offering new possibilities for the application of LC-based optical materials and devices in display technology.
高相干性造成的激光斑点严重影响图像质量。传统的光学方法无法在不影响光路中激光相干性的情况下有效抑制斑点。在这项研究中,我们开发了一种方法,利用新型聚合物稳定液晶屏(PSLCS)显示图像,在保持激光相干性和高亮度的同时,有效抑制斑点。对 PSLCS 反射的光的散射引起的强度波动进行了评估,以揭示装饰相关性变化。通过调整驱动参数,确定了抑制斑点并通过激光投影和 AR 成像获得清晰、高分辨率图像的最佳参数。在不使用任何额外光学元件的情况下,斑点抑制效率达到了 67.34%,超过了其他类似方法。实验验证了 PSLCS 的多平面 AR 成像性能,据我们所知,这是首次研究 AR 成像中的图像质量和斑点抑制效果。所提出的高性价比激光斑点抑制方法实现了高质量成像,为基于 LC 的光学材料和器件在显示技术中的应用提供了新的可能性。
{"title":"Laser Speckle Suppression in Augmented Reality Displays Based on Static and Low-Loss Polymer-Stabilized Liquid Crystal Screens","authors":"Xin Jiang;Weilong Zhou;Wen Dong;Zhu Wang;Yifei Xie;Xinyue Tang;Zichun Le","doi":"10.1109/JPHOT.2024.3483209","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3483209","url":null,"abstract":"Laser speckle caused by high coherence severely affects the image quality. The traditional optical approaches cannot effectively suppress speckles without compromising the coherence of the laser in the optical path. In this study, we develop a method in which a novel polymer-stabilized liquid crystal screen (PSLCS) was used to display images for efficient speckle suppression while preserving the coherence and high brightness of lasers. The scattering-induced fluctuations in the intensity of the light reflected from the PSLCS are evaluated to reveal decorrelation variation. The optimal parameters for suppressing speckles and obtaining a clear and high-resolution image via both laser projection and AR imaging are identified by adjusting the driving parameters. A speckle suppression efficiency of 67.34%, which exceeds that achieved by other similar methods, was achieved without using any additional optical elements. An experiment was implemented for verifying the performance of multi-plane AR imaging by a PSLCS, which, to our knowledge, is the first study to investigate the image quality and speckle suppression effect in AR imaging. The proposed cost-effective laser speckle suppression method enables high quality imaging, offering new possibilities for the application of LC-based optical materials and devices in display technology.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 6","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10721275","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142524178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We proposed a DHM system with improved spatial resolution compared with that of the polarized camera-based DHM system by employing a liquid crystal phase modulator (LCPM). The LCPM-based holographic interferometry optical system can reliably construct a four-step phase shifting scheme by changing the applied voltage, thus eliminating the need for mechanical moving parts. The spatial resolution characteristics of the proposed DHM system were analyzed using the 1951 USAF resolution target. These characteristics showed a fourfold improvement over the polarized camera-based DHM system. Additionally, the 3D information capturing capability of the proposed DHM system was experimentally confirmed using a via-hole array sample produced through the semiconductor fabrication process.
{"title":"Development of a Spatial Resolution-Enhanced Digital-Hologram Microscope With a Liquid Crystal Phase Modulator","authors":"Ha-Mong Shim;Ki-Dong Lim;Min-Kyu Park;Kwang-Hoon Lee;Jin Hyeok Kim;Sungjin Lim;Kyung-Il Joo","doi":"10.1109/JPHOT.2024.3481418","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3481418","url":null,"abstract":"We proposed a DHM system with improved spatial resolution compared with that of the polarized camera-based DHM system by employing a liquid crystal phase modulator (LCPM). The LCPM-based holographic interferometry optical system can reliably construct a four-step phase shifting scheme by changing the applied voltage, thus eliminating the need for mechanical moving parts. The spatial resolution characteristics of the proposed DHM system were analyzed using the 1951 USAF resolution target. These characteristics showed a fourfold improvement over the polarized camera-based DHM system. Additionally, the 3D information capturing capability of the proposed DHM system was experimentally confirmed using a via-hole array sample produced through the semiconductor fabrication process.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 6","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10720202","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142524127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}