Article
Optics
Runzhou Zhang, Kaiheng Zou, Xinzhou Su, Yuxiang Duan, Huibin Zhou, Haoqian Song, Hao Song, Amir Minoofar, Nanzhe Hu, Kai Pang, Robert W. Boyd, Moshe Tur, Alan E. Willner
Summary: Free-space-optical (FSO) communications benefit from power-efficient modulation formats and detection methods. Differential-phase-shift-keying (DPSK) is more optical-power efficient than intensity modulation when detecting both output arms in the receiver. However, turbulence-induced modal coupling loss can cause high power loss in the differential receiver. In this study, a turbulence-resilient DPSK FSO link is demonstrated, and the turbulence-induced modal coupling loss is compensated by optoelectronic (O/E) mixing of higher-order spatial modes.
OPTICS COMMUNICATIONS
(2023)
Article
Optics
Yang Cao, Wenqing Li, Jing Zhang, Xiaofeng Peng, Yue Li
Summary: This paper proposes a segmented turbulent partial order construction method to solve the high complexity issue of polarization code construction in free-space optical communication. By introducing the generalized partial order technique and utilizing Monte Carlo simulation, the method determines the reliability relationship between sub-channels in strong turbulence and constructs the polarization code with optimal parameter values based on different signal-to-noise ratio ranges. The simulation results demonstrate similar communication performance compared to the conventional Monte Carlo method, with negligible construction complexity.
Article
Optics
Ritu Gupta, Tara Singh Kamal
Summary: Various channel coding schemes have been used to alleviate turbulence induced fading effects in free space optical communication systems, with TCM coded OFDM systems showing promising performance. Integration of TCM with OFDM helps solve bandwidth issues and bit rate degradation, leading to high-performance wireless communication systems.
Article
Optics
Suping Jiao, Jifang Qiu, Yuchen Chen, Ran Tao, Wenjie Guo, Yan Li, Jian Wu
Summary: In this paper, we propose 4-channel and 6-channel spatial light receivers based on silicon-on-insulator (SOI) using an inverse design method. The receivers demonstrate low insertion losses and mean cross talks, making them suitable for free space optical communication systems.
Article
Optics
Sung-Jin Kim, Sang-Kook Han
Summary: A novel approximated misalignment model is developed for the position detection in the pointing, acquisition, and tracking system with multiple incident beams in free-space optical communication. The study proposes a statistical misalignment model and analyzes the transmission performance to achieve power-efficient and reliable FSO communication.
OPTICS COMMUNICATIONS
(2022)
Article
Optics
Vijay N. Afria, Ivan B. Djordjevic
Summary: To improve the reliability of entanglement-assisted communication in turbulent free-space optical (FSO) channels, the proposal is to use optical phase-conjugation on turbulence-affected signal photons and employ adaptive optics. Experimental demonstration at an outdoor 1.45 km FSO link in strong turbulence regime shows that reliable entanglement-assisted communication is achievable.
Article
Physics, Multidisciplinary
Gamze Nur Secilmis, Kholoud Elmabruk
Summary: In this study, the numerical investigation is conducted to explore the ability of laser beams carrying orbital angular momentum to reduce the scintillation level of Gaussian beams propagating in atmospheric turbulence. The effects of topological charge, beam waist, operating wavelength, and receiver radius on the scintillation indices are examined in detail. The results show that the Gaussian beams carrying orbital angular momentum have an advantage over fundamental Gaussian beams in communication links longer than 2.5 Km. It is also found that Gaussian beams carrying orbital angular momentum with small beam waist and high wavelength can significantly reduce the scintillation index. Therefore, these findings are significant for the design of optical communication links utilizing laser beams carrying orbital angular momentum.
Article
Multidisciplinary Sciences
Ziyi Zhu, Molly Janasik, Alexander Fyffe, Darrick Hay, Yiyu Zhou, Brian Kantor, Taylor Winder, Robert W. Boyd, Gerd Leuchs, Zhimin Shi
Summary: Free-space optical communication shows promise for versatile and high-bandwidth communication, but atmospheric turbulence can distort spatial modes. The authors demonstrate an experimentally turbulent-resistant communication protocol using vector beams to transmit high-dimensional information without the need for adaptive optics.
NATURE COMMUNICATIONS
(2021)
Article
Computer Science, Information Systems
Mohammed Elamassie, Murat Uysal
Summary: This study proposes a feedback-free adaptive modulation selection algorithm for Free Space Optical (FSO) communication systems, which aims to maximize average throughput by selecting the largest modulation order while ensuring that the required transmit power does not exceed the maximum power. Numerical results confirm the superiority of the proposed adaptive algorithm.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Dongkyu Kim, Dohoon Lim, Kyungdeuk Park, Yong Sup Ihn
Summary: In this study, a quantum-correlation-based free-space optical link over 250 m was demonstrated using an outdoor active reflector. Atmospheric turbulence effects were corrected using a tracking laser, and beam path drift was controlled using wireless optical feedback. This work provides valuable knowledge for improved control of beam paths in outdoor conditions.
CURRENT APPLIED PHYSICS
(2022)
Review
Optics
R. G. Sangeetha, C. Hemanth, Ishu Jaiswal
Summary: Free-Space Optical Communication (FSOC) system uses line-of-sight technology for long-distance transmission at gigabits per second (Gbps) data rates. The research analyzes the performance of different modulation techniques in FSO systems, considering factors such as outage probability, bit error rate, and signal-to-noise ratio. The findings show that M-ary QAM and OFDM-based FSO system can achieve long-distance communication (7000 m) at data rates ranging from 4.1 Gbits/s to 10.94 Gbits/s.
Article
Chemistry, Multidisciplinary
Ming Li, Pengxin Zhang, Jiawei Han
Summary: Free-space optical communication has many advantages, but the susceptibility to atmospheric turbulence is a major challenge. Understanding and measuring the atmospheric coherence length is important for optimizing system design and reducing the effects of atmospheric turbulence.
APPLIED SCIENCES-BASEL
(2022)
Article
Physics, Multidisciplinary
Halit Bakir, Kholoud Elmabruk
Summary: This study develops a deep-learning-based approach to detect turbulence-induced mode distortion in free-space optical communication links utilizing orbital angular momentum. The proposed models are trained with a dataset created based on intensity beam profiles propagated in different turbulent atmospheres. The results show that the proposed approach achieves high accuracy in distinguishing and quantifying the distortion in transmitted beams.
Article
Engineering, Electrical & Electronic
Haibo Wang, Zaichen Zhang, Bingcheng Zhu, Jian Dang, Liang Wu
Summary: This article investigates the performance of an ORIS-assisted hybrid RF and FSO communication system. By considering the physical models of ORIS, RF channel, atmospheric turbulence, and pointing error, closed-form solutions for the system's outage probability and BER have been derived. The results show that RF-FSO links with ORISs perform slightly worse than traditional RF-FSO links, but the performance degradation introduced by ORIS is relatively small, and the FSO link benefits from a higher degree of beam adjustment freedom.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Wenjng Guo, Yueying Zhan, Theodoros A. Tsiftsis, Lei Yang
Summary: This paper investigates the channel model and performance metrics of hovering UAV-assisted FSO links, and analyzes them through theoretical derivation and Monte-Carlo simulations. The research findings show that the performance of this link can be optimized by carefully designing the ratio of optical beam divergence angle to RMS of PEs.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Hang Dong, Zhixin Sun, Jingyi Li, Yahui Li, Wei Zhang, Guangyong Jin
Summary: This paper calculates thermal stresses and adsorption forces to determine laser cleaning conditions and establishes relevant models. Experimental results show that the removal effect is better with increasing nanosecond pulse delay, with the best effect achieved at 600 milliseconds pulse delay. Based on the findings, the mechanisms of oxide film removal involve thermal stress against adsorption and plasma shock wave breaking the oxide layer.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Junjie Zhang, Wenjun Li, Bingtao Li, Zheng-Da Hu, Jicheng Wang, Feng Zhang, Lei Wang
Summary: A multilayer thin film device structure based on Tamm plasmons is proposed for high-performance near-infrared hot electron photodetectors. By optimizing the device structure parameters, high responsivity detection can be achieved.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Hong Huang, Zhiguang Han
Summary: This paper proposes a new ghost imaging reconstruction method using ordered orthogonal Hadamard derived speckle as the illumination speckle series, and introduces the alternating direction multiplier method to improve the imaging performance. The evaluation results show that the method can achieve high-quality reconstructed images under low sampling conditions.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Moritsugu Sakamoto, Yuki Ono, Kohei Noda, Tomoyuki Sasaki, Nobuhiro Kawatsuki, Masayuki Tanaka, Hiroshi Ono
Summary: The effect of wavelength and polarization of illuminating light in polarization imaging for birefringent objects placed behind a scattering structure was experimentally investigated. The result shows that the spatial distribution of the birefringent object was more clearly visualized in the longer wavelength combined with circularly polarized light illumination. This finding indicates the potential of using polarization imaging with circularly polarized light illumination in the near-infrared range for visualizing birefringent objects with scattering.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Peihui Du, Hongfang Wang, Pengwei Li, Rukeyemuhan Abadula, Hmbat Batelbek, Min Gao
Summary: In this study, we theoretically demonstrate the strong coupling between Tamm plasmons and exciton polaritons in metal Al/DBR-molecular structures, extending the operating wavelength to the deep ultraviolet region. The coupling strength can be effectively manipulated by adjusting the structure parameters, offering potential benefits for the development of new-style optical filters.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Priyanka Chaudhary, Akhilesh Kumar Mishra
Summary: We design and numerically investigate the switching dynamics between two outer waveguides in a parity-time (PT)-symmetric adiabatically coupled three waveguides nonlinear directional coupler (NLDC) system. The study shows that the device can provide switching even when the middle waveguide is nonlinear and the outer waveguides are linear. Furthermore, the effect of loss to gain ratio on critical switching power and the impact of launched light power and gain (loss) value on transmitted power are also studied.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Wei Feng, Yongcong Yi, Shuyang Li, Zhi Xiong, Boya Xie, Zhen Zeng
Summary: Traditional imaging techniques are ineffective in achieving clear underwater imaging due to the presence of scattering media. Single-pixel imaging (SPI) system based on Unet++ offers a solution for reconstructing high-quality images in highly turbid water environments.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Xiaorui Qu, Jufeng Zhao, Haijun Tian, Junjie Zhu, Guangmang Cui
Summary: This paper studies the structural similarity between RGB and spectral images and proposes a non-iterative Images Structure Similarity (ISS) method for fast reconstruction of spectral images. Additionally, the input of the Deep Image Prior (DIP) method is optimized for the first time by using the initial spectral data reconstructed by ISS, leading to an improved starting value for the iteration. The experimental results show that the proposed method can enhance the reconstruction quality in both spectral and spatial resolutions, while significantly reducing the reconstruction time compared to other DIP-based methods.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Donghe Sheng, Zhe Han, Zanyang Qiao, Tianpei Dong, Chenxi Wang, Huiping Tian
Summary: In this study, a distributed multi-parameter sensor based on an etched few-mode multi-core fiber is proposed, allowing simultaneous sensing of temperature, strain, and sample refractive index. By combining space division multiplexing and stimulated Brillouin scattering, the sensor achieves high sensitivity in detecting these parameters.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Dehao Chen, Zhenwu Mo, Zehong Liang, Junjie Jiang, Huilin Tang, Yidan Sun, Ziyu Wang, Quanfeng Wei, Yanru Chen, Dongmei Deng
Summary: In this study, a novel family of elliptical Airyprime vortex beams (EAPVBs) is introduced, which inherits the excellent self-focusing properties of the circular Airyprime vortex beam (CAPVB). The asymmetric focusing of EAPVB leads to some novel properties, such as the splitting of high-order optical vortex and the formation of two foci. By taking advantage of these properties, EAPVB is constructed as a tunable optical bottle for particle capture.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Xiao Ma, Qiongchan Shao, Jian-Jun He
Summary: In this study, an SHS chip based on Su8 waveguide was designed and fabricated. By physically adjusting the metal electrodes and compensating for transmissivity fluctuations, the generation of side ripples was successfully suppressed.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Hongbin Zhang, Jiansen Du, Zongtao Chi, Hailin Cong, Bin Wang
Summary: In this paper, a novel type of dual-wavelength confocal metalens is proposed to solve the spatial crosstalk between two wavelengths. The metalens can greatly reduce the spatial crosstalk and achieve high precision and efficiency in confocal imaging. It can also focus light in specific wavelength ranges, making it suitable for imaging, microscopy, and optical fiber communication.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Rui Qiu, Guanmao Zhang, Shaokai Du, Jie Liu, Hongyu Jib, Kaiyun Bi, Bochuan Xing, Guangchao Diao
Summary: Recent research has developed an achromatic metalens that shows potential for replacing traditional lenses. This study focuses on a continuously variable focus height broadband achromatic metalens for long-wavelength infrared applications. By optimizing materials and parameters, chromatic aberration is effectively corrected, making it suitable for high-resolution LWIR imaging and spectroscopy systems.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Marcos Troncoso-Costas, Gaurav Jain, Yiming Li, Mohammed Patel, Lakshmi Narayanan Venkatasubramani, Sean O'Duill, Frank Smyth, Andrew Ellis, Francisco Diaz-Otero, Colm Browning, Liam Barry
Summary: In this work, a fast-switching tuneable laser capable of wide wavelength coverage, low noise and linewidth levels suitable for high-order modulation formats is demonstrated. The laser is characterized to cover a wavelength range of 35 nm in the C-band with nanosecond switching time. It is used to successfully demonstrate 480 Gbit/s 16QAM transmission over 25 km of single-mode fiber for a wavelength range of 19 nm.
OPTICS COMMUNICATIONS
(2024)
Article
Optics
Takeshi Moriyasu, Masahiko Tani, Hideaki Kitahara, Takashi Furuya, Jessica Afalla, Toshiro Kohmoto, Daishiro Koide, Hiroki Sato, Mitsutaka Kumakura
Summary: Optical pump-terahertz probe spectroscopy was used to study the photocarrier dynamics and optical characteristics of semiconductor Si. The results showed that the thickness of Si influenced the transmitted terahertz field amplitude and peak delay time, indicating differences in photocarrier dynamics between different Si materials.
OPTICS COMMUNICATIONS
(2024)
