Journal of Optics最新文献_第6页

Low-complexity EVM estimation based on artificial neural networks for coherent optical systems 基于人工神经网络的相干光系统低复杂度 EVM 估算

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-06-12 DOI: 10.1088/2040-8986/ad529f

Dhirendra Kumar Jha and Jitendra K Mishra

{"title":"Low-complexity EVM estimation based on artificial neural networks for coherent optical systems","authors":"Dhirendra Kumar Jha and Jitendra K Mishra","doi":"10.1088/2040-8986/ad529f","DOIUrl":"https://doi.org/10.1088/2040-8986/ad529f","url":null,"abstract":"With continuous growth in modulation formats, the requirement for autonomous devices is becoming more important than ever. Predicting error vector magnitude (EVM) of m-ary quadrature amplitude modulation (mQAM) are intricate issue for the effective design of transmission systems. Existing estimation techniques have survived through repetitive processes that are frequently computationally expensive, and time-consuming. Recently deep learning approaches demonstrated good performance as useful computational tools, offering a different way for accelerating such mQAM simulations. This paper introduces an artificial neural network (ANN) architecture that aims to forecast the EVM of the popular modulation forms including 18 Gbaud 8QAM, 14 Gbaud 16QAM, and 10 Gbaud 64QAM under different transmission conditions. Amplitude histograms (AHs) are produced from constellation diagrams obtained with varying launch power, laser linewidth, OSNR, and transmission distance by an offline preprocessing flow. The fully trained framework exhibits superior performance in terms of computing cost compared to the simulation experiments. The overall execution time of the ANN-based modeling method is approximately 234 s as opposed to more than 23000 s when employing the simulation technique, resulting in a 99% reduction in computation time. As a result, this technology opens the door to quick, all-encompassing techniques for characterizing and analyzing optical fiber problems.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"27 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141529382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

A theoretical study on deep ultraviolet supercontinuum generation in subwavelength optical fiber 亚波长光纤中深紫外超连续真空产生的理论研究

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-06-11 DOI: 10.1088/2040-8986/ad529e

Weihua Shi, Yuying Gu, Tiantian Zhang

引用次数: 0

Optical trimer: a theoretical physics approach to waveguide couplers 光学三聚体：波导耦合器的理论物理方法

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-06-11 DOI: 10.1088/2040-8986/ad44aa

A Stoffel, S F Caballero-Benitez and B M Rodríguez-Lara

{"title":"Optical trimer: a theoretical physics approach to waveguide couplers","authors":"A Stoffel, S F Caballero-Benitez and B M Rodríguez-Lara","doi":"10.1088/2040-8986/ad44aa","DOIUrl":"https://doi.org/10.1088/2040-8986/ad44aa","url":null,"abstract":"We study electromagnetic field propagation through an ideal, passive, three-dimensional, triangular three-waveguide coupler using a symmetry-based approach that capitalizes on the underlying su(3) symmetry. The planar version of this platform has already demonstrated its utility in photonic circuit design, enabling optical sampling, filtering, modulating, multiplexing, and switching. We aim to provide a practical tutorial on using group theory for the analysis of photonic lattices for those less familiar with abstract algebra methods. This approach serves as a powerful tool for optical designs. To illustrate this, we focus on the equilateral trimer, connected to the discrete Fourier transform, and the isosceles trimer, related to the golden ratio, providing stable single waveguide output. We also explore a scenario where the coupling in an equilateral coupler changes linearly with propagation distance. Going beyond the standard optical-quantum analogy, we show that coupled-mode equations for intensity and phase allows us to calculate envelopes for inputs within an intensity class, as well as individual input field amplitudes. This approach streamlines the design process by eliminating the need for point-to-point propagation calculations, highlighting the power of group theory in the field of photonic design.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"39 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141529384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Tackling the focal shift effect for metalenses 解决金属透镜的焦移效应

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-06-11 DOI: 10.1088/2040-8986/ad52a0

Farhan Ali, Ramin Yazdaanpanah, Serap Aksu

{"title":"Tackling the focal shift effect for metalenses","authors":"Farhan Ali, Ramin Yazdaanpanah, Serap Aksu","doi":"10.1088/2040-8986/ad52a0","DOIUrl":"https://doi.org/10.1088/2040-8986/ad52a0","url":null,"abstract":"We present a theoretical analysis aimed at comprehending and mitigating the focal shift phenomenon in planar dielectric metalenses. To conduct this analysis, we introduce metalens designs consisting of silicon and germanium nanoblocks on a calcium fluoride substrate, operating in the mid-IR frequency range. The lensing performance of these metalenses is investigated using the finite-difference time-domain method, and they operate at wavelengths of 3 and 4 <italic toggle=\"yes\">µ</italic>m with a polarization conversion efficiency close to unity. Our findings indicate a strong correlation between the focal shift phenomena on dielectric metalenses and the numerical aperture (NA), revealing that increasing the Fresnel number is not always an effective approach to minimizing the focal shift. In contrast to previous studies, we define a critical NA, independent of the lens size, where the focal shift reaches a minimum, resulting in a symmetric focal intensity distribution and ultimately yielding a better-performing metalens. We demonstrate that for NAs greater than the determined critical value, a positive focal shift is observed on planar metalenses, diverging from the conventional negative shift predicted by existing models. Additionally, we show that by selecting a metalens within a specific NA range and with smaller diameters, high focusing efficiencies can be achieved. The focusing efficiency of the studied metalenses is measured as high as 70%, marking one of the best values reported for the IR range to date. These results serve as a guide for improving the agreement between experimental and designed metalens features, enhancing their practical applications.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"14 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141529385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Hot-carrier thermophotovoltaic systems 热载体热光电系统

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-05-21 DOI: 10.1088/2040-8986/ad4727

Kartika N Nimje, Maxime Giteau and Georgia T Papadakis

引用次数: 0

High Q chiroptical responses with maximum chirality in all-dielectric metasurfaces driven by quasi-bound states in the continuum 由连续体中的准束缚态驱动的全介质元表面中具有最大手性的高 Q 值iroptical 响应

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-05-19 DOI: 10.1088/2040-8986/ad44ab

Tian Ma, Jiangkun Tian, Wei Sang, Doudou Wang and Jun Li

{"title":"High Q chiroptical responses with maximum chirality in all-dielectric metasurfaces driven by quasi-bound states in the continuum","authors":"Tian Ma, Jiangkun Tian, Wei Sang, Doudou Wang and Jun Li","doi":"10.1088/2040-8986/ad44ab","DOIUrl":"https://doi.org/10.1088/2040-8986/ad44ab","url":null,"abstract":"Chiral metasurfaces have attracted considerable attention because of their immense potential for diverse applications requiring chiral light-matter interactions. Recently, boosted by a mechanism based on the concept of bound states in the continuum (BICs), high Q factor chiroptical resonances have been exhibited by breaking the inversion symmetries of planar metasurfaces. However, the optical chirality of these chiral metasurfaces is generally intolerable with respect to the structural geometries, especially the geometric asymmetry. Here, we present a novel chiral quasi-BIC with strong optical chirality in an all-dielectric metasurface. By simultaneously breaking the in-plane rotational and mirror symmetries, the chiral metasurface shows enhanced chiroptical resonances with near-unity CD (∼0.996) and high Q factors (∼2274) at terahertz frequencies. Further analyses based on numerical simulations reveal that the CD of the chiroptical resonance depicts exceptional remarkable tolerableness to the geometry asymmetry when are present in a broad range, while the corresponding Q factor is modulated accordingly. The results may develop a novel approach to manipulating the advanced optical chirality for potential applications requiring strong CD with enhanced light-matter interactions.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"35 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141147590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Adaptive multi-spectral mimicking with 2D-material nanoresonator networks 利用二维材料纳米震荡器网络进行自适应多光谱模拟

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-05-16 DOI: 10.1088/2040-8986/ad4722

Yujie Luo, Thomas Christensen and Ognjen Ilic

引用次数: 0

Propagation characteristics of twisted cosine-Gaussian Schell-model beams 扭曲余弦高斯谢尔模型光束的传播特性

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-05-14 DOI: 10.1088/2040-8986/ad4724

Shijie Dong, Yunzhe Yang, Yujie Zhou, Xinzhong Li and Miaomiao Tang

引用次数: 0

Switching between slow light and fast light by static magnetic field in a degenerate four-level atomic system at room temperature 室温下退化四级原子体系中的静磁场在慢光和快光之间的切换

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-05-14 DOI: 10.1088/2040-8986/ad4728

Nguyen Van Phu, Nguyen Huy Bang, Luong Thi Yen Nga and Le Van Doai

{"title":"Switching between slow light and fast light by static magnetic field in a degenerate four-level atomic system at room temperature","authors":"Nguyen Van Phu, Nguyen Huy Bang, Luong Thi Yen Nga and Le Van Doai","doi":"10.1088/2040-8986/ad4728","DOIUrl":"https://doi.org/10.1088/2040-8986/ad4728","url":null,"abstract":"The optical response of a magnetic-degenerated four-level atom system to the two left and right circular polarization components of the probe field is represented at room temperature. The absorption spectrum and group index for the two polarization components of the probe field are controlled according to the static magnetic field and the coupling field under electromagnetically induced transparency condition. By varying the strength of the static magnetic field, the optical response of the atomic medium can be changed from transparency to absorption or vice versa and hence the amplitude of group index also changes from positive extreme to negative extreme or vice versa. The same phenomenon also occurs when changing the coupling field intensity. In addition, temperature also significantly influence on the optical response of the atomic medium, which changes not only the amplitude but also the sign of the group index as the temperature increases. Our analytical results can be useful for experimental observation and related applications of light group index/velocity at room temperature.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"5 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140940170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Coexistence of varied intensities, phases, and polarization states along the direction of beam propagation 不同强度、相位和偏振态沿光束传播方向共存

IF 2.1 4区物理与天体物理

Journal of Optics Pub Date : 2024-05-13 DOI: 10.1088/2040-8986/ad4725

Jianhe Yang and Shaohua Tao

引用次数: 0