Volume: 2 Issue 1
6 Article(s)

Export citation format
Diffraction, Gratings, and Holography
Review of Fresnel incoherent correlation holography with linear and non-linear correlations [Invited] | On the Cover
Vijayakumar Anand, Tomas Katkus, Soon Hock Ng, and Saulius Juodkazis
Fresnel incoherent correlation holography (FINCH) is a well-established incoherent imaging technique. In FINCH, three self-interference holograms are recorded with calculated phase differences between the two interfering, differently modulated object waves and projected into a complex hologram. The object is reconstructed without the twin image and bias terms by a numerical Fresnel back propagation of the complex hologram. A modified approach to implement FINCH by a single camera shot by pre-calibrating the system involving recording of the point spread function library and reconstruction by a non-linear cross correlation has been introduced recently. The expression of the imaging characteristics from the modulation functions in original FINCH and the modified approach by pre-calibration in spatial and polarization multiplexing schemes are reviewed. The study reveals that a reconstructing function completely independent of the function of the phase mask is required for the faithful expression of the characteristics of the modulating function in image reconstruction. In the polarization multiplexing method by non-linear cross correlation, a partial expression was observed, while in the spatial multiplexing method by non-linear cross correlation, the imaging characteristics converged towards a uniform behavior.
Review of Optics: a virtual journal
  • Publication Date: Feb. 10, 2021
  • Vol. 19 Issue 2 020501 (2021)
Integrated Optics
Intelligent algorithms: new avenues for designing nanophotonic devices [Invited] | On the Cover
Lifeng Ma, Jing Li, Zhouhui Liu, Yuxuan Zhang, Nianen Zhang, Shuqiao Zheng, and Cuicui Lu
The research on nanophotonic devices has made great progress during the past decades. It is the unremitting pursuit of researchers that realize various device functions to meet practical applications. However, most of the traditional methods rely on human experience and physical inspiration for structural design and parameter optimization, which usually require a lot of resources, and the performance of the designed device is limited. Intelligent algorithms, which are composed of rich optimized algorithms, show a vigorous development trend in the field of nanophotonic devices in recent years. The design of nanophotonic devices by intelligent algorithms can break the restrictions of traditional methods and predict novel configurations, which is universal and efficient for different materials, different structures, different modes, different wavelengths, etc. In this review, intelligent algorithms for designing nanophotonic devices are introduced from their concepts to their applications, including deep learning methods, the gradient-based inverse design method, swarm intelligence algorithms, individual inspired algorithms, and some other algorithms. The design principle based on intelligent algorithms and the design of typical new nanophotonic devices are reviewed. Intelligent algorithms can play an important role in designing complex functions and improving the performances of nanophotonic devices, which provide new avenues for the realization of photonic chips.
Review of Optics: a virtual journal
  • Publication Date: Jan. 10, 2021
  • Vol. 19 Issue 1 011301 (2021)
Carrier dynamic process in all-inorganic halide perovskites explored by photoluminescence spectra
Jing Chen, Chao Zhang, Xiaolin Liu, Lin Peng, Jia Lin, and Xianfeng Chen
Recently, all-inorganic halide perovskites have received enormous attention because of their excellent optoelectronic properties. Among them, the power conversion efficiency (PCE) of all-inorganic halide perovskite solar cells has made rapid progress in the last few years. However, understanding the intrinsic physical nature of halide perovskites, especially the dynamic process of photo-generated carriers, is a key for improving the PCE. In this review, we introduced and summarized the photoluminescence (PL) technique used to explore the carrier dynamic process in all-inorganic halide perovskites. Several physical models were proposed to investigate the dynamic parameters, i.e., recombination lifetime and diffusion length, by analyzing the steady-state PL as well as the time-resolved PL spectra. We also discussed the distinction of PL spectral behavior between bulk halide perovskite samples and those grown with transport layers due to the participation of different dominant dynamic paths. Finally, we briefly described some other optical techniques reported to study the relevant physical properties of all-inorganic halide perovskites.
Review of Optics: a virtual journal
  • Publication Date: Jan. 25, 2021
  • Vol. 9 Issue 2 02000151 (2021)
Organic photoresponsive materials for information storage: a review
Yanling Zhuang, Xiuli Ren, Xueting Che, Shujuan Liu, Wei Huang, and Qiang Zhao
Organic photoresponsive materials can undergo various reversible variations in certain physical and chemical properties, such as optical properties, electrochemical properties, conformation, and conductivity, upon photoirradiation. They have been widely applied in various optoelectronic fields, especially in information storage. We summarize research progress on organic photoresponsive materials for information storage. First, the design strategies and photoswitching mechanisms for various kinds of organic photoresponsive materials, including small organic molecules, metal complexes, polymers, supramolecules, and cholesteric liquid crystals, are systematically summarized. These materials exhibit reversible changes of absorption and/or emission properties in response to different wavelengths of light. Subsequently, the applications of these organic materials in information storage, such as data (re)writing and erasing, encryption and decryption, and anticounterfeiting, are introduced in detail. Finally, the current challenges and future directions in this rapidly growing research field are discussed. The review will provide important guidance on the future works about the design of excellent organic photoresponsive materials for optoelectronic applications.
Review of Optics: a virtual journal
  • Publication Date: Dec. 08, 2020
  • Vol. 3 Issue 1 014001 (2021)
Generation of polarization and phase singular beams in fibers and fiber lasers
Dong Mao, Yang Zheng, Chao Zeng, Hua Lu, Cong Wang, Han Zhang, Wending Zhang, Ting Mei, and Jianlin Zhao
Cylindrical vector beams and vortex beams, two types of typical singular optical beams characterized by axially symmetric polarization and helical phase front, possess the unique focusing property and the ability of carrying orbital angular momentum. We discuss the formation mechanisms of such singular beams in few-mode fibers under the vortex basis and show recent advances in generating techniques that are mainly based on long-period fiber gratings, mode-selective couplers, offset-spliced fibers, and tapered fibers. The performances of cylindrical vector beams and vortex beams generated in fibers and fiber lasers are summarized and compared to give a comprehensive understanding of singular beams and to promote their practical applications.
Review of Optics: a virtual journal
  • Publication Date: Jan. 01, 2021
  • Vol. 3 Issue 1 014002 (2021)
Light field on a chip: metasurface-based multicolor holograms
Dandan Wen, Jasper J. Cadusch, Jiajun Meng, and Kenneth B. Crozier
Multicolor holography can faithfully record the color, depth, parallax, and other properties of scenes and have thus found numerous applications, for example, in optical document security, nonvolatile data storage, and virtual or augmented reality systems. Nanophotonic metasurfaces present multiple degrees of freedom to manipulate the properties of optical fields at visible wavelengths. These in turn provide opportunities for metasurface-based multicolor holography. We describe recent developments in multicolor metasurface holograms. These are categorized based on their color-separating mechanisms rather than their structural properties, such as whether they are plasmonic or dielectric. We hope this review will provide readers with new insights and thus help extend applications of metasurface-based multicolor holography to other fields.
Review of Optics: a virtual journal
  • Publication Date: Feb. 26, 2021
  • Vol. 3 Issue 2 024001 (2021)