Beauty of Math in Ocean Optics: Two-Stream Equations of Åas
Lee Zhongping
Solar radiation in the visible domain can penetrate aquatic environment, which drives photon-related processes including phytoplankton photosynthesis and heating of the upper water column. In addition, the scattered light in the water column can emerge (escape) from water, which forms the bases to sense properties in aquatic environments using sensors onboard satellites. Thus, an understanding of the processes and properties related to the propagation of solar radiation in-and-out of water is a basic requirement in ocean optics and ocean color remote sensing. The spatial (and spectral for inelastic scattering) variation of radiance is governed by the radiative transfer equation, which is not directly applicable to infer in-water optical properties or to describe the relationships between the optical properties measured in the field and inherent optical properties related to environmental properties. Through simple mathematical derivations, or manipulations, of the radiative transfer equation (RTE), ?as transferred the RTE into a set of two equations describing the change of upwelling and downwelling irradiance with depth, and further obtained concise analytical relationships between the apparent and inherent optical properties. These equations not only form the basic theoretical relationships in ocean optics, but also lay the foundation of semi-analytical algorithms in ocean color remote sensing.
  • Jun. 15, 2022
  • Acta Optica Sinica
  • Vol. 42 Issue 12 1200004 (2022)
  • DOI:10.3788/AOS202242.1200004
[in Chinese]
Li Zhengjia
  • Jun. 13, 2022
  • Chinese Journal of Lasers
  • Vol. 49 Issue 12 1200001 (2022)
  • DOI:
[in Chinese]
Zhang Xinliang, Zeng Xiaoyan, Tang Ming, and Sun Qizhen
  • Jun. 13, 2022
  • Chinese Journal of Lasers
  • Vol. 49 Issue 12 1200000 (2022)
  • DOI:
Modulating properties by light ion irradiation: From novel functional materials to semiconductor power devices
Yuan Ye, Zhou Shengqiang, and Wang Xinqiang
In this review, the application of light ion irradiation is discussed for tailoring novel functional materials and for improving the performance in SiC or Si based electrical power devices. The deep traps and electronic disorder produced by light ion irradiation can modify the electrical, magnetic, and optical properties of films (e.g., dilute ferromagnetic semiconductors and topological materials). Additionally, benefiting from the high reproducibility, precise manipulation of functional depth and density of defects, as well as the flexible patternability, the helium or proton ion irradiation has been successfully employed in improving the dynamic performance of SiC and Si based PiN diode power devices by reducing their majority carrier lifetime, although the static performance is sacrificed due to deep level traps. Such a trade-off has been regarded as the key point to compromise the static and dynamic performances of power devices. As a result, herein the light ion irradiation is highlighted in both exploring new physics and optimizing the performance in functional materials and electrical devices.
  • Jun. 10, 2022
  • Journal of Semiconductors
  • Vol. 43 Issue 6 063101 (2022)
  • DOI:10.1088/1674-4926/43/6/063101
Graphene synthesis, fabrication, characterization based on bottom-up and top-down approaches: An overview
Olatomiwa Agbolade Lukman, Adam Tijjani, Gopinath Subash C. B., Kolawole Sanusi Yekinni, Olayinka Oyeshola Hakeem, and Hashim U.
This study presents an overview on graphene synthesis, fabrication and different characterization techniques utilized in the production. Since its discovery in 2004 by Andre Geim and Kostya Novoselov several research articles have been published globally to this effect, owing to graphene’s extraordinary, and exclusive characteristics which include optical transparency, excellent thermal, and mechanical properties. The properties and applications of this two-dimensional carbon crystal composed of single-layered material have created new avenues for the development of high-performance future electronics and technologies in energy storage and conversion for the sustainable energy. However, despite its potential and current status globally the difficulty in the production of monolayer graphene sheet still persists. Therefore, this review highlighted two approaches in the synthesis of graphene, which are the top-down and bottom-up approaches and examined the advantages and failings of the methods involved. In addition, the prospects and failings of these methods are investigated, as they are essential in optimizing the production method of graphene vital for expanding the yield, and producing high-quality graphene.
  • Jun. 10, 2022
  • Journal of Semiconductors
  • Vol. 43 Issue 6 061101 (2022)
  • DOI:10.1088/1674-4926/43/6/061101
Characterization of interfaces: Lessons from the past for the future of perovskite solar cells
Wang Wanlong, Zhang Dongyang, Liu Rong, Gangadharan Deepak Thrithamarassery, Tan Furui, and Saidaminov Makhsud I.
A photovoltaic technology historically goes through two major steps to evolve into a mature technology. The first step involves advances in materials and is usually accompanied by the rapid improvement of power conversion efficiency. The second step focuses on interfaces and is usually accompanied by significant stability improvement. As an emerging generation of photovoltaic technology, perovskite solar cells are transitioning to the second step of their development when a significant focus shifts toward interface studies and engineering. While various interface engineering strategies have been developed, interfacial characterization is crucial to show the effectiveness of interfacial modification. Here, we review the characterization techniques that have been utilized in studying interface properties in perovskite solar cells. We first summarize the main roles of interfaces in perovskite solar cells, and then we discuss some typical characterization methodologies for morphological, optical, and electrical studies of interfaces. Successful experiences and existing problems are analyzed when discussing some commonly used methods. We then analyze the challenges and provide an outlook for further development of interfacial characterizations. This review aims to evoke strengthened research devotion on novel and persuasive interfacial engineering.
  • Jun. 10, 2022
  • Journal of Semiconductors
  • Vol. 43 Issue 5 051202 (2022)
  • DOI:10.1088/1674-4926/43/5/051202
Multifunctional neurosynaptic devices for human perception systems
Wen Wei, Guo Yunlong, and Liu Yunqi
  • Jun. 10, 2022
  • Journal of Semiconductors
  • Vol. 43 Issue 5 051201 (2022)
  • DOI:10.1088/1674-4926/43/5/051201
Advances in lithium niobate photonics: development status and perspectives | Article Video
Guanyu Chen, Nanxi Li, Jun Da Ng, Hong-Lin Lin, Yanyan Zhou, Yuan Hsing Fu, Lennon Yao Ting Lee, Yu Yu, Ai-Qun Liu, and Aaron J. Danner
Lithium niobate (LN) has experienced significant developments during past decades due to its versatile properties, especially its large electro-optic (EO) coefficient. For example, bulk LN-based modulators with high speeds and a superior linearity are widely used in typical fiber-optic communication systems. However, with ever-increasing demands for signal transmission capacity, the high power and large size of bulk LN-based devices pose great challenges, especially when one of its counterparts, integrated silicon photonics, has experienced dramatic developments in recent decades. Not long ago, high-quality thin-film LN on insulator (LNOI) became commercially available, which has paved the way for integrated LN photonics and opened a hot research area of LN photonics devices. LNOI allows a large refractive index contrast, thus light can be confined within a more compact structure. Together with other properties of LN, such as nonlinear/acousto-optic/pyroelectric effects, various kinds of high-performance integrated LN devices can be demonstrated. A comprehensive summary of advances in LN photonics is provided. As LN photonics has experienced several decades of development, our review includes some of the typical bulk LN devices as well as recently developed thin film LN devices. In this way, readers may be inspired by a complete picture of the evolution of this technology. We first introduce the basic material properties of LN and several key processing technologies for fabricating photonics devices. After that, various kinds of functional devices based on different effects are summarized. Finally, we give a short summary and perspective of LN photonics. We hope this review can give readers more insight into recent advances in LN photonics and contribute to the further development of LN related research.
  • Jun. 09, 2022
  • Advanced Photonics
  • Vol. 4 Issue 3 034003 (2022)
  • DOI:10.1117/1.AP.4.3.034003
Three-dimensional direct laser writing of biomimetic neuron interfaces in the era of artificial intelligence: principles, materials, and applications
Haoyi Yu, Qiming Zhang, Xi Chen, Haitao Luan, and Min Gu
The creation of biomimetic neuron interfaces (BNIs) has become imperative for different research fields from neural science to artificial intelligence. BNIs are two-dimensional or three-dimensional (3D) artificial interfaces mimicking the geometrical and functional characteristics of biological neural networks to rebuild, understand, and improve neuronal functions. The study of BNI holds the key for curing neuron disorder diseases and creating innovative artificial neural networks (ANNs). To achieve these goals, 3D direct laser writing (DLW) has proven to be a powerful method for BNI with complex geometries. However, the need for scaled-up, high speed fabrication of BNI demands the integration of DLW techniques with ANNs. ANNs, computing algorithms inspired by biological neurons, have shown their unprecedented ability to improve efficiency in data processing. The integration of ANNs and DLW techniques promises an innovative pathway for efficient fabrication of large-scale BNI and can also inspire the design and optimization of novel BNI for ANNs. This perspective reviews advances in DLW of BNI and discusses the role of ANNs in the design and fabrication of BNI.
  • Jun. 09, 2022
  • Advanced Photonics
  • Vol. 4 Issue 3 034002 (2022)
  • DOI:10.1117/1.AP.4.3.034002
Research Progress of Terahertz Wave in 6G Communication Network
Li Li, Ge Hongyi, Jiang Yuying, Li Guangming, Ming Lü, Wang Fei, and Zhang Yuan
The global 5G communication network subscriber base has surpassed 400 million as of May 2021, thanks to the commercial deployment of 5G communication technologies around the world. Research on the next-generation wireless communication technologies has been conducted to address the demand for ultrahigh data rates and ultralow latency for future applications. The large number of absolute bandwidth resources in the terahertz band is the most significant advantage of the terahertz communication, making it suitable for various applications. Herein, the relevant research in the field of terahertz communication is described. First, we introduce the plan and vision of 6G communication network, as well as the current status of the terahertz communication technology on a domestic and worldwide scale. Second, the key terahertz communication technology and potential application scenarios are discussed. Finally, we present a summary of the current research results and an outlook on future research directions to provide new ideas for moving into the “terahertz era.”
  • Jun. 09, 2022
  • Laser & Optoelectronics Progress
  • Vol. 59 Issue 13 1300007 (2022)
  • DOI:10.3788/LOP202259.1300007