In recent years, the explosive development of artificial intelligence implementing by artificial neural networks (ANNs) creates inconceivable demands for computing hardware. However, conventional computing hardware based on electronic transistor and von Neumann architecture cannot satisfy such an inconceivable demand due to the unsustainability of Moore’s Law and the failure of Dennard’s scaling rules. Fortunately, analog optical computing offers an alternative way to release unprecedented computational capability to accelerate varies computing drained tasks. In this article, the challenges of the modern computing technologies and potential solutions are briefly explained in Chapter 1. In Chapter 2, the latest research progresses of analog optical computing are separated into three directions: vector/matrix manipulation, reservoir computing and photonic Ising machine. Each direction has been explicitly summarized and discussed. The last chapter explains the prospects and the new challenges of analog optical computing.
Distributed time-domain Brillouin scattering fiber sensors have been widely used to measure the changes of the temperature and strain. The linear dependence of the temperature and strain on the Brillouin frequency shift enabled the distributed temperature and strain sensing based on mapping of the Brillouin gain spectrum. In addition, an acoustic wave can be detected by the four wave mixing (FWM) associated SBS process, in which phase matching condition is satisfied via up-down conversion of SBS process through birefringence matching before and after the conversion process. Brillouin scattering can be considered as the scattering of a pump wave from a moving grating (acoustic phonon) which induces a Doppler frequency shift in the resulting Stokes wave. The frequency shift is dependent on many factors including the velocity of sound in the scattering medium as well as the index of refraction. Such a process can be used to monitor the gain of random fiber laser based on SBS, the distributed acoustic wave reflect the distributed SBS gain for random lasing radiation, as well as the relative intensity noise inside the laser gain medium. In this review paper, the distributed time-domain sensing system based on Brillouin scattering including Brillouin optical time-domain reflectometry (BOTDR), Brillouin optical time-domain analysis (BOTDA), and FWM enhanced SBS for acoustic wave detection are introduced for their working principles and recent progress. The distributed Brillouin sensors based on specialty fibers for simultaneous temperature and strain measurement are summarized. Applications for the Brillouin scattering time-domain sensors are briefly discussed.
Editor-in-Chief Min Gu "It is no doubt that photonics has become a key enabling technology platform for our sustainable life. It is at this exciting time that we welcome the arrival of the inaugural issue of the journal, PhotoniX, to our photonics community. We aim that the new journal not only truly showcases the enabling power of photonics, but also strives to develop this power into cultivating industries as well as improving the competitiveness, the scope and depth of science and technology in general..."
Editor-in-Chief Min Qiu "This open-access journal focuses on photonic technology with cutting-edge, multidisciplinary and derivative characteristics, aiming to become a platform to promote the international frontier "Enabling Technology". It comes at a crucial moment when both academia and industry urgently need a platform to explore the true enabling power of photonics..."
Editor-in-Chief: Min Gu
He is Executive Chancellor and Distinguished Professor of University of Shanghai for Science and Technology. He was Distinguished Professor and Associate Deputy Vice-Chancellor at RMIT University and a Laureate Fellow of the Australian Research Council. He is an author of 4 standard reference books and has over 500 publications in nano/biophotonics. He is an elected fellow of the Australian Academy of Science and the Australian Academy of Technological Sciences and Engineering as well as foreign fellow of the Chinese Academy of Engineering. He is also an elected fellow of the AIP, the OSA, the SPIE, the InstP, and the IEEE. He was President of the International Society of Optics within Life Sciences, Vice President of the Board of the International Commission for Optics (ICO) (Chair of the ICO Prize Committee) and a Director of the Board of the Optical Society of America (Chair of the International Council). He was awarded the Einstein Professorship, the W. H. (Beattie) Steel Medal, the Ian Wark Medal, the Boas Medal and the Victoria Prize for Science and Innovation. He is a winner of the 2019 Dennis Gabor Award of SPIE.
Editor-in-Chief: Min Qiu
He received the Ph.D. degree from Zhejiang University in 1999. He received his second Ph.D. degree and became an assistant professor at the Royal Institute of Technology (KTH), Stockholm, Sweden, in 2001. He became a full professor (Professor of Photonics) at KTH in 2009. Since 2010, he became a distinguished professor at Zhejiang University. He was the Director of State Key Laboratory of Modern Optical Instrumentation, Zhejiang University. He joined Westlake University as a Chair Professor of Photonics in April 2018. His research interests include nanofabrication technology, nanophotonics, and green photonics. He was elected a fellow of the Institute of Electrical and Electronics Engineers (IEEE) in 2015, a fellow of the Optical Society of America (OSA) and a fellow of the International Society for Optics and Photonics (SPIE) in 2013. He is leading a project on solar thermal energy utilization through the National Key Research and Development Program of China (No. 2017YFA0205700). He is currently an editor of Optics Communications (Elsevier), a topical editor of Light: Science and Applications (Springer Nature), and an associate editor of Science Bulletin (Science China Press).