Underwater wireless information transfer is of great interest to the military, industry, and the scientific community, as it plays an important role in tactical surveillance, pollution monitoring, oil control and maintenance, offshore explorations, climate change monitoring, and oceanography research. In order to facilitate all these activities, there is an increase in the number of unmanned vehicles or devices deployed underwater, which require high bandwidth and high capacity for information transfer underwater. Although tremendous progress has been made in the field of acoustic communication underwater, however, it is limited by bandwidth. All this has led to the proliferation of underwater optical wireless communication (UOWC), as it provides higher data rates than the traditional acoustic communication systems with significantly lower power consumption and simpler computational complexities for short-range wireless links. UOWC has many potential applications ranging from deep oceans to coastal waters. However, the biggest challenge for underwater wireless communication originates from the fundamental characteristics of ocean or sea water; addressing these challenges requires a thorough understanding of complex physio-chemical biological systems. In this paper, the main focus is to understand the feasibility and the reliability of high data rate underwater optical links due to various propagation phenomena that impact the performance of the system. This paper provides an exhaustive overview of recent advances in UOWC. Channel characterization, modulation schemes, coding techniques, and various sources of noise which are specific to UOWC are discussed. This paper not only provides exhaustive research in underwater optical communication but also aims to provide the development of new ideas that would help in the growth of future underwater communication. A hybrid approach to an acousto-optic communication system is presented that complements the existing acoustic system, resulting in high data rates, low latency, and an energy-efficient system.

Underwater Optical Wireless Communication

Underwater wireless communications refer to data transmission in unguided water environment through wireless carriers, i.e., radio-frequency (RF) wave, acoustic wave, and optical wave. In comparison to RF and acoustic counterparts, underwater optical wireless communication (UOWC) can provide a much higher transmission bandwidth and much higher data rate. Therefore, we focus, in this paper, on the UOWC that employs optical wave as the transmission carrier. In recent years, many potential applications of UOWC systems have been proposed for environmental monitoring, offshore exploration, disaster precaution, and military operations. However, UOWC systems also suffer from severe absorption and scattering introduced by underwater channels. In order to overcome these technical barriers, several new system design approaches, which are different from the conventional terrestrial free-space optical communication, have been explored in recent years. We provide a comprehensive and exhaustive survey of the state-of-the-art UOWC research in three aspects: 1) channel characterization; 2) modulation; and 3) coding techniques, together with the practical implementations of UOWC.

A Survey of Underwater Optical Wireless Communications

* The only book describing applications of nonlinear fiber optics * Two new chapters on the latest developments: highly nonlinear fibers and quantum applications* Coverage of biomedical applications* Problems provided at the end of each chapterThe development of new highly nonlinear fibers - referred to as microstructured fibers, holey fibers and photonic crystal fibers - is the next generation technology for all-optical signal processing and biomedical applications. This new edition has been thoroughly updated to incorporate these key technology developments.The book presents sound coverage of the fundamentals of lightwave technology, along with material on pulse compression techniques and rare-earth-doped fiber amplifiers and lasers. The extensively revised chapters include information on fiber-optic communication systems and the ultrafast signal processing techniques that make use of nonlinear phenomena in optical fibers.New material focuses on the applications of highly nonlinear fibers in areas ranging from wavelength laser tuning and nonlinear spectroscopy to biomedical imaging and frequency metrology. Technologies such as quantum cryptography, quantum computing, and quantum communications are also covered in a new chapter.This book will be an ideal reference for: RD scientists involved with research on fiber amplifiers and lasers; graduate students and researchers working in the fields of optical communications and quantum information. * The only book on how to develop nonlinear fiber optic applications* Two new chapters on the latest developments; Highly Nonlinear Fibers and Quantum Applications* Coverage of biomedical applications

Applications of nonlinear fiber optics

Acaricide resistance in cattle ticks and approaches to its management: The state of play

http://ieeexplore.ieee.org/iel5/5/31255/01454920.pdf

Optical communications

This article deals with the effect of salinity variation on underwater wireless optical communication (UWOC). Effect of different concentration of salt on underwater optical communication has been ...

Analysis on the effect of salinity in underwater wireless optical communication

With the performance enhancements in all-optical signal processing and switching schemes in terms of data rate and processing speed, various devices enabled with all-optical operation are becoming primary requirements for current and future telecommunications and data networks. All-optical logic gates represent the best solution to realize both combinational as well as sequential devices in the optical domain, representing the basic building blocks for optical computing circuits. We propose herein an all-optical cascaded adder whose elementary blocks are a half-adder and full-adder, designed using semiconductor optical amplifier (SOA)-based Mach–Zehnder interferometer (MZI) gate configurations. They have high thermal stability and require low power. The nonlinear effects in the SOA device are used to implement different logic operations. The proposed cascaded adder was simulated in OptiSystem. The optical signal-to-noise ratio, bit error rate (BER), and Q-factor values were evaluated for different data rates. The design showed good performance up to 60 Gbps. The proposed design could find application in implementation of multistage arithmetic logic units.

Design and performance analysis of all-optical cascaded adder using SOA-based MZI

A new generation of mobile communications has been evolving for every 10 years, keeping in mind the enormous data traffic, huge capacity requirements, excellent quality of service with minimal latency; there is a shift in paradigm toward the upcoming 5G technology which is expected to be rolled out by 2020 that promises to meet the requirements stated above. 5G is envisaged to be a merged framework of wide range of applications ranging from device-to-device communications, smart grid to Internet of Things and many more. In this survey paper, a brief discussion on the major pillars of 5G which are millimeter wave technology, massive MIMO, ultra-dense network, beamforming and full-duplex transmission are presented. This survey paper also focuses on the role of optics in 5G technology, sometimes commonly referred to as microwave photonics, an interdisciplinary research platform. Due to huge bandwidth and enormous capacity upgrade, optical fibers are considered to be ideal backhaul and fronthaul media rather than copper cables in order to support small cells and next-generation networks. These advantages of optical fiber technology enable integrated optical and wireless access technologies for 5G wireless communications an interdisciplinary area of research.

A survey on role of photonic technologies in 5G communication systems

With the advancements in technology, reversible logic has been an attractive field of research over the past few years. Reversible logic finds applications in various fields which include optical computing, low power CMOS, digital signal processing, nanotechnology, cryptography, etc. Classical logic circuits result in the release of energy for every bit of information processed. This release of energy even though in small amount may become considerable in the case of complex circuits or systems containing millions of such logic gates. This paper focusses on implementation of a new 3 × 3 reversible logic gate in optical domain using Mach–Zehnder Interferometer. Simulation of the proposed design is carried out in OptiSystem software at a data rate of 10 Gbps. Different applications of the proposed reversible gate along with their performance parameters are also discussed.

All Optical new 3 × 3 reversible logic gate using Mach–Zehnder Interferometer

Four-fold increase in users of time-wavelength division multiplexing (TWDM) passive optical network (PON) by delayed optical amplitude modulation (AM) upstream

Shanthi Prince

Papers

Analysis on the effect of salinity in underwater wireless optical communication

Design and performance analysis of all-optical cascaded adder using SOA-based MZI

A survey on role of photonic technologies in 5G communication systems

All Optical new 3 × 3 reversible logic gate using Mach–Zehnder Interferometer

Four-fold increase in users of time-wavelength division multiplexing (TWDM) passive optical network (PON) by delayed optical amplitude modulation (AM) upstream