* 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

In recent years, reversible logic has emerged as a promising computing paradigm having application in low-power CMOS, quantum computing, nanotechnology and optical computing. Optical logic gates have the potential to work at macroscopic (light pulses carry information), or quantum (single photons carry information) levels with great efficiency. However, relatively little has been published on designing reversible logic circuits in all-optical domain. In this paper, we propose and design a novel scheme of Toffoli and Feynman gates in all-optical domain. We have described their principle of operations and used a theoretical model to assist this task, finally confirming through numerical simulations. Semiconductor optical amplifier (SOA)-based Mach–Zehnder interferometer (MZI) can play a significant role in this field of ultra-fast all-optical signal processing. The all-optical reversible circuits presented in this paper will be useful to perform different arithmetic (full adder, BCD adder) and logical (realization of Boolean function) operations in the domain of reversible logic-based information processing.

Mach–Zehnder interferometer-based all-optical reversible logic gate

Neuromorphic photonics has recently emerged as a promising hardware accelerator, with significant potential speed and energy advantages over digital electronics for machine learning algorithms, such as neural networks of various types. Integrated photonic networks are particularly powerful in performing analog computing of matrix-vector multiplication (MVM) as they afford unparalleled speed and bandwidth density for data transmission. Incorporating nonvolatile phase-change materials in integrated photonic devices enables indispensable programming and in-memory computing capabilities for on-chip optical computing. Here, we demonstrate a multimode photonic computing core consisting of an array of programable mode converters based on on-waveguide metasurfaces made of phase-change materials. The programmable converters utilize the refractive index change of the phase-change material Ge2Sb2Te5 during phase transition to control the waveguide spatial modes with a very high precision of up to 64 levels in modal contrast. This contrast is used to represent the matrix elements, with 6-bit resolution and both positive and negative values, to perform MVM computation in neural network algorithms. We demonstrate a prototypical optical convolutional neural network that can perform image processing and recognition tasks with high accuracy. With a broad operation bandwidth and a compact device footprint, the demonstrated multimode photonic core is promising toward large-scale photonic neural networks with ultrahigh computation throughputs. Integrated optical computing requires programmable photonic and nonlinear elements. The authors demonstrate a phase-change metasurface mode converter, which can be programmed to control the waveguide mode contrast, and build an optical convolutional neural network to perform image processing tasks.

/pdf/programmable-phase-change-metasurfaces-on-waveguides-for-2k5x4demoz.pdf

Programmable phase-change metasurfaces on waveguides for multimode photonic convolutional neural network.

A new design for concurrent implementation of all-optical half-adder and AND & XOR logic gates based on nonlinear photonic crystal ring resonator has been proposed. The finite different time domain and plane wave expansion methods are used to analyze the behavior of the structure. The ring resonator has a low switching time of about 0.85 ps and low switching power equal to $$277\,\text{ mW}/\upmu \text{m}^{2}$$
 . The simulation results show that the contrast ratio is 12.78 dB for AND gate and 5.67 dB for XOR gate. Moreover, the operational wavelength of the input ports is $$1.55\,\upmu \text{m}$$
 . Since the structure has a simple geometric shape with clear operating principle, it is potentially applicable for photonic integrated circuits.

Concurrent implementation of all-optical half-adder and AND & XOR logic gates based on nonlinear photonic crystal

Neuromorphic photonics has recently emerged as a promising hardware accelerator, with significant potential speed and energy advantages over digital electronics, for machine learning algorithms such as neural networks of various types. Integrated photonic networks are particularly powerful in performing analog computing of matrix-vector multiplication (MVM) as they afford unparalleled speed and bandwidth density for data transmission. Incorporating nonvolatile phase-change materials in integrated photonic devices enables indispensable programming and in-memory computing capabilities for on-chip optical computing. Here, we demonstrate a multimode photonic computing core consisting of an array of programable mode converters based on metasurface made of phase-change materials. The programmable converters utilize the refractive index change of the phase-change material Ge-Sb-Te during phase transition to control the waveguide spatial modes with a very high precision of up 64 levels in modal contrast. This contrast is used to represent the matrix elements, with 6-bit resolution and both positive and negative values, to perform MVM computation in neural network algorithms. We demonstrate an optical convolutional neural network that can perform image processing and classification tasks with high accuracy. With a broad operation bandwidth and a compact device footprint, the demonstrated multimode photonic core is very promising toward a large-scale photonic processor for high-throughput optical neural networks.

/pdf/programmable-phase-change-metasurfaces-on-waveguides-for-10mt0zq5tn.pdf

Programmable Phase-change Metasurfaces on Waveguides for Multimode Photonic Convolutional Neural Network

We propose and describe an all-optical prefix tree adder with the help of a terahertz optical asymmetric demultiplexer (TOAD) using a set of optical switches. The prefix tree adder is useful in compound adder implementation. It is preferred over the ripple carry adder and the carry lookahead adder. We also describe the principle and possibilities of the all-optical prefix tree adder. The theoretical model is presented and verified through numerical simulation. The new method promises higher processing speed and accuracy. The model can be extended for studying more complex all-optical circuits of enhanced functionality in which the prefix tree adder is the basic building block.

All-optical prefix tree adder with the help of terahertz optical asymmetric demultiplexer

An all-optical binary-coded decimal (BCD) adder with the help of Terahertz Optical Asymmetric Demultiplexer (TOAD) is proposed and described The paper describes the all optical BCD adder by using a set of all-optical full-adder, optical beam combiner, and optical switch In electronic computing systems, BCD is an encoding for decimal numbers in which each digit is represented by its own binary sequence Its main virtue is that it allows easy conversion to decimal digits for printing or display and faster decimal calculations Numerical simulations (by Mathlab65) result confirming described methods and conclusion are given in this paper

http://ieeexplore.ieee.org/iel5/5398767/5407062/05407180.pdf

All-optical binary coded decimal (BCD) adder

All-optical 4-bit binary to 2's complement converter has been designed with the help of Terahertz optical asymmetric demultiplexer (TOAD) switches The paper describes all-optical conversion scheme using a set of all-optical switches 2's complement is common in computer systems and is used in binary subtraction and for logical manipulation The operations of the circuit are studied theoretically and analyzed through numerical simulations

4-bit all-optical binary to two's complement converter

All-optical 5-bit binary coded decimal (BCD) to binary converter has been designed with the help of Semiconductor Optical Amplifier (SOA) — assisted Sagnac switches. Binary is handy because we can easily use something physical to represent numbers. We use laser source for incoming pulse and input data. When it is on, it means 1-state and when it is off, it means 0-state. The paper describes all-optical conversion scheme using a set of all-optical NOT and AND gates. The circuit can perform the conversion at very high speed. The operations of the circuit are studied theoretically. We also make the simulation of this proposed circuit.

All-optical binary coded decimal to Binary converter with the help of terahertz asymetric demultiplexer based switch

In this article, an all-optical adder based incrementer/decrementer circuit is proposed and described with the help of Semiconductor Optical Amplifier (SOA)-assisted Sagnac switch. The proposed design is more efficient in terms of speed and hardware complexity. The article describes the incrementer/decrementers using a set of optical half adder and full adder. The principle and possibilities of all-optical incrementer/decrementers is explained. A theoretical model is presented and verified through numerical simulation. The new method promises both higher processing speed and accuracy. The model can be extended for studying more complex all-optical circuit of enhanced functionality in which incrementer/decrementers is the basic building block.

Dilip Kumar Gayen

Papers

All-optical prefix tree adder with the help of terahertz optical asymmetric demultiplexer

All-optical binary coded decimal (BCD) adder

4-bit all-optical binary to two's complement converter

All-optical binary coded decimal to Binary converter with the help of terahertz asymetric demultiplexer based switch

All-Optical Incrementer/Decrementer with the Help of Semiconductor Optical Amplifier-Assisted Sagnac Switch