All-optical Signal Processing Technology Research Articles

All-Optical Signal Processing in Ultrafast Optical Communication

Optical communication technology plays a crucial role in today's information age, as a result of the continuous advancement of social informatization. An array of nascent technologies, encompassing edge computing, the Internet of Things, big data, and artificial intelligence, have grown rapidly, leading to an increased demand for information transmission, which in turn has resulted in higher requirements for the development of optical communication technology. The emergence of ultrafast optical communication, which uses all-optical signal processing technology, has made data transmission faster and more reliable. This article introduces three basic methods for implementing all-optical signal processing (optical modulation, regeneration, and interconnection) based on all-optical and electronic signal processing. It examines the issues and difficulties that arise within particular application contexts and explores the progression of several correlated technologies in the times ahead. The field of all-optical signal processing is experiencing rapid growth and has the potential to bring revolutionary changes to various industries. Anticipated outcomes entail the attainment of ultra-long distance and ultra-high-capacity transmission, as facilitated by the ongoing advancements in hardware and all-optical signal processing technology. Meanwhile, the relentless pursuit of high-performance goals drives the continuous progress of ultrafast optical communication.

Two-dimensional material integrated micro-nano fiber, the new opportunity in all-optical signal processing

Abstract With the development of all-optical networks, all-optical devices have become a research hotspot in recent years. Two-dimensional materials, represented by graphene and black phosphorus, have attracted great interest in the scientific community due to their excellent optical, electrical, magnetic, and mechanical properties. Bridging the gap between fiber optics and nanotechnology, microfibers can interact with light and matter at the micro or even nanoscale. By combining two-dimensional materials with microfibers, composite waveguides can be formed. They have the advantages of high nonlinear effect, all-fiber structure, and high damage threshold, etc. The composite waveguide can be directly applied to optical fiber communication systems, and plays an important role in the field of all-optical signal processing with a huge application prospect. In this review, the properties of typical 2D materials are first introduced. Next, the preparation methods of the relevant equipments are introduced and compared. Then, the all-optical signal processing technology based on 2D material-integrated microfiber composite waveguide is reviewed. The latest developments of all-optical modulators, all-optical wavelength converters, all-optical logic gates and all-optical thresholding devices are presented. Finally, the challenges and opportunities for the future development of 2D materials-integrated microfiber optoelectronic devices are summarized.

Optimization of quantum light sources and four-wave mixing based on a reconfigurable silicon ring resonator.

Being a key component on a photonic chip, the microring usually specializes in a certain nonlinear optical process and can not simultaneously meet different working conditions for different processes. Here, we theoretically and experimentally investigate a reconfigurable silicon microring resonator to act as a optimization strategy for both classical four-wave mixing and quantum light sources. Experimental results show that the four-wave mixing efficiency with continuous wave and pulsed pump can be both optimized to a high value well matching numerical analysis. A variety of quantum light sources - including the heralded single-photon source, two-photon source and multi-photon source - are demonstrated to present a high performance and their key parameters including the pair generation rates (PGR), the heralding efficiency (HE) and the coincidence-to-accidental ratio (CAR) are controllable and optimizable. Such tunable nonlinear converter is immune to fabrication variations and can be popularized to other nonlinear optical materials, providing a simple and compact post-fabrication trimming strategy for on-chip all-optical signal processing and photonic quantum technologies.

A scientific report of non-singular techniques on microring resonators: An application to optical technology

It is a scientific fact that all-optical signal processing technology is an effect approach to overcome the inherent speed limitations of conventional electronics; this is because of the rapid development of high-speed optical communication networks. This manuscript is dedicated to investigate the fractional modeling of microring resonators subject to the inputs and outputs of the two all-optical ring resonators. The mathematical modeling is based on ring resonators within the limitations of time-dependent relations and coupled mode theory. The mathematical analysis is prescribed for amplitude subject to the initial and boundary conditions’ validations along with two categories of source terms, namely, periodic and exponential sources. The fractional mathematical model of microring resonators is solved by means of Laplace transform method by employing the concept of infinite series and gamma functions.The graphical illustration is discussed via fractional techniques of Atangana-Baleanu and Caputo-Fabrizio fractional operator on the basis of embedded parameters namely optical frequency and quality factor lifetime of photon. At last, a comparative analysis of amplitude is also presented for knowing the hidden aspects of microring resonators through classical verses non classical approaches.

Recent Advances of Spatial Self-Phase Modulation in 2D Materials and Passive Photonic Device Applications.

Optical nonlinearity in 2D materials excited by spatial Gaussian laser beam is a novel and peculiar optical phenomenon, which exhibits many novel and interesting applications in optical nonlinear devices. Passive photonic devices, such as optical switches, optical logical gates, photonic diodes, and optical modulators, are the key compositions in the future all-optical signal-processing technologies. Passive photonic devices using 2D materials to achieve the device functionality have attracted widespread concern in the past decade. In this Review, an overview of the spatial self-phase modulation (SSPM) in 2D materials is summarized, including the operating mechanism, optical parameter measurement, and tuning for 2D materials, and applications in photonic devices. Moreover, some current challenges are also proposed to solve, and some possible applications of SSPM method are predicted for the future. Therefore, it is anticipated that this summary can contribute to the application of 2D material-based spatial effect in all-optical signal-processing technologies.

1D@0D hybrid dimensional heterojunction-based photonics logical gate and isolator

Optical logic gate and isolator are the key components for the optical packet switching, optical address recognition, optical computing, which will play an important role in the future high-speed and large-capacity all-optical signal-processing technologies. In the investigation of materials science, we found that low-dimensional materials have feasibility and reliability in the development of optical logic gates and isolators in all-optical signal processing technology. We demonstrate that zero-dimensional bismuthene quantum dots (0D Bi QDs) can be developed as sensitizers to enhance the nonlinear optical response of one-dimensional tellurium nanotubes (1D Te NTs), and the 1D@0D Te@Bi QD NTs hybrid dimensional heterojunction is found to possess high stability and a strong Kerr effect. Taking advantage of the strong light-matter interaction, a hybrid dimensional heterojunction-based logical gate is designed to realize the OR function with optical method. Moreover, another nonlinear isolator, which utilizes the Te@Bi QD NTs/SnS2 hybrid structure, is designed to achieve a unidirectional nonlinear optical response based on the strong Kerr nonlinearity. This investigation has enriched the application of SSPM method that can be considered an important step for new materials in all-optical signal processing technologies.

All-optical signal processing technologies in flexible optical networks

All-optical signal processing has always been critical assistance for the flexible optical networks (FONs) development which realizes various signal processing functions in all-optical domain avoiding electronic bottlenecks. The sustained demands for the transmission capacity and network functions drive the optical networks to enlarge the bandwidth, extend formats and increase network structures. The optical vectors are multiplexed in four domains at least in practical which are amplitude, phase, polarization and wavelength, and more multiplexing technologies are under researching. Moreover, various kinds of optical networks are employed to fulfill the constantly emerging applications such as core, metro and access networks. Facing the higher-order modulation formats, multiple multiplexing technologies and more and more complicated network structure, the future FON needs to have the feature of modulation format transparency, bandwidth transparency, wavelength transparency (3T), multi-function, multi-channel, multi-network (3M), self-perceiving, self-learning, self-adapting (3S). The transmission capacity, network flexibility and efficiency will always be the critical index for the whole network performance. The all-optical signal processing technologies have great potential in realizing the FON with the feature of 3T, 3M and 3S to process the multiple multiplexing optical signals and the problems among various optical networks. In this paper, the future FON features including 3T, 3M and 3S are introduced in detail, and the key issues in the ultra-large-capacity FON (e.g., 400G FON) are analyzed including transmission distance, flexible connecting and performance monitoring. Then, the crucial all-optical signal processing technologies and the principle and important applications of the phase-sensitive amplifier are introduced. Finally, the current existing problems and future developing trend for the all-optical signal processing technologies are discussed.

Coherent control of Kerr nonlinearity via double dark resonances

A theoretical scheme for enhanced Kerr nonlinearity is proposed in a four-level ladder-type atomic system based on double dark resonances (DDRs). We solve the relevant density matrix equations in steady state and utilize the perturbation theory to obtain the analytical expressions for the third order susceptibility of the atomic system. The influence of system parameters on behavior of the first and third order susceptibilities is then discussed. In particular, it is found that an enhanced Kerr nonlinearity with reduced linear and nonlinear absorption is obtained around zero probe detuning under the slow light condition through proper adjusting the laser field intensity and frequency detuning of driving fields. The dressed state analysis is employed to explain the physical origin of the obtained result. The obtained results may be important for all-optical signal processing and quantum information technology.

Ultrafast All-Optical Signal Processing Based on Single Semiconductor Optical Amplifier and Optical Filtering

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> We propose and demonstrate several all-optical signal-processing technologies, including wavelength conversion (WC), leading/trailing edge detection, and logic gates based on a semiconductor optical amplifier (SOA) and a detuning optical bandpass filter (OBF). The system is based on pump-probe scheme. When the pump signal is return-to-zero (RZ) format, both inverted WC and noninverted WC at 40 Gb/s are obtained, and the polarity variation is highly dependent on the OBF detuning. When the pump signal is nonreturn-to-zero (NRZ) format, both the inverted WC and leading/trailing edge detection are obtained. In the inverted WC, the OBF detuning is small, and it helps to accelerate the amplitude recovery. However, in the noninverted WC and pulse edge detection, the OBF detuning is relatively large, and it acts as frequency–amplitude conversion. Finally, we present all-optical reconfigurable logic gates based on various nonlinearities in an SOA. The logic gates including <emphasis emphasistype="smcaps">and</emphasis>, <emphasis emphasistype="smcaps">nor</emphasis>/<emphasis emphasistype="smcaps">not</emphasis>, and <emphasis emphasistype="smcaps">or</emphasis> are obtained by four-wave mixing, cross-gain modulation, and transient cross-phase modulation in the SOA, respectively. The <emphasis emphasistype="smcaps">nor</emphasis> and <emphasis emphasistype="smcaps">or</emphasis> gates are capable of operating at 40 Gb/s with the help of the OBF detuning. The <emphasis emphasistype="smcaps">xnor</emphasis> gate is implemented by combining the <emphasis emphasistype="smcaps">and</emphasis> output and <emphasis emphasistype="smcaps">nor</emphasis> output. </para>

All-optical signal processing using /spl chi//sup (2)/ nonlinearities in guided-wave devices

The authors present a review of all-optical signal-processing technologies based on /spl chi//sup (2)/ nonlinear interactions in guided-wave devices and their applications for telecommunication. In this study, the main focus is on three-wave interactions in annealed proton-exchanged periodically poled lithium niobate waveguides due to their suitable properties with respect to nonlinear mixing efficiency, propagation loss, and ease of fabrication. These devices allow the implementation of advanced all-optical signal-processing functions for next-generation networks with signal bandwidths beyond 1 THz. In this paper, integrated structures that will allow for improvements of current signal-processing functions as well as the implementation of novel device concepts are also presented.

Demonstration of a Variable Optical Delay for a Recirculating Buffer by Using All-Optical Signal Processing

We demonstrate a variable optical delay by using a recirculating loop that is controlled by all-optical signal processing technology. This concept can be utilized in all-optical recirculating buffers. The variable optical delay is realized by using an optical threshold function and a wavelength converter. We show that in case of packet contention, one optical packet is recirculated four times in the loop and when the contention disappears, the packet is routed out of the optical loop.

All-optical signal processing in ultrahigh-speed optical transmission

The coming broadband era will require very high-speed technologies that can handle more than 100-Gb/s for both transmission lines and transmission nodes. Novel all-optical signal processing technologies that offer unsurpassed performance are urgently required. This article briefly reviews the essential photonic technologies required for high-speed optical TDM transmission, including ultrashort optical pulse generation, all-optical multiplexing/demultiplexing, and optical timing extraction techniques. Recent all-optical TDM transmission experiments up to 100 Gb/s are introduced together with major issues and future prospects. >