Optical Control Signal Research Articles

Multi-attractor chaotic system based on optical control signals and its application

Multi-attractor chaotic system based on optical control signals and its application

Optically biased and controlled signal processing in silicon photonics.

Optically biased and controlled signal processing is demonstrated in a commercial foundry silicon photonics integrated circuit process. Data and control signals are carried by different wavelengths in a WDM format. Optical signals on bias and control channels are converted to electrical voltages using series stacked photodiodes operating in photoconductive mode. Two examples of this scheme, namely, an amplitude modulator and a two-tap sequence detector capable of supporting different modulation formats, are experimentally demonstrated. The amplitude modulator requires 0.25 mW of optical control signal power to tune its optical output power by 15 dB. The two-tap sequence detector maps the consecutive symbols of a modulated signal such as OOK, PAM-3, and PAM-4, to distinct levels. A maximum control signal power of 5 mW is needed to calibrate and bias the sequence detector. This latter scheme may be extended to detect longer sequences and other modulation formats.

Optical switching beyond a million cycles of low-loss phase change material Sb2Se3

The development of the next generation of optical phase change technologies for integrated photonic and free-space platforms relies on the availability of materials that can be switched repeatedly over large volumes and with low optical losses. In recent years, the antimony-based chalcogenide phase-change material Sb2Se3 has been identified as particularly promising for a number of applications owing to good optical transparency in the near-infrared part of the spectrum and a high refractive index close to silicon. The crystallization temperature of Sb2Se3 of around 460 K allows switching to be achieved at moderate energies using optical or electrical control signals while providing sufficient data retention time for non-volatile storage. Here, we investigate the parameter space for optical switching of films of Sb2Se3 for a range of film thicknesses relevant to optical applications. By identifying optimal switching conditions, we demonstrate endurance of up to 107 cycles at reversible switching rates of 20 kHz. Our work demonstrates that the combination of intrinsic film parameters with pumping conditions is particularly critical for achieving high endurance in optical phase change applications.

Fluid Multivalent Recognition Accelerating and Boosting Upconversion Luminescence-Activated DNA Nanomachines for Rapid and Sensitive In Vivo Imaging.

By integrating near-infrared (NIR) light-dependent optical control and DNA walkers-based signal amplification, upconversion luminescence-activated DNA nanomachines hold great potential in conducting an in vivo analysis. For the typical DNA nanomachines, the immobile multivalent recognition interface greatly compromised the reaction kinetics and amplification efficiency due to the cleavage-dependent response mode. In this work, novel upconversion luminescence-activated DNA nanomachines with a fluid multivalent recognition interface were reported for rapid and sensitive in vivo imaging. As a proof-of-concept study, the photolocked DNAzyme-based walker system was anchored on the surface of phospholipid membrane-coated upconversion nanoparticles through the cholesterol-phospholipid interaction to acquire a fluid multivalent recognition interface. Upon sequential inputs of NIR light and metal ions, the formed DNA nanomachines were autonomously initiated and generated a cascade of amplified signal. Relative to the typical DNA nanomachines, the proposed ones possess an accelerated reaction rate and an improved amplification capability owing to a higher local concentration by the lateral mobility. The present work provides a versatile alternative for performing precise and highly efficient in vivo analysis.

2D Heterostructures Induced Charge Transfer and Trapping for Hybrid Optically and Electrically Controllable Nonvolatile Memory

AbstractNonvolatile memory is an indispensable component of electronic devices. However, the current technology makes it difficult to satisfy the emerging big data demand. To circumvent the existing problems, herein, a first attempt is made to achieve multifunctional nonvolatile memory based on all 2D heterostructures, consisting of histidine‐doped molybdenum disulfide quantum disks mixed with graphene oxide and a graphene macroscopic heterojunction. The designed device possesses intriguing hybrid electrically and optically controllable nonvolatile memory functionalities. By harnessing the unique properties of these materials, memory devices demonstrate long‐term stability and nonvolatile characteristics under both optical and electrical control signals. These devices possess outstanding features, such as multiple read‐write cycles, multi levels, and fast switching speeds, overcoming the limitations of traditional components. To explore the underlying physical mechanism, the Fermi level of graphene is measured and it is confirmed that the charge transfer and trapping across the heterojunctions are the major factors responsible for the observed behavior. This study demonstrates that 2D heterostructures for hybrid optically and electrically controllable nonvolatile memory pave an alternative route for the next‐generation information technology.

Dynamic acylhydrazone bonds cross-linked chromotropic photonic-ionic skin with self-healing and high resilience for interactive human-machine interface

Advanced skin systems realize perception and interaction with the environment through synergistic electrical and color signals generated by transmitting ions and manipulating photonic structures. Here, inspired by chameleon skins, a novel self-healing and resilient photonic-ionic skin (PI-skin) with electro-optical dual response is ingeniously constructed integrating the ordered micro-nano array and the dynamically covalently cross-linked ionogel. The elaborately designed polycation network with weak inter-chain interactions can promote the uniform distribution of high-content low-viscosity ionic liquid (IL), effectively eliminating energy dissipation and resulting in high resilience. Dynamic acylhydrazone bonds are served as reversible chemical crosslinking to realize high-efficiency self-healing and further enhance resilience. Notably, the artificially manipulated transition of the photonic array from dense packing to non-dense packing endows sensitive chromotropic properties synchronized with electrical response under stretched (Δλ > 130 nm) and compressed (Δλ > 160 nm). Furthermore, by harnessing the correspondence between electrical and optical signals, the control of optical signals over electrical signals is achieved for inputting complex coded information and constructing interactive human–machine interfaces. This work not only inspires the design and construction of high-level artificial skins but also stimulates the development of visual interactive devices and smart electronic/ionic products.

High-performance 1×4 - demultiplexer for next-generation all-optical telecommunication systems

In this paper the new 1×4 optical demultiplexer for next-generation all-optical switching systems is proposed. The controlled mirrors are the main elements of this device. The control voltage for this mirror is generated by a rectenna from an optical control signal. In according to operation principle this optical signal enters the system simultaneously with an information signal. The analytical approach of calculation energy losses in the demultiplexer based on the translation matrix method is proposed. And also the analytical method of performance calculation is offered for the first time. First of all, the delay time due the transient mode in the power supply circuit is found. The equivalent electrical scheme of the optical demultiplexer is proposed for the first time. Note that the theoretical results obtained in this work can be used for analysing various controlled optical devices. The numerical calculations in accordance to the presented methods are carried out also.

Design and development of the optical control network active phased array radar

Active phased array radars for the atmospheric research have various advantages such as full beam agility in 360°, improved signal-to-noise ratio and improved sensitivity. These radars have distributed transmit–receive modules feeding to the individual antenna system in the antenna array field. In order to control and monitor the field-located transmit–receive modules from centralized radar controller which will be located few hundred meters away from the field, control signals plays an important role in controlling the radar subsystems. Earlier generation radars used electrical cables to transfer such type of signals, where signal speed and bandwidth are limited. In addition, the electromagnetic interference also affects the transmit and receiving signals. To overcome these problems, a new technical approach has been developed over optical interface for active phased array radar. In this paper, we present the design and development of the optical control signal network for 53 MHz active phased array radar. The design details, component selection and the link budget calculations are explained in detail and the test results are provided.

Optical addressing of nanomechanical metamaterials with subwavelength resolution

Metamaterials that offer “on-demand” control of individual metamolecules are termed “randomly accessible metamaterials.” They can be useful for manipulation of the wavefront of electromagnetic radiation, for tailoring of the nearfield, and ultimately for multichannel data processing. Here, we demonstrate how light can be used to actuate individual metamaterial elements on demand. Selectivity is achieved by constructing the metamaterial from nanomechanical elements that are designed to have slightly different mechanical resonance frequencies. Actuation is controlled by modulation of the optical control signal at the mechanical resonance frequencies of targeted elements, providing an all-optical route to randomly accessible metamaterials with spatial resolution beyond the diffraction limit.

Periodic soliton trains in nonlinear magneto-optical media

The combination of the vector nature (i.e. polarization) of light in materials with nonlinearity can give rise to outstanding phenomena in the transmission of nonlinear optical fields. When the optical medium has been initially altered by a magnetic field, magneto-optical effects introduce additional interesting phenomena such as the possible control of optical signals by a magnetic field. The present work addresses the problem of optical-soliton generation from pulsed radiations interacting with a quasi-resonant magneto-optical medium, under normal Zeeman effect. It is shown that multi-soliton structures can be generated in the magneto-optical medium under specific conditions, these include periodic trains of bright and dark optical solitons having finite temporal periods.

All-optical switch based on 1×3 multimode interference couplers

In this paper, a new all-optical switch based on 1×3 and 3×3 General Interference (GI) multimode interference (MMI) structures is proposed. By using nonlinear directional couplers in two arms of the structure as phase shifters, all-optical switching mechanism can be achieved. In this study, we use chalcogenide glass on silica for designing the device structure. The switching states of the device can be controlled by adjusting the optical control signals at the phase shifters. The transfer matrix method and beam propagation method (BPM) are used for designing and optimizing the device structure.

Design of ultrafast all-optical pulsed-mode 2 $$\times $$ × 2 crossbar switch using quantum-dot semiconductor optical amplifier-based Mach–Zehnder interferometer

An all-optical 2 $$\times $$? 2 crossbar switch capable of pulsed-mode operation and of handling ultrafast information is proposed and analytically designed. For this purpose, the quantum-dot semiconductor optical amplifier (QD-SOA)-based Mach---Zehnder interferometer (MZI) is employed as two-input two-output switching unit, in which the direction where the input data are forwarded is controlled by a single, purely lightwave excitation of alternating binary content. The performance of the crossbar switch under bitwise pulsed-mode of operation is thoroughly investigated and assessed by means of numerical simulation to find the range of permissible values of critical operating parameters. These parameters are distinguished depending on whether they affect the saturation level of the QD-SOA that is influenced by the optical control signal or translate the associated gain changes into differential phase shift between the MZI arms. This approach highlights the prominent role of the QD-SOA linewidth enhancement factor, which must be chosen to be sufficiently high so that the required switching procedure takes place properly. With this necessary condition, which holds in real QD-SOA devices, it can be determined how the rest parameters must be selected and combined so that the defined performance metrics become acceptable. Finally, an efficient technique for balancing the local extinction ratios in the switched and in the non-switched states of the crossbar configuration is applied in order to optimize its performance and favor its practical use. The guidelines derived for the design of the scheme are technologically satisfiable and can be useful for its implementation and exploitation in diverse switching applications.

160-Gb/s Silicon All-Optical Packet Switch for Buffer-less Optical Burst Switching

We experimentally demonstrate a 160-Gb/s Ethernet packet switch using an 8.6-mm-long silicon nanowire for optical burst switching, based on cross phase modulation in silicon. One of the four packets at the bit rate of 160 Gb/s is switched by an optical control signal using a silicon based 1 × 1 all-optical packet switch. Error free performance (BER <; 1E-9) is achieved for the switched packet. The use of optical burst switching protocols could eliminate the need for optical buffering in silicon packet switch based optical burst switching, which might be desirable for high-speed interconnects within a short-reach and small-scale network, such as board-to-board interconnects, chip-to-chip interconnects, and on-chip interconnects.

All‐optical packet buffer system based on controllable‐delay recirculating loop

ABSTRACTWe present an all‐optical packet buffer system that enables variable delay of the incoming packets in the optical domain based on the controllable‐delay recirculating loop. It consists of two optical logic gate stages based on cross gain modulation nonlinear effect of semiconductor optical amplifiers to control the amount of delay. Incoming optical packets were either stored in the recirculating loop or routed to the system output by an optical control signal. The validity of the system has been experimentally verified using the optical bit sequences operating at 1 Gbps. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2058–2061, 2014

All-optical switches based on 3 × 3 generalized multimode interference structure

Multimode interference in optical waveguide is attractive for optical signal processing in recent years. In this paper, we propose and design a 3×3 all-optical switch using 3×3 General Interference Multimode Interference (GI-MMI) structures. Nonlinear directional couplers based on the Kerr effect in two arms of the structure are used as phase shifters. We use chalcogenide glass on silica platform for designing the device structure. The switching states of the device can be controlled by adjusting the optical control signals at the phase shifters in the two arms. The transfer matrix method (TMM) and beam propagation method (BPM) are used for designing and optimizing the device structure.

All-Optical Switches Based on 3×3 Multimode Interference Couplers Using Nonlinear Directional Couplers

Multimode interference in optical waveguide is attractive for all optical switching. In this paper, a novel 3×3 all-optical switch based on 3×3 multimode interference (MMI) structures is proposed. Nonlinear directional couplers in two arms of the structure are used as phase shifters. In this study, we use chalcogenide glass on silica for designing the device structure. The switching states of the device can be controlled by adjusting the optical control signals at the phase shifters. The transfer matrix method and beam propagation method (BPM) are used for designing and optimizing the device structure.

M-QAM Six-Port Modulator Using Only Binary Baseband Data, Electrical or Optical

A new circuit architecture for a direct-carrier six-port modulator is proposed. The proposed architecture uses parallel binary-valued baseband signals to control binary-valued impedance loads for generation of rectangular M-QAM modulation. A theoretical model of the proposed modulator is also derived. A prototype modulator for 64 quadrature amplitude modulation is designed and fabricated for a center frequency of 2.5 GHz for verification of the proposed architecture. The measurements verify the theory and show that good performance can be obtained with the proposed architecture. The proposed modulator does not require any digital-to-analog converter and can operate with both electrical and optical control signals.

Nanoscale all-optical plasmonic switching using electromagnetically induced transparency

An all-optical switch composed of two interacting nanoparticles in front of an optical dielectric slab waveguide is proposed. An incident optical signal is coupled to the optical waveguide after scattering by the two nanoparticles. The scattered fields interfere constructively or destructively depending on the degree of optical transparency the nanoparticles induced by an optical control signal. The considered nanoparticles have a metallic core coated by an outer shell with three-level clusters such that the nanoparticles can exhibit electromagnetically induced transparency. A dipole-approximation model-based analysis reveals that a high rejection ratio can be achieved using the proposed configuration.

SiC multilayer photonic structures with self optical bias amplification

ABSTRACTStacked layered pin a-SiC/a-Si devices based on a filter design are approached from a reconfigurable point of view. This paper shows that a double SiC/Si pin photodiode can be de-composed into two photonic active filters changeable in function. Reconfiguration is provided by optical control signals to the optoelectronic front and back pin building blocks. Depending on the wavelength and irradiation side of the external optical bias the device acts either as a short- and a long- pass band filter or as a band-stop filter, amplifying or rejecting a specific wavelength range. Particular attention is given to the amplification coefficient weights, which allow taking into account the wavelength background effects. We illustrate these effects in detail and discuss the filters transfer function characteristics. We present examples of filters and we propose a reconfigurable device for directed optical logic. An algorithm to decode the information is presented. An optoelectronic model supports the optoelectronic logic architecture.

Linear feedforward control of two-level quantum system by modulated external field

We propose a model of feedforward (open-loop) optical control of two-level atom in the linear form. This model allows to express the general form of solution for the atomic level populations via the arbitrary shapes of the control signal. Then we make numerical investigations of different shapes for the optical control signal.