All-optical Gate Research Articles

Photonic quantum walk with ultrafast time-bin encoding

The quantum walk (QW) has proven to be a valuable testbed for fundamental inquiries in quantum technology applications such as quantum simulation and quantum search algorithms. Many benefits have been found by exploring implementations of QWs in various physical systems, including photonic platforms. Here, we propose a platform to perform quantum walks based on ultrafast time-bin encoding (UTBE) and all-optical Kerr gating. This platform supports the scalability of quantum walks to a large number of steps and walkers while retaining a significant degree of programmability. More importantly, ultrafast time bins are encoded at the picosecond time scale, far away from mechanical fluctuations. This enables the scalability of our platform to many modes while preserving excellent interferometric phase stability over extremely long periods of time without requiring active phase stabilization. Our 18-step QW is shown to preserve interferometric phase stability over a period of 50 h, with an overall walk fidelity maintained above 95%.

Design of a Photonic Crystal Exclusive-OR Gate Using Recurrent Neural Networks

In this paper, a novel approach to design a photonic crystal exclusive-OR (XOR) gate with high performance using recurrent neural network (RNN) is proposed, integrating the principles of symmetry and asymmetry inherent in photonic structures. The proposed model realizes the nonlinearities and dispersion properties in photonic systems, optimizing the waveguide paths and interference patterns to improve the performance of the logic gate. Simulation results demonstrate that the presented RNN design not only achieves high fidelity in the logical operation but also significantly enhances the functionality of the all-optical gate. This integration of machine learning with photonic crystal technology opens a new era for developing compact, energy-efficient photonic circuits for high-speed optical computing. Finally, the performance of the designed all-optical gate is compared with other related methods, which shows that the proposed gate outperforms other works. The results show that the obtained output power of the proposed all-optical XOR gate is 0, 0.813, 0.82, and 1 × 10−7 in the logical states.

All-Optical 3-Input XOR Gate Design Using 4:1 Optical Multiplexer with the Proper Application of Nonlinear Kerr Switches

All-Optical 3-Input XOR Gate Design Using 4:1 Optical Multiplexer with the Proper Application of Nonlinear Kerr Switches

Invertible all-optical logic gate on chip.

We demonstrate an invertible all-optical gate on chip, with the roles of control and signal switchable by slightly adjusting their relative arrival time at the gate. It is based on the quantum Zeno blockade (QZB) driven by sum-frequency generation (SFG) in a periodically poled lithium niobate microring resonator. For two nearly identical nanosecond pulses, the later arriving pulse is modulated by the earlier arriving one, resulting in 2.4 and 3.9 power extinction between the two, respectively, when their peak powers are 1 mW and 2 mW, respectively. Our results, while to be improved and enriched, herald a new, to the best of our knowledge, paradigm of logical gates and circuits for exotic applications.

Location Qubits in a Multiple-Quantum-Dot System.

A physical platform for nodes of the envisioned quantum Internet is long-sought. Here we propose such a platform, along with a conceptually simple and experimentally uncomplicated quantum information processing scheme, realized in a system of multiple crystal-phase quantum dots. We introduce novel location qubits, describe a method to construct a universal set of all-optical quantum gates, and simulate their performance in realistic structures, including decoherence sources. Our results show that location qubits are robust against the main decoherence mechanisms, and realistic single-qubit gate fidelities exceed 99.9%. Our scheme paves a clear way toward constructing multiqubit solid-state quantum registers with a built-in photonic interface─a key building block of the forthcoming quantum Internet.

Role of Pyramidal Low-Dimensional Semiconductors in Advancing the Field of Optoelectronics

Numerous optoelectronic devices based on low-dimensional nanostructures have been developed in recent years. Among these, pyramidal low-dimensional semiconductors (zero- and one-dimensional nanomaterials) have been favored in the field of optoelectronics. In this review, we discuss in detail the structures, preparation methods, band structures, electronic properties, and optoelectronic applications (photocatalysis, photoelectric detection, solar cells, light-emitting diodes, lasers, and optical quantum information processing) of pyramidal low-dimensional semiconductors and demonstrate their excellent photoelectric performances. More specifically, pyramidal semiconductor quantum dots (PSQDs) possess higher mobilities and longer lifetimes, which would be more suitable for photovoltaic devices requiring fast carrier transport. In addition, the linear polarization direction of exciton emission is easily controlled via the direction of magnetic field in PSQDs with C3v symmetry, so that all-optical multi-qubit gates based on electron spin as a quantum bit could be realized. Therefore, the use of PSQDs (e.g., InAs, GaN, InGaAs, and InGaN) as effective candidates for constructing optical quantum devices is examined due to the growing interest in optical quantum information processing. Pyramidal semiconductor nanorods (PSNRs) and pyramidal semiconductor nanowires (PSNWRs) also exhibit the more efficient separation of electron-hole pairs and strong light absorption effects, which are expected to be widely utilized in light-receiving devices. Finally, this review concludes with a summary of the current problems and suggestions for potential future research directions in the context of pyramidal low-dimensional semiconductors.

Ultra-fast and compact optical Galois field adder based on the LPhC structure and phase shift keying.

In this study, we propose a novel, to the best of our knowledge, all-optical Galois field (AOGF) adder that utilizes logic all-optical XOR gates. The design is founded on optical beams' constructive and destructive interference phenomenon and incorporates the phase shift keying technique within a two-dimensional linear photonic crystal (2D-LPhC) structure. The suggested AOGF adder comprises eight input ports and four output ports. We employ the finite difference time domain (FDTD) procedure to obtain the electric field distribution in this structure. The FDTD simulation results of the proposed AOGF adder demonstrate that the minimum and maximum values of the normalized power at ON and OFF states (P 1,min, P 0,max) for the output ports are 95% and 1.7%, respectively. Additionally, we obtain different functional parameters, including the ON-OFF contrast ratio, rise time, fall time, and total footprint, which are measured at 17.47dB, 0.1ps, 0.05ps, and 147µm 2, respectively.

2D FDTD Electromagnetic Simulation of an Ultracompact All Optical Logic Gate Based on 2D Photonic Crystal for Ultrafast Applications

In this paper, the concept of photonic crystals (PhCs) is fundamental to designing and simulating an all-optical logic gate device. We proposed an all-optical switch composed of two-dimensional (2D) photonic crystal waveguides with a central photonic crystal ring resonator (PCRR). The new all-optical NAND logic gate device comprises two linear waveguides coupled to each other through a single compact PCRR. The plane wave expansion (PWE) and finite-difference time-domain (FDTD) methods are applied to simulate the properties of the system. The structure is implemented on the operational wavelength of 1700 nm on an air wafer of only 12 μm × 12 μm. Indeed, the simulation results show that the proposed all-optical NAND gate is a strong candidate for ultrafast photonic integrated circuits (PICs) for applications in optical communications, being advantageous with high transmitting power, with simple design, and without the use of optical amplifiers and nonlinear materials.

All-optical simultaneous OR and NAND gates using photonic crystal ring resonator and Kerr effect

All-optical simultaneous OR and NAND gates design is proposed using a simple nonlinear photonic crystal ring resonator based on the chalcogenide glass (Ag20As32Se48) material which is one of the promising materials for all-optical devices. The structure consists of an octagonal ring resonator between two waveguides, which uses the switching threshold mechanism based on the Kerr effect to perform two simultaneous logic gates functions. The plane wave expansion (PWE) method is used to obtain the band diagram in the proposed structure, and the two-dimensional finite difference time domain (2D-FDTD) method is used in the simulation to evaluate the performance of the proposed design. The resonance wavelength is 1551.3 nm, with a high transmission and coupling efficiency of about 100%. The proposed optical OR and NAND logic gates have high contrast ratios of 21.15 dB and 28.19 dB, respectively, with a quality factor of 596.65. The operating power intensity of the proposed structure is 1 kW μm−2, and the threshold power intensity is obtained at 2.8 kW μm−2. The proposed gates provide transmitted power of not less than 0.5. The size of the structure is 20.5 μm × 18.17 μm. The proposed structure is compact, works on low operational power intensity, and has the ability for dense integration. The simplicity and small size of the structure make it easy to fabricate for future integration in all-optical circuits.

Ultra compact, high contrast ratio all optical NOR gate using two dimensional photonic crystals

An all-optical NOR gate is implemented using a two-dimensional photonic crystal waveguide. The paper provides a structure of an all-optical NOR gate constructed by introducing a line and point defect. The proposed NOR gate uses a hexagonal lattice structure with E shaped waveguide. The contrast ratio, response time and bit rate of three input NOR gate are 29.59 dB, 0.8 ps and 1.19 Tbps, respectively. The proposed gate is constructed with the operating wavelength of 1550 nm. The structure has been simulated and analyzed using Finite Difference Time Domain (FDTD) and Plane Wave Expansion (PWE) methods. It offers high contrast ratio, better response time with ultra-compact size. Hence it is suitable for high speed optical integrated circuits and switching devices.

Implementation of all-optical single qubit gates using Si3N4 based micro ring resonator

Quantum logic gates are the key element and basic brick for quantum computing and quantum communication process. This work intended a unique method to implement the Pauli single qubit X, Z, and Y quantum gates using the Si3N4 based optical micro ring resonators. The magnitude and phase encoding of the light signal has been done to get the desired result. To obtain the desired phase shifts of the light signal in the micro ring resonators, different pump power has been employed. The mathematical simulation results validated the proposed model for all-optical Pauli X, Z, and Y quantum gates. The key performance parameters of the proposed model like extinction ratio of 20.29 dB, Quality factor of 7750 and contrast ratio of 19.54 dB are obtained. The proposed model was evaluated and compared with the other reported work as shown better performance to them.

Realization of Tristate Pauli-X, Y and Z gates on photonic crystal using wavelength encoding

Pauli gates using phase encoding technique are well-known in quantum optical computing. In this paper, all-optical Tristate Pauli quantum gates are designed by using the wavelength encoding technique. In addition to this, four Y-gates, two Z-gates and one from each gate are integrated separately. Then the Pauli-X gate, integrated Pauli-Y gate, integrated Pauli-Z gate and integrated Pauli-X, Y and Z gate are designed on Photonic crystal-based layouts which improve the bit rate and response time significantly. Simulation results are realized by finite difference time domain (FDTD) method.The states of signals are identified by their wavelengths which eliminates the troublesome of maintaining the specific phases or polarization of states. Here, the simulation results prove the feasibility of the operations. The designing of all-optical logic systems on photonic crystal makes these suitable for ultrafast quantum computing.

Polarization encoded all-optical ternary MAX and MIN gate using semiconductor optical amplifier-based switch: design and analysis

Polarization encoded all-optical ternary MAX and MIN gate using semiconductor optical amplifier-based switch: design and analysis

Investigations of all-optical gates based on linear photonic crystals using the PSK technique and beam interference effect

ABSTRACT In this paper, all optical OR, AND, NOR and NAND gates based on linear photonic crystals (LPhCs) have been numerically designed and simulated by the plane wave expansion (PWE) and finite difference time domain (FDTD) methods. The LPhC fundamental structure with cross-section of 114 is used for designing the proposed all optical gates (AOGATEs), which is composed of 15 × 23 cubic matrix of dielectric silicon rods in air substrate. The mechanism of the proposed AOGATEs is performed based on phase shift keying (PSK) technique and beam interference effect. Simulation results by FDTD approach illustrate the minimum contrast ratio of 8.88 and 10.31 dB for all optical AND/NOR and OR/NAND logic gates, respectively. Also, the minimum bit rate is obtained as 3.34 Tb/s for AND/NOR and 5 Tb/s for OR/NAND logic gates.

Simulation and Numerical Analysis of SOA Based All Optical NAND Gate for High Data Rate Communication

As a result of the development of advanced semiconductor-based optical switching devices and their commercialization, concepts and technologies in all-optical signal processing have evolved significantly in the past few years. In order to realize logical operations in photonic computing, universal gates are needed. In this research, the simple and compact all-optical NAND gate was designed using SOA and simulated at a high data rate of 10Gbps to 40 Gbps. The performance of the proposed NAND gate is shown by the numerical analysis for various input combinations and SOA. By changing wavelengths, injection currents, confinement factors, as well as optical components such as sources, amplifiers, and filters, a numerical analysis is performed. Unique results were obtained at a 10 Gbps data rate for NRZ-L user-defined bit sequences. This kind of all-optical NAND gate will be the perfect alternative in the field of optical computing to realize a high-speed optical communication network. An extinction ratio of 11.48 dB is achieved at a high-speed data rate of 10 Gbps to 40Gbps. The output spectrum of the designed NAND logic is also received for a wide input spectrum and the system responds selectively for the input wavelength at 1548.3 nm which is the probe signal wavelength.

Nanoscale plasmonic logic gates design by using an elliptical resonator.

This study implemented AND, NAND, OR, XOR, NOR, XNOR, and NOT plasmonic logic gates using the finite element method. The all-optical nanoscale logic gates were designed using a single structure based on the technology of insulator-metal-insulator nanoscale plasmonic waveguides. The phase of optical waves and the position of the control and input ports are the most important factors for attaining the optimal transmission value based on interference between the input and control ports. The transmission threshold is 35%, and 850 nm is the operating wavelength. This design creates nanoscale logic gates with a structure dimension of 250nm×250nm. The transmission threshold, modulation depth, contrast ratio, and insertion loss criteria were proposed to evaluate the efficacy of the all-optical gates.

Silicon microring resonator based all-optical 3-input majority gate and its applications

In this study, we propose an all-optical majority gate using silicon waveguide-based microring resonator for the first time to our knowledge. All-optical microring resonator based majority gate has attractive properties such as energy-efficient, ultra-high-speed, and compact which are essential for optical computing. We have designed different logic circuits such as AND, OR, NOR, NAND, and one-bit full adder by exploiting the majority gate with inverter circuits. Optoelectronic conversion which limits the operational speed is avoided in our design. The operational speed of our design is nearly 260 Gbps. The required pump power for switching is only 1.66 mW for micro-ring resonator based switch which is very less comparatively. These designs have been realized in MATLAB as well as in Ansys Lumerical finite difference time domain (FDTD) simulation platform. The "figure of merits" of the presented majority gate is achieved numerically through simulation. The obtained values of extinction ratio and contrast ratio are much higher for the proposed majority gate and the values are 28.11 dB and 32.88 dB, respectively. The on-off ratio is also high for single microring resonator and it is 38.2 dB.

High-performance chiral all-optical OR logic gate based on topological edge states of valley photonic crystal

For all-optical communication and information processing, it is necessary to develop all-optical logic gates based on photonic structures that can directly perform logic operations. All-optical logic gates have been demonstrated based on conventional waveguides and interferometry, as well as photonic crystal structures. Nonetheless, any defects in those structures will introduce high scattering loss, which compromises the fidelity and contrast ratio of the information process. Based on the spin-valley locking effect that can achieve defect-immune unidirectional transmission of topological edge states in valley photonic crystals (VPCs), we propose a high-performance all-optical logic OR gate based on a VPC structure. By tuning the working bandwidth of the two input channels, we prevent interference between the two channels to achieve a stable and high-fidelity output. The transmittance of both channels is higher than 0.8, and a high contrast ratio of 28.8 dB is achieved. Moreover, the chirality of the logic gate originated from the spin-valley locking effect allows using different circularly polarized light as inputs, representing “1” or “0”, which is highly desired in quantum computing. The device’s footprint is 18 μm × 12 μm, allowing high-density on-chip integration. In addition, this design can be experimentally fabricated using current nanofabrication techniques and will have potential applications in optical communication, information processing, and quantum computing.

Design of a Compact Polarization-Independent All-Optical and Logic Gate Based on Silicon Photonic Crystal

Design of a Compact Polarization-Independent All-Optical and Logic Gate Based on Silicon Photonic Crystal

A Review on Nonlinearity in Semiconductor optical Amplifer as Application in all Optical Signal Processing

The optical signal processing is the future of communication network. High speed all-optical packet routing is one of the essential applications of all-optical networks which is only possible with the development of all-optical logic technology. The development of optical logic elements and circuits are the steps in the growth of this technology and higher speed up to Tbit/sec can be achieved. The optical carrier frequency range 1013 to 1016 Hz provides enormous potential bandwidth with superior information carrying capacity over a long transmission distance. The need of higher capacity is continuing to encourage research in wavelength division multiplexing (WDM) and optical time division multiplexing (OTDM) based transmission systems, which need optical demultiplexing and wavelength conversion technology. Therefore, for high-speed optical networks, it is required to develop the all-optical gates to avoid power consumption in opto-electronics conversion. All optical logic gates perform computing operations, storage and transmission of data using light also known as optical computing. Optical technology promises massive upgrades in the efficiency and speed of computers, aswell as significant shrinkage in their size and cost. The non-linear optical device to be used i.e. Semiconductor Optical Amplifier (SOA) has proved to be the promising for all optical functions like wavelength conversion, logic functions, signal representation in all optical domain. Its compact size, high gain, fast response, strong refractive index variation, easy to manufacture and integration, and power efficiency makes it most optimum device for optical signal processing. In this paper, the application of SOA in optical processing is thoroughly reviewed and orient towards the latest application in neural networks.