All-optical Logic Research Articles

All-optical photonic crystal logic gates and functions based on threshold logic

All-optical photonic crystal logic gates and functions based on threshold logic

Numerical analysis of All-Optical universal NAND and NOR photonic crystal logic gates by creating holes in silicon material

All-optical NAND and NOR logical gates based on two-dimensional photonic crystals have been designed and analyzed in this research. A hole in the silicon substrate was created to design the desired gates, and the light emission analysis was performed using the FDTD numerical method. Most of the circuits that have been designed so far based on photonic crystals have included dielectric rods in the airfield. This research uses a hole in the silicon substrate, which is more suitable for fabrication. The proposed structure is created symmetrically using a small photonic crystal. The simulation results show that this small structure can be used as two NAND and NOR gates, which have a suitable power difference in the upper and lower logic states. Therefore, the proposed structure is suitable for precise logic circuits and high transmission speed. Due to the simplicity of structure and small size, the output stable time for NAND and NOR gates are 0.9 ps and 0.67 ps, respectively, indicating the gates’ low delay time. Also, the value of the contrast ratio for NAND and NOR gates is 7.26 dB and 6.35 dB, respectively, which indicates the appropriate power difference in the upper and lower logic states.

Dual-band all-optical logic gates for communication based on coherent control of gold-film stacked metamaterials

Dual-band all-optical logic gates for communication based on coherent control of gold-film stacked metamaterials

Anisotropic nonlinear optical responses of Ta2NiS5 flake towards ultrafast logic gates and secure all-optical information transmission

Abstract Optical logic gates based on nonlinear optical property of material with ultrafast response speed and excellent computational processing power can break the performance bottleneck of electronic transistors. As one of the layered 2D materials, Ta2NiS5 exhibits high anisotropic mobility, exotic electrical response, and intriguing optical properties. Due to the low-symmetrical crystal structures, it possesses in-plane anisotropic physical properties. The optical absorption information of Ta2NiS5 is investigated by anisotropic linear absorption spectra, femtosecond laser intensity scanning (I-scan), and non-degenerate pump-probe technology. The I-scan results show a distinct maximum of ∼4.9 % saturable absorption (SA) and ∼4 % reverse saturable absorption (RSA) at different polarization directions of the incident laser. And, these unique nonlinear optical (NLO) properties originate from the anisotropic optical transition probability. Furthermore, the novel Ta2NiS5-based all-optical logic gates are proposed by manipulating the NLO absorption processes. And, the all-optical OR and NOR logic gates possess an ultrafast response speed approaching 1.7 THz. Meanwhile, an all-optical information transmission method with higher security and accuracy is achieved, which has promising potential to avoid the disclosure of information. This work provides a new path for designing versatile and novel optical applications based on Ta2NiS5 materials.

Ultrafast Charge Transfer-Induced Unusual Nonlinear Optical Response in ReSe2/ReS2 Heterostructure.

Ultrafast charge transfer in van der Waals heterostructures can effectively engineer the optical and electrical properties of two-dimensional semiconductors for designing photonic and optoelectronic devices. However, the nonlinear absorption conversion dynamics with the pump intensity and the underlying physical mechanisms in a type-II heterostructure remain largely unexplored, yet hold considerable potential for all-optical logic gates. Herein, two-dimensional ReSe2/ReS2 heterostructure is designed to realize an unusual transition from reverse saturable absorption to saturable absorption (SA) with a conversion pump intensity threshold of approximately 170 GW/cm2. Such an intriguing phenomenon is attributed to the decrease of two-photon absorption (TPA) of ReS2 and the increase of SA of ReSe2 with the pump intensity. Based on the characterization results of X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, femtosecond transient absorption spectrum, Kelvin probe force microscopy, and density functional theory calculation, a type-II charge-transfer-energy level model is proposed combined with the TPA of ReS2 and SA of ReSe2 processes. The results reveal the critical role of ultrafast interfacial charge transfer in tuning the unusual nonlinear absorption and improving the SA of ReSe2/ReS2 under different excitation wavelengths. Our finding deepens the understanding of nonlinear absorption physical mechanisms in two-dimensional heterostructure materials, which may further diversify the nonlinear optical materials and photonic devices.

Investigation of metal-insulator-metal waveguides with elliptical-nanodisk resonator for high contrast ratio all-optical logic gates

Abstract This research focuses on the design and analysis of all-optical Exclusive OR(XOR), NOT, and OR logic gates based on metal-insulator-metal waveguides with elliptical-nanodisk resonators. The functionality of the proposed optical logic gates is determined by constructive and deconstructive signals which are applied to the input ports and control ports. To show the logic 0 (low) and logic 1 (high) output states, the limit of threshold transmission is 1.775 × 10−13 ∼0. The transmission (T) and contrast ratio (CR) are obtained to present the performance of the optical logic gates via the method of finite-difference time-domain. The maximum transmission is reached for the OR gate as 1.38 and the highest contrast ratio is 124.75 dB for the XOR and NOT logic gates. The designed logic devices are promising for improving more efficient optical signal information processing devices.

Dual-channel intrinsic and nonlinear chirality for an all-optical logic operation.

Chiral metasurfaces hold excellent performance in enhancing spin-dependent light-matter interaction, showing broad application prospects in areas such as chiral imaging, chiral light sources, and chiral sensing. However, utilizing resonant metasurfaces to achieve all-optical logic gates has not been reported yet. In this work, dual-channel intrinsic and nonlinear chiroptical responses are achieved on lithium niobate metasurfaces. The combination of bound states in the continuum (BICs) resonant modes with chiral metasurfaces has revealed its linear and nonlinear chirality. The metasurface achieves linear circular dichroism above 0.9 and nonlinear circular dichroism close to 0.9 on the dual-band. Based on the second-order nonlinear chiroptical response, multiple all-optical logic gates (including NOT, OR, NAND, AND, and NOR) can be realized on the chiral metasurfaces. Our results confirm the operability of resonant metasurfaces in realizing all-optical logic gates, offering a potentially promising approach for the development of new, to the best of our knowledge, all-optical logic devices.

All-optical combinational logical units featuring fifth-order cascade

Modern computational technologies are increasingly encountering significant limitations, driving a shift towards alternative paradigms such as optical computing. In this study, we introduce novel all-optical combinational logic units based on diffractive neural networks (D2NNs), designed to perform high-order logical operations both efficiently and swiftly using only two modulation layers. This innovative design offers increased processing speed, improved energy efficiency, robust environmental stability, and high error tolerance, making it exceptionally well-suited for a broad spectrum of applications in optical computing and communications. By leveraging transfer learning, we successfully developed a fifth-order cascaded combinational logic circuit for practical information transmission system. Furthermore, we reveal a pioneering application of our device in Optical Time Division Multiplexing (OTDM), demonstrating its capability to manage high-speed data transfer seamlessly without the need for electronic conversion. Extensive simulations and experimental validations highlight the potential of our model as a foundational technology for future optical computing architectures, paving the way toward more sustainable and efficient optical data processing platforms.

Dual-band all-optical logic gate based on coherent control principles

In this paper, we present a dual-band all-optical logic gate based on a coherent perfect absorption metasurface. By utilizing the principle of coherent perfect absorption, we can manipulate the interference between two input signals by adjusting their relative phase difference. This allows us to implement logic functions such as AND, OR, and XOR in the second (1310 nm) and third (1550 nm) windows of the communication band. Moreover, we present the concept of "contrast" as a quantitative metric to assess the performance of each logic gate. The simulation results show that the contrast between the AND gate and the XOR gate can reach 6.4 dB and 17.8 dB at 1310 nm, as well as 6.1 dB and 18.9 dB at 1550 nm, rendering it highly advantageous for practical applications. The realization of ultrafast operation and low power consumption in coherent perfect absorption metasurfaces would significantly contribute to advancing the progress of optical data processing.

Ultrafast Saturable to Reverse Saturable Absorption Transition in CoTCPP SURMOF Nanofilms and its Application to All-optical Logic and Encryption

Ultrafast Saturable to Reverse Saturable Absorption Transition in CoTCPP SURMOF Nanofilms and its Application to All-optical Logic and Encryption

Universal all-optical zero-bias logic gates in silicon photonics.

Universal all-optical (optical input - optical output) logic gates, realized in a commercial foundry silicon photonics process, are reported. Microring resonator modulator and zero-biased stacked photodiodes are used to create the required optical input-output nonlinear transfer function for optical gate realizations. Several logic gate functions, specifically NOR which is a universal logic gate that can be used to implement any logic, are demonstrated. Logic operation on 10 Mbps data streams is demonstrated using universal optical logic gates without requiring any electrical supply voltage. The total optical power required for one such universal logic gate is 160 µW.

A novel method of high-speed all-optical logic gate based on metalens

This paper introduces a novel approach to constructing all-optical logic gates based on metalens. The designed structure enables the realization of five commonly used logic gates (AND, OR, NOT, XOR, XNOR). Each logic gate is composed of two to three metalenses. The advantages of this approach are as follows: 1. Metalens offer flexible phase control capabilities, overcoming the strict phase requirements in traditional optical logic gate design. 2. The miniaturization of the metalens makes integration possible and provides a potential method for high-speed parallel optical computing. 3. By controlling different types and quantities of metalens, various types of logic gates can be formed, enhancing programmability during use. The contrast values for the designed logic gates are as follows: 27.95 dB (OR), 18.18 dB (AND), 10.83 dB (NOT), 10.29 dB (XNOR), and 13.56 dB (XOR). With similar structures, the bit rates for the five logic gates at a 50% duty cycle range from 1.04 to 1.05 Tb/s. Overall, these results demonstrate a successful balance between contrast and transmission speed when utilizing metalens to realize all-optical logic gates. From the results, the logic gate proposed in this paper has high contrast and transmission speed, which proves the rationality of using metalens to realize all-optical logic gate.

All-optical NOT, OR, and XOR Logic Gates Using Silicon Slot Waveguides

All-optical NOT, OR, and Exclusive OR(XOR) logic gates utilizing silicon slot waveguides are proposed and numerically analyzed in this work. The structure has a silicon slab with slot regions such as two input waveguides and square cavity resonators and one output waveguide. The optical spectra of the designed structures are attained with the method of finite difference time domain. The all-optical logic gate features of the design are achieved by applying optical signals with 00 or 1800 phase differences from the input ports. Basic parameters such as transmission spectrum (T), modulation depth (MD), and contrast ratio (CR) are performed to show the optical features and ability of the proposed logic gates. The threshold transmission limit is 1.7% to define the status of the output ports as ON or OFF. At 689.5 nm, the maximum transmission, modulation depth, and contrast ratio are 149%, 97%, and 15.36 dB, respectively.

Realization of all-optical logic gates using MIM waveguides and a rectangular ring resonator

In this study, all-optical OR, exclusive OR (XOR), NOR, XNOR, AND, NAND, and NOT logic gates using metal-insulator-metal (MIM) waveguides with a rectangular ring resonator are designed and analyzed. The structure has a silver plate with three input waveguides, one output waveguide, and a rectangular ring resonator. One of the input ports is used as a control port. The finite-difference time-domain (FDTD) method is utilized to obtain the optical spectrum of the proposed structures. To realize all-optical logic gate properties of the designed structures, optical signals with the same phase or different phases are passed through the waveguides. Transmission spectrum (T), contrast ratio (CR), and modulation depth (MD) parameters are obtained to determine the performances of all-optical logic gates. To determine the logic 1 (ON) and logic 0 (OFF) states of the output ports, the threshold transmission value is accepted as 0.23 for all-optical logic gates. For the proposed designs, the highest transmission, contrast ratio, and modulation depth values are 217%, 6.75 dB, and 100%, respectively. The structure also supports a data rate of 24 Tb/s. The designed optical logic gates have valuable features for developing high-performance optical devices.

Broadband terahertz absorption and Q-switching behavior of 5-chloro-2-nitroaniline (5C2NA) crystals

Abstract Growth of transparent 5-chloro-2-nitroaniline (5C2NA) crystals was achieved through the slow evaporation technique. Analysis via X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy confirmed the crystalline nature of the organic crystals and revealing distinct molecular fingerprints of 5C2NA respectively. UV-VIS and Photoluminescence (PL) spectroscopy were employed to study the material's band gap and ground state absorption respectively. Thermogravimetric analysis (TGA) analysis indicated the stability of the grown crystals up to 211ºC. Dielectric measurements and Urbach plot suggested the presence of fewer defects in 5C2NA crystals. Time domain terahertz spectroscopy was utilized to observe the variation of absorption coefficient and refractive index in the terahertz frequency regime. Nonlinear optical effects such as saturable absorption (SA) and reverse saturable absorption (RSA), are pivotal in the development of all-optical logic gates. The transition between SA and RSA possesses a significant importance in optoelectronic applications. In this study, we investigate the 5C2NA crystal, revealing its ability to exhibit both SA and RSA under Z scan technique with varying pump intensities. The switching properties observed in 5C2NA can be harnessed for applications such as all-optical logic gates, rapid optical switching, optical limiting, mode storage, and more.

Comprehensive design of all-optical logic devices utilizing polarization holography.

Polarization holography has emerged as a promising method for manipulating the amplitude, phase, and polarization states of light waves. This study proposes what we believe to be a novel design method for various all-optical logic devices, including a complete set of all-optical Boolean logic gates and a polarization-controlled 1 × 4 optical switch, utilizing polarization holography. Through the angle multiplexing technique, specially designed polarization holograms are recorded in polarization-sensitive material, transforming it into all-optical Boolean logic gates and a polarization-controlled 1 × 4 optical switch. The all-optical logic devices developed in this work function as passive diffractive optical elements, enabled by a single piece of polarization-sensitive material, eliminating the need for additional circuit control. This approach offers the advantages of a simple structure, low cost, and instantaneous response. We contend that this advancement will facilitate the expansion of the application domains of polarization holography, particularly enhancing the capabilities of all-optical information processing.

Design of All-Optical D Flip Flop Memory Unit Based on Photonic Crystal.

This paper proposes a unique configuration for an all-optical D Flip Flop (D-FF) utilizing a quasi-square ring resonator (RR) and T-Splitter, as well as NOT and OR logic gates within a 2-dimensional square lattice photonic crystal (PC) structure. The components realizing the all-optical D-FF comprise of optical waveguides in a 2D square lattice PC of 45 × 23 silicon (Si) rods in a silica (SiO2) substrate. The utilization of these specific materials has facilitated the fabrication process of the design, diverging from alternative approaches that employ an air substrate, a method inherently unattainable in fabrication. The configuration underwent examination and simulation utilizing both plane-wave expansion (PWE) and finite-difference time-domain (FDTD) methodologies. The simulation outcomes demonstrate that the designed waveguides and RR effectively execute the operational principles of the D-FF by guiding light as intended. The suggested configuration holds promise as a logic block within all-optical arithmetic logic units (ALUs) designed for digital computing optical circuits. The design underwent optimization for operation within the C-band spectrum, particularly at 1550 nm. The outcomes reveal a distinct differentiation between logic states '1' and '0', enhancing robust decision-making on the receiver side and minimizing logic errors in the photonic decision circuit. The D-FF displays a contrast ratio (CR) of 4.77 dB, a stabilization time of 0.66 psec, and a footprint of 21 μm × 12 μm.

All-optical temporal logic gates in localized exciton polaritons

Exciton polaritons—quasi-particle excitations consisting of strongly coupled photons and excitons—present fascinating possibilities for photonic circuits, owing to their strong nonlinearity, ultrafast reaction times and their ability to form macroscopic quantum states at room temperature via non-equilibrium condensation. Past implementations of transistors and logic gates with exciton polaritons have been mostly realized using the spatial propagation of polariton fluids, which place high demands on the fabrication of the microcavities and typically require complex manipulations. In this work we have implemented the full set of logical gate functionalities (that is, temporal AND, OR and NOT gates) in localized exciton polaritons at room temperature, on the basis of precisely controlling the interplay between polariton condensate and exciton reservoir dynamics, using a two-pulse excitation scheme. The dynamics intrinsically covers the cascadability required by the logical operations, enabling efficient information processing without the need for spatial flow. The temporal polariton logic gates demonstrate advantages in ultrafast switching, universality and simplified compatibility with other dimensional controls, showing great potential for building polariton logic networks in strongly coupled light–matter systems.

All-Optic Logical Operations Based on the Visible-Near Infrared Bipolar Optical Response.

The burgeoning need for extensive data processing has sparked enthusiasm for the development of a novel optical logic gate platform. In this study, junction field-effect phototransistors based on molybdenum disulfide/Germanium (MoS2/Ge) heterojunctions are constructed as optical logic units. This device demonstrates a positive photoresponse that is attributed to the photoconductivity effect occurring upon irradiation with visible (Vis) light. Under the illumination of near-infrared (NIR) optics with wavelengths within the communication band, the device shows a negative photoresponse, which is associated with the interlayer Coulomb interactions. The current state of the device can be effectively modulated as different logical states by precisely tuning the wavelength and power density of the optical. Within a 3×3 MoS2/Ge phototransistor array, five essentially all-optical logic gates ("AND," "OR," "NAND," "NOT," and "NOR") can be achieved in every signal unit. Furthermore, three complex all-optical logical operations are demonstrated by integrating two MoS2/Ge phototransistors in series. Compared to electronic designs, these all-optical logic devices offer a significant reduction in transistor number, with savings of 50-94% when implementing the above-mentioned functions. These results present opportunities for the development of photonic chips with low power consumption, high fidelity, and large volumes.

3985Utilizing EllipticalRingIMI-Plasmonic Waveguides, Nanomaterials in Nanophotonic Structure for All-Optical 2 × 1 Demultiplexer

In many industries, particularly electronics, photonic devices are indispensable. However, the diffraction limit and miniaturization are the two problems that have hampered the development of photonics devices. These problems are resolved by plasmonic devices, which enable nanophononics and nanodevices. One of the primary all-optical demultiplexer components utilized in an all-optical Athematic Logic Unit (ALU), which is regarded as the basic building block for all-optical computers, is a plasmonic demultiplexerThis paper provides a new design for an elliptical ring insulator-metal-insulator (IMI) plasmonic waveguide-based all-optical demultiplexer (Demux). The suggested device has a small footprint (300 nm × 250 nm) and works at a 1550 nm wavelength. Demux has a 0.5 transmission threshold between logic zero and logic one states. Transmission (T), extinction ratio (contrast ratio (CR)), modulation depth (MD), and insertion loss (IL) are the four metrics that best explain the performance of the plasmonic Demux. The suggested structural dimensions are outstanding and optimal based on the values of MD for Demux which is (95.87%). The device's maximum transmission efficiency is 56.84%. The suggested plasmonic Demux structure makes a substantial contribution to all-optical signal processing Nano-circuits and nano-photonics integrated circuits. Using COMSOL Multiphysics, wesimulate the proposed plasmonic Demux using the Finite Element Method (FEM).