Optical Gate Research Articles

Ethanol‐Induced Reversible Phase Transition in Antimony Halides for Morse Code Anti‐Counterfeiting and Optical Logic Gates

Ethanol‐Induced Reversible Phase Transition in Antimony Halides for Morse Code Anti‐Counterfeiting and Optical Logic Gates

A fully automated social interaction chamber for studying social threat learning in mice

Social interactions are fundamental for our survival as a predominately social species. We need and seek positive social interactions to navigate the world. However, when social interactions are negative, and occur in the presence of an aversive event, learning occurs to associate such social interactions as threatening. Gaining insight into the neural circuits that drive social threat learning is crucial for understanding social interactions. Animal models can be leveraged to employ technologies that allow us to track neuronal processes with very high resolution to obtain a better understanding of the neural circuits involved. To accomplish this, we need robust behavioral models that are replicable and high throughput. Here, we present an open-source social interaction chamber that detects social interaction and automatically pairs it with foot shock. The social interaction chamber is designed to easily integrate into modular chambers commonly used for auditory and context threat learning. It contains an array of optical gates that precisely track mouse-to-mouse interactions in real time with digital triggers that can communicate with external devices to deliver a foot shock. We find that pairing social interactions with electric foot shock using our fully automated social interaction chamber is optimal for social threat associations. We further demonstrate that timing of social contact with foot shock produces optimal learning.

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.

Femtosecond Third-Order Nonlinear Electronic Responses of 2D Metallic NbSe2

This manuscript reports on the third-order nonlinear optical responses of two-dimensional metallic NbSe2 suspended in acetonitrile (ACN). The standard Z-scan technique was employed with 190 fs optical pulses at 790 nm, a repetition rate of 750 Hz, and an intensity ranging from 30 to 300 GW/cm2. A self-focusing nonlinear refractive index (NLR), n2=+(1.8±0.1)×10−15 cm2/W, and a nonlinear absorption (NLA) coefficient, α2=+(3.5±0.2)×10−2 cm/GW, were measured, with the NLA arising from a two-photon process. Aiming to further understand the material’s electronic nonlinearities, we also employed the Optical Kerr Gate (OKG) to evaluate the material’s time response and measure the NLR coefficient in an optical intensity range different from the one used in the Z-scan. For optical pulses of 170 fs at 800 nm and a repetition rate of 76 MHz, the modulus of the NLR coefficient was measured to be n2=4.2±0.5×10−14 cm2/W for intensities up to 650 MW/cm2, with the material’s time response limited by the pulse duration. The ultrafast time response and electronic optical nonlinearities are explained based on the material’s 2D structure.

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.

Realization of controlled Remote implementation of operation

Controlled remote implementation of operation (CRIO) enables to implement operations on a remote state with strong security. We transmit implementations by entangling qubits in photon-cavity-atom system. The photons transferred in fiber and the atoms embedded in optical cavity construct CZ gates. The gates transfer implementations between participants with the permission of controller. We also construct nonadiabatic holonomic controlled gate between alkali metal atoms. Decoherence and dissipation decrease the fidelity of the implementation operators. We apply anti-blockade effect and dynamical scheme to improve the robustness of the gate.

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.

Design of Ultra-Compact and Multifunctional Optical Logic Gate Based on Sb2Se3-SOI Hybrid Platform.

Optical logic devices are essential functional devices for achieving optical signal processing. In this study, we design an ultra-compact (4.92 × 2.52 μm2) reconfigurable optical logic gate by using inverse design method with DBS algorithm based on Sb2Se3-SOI integrated platform. By selecting different amorphous/crystalline distributions of Sb2Se3 via programmable electrical triggers, the designed structure can switch between OR, XOR, NOT or AND logic gate. This structure works well for all four logic functions in the wavelength range of 1540-1560 nm. Especially at the wavelength of 1550 nm, the Contrast Ratios for XOR, NOT and AND logic gate are 13.77 dB, 11.69 dB and 3.01 dB, respectively, indicating good logical judgment ability of the device. Our design is robust to a certain range of fabrication imperfections. Even if performance weakens due to deviations, improvements can be obtained by rearranging the configurations of Sb2Se3 without reproducing the whole device.

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.

Binary Adder, Subtractor and Parity Checker Based on Optical Logic Gates

We propose schemes for binary adder, subtractor and parity checker using optical logic gates. These schemes could be useful for calculations using optical systems. Utilizing optical logic gates, we can achieve functions of binary adder, subtractor and parity checker of high-speed optical signals. Due to two-photon absorption in the wetting layer, quantum dot-semiconductor optical amplifier Mach-Zehnder interferometer (QD-SOA-MZI) can work as high data rate optical logic gates. The simulated result supports the idea that it is possible to realize all-optical binary adder, subtractor and parity checker at high optical signal rates.

Anion Effect on the Excited-State Intramolecular Proton Transfer of 4'-N,N-Diethylamino-3-hydroxyflavone in Ionic Liquids.

The excited-state intramolecular proton transfer (ESIPT) reaction of 4'-N,N,-diethylamino-3-hydroxyflavone (C2HF) was studied using time-resolved fluorescence measurements in ionic liquids (ILs) of various anions with a fixed cation (1-ethyl-3-methylimidazolium [C2mim]+). C2HF showed an ESIPT reaction from the normal excited state (N*; keto form) to the tautomer excited state (T*; enol form) where both states are emissive. The ESIPT rate and yield were obtained by analyzing the time-resolved fluorescence spectra measured using the optical Kerr gate method. Both the ESIPT rate and yield decreased with increasing hydrogen-bond accepting ability of the anion. According to density functional theory calculations, the complex formation energy between C2HF and the anion became significantly negative with increasing the hydrogen-bond accepting ability of anion. The pseudoequilibrium constant between N* and T* ([T*]/[N*]) in the electronic excited state decreased with increasing hydrogen-bond accepting ability of the anion, while it increased with increasing the alkyl-chain length of alkyl sulfonate. The excitation wavelength dependence of the ESIPT rate and yield was studied for C2HF in [C2mim][C6H13SO3]. The ESIPT yield decreased by nearly a factor of 2 with increasing excitation wavelength from 360 to 425 nm, although the change in the ESIPT rate was small. The solvation heterogeneity due to the alkyl chain in the anion was considered to be the reason for the excitation wavelength dependence.

Ultrafast Visual Detection of a Trace Amount of Water by Highly Efficient Hybrid Manganese Halides.

A quantitative water detection method is urgently needed in storage facilities, space exploration, and the chemical industry. Although numerous physical techniques have been widely utilized to determine the water content, they still suffer from many disadvantages such as highly expensive special instruments, complicated analysis processes, etc. Hence, a convenient, rapid, and sensitive water analysis method is highly desirable. Herein, we developed a visual fluorescence sensing technology for water detection based on reversible PL off-on switching of organic-inorganic hybrid zero-dimensional (0D) manganese halides. In this work, a family of hybrid manganese halides were synthesized through a facile solution method, namely, [NH4(18-Crown-6)]2MnBr4, [Ca(18-Crown-6)·3H2O](18-Crown-6)MnBr4, [NH4(dibenzo-18-Crown-6)]2MnBr4, and [Ca(dibenzo-18-Crown-6)·2H2O]MnBr4. Excited by UV light, these highly crystalline manganese halides exhibit strong green light emissions from the d-d electron transition of Mn2+ with near-unity photoluminescence quantum yield and submillisecond lifetime. Benefiting from the dynamic and weak ionic bonding interactions, these 0D manganese halides display reversible water-response on/off luminescence switching but fail in any other aprotic solvents. Therefore, these 0D hybrid manganese halides can be explored as ultrafast visual fluorescence probes to detect the trace amount of water in organic solvents with multiple superiorities of rapid response time (< 2 s), ultralow detection limit (9.71 ppm), excellent repeatability, etc. The reversible water-response luminescent on/off switching also provides a binary optical gate with advanced applications in anticounterfeiting and information security, etc.

Optical Kerr effect for underlying the orientational and translational fluctuations of molecular interactions in non-polar CS2 vapor and liquid states

A femtosecond optical Kerr gate is used for first time to experimentally study the temporal behavior of the molecular interactions of carbon disulfide (CS2) vapor in comparison to its liquid state. This Kerr effect is observed due to the optical birefringence induced in a CS2 sample. Results show that the Kerr relaxation time in the vapor state is faster than in the liquid state, with an overall exponential fit of 0.8 ps molecular relaxation time versus 1.7 ps, respectively. A faster relaxation decay time is observed for the first time in free CS2 molecules, this is attributed to fewer neighboring intermolecular interactions, which results in a lower local viscosity in the vapor compared to the liquid state. Fitting the temporal response of the Kerr vapor signal to individual components of n2 arising from the ultrafast and fast components yields two main decay times: τultrfast = 126 fs and τfast = 530 fs molecular relaxation times, one which agrees with the Debye equation for the air viscosity (associated to the free rotation in air) giving 126 fs and the other is approximately close to the translational diffusion equation producing 530 fs, respectively. In the liquid state, fitting yields three main components: τultrfast = 50 as, τfast = 500 fs, and τslow = 1.5 ps, overall, the tail fits the 1.7 ps molecular relaxation time.

Inverse design of ultra-compact optical logic gates by genetic algorithm

Optical logic gates play a crucial role in all-optical signal processing systems. Traditional methods of designing logic gates require manual adjustment of structural parameters. In this paper, we utilize a genetic algorithm for inverse design, and the optical AND, OR, and NOT logic gates are achieved on a silicon platform at the working wavelength of 1.55 μm. The total area of the logic gates is fixed at 2.2 μm × 2.2 μm, convenient to be integrated with other functional devices, the optimized structural parameters are acquired for different logic gates and the contrast ratios of the OR, AND, and NOT gates are 8.55, 5.32, and 4.14 dB, respectively. The design is characterized by a compact structure, high contrast, and a high degree of freedom, offering a valuable reference for photonic integrated circuits.

Tunable metasurfaces for implementing terahertz controllable NOT logic gate functions

Compared with traditional electrical logic gates, optical or terahertz (THz) computing logic gates have faster computing speeds and lower power consumption, and can better meet the huge data computing needs. However, there are limitations inherent in existing optical logic gates, such as single input/output channels and susceptibility to interference. Here, we proposed a new approach utilizing polarization-sensitive graphene-vanadium dioxide metasurface THz logic gates. Benefitting from two actively tunable materials, the proposed controlled-NOT logic gate(CNOT LG) enables versatile functionality through a dual-parameter control system. This system allows for the realization of multiple output states under diverse polarized illuminating conditions, aligning with the expected input-output logic relationship of the CNOT LG. Furthermore, to demonstrate the robustness of the designed THz CNOT LG metasurface, we designed an imaging array harnessing the dynamic control capabilities of tunable meta-atoms, facilitating clear near-field imaging. This research is promising for advancing CNOT LG applications in the THz spectrum. It has potential applications in telecommunications, sensing, and imaging.

Optical Cryptographic Circuit Technology Consisting of Optical Logic Gates for a Secure Information-processing Platform

Optical Cryptographic Circuit Technology Consisting of Optical Logic Gates for a Secure Information-processing Platform

Vortex beam induced spatial modulation of quantum-optical effects in a coherent atomic medium

We have studied two-dimensional absorption, gain, and corresponding refractive index profiles in a ladder-type three-level atomic system interacting with three coherent fields. One is a weak probe field considered as a plane wave, while the other two are the control fields taken as two Laguerre–Gaussian doughnut beams. Position dependence of two vortex beams induces the spatially modulated coherence at the condition of resonance, which enables us to obtain space-dependent absorption, transparency, gain without inversion (GWI), and refractive index enhancement in the present scheme. The azimuthal modulation of coherence effects is attributed to the presence of optical angular momentum of the vortex beams. Under the influence of an additional travelling wave field with the presence of two vortex beams, the present model leads us to obtain an ultra-large enhancement of refractive index at the resonant detuning of the fields. This phenomenon makes the atom-field system to play the equivalent role of a high-refractive-index prism. The role of near dipole–dipole (NDD) interaction on the modulation of position-dependent coherence effects has also been investigated. It has been shown that, without any inclusion of the travelling wave field in the system, the phenomenon of resonant enhancement of refractive index may also occur in the presence of NDD effect. The new way of generating spatially controlled GWI and nonlinear refractive index enhancement is specific to the present model. This work seems to be useful for finding its applications in spatially modulated coherence controlled electromagnetically induced transparency-based quantum devices like quantum optical memory, switches, and quantum logic gates, where the refractive index switching phenomenon is a prerequisite.

Ternary logic in the optical controlled-SWAP gate based on Laguerre-Gaussian modes of light

The need set by a computational industry to increase processing power, while simultaneously reducing the energy consumption of data centers, became a challenge for modern computational systems. In this work, we propose an optical communication solution, that could serve as a building block for future computing systems, due to its versatility. The solution arises from Landauer’s principle and utilizes reversible logic, manifested as an optical logical gate with structured light, here represented as Laguerre-Gaussian modes. We introduced a phase-shift-based encoding technique and incorporated multi-valued logic in the form of a ternary numeral system to determine the similarity between two images through the free space communication protocol.

Above-77 K operation of charge sensitive infrared phototransistor with dynamically controlled optical gate

Charge sensitive infrared phototransistors (CSIPs) show great promise for sensitive mid-infrared photodetection, extending up to single-photon counting, owing to the built-in amplification mechanism. However, the operating temperature of previously reported CSIPs has been limited to below 30 K. In this work, we propose a technique that enhances the operating temperature to above liquid nitrogen temperature by dynamically controlling the electrostatic potential of the optical floating gate (FG). This control effectively suppresses the annihilation of photogenerated holes in the FG, mitigating the vertical recombination process of thermally excited electrons. We detected the photosignal up to ∼85 K under a photon flux of Φ∼3.6×108 s−1. An outstanding photoresponsivity (R=39.11 A/W) to external blinking light at the peak wavelength of λ=11μm is achieved at 77 K. Our work not only extends the practical application of CSIPs, meeting the high demand for high temperature operation, but also offers more flexibility in fabricating more general highly sensitive phototransistors.