- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Spectral and temporal optical signal generation using randomly distributed quantum dots
摘要： Quantum dots (QDs) have a great potential for realizing information processing because of their signal-modulation capability based on energy transfer. We present a method for generating diverse temporal and spectral signals based on the energy transfer between multiple QDs. The method uses randomly distributed QDs, so it is not necessary to precisely arrange a QD network. With multiple energy transfers between QDs, a variety of signals within the QD network can be generated by optical inputs. Experimental results revealed that fluorescence decays of dense QDs were faster when the density of QDs or the irradiation intensity decreased. Furthermore, depending on the positions, stacked QDs showed different spectral responses. The randomly distributed QDs can generate diverse signals, which is essential for signal processing to handle temporal information.
关键词： Optical computing system,Fluorescence,Energy transfer
更新于2025-09-19 17:13:59
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All-optical majority gate based on an injection-locked laser
摘要： An all-optical computer has remained an elusive concept. To construct a practical computing primitive equivalent to an electronic Boolean logic, one should utilize nonlinearity that overcomes weaknesses that plague many optical processing schemes. An advantageous nonlinearity provides a complete set of logic operations and allows cascaded operations without changes in wavelength or in signal encoding format. Here we demonstrate an all-optical majority gate based on a vertical-cavity surface-emitting laser (VCSEL). Using emulated signal coupling, the arrangement provides Bit Error Ratio (BER) of 10?6 at the rate of 1 GHz without changes in the wavelength or in the signal encoding format. Cascaded operation of the injection-locked laser majority gate is simulated on a full adder and a 3-bit ripple-carry adder circuits. Finally, utilizing the spin-flip model semiconductor laser rate equations, we prove that injection-locked lasers may perform normalization operations in the steady-state with an arbitrary linear state of polarization.
关键词： nonlinearity,injection-locked laser,cascaded operations,VCSEL,all-optical computing,majority gate
更新于2025-09-19 17:13:59
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All-optical OR/XOR logic gate using PhC-based T-shaped waveguide with high-contrast output to implement 3-bit binary to gray code converter
摘要： In this article, a theoretical analysis on T-shaped waveguide is performed using coupled mode theory which admits its operation as power combiner, splitter and diverter. These applications of the waveguide can very well be utilized to project it as OR and XOR logic gates. In order to achieve this, the T-shaped waveguide is mapped onto the photonic crystal of square-type lattice and the validity is observed with the theoretical analysis. Later, the designed T-shaped waveguide is used to define OR and XOR gates, which results in the contrast ratio and response time of 54.43 dB and < 1 ps, respectively, at 1550 nm. Further, the higher contrast ratio of the T-shaped waveguide-based XOR logic gate allows it to cascade with itself in a single stage to realize a 3-bit binary to gray code converter. The simulation results show that the code converter operates with contrast ratio of above 9.82 dB at the output ports. Finally, the fair results obtained from theoretical analysis and numerical simulation conclude that the T-shaped waveguide can be a potential component as logic gate in the future photonic integrated circuits.
关键词： Photonic crystals,Binary to gray code converter,Optical computing,T-shaped waveguide
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Optical Computing of Mathematical Derivatives using Dispersion and Coherent Detection
摘要： Early attempts in the field of optical computing were futile because they aimed to construct an all-optical equivalent of the digital computer [1]. However, photonics does have potential for performing certain computing functions in the analog domain [1]. These analog photonic hardware accelerators precede an optical-to-electrical conversion and alleviate bandwidth, dynamic range and power consumption bottlenecks on the subsequent electronics [2]. Far from a general purpose computer, photonic hardware accelerators are custom designed to perform specific signal transformations in real time and in analog domain. The computational operations that have already been realized by these analog optical computing primitives include integration [3], data compression [4], range compression [7]. Optical time~bandwidth implementation of temporal differentiation has been demonstrated in two ways: field differentiators realized using a micro-ring resonator [8] and intensity differentiators implemented using phase modulation [9]. Inspired by the physics of Photonic Time Stretch technology [10], and its spin-off in the form of the Phase Stretch Transform [11, 12] we propose a novel computational approach for calculating mathematical derivatives. The proposed all-optical differentiator consists of group delay dispersion primitives and coherent detection as shown in Figure 1. The re-configurability to compute different orders of differentiation is realized simply by controlling the applied group delay dispersion spectrum. The simulation results presented in Figure 2 demonstrate that the computation of any-order of differentiation of the input signal is possible. As shown in Figure 2, the imaginary component of the output gives the m-th order of differentiation while the real component of the output recovers the input signal. The proposed approach has promising applications in signal classification and is also easy to implement enabling realization of a real-time, low power and broad band optical differentiation functions.
关键词： photonic time stretch,coherent detection,phase stretch transform,optical computing,mathematical derivatives,dispersion
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE Photonics Conference (IPC) - San Antonio, TX, USA (2019.9.29-2019.10.3)] 2019 IEEE Photonics Conference (IPC) - Multi-Operand Directed Logic-Based Electro-Optic Gates for Ultracompact Optical Computing
摘要： We propose and experimentally demonstrate a multi-operand electro-optic logic gate that allows a single gate to be controlled by several inputs simultaneously. A thorough analysis of its performance is fully implemented, which shows its potential to outperform the traditional logic gate in many aspects. In this paper, we propose and experimentally demonstrate a multi-operand gate and explore the ability in optical computing. The results show that the proposed logic gate is able to outperform the conventional logic gate and achieve an ultracompact optical computing circuit.
关键词： Optical computing,Optical logic devices,Integrated optics devices,Optical logic
更新于2025-09-11 14:15:04
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Femto-Farad Optoelectronic Coupling and Low-Latency Nanophotonic Computing
摘要： We demonstrate that the capacitance of OE/EO conversion devices, such as photo-detectors and electro-optic modulators, can be reduced down to a fF level by use of photonic crystals. This enables us to drastically reduce the energy efficiency of OE/EO conversion. We show that on-chip high-speed photo-receivers can be operated without any electrical power, and pseudo-all-optical-nonlinear devices can be realized by a combination of a fF photodetector and a fF electro-optic modulator. Integrated nanophotonics technologies, including those fF-optoelectronic devices, will enable optical pass-gate logic circuits for low-latency optical computation. We present our novel designs for various examples including optical full adder circuits. In addition, we show linear optic gates for logic functions which enable extremely small latency.
关键词： photodetector,nanophotonics,optical computing,optical transistor,electro-optic modulator,photonic crystal
更新于2025-09-10 09:29:36
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Implementation of polarization-encoded quantum Toffoli gate
摘要： Optics plays an important role in data processing. In this context, optical nonlinear material is very useful for superfast switching operations. Again polarization-based encoding and decoding technique plays a convenient way for data processing. In this paper, a new method to implement a quantum Toffoli gate with the active use of optical nonlinear material and polarization-based encoding technique is reported.
关键词： Optical nonlinear material,Quantum logic gate,Polarization encoding,Optical computing,Kerr effect
更新于2025-09-09 09:28:46
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Electronically programmable photonic molecule
摘要： Physical systems with discrete energy levels are ubiquitous in nature and are fundamental building blocks of quantum technology. Realizing controllable artificial atom- and molecule-like systems for light would enable coherent and dynamic control of the frequency, amplitude and phase of photons. In this work, we demonstrate a ‘photonic molecule’ with two distinct energy levels using coupled lithium niobate microring resonators and control it by external microwave excitation. We show that the frequency and phase of light can be precisely controlled by programmed microwave signals, using concepts of canonical two-level systems including Autler–Townes splitting, Stark shift, Rabi oscillation and Ramsey interference. Through such coherent control, we show on-demand optical storage and retrieval by reconfiguring the photonic molecule into a bright–dark mode pair. These results of dynamic control of light in a programmable and scalable electro-optic system open doors to applications in microwave signal processing, quantum photonic gates in the frequency domain and exploring concepts in optical computing and topological physics.
关键词： topological physics,coherent control,optical computing,microring resonators,lithium niobate,optical storage,microwave excitation,photonic molecule,quantum photonics
更新于2025-09-04 15:30:14