在二维光子晶体中嵌入了线缺陷，利用线性干涉效应和波导耦合，设计了一种基于二维光子晶体的同或门和与非门结构。主要采用平面波展开法对该二维光子晶体的能带结构进行分析，采用时域有限差分法，结合线性干涉效应，在Rsoft平台对所设计的同或门和与非门进行稳定电场图和归一化功率仿真。仿真结果标明：设计的同或门对比度高达29.5 dB，响应时间为0.073 ps，数据传输速率为13.7 Tbit/s；设计的与非门对比度高达24.15 dB，响应时间为0.08 ps，数据传输速率为12.5 Tbit/s。这些结果表明所设计的结构对比度高、响应时间短和数据传输速率快。

为了加速光子晶体性能分析和全光逻辑门的设计，提出了利用神经网络设计基于带隙传输的光子晶体全光逻辑门。使用逆向神经网络，根据需要的群折射率、光子带隙和工作频率等光学性质，成功逆向预测光子晶体逻辑门的结构参数。仿真结果表明：该逻辑门能在时域实现AND和NOT运算；对比输入和运算输出的脉冲宽度，AND运算脉宽仅变化3.6%，实现稳定的包络和精确的“数字”逻辑运算。

Optical logic gates play important roles in all-optical logic circuits, which lie at the heart of the next-generation optical computing technology. However, the intrinsic contradiction between compactness and robustness hinders the development in this field. Here, we propose a simple design principle that can possess multiple-input-output states according to the incident circular polarization and direction based on the metasurface doublet, which enables controlled-NOT logic gates in infrared region. Therefore, the directional asymmetric electromagnetic transmission can be achieved. As a proof of concept, a spin-dependent Janus metasurface is designed and experimentally verified that four distinct images corresponding to four input states can be captured in the far-field. In addition, since the design method is derived from geometric optics, it can be easily applied to other spectra. We believe that the proposed metasurface doublet may empower many potential applications in chiral imaging, chiroptical spectroscopy and optical computing.

In the era of accelerated development in artificial intelligence as well as explosive growth of information and data throughput, underlying hardware devices that can integrate perception and memory while simultaneously offering the benefits of low power consumption and high transmission rates are particularly valuable. Neuromorphic devices inspired by the human brain are considered to be one of the most promising successors to the efficient in-sensory process. In this paper, a homojunction-based multi-functional optoelectronic synapse (MFOS) is proposed and testified. It enables a series of basic electrical synaptic plasticity, including paired-pulse facilitation/depression (PPF/PPD) and long-term promotion/depression (LTP/LTD). In addition, the synaptic behaviors induced by electrical signals could be instead achieved through optical signals, where its sensitivity to optical frequency allows the MFOS to simulate high-pass filtering applications in situ and the perception capability integrated into memory endows it with the information acquisition and processing functions as a visual system. Meanwhile, the MFOS exhibits its performances of associative learning and logic gates following the illumination with two different wavelengths. As a result, the proposed MFOS offers a solution for the realization of intelligent visual system and bionic electronic eye, and will provide more diverse application scenarios for future neuromorphic computing.

The basic indexes of all-optical integrated photonic circuits include high-density integration, ultrafast response and ultra-low energy consumption. Traditional methods mainly adopt conventional micro/nano-structures. The overall size of the circuit is large, usually reaches hundreds of microns. Besides, it is difficult to balance the ultrafast response and ultra-low energy consumption problem, and the crosstalk between two traditional devices is difficult to overcome. Here, we propose and experimentally demonstrate an approach based on inverse design method to realize a high-density, ultrafast and ultra-low energy consumption integrated photonic circuit with two all-optical switches controlling the input states of an all-optical XOR logic gate. The feature size of the whole circuit is only 2.5 μm × 7 μm, and that of a single device is 2 μm × 2 μm. The distance between two adjacent devices is as small as 1.5 μm, within wavelength magnitude scale. Theoretical response time of the circuit is 150 fs, and the threshold energy is within 10 fJ/bit. We have also considered the crosstalk problem. The circuit also realizes a function of identifying two-digit logic signal results. Our work provides a new idea for the design of ultrafast, ultra-low energy consumption all-optical devices and the implementation of high-density photonic integrated circuits.The basic indexes of all-optical integrated photonic circuits include high-density integration, ultrafast response and ultra-low energy consumption. Traditional methods mainly adopt conventional micro/nano-structures. The overall size of the circuit is large, usually reaches hundreds of microns. Besides, it is difficult to balance the ultrafast response and ultra-low energy consumption problem, and the crosstalk between two traditional devices is difficult to overcome. Here, we propose and experimentally demonstrate an approach based on inverse design method to realize a high-density, ultrafast and ultra-low energy consumption integrated photonic circuit with two all-optical switches controlling the input states of an all-optical XOR logic gate. The feature size of the whole circuit is only 2.5 μm × 7 μm, and that of a single device is 2 μm × 2 μm. The distance between two adjacent devices is as small as 1.5 μm, within wavelength magnitude scale. Theoretical response time of the circuit is 150 fs, and the threshold energy is within 10 fJ/bit. We have also considered the crosstalk problem. The circuit also realizes a function of identifying two-digit logic signal results. Our work provides a new idea for the design of ultrafast, ultra-low energy consumption all-optical devices and the implementation of high-density photonic integrated circuits.

基于电流调制和光注入共同作用下的带有饱和吸收体的垂直腔面发射激光器（VCSEL-SA），提出了一种可重构的光电逻辑门（NOT，NAND，NOR，XOR），数值研究了电流调制下VCSEL-SA的spiking动力学特性，及电流调制下光注入VCSEL-SA的逻辑运算性能。研究结果表明，对于电流调制下的光注入VCSEL-SA，光电逻辑门可以在一定的偏置电流范围内实现。通过选取合适的调制电流，可以实现重构的逻辑运算（NAND，NOR），且两个调制信号之间的时延对逻辑运算性能影响较小。通过改变电流调制信号的输入方式并移除光注入信号，VCSEL-SA可以实现XOR逻辑运算。此外，基于电流调制下光注入VCSEL-SA的可重构逻辑运算对噪声有较好的容忍性。研究结果可为未来光子神经网络解决复杂的信号处理任务提供一定的理论基础。