旋变幅值误差和正交误差在角速度频谱上表现为旋变转频的二次谐波，是旋变测角误差的主要来源，影响伺服系统角速度控制精度和稳定度。本文提出了一种基于特征频率参考的二次谐波误差自校正方法。首先，分析旋变测角误差产生的机理，获知其幅值误差和正交误差的互不相关性，并证明对旋变输出信号进行幅值调整和相位差调整可实现二次谐波误差校正。然后，在旋变和旋变数字信号转换器（Resolver-to-Digital Converter，RDC）之间设计基于比例放大的幅值校正器和基于交叉调节的相角校正器。最后，根据误差信号在线性控制系统中特征频率不变的特性，对伺服系统进行匀速控制，以角速度频谱中二次谐波频率的幅值为参考基准，分别调整幅值校正器和相角校正器，校正二次谐波误差。实验结果表明：本方法可将旋变二次谐波测角误差幅值降低78.5%，伺服系统速率波动量降低40.5%。本方法实现了旋变二次谐波测角误差的自校正，大幅提升了旋变的测角精度和伺服系统的转速控制稳定度。

We propose and numerically demonstrate a photonic computing primitive designed for integrated spiking neural networks (SNNs) based on add-drop ring microresonators (ADRMRs) and electrically reconfigurable phase-change material (PCM) photonic switches. In this neuromorphic system, the passive silicon-based ADRMR, equipped with a power-tunable auxiliary light, effectively demonstrates nonlinearity-induced dual neural dynamics encompassing spiking response and synaptic plasticity that can generate single-wavelength optical neural spikes with synaptic weight. By cascading these ADRMRs with different resonant wavelengths, weighted multiple-wavelength spikes can be feasibly output from the ADRMR-based hardware arrays when external wavelength-addressable optical pulses are injected; subsequently, the cumulative power of these weighted output spikes is utilized to ascertain the activation status of the reconfigurable PCM photonic switches. Moreover, the reconfigurable mechanism driving the interconversion of the PCMs between the resonant-bonded crystalline states and the covalent-bonded amorphous states is achieved through precise thermal modulation. Drawing from the thermal properties, an innovative thermodynamic leaky integrate-and-firing (TLIF) neuron system is proposed. With the TLIF neuron system as the fundamental unit, a fully connected SNN is constructed to complete a classic deep learning task: the recognition of handwritten digit patterns. The simulation results reveal that the exemplary SNN can effectively recognize 10 numbers directly in the optical domain by employing the surrogate gradient algorithm. The theoretical verification of our architecture paves a whole new path for integrated photonic SNNs, with the potential to advance the field of neuromorphic photonic systems and enable more efficient spiking information processing.

利用旋转移相技术的几何相位调控方法，提出一种基于传输相位差概念的波束扫描高功率微波反射阵列天线。电磁仿真结果表明，所设计的三叉戟形反射阵列天线单元工作于9.5～10.5 GHz，在0～40°入射角度下具有360°范围内的线性相位调控能力，真空条件下的功率容量达到1.11 GW。采用该单元设计了半径为200 mm的圆形口径反射阵列天线，并使用全波仿真软件进行验证，利用口径相位分布的可重构特性，所设计的反射阵列天线可以实现±40°范围内的波束扫描。在10 GHz时，波束扫描过程中的增益下降小于1.7 dB，最大增益达到31.1 dBi，对应口径效率为73.42%，最低口径效率超过50%，副瓣电平和轴比始终低于−18.7 dB和1.6 dB。

传统的透射式空馈阵列存在功率容量低的缺点，不能直接应用于高功率微波领域。现有的高功率空馈阵列布局不够灵活，波束扫描速度较慢，不能充分发挥空馈阵列在系统集成方面的优势。提出并设计了一种新型的采用空间馈电的螺旋辐射单元，并构建了一种透射式空馈螺旋阵列天线，通过控制单个螺旋旋转可以实现二维波束扫描，在设计上更加灵活，可根据实际应用需求调整阵列布局，符合高功率微波天线紧凑化、模块化的发展趋势。仿真设计了包含324个单元的透镜阵列，数值模拟结果表明，单元反射系数S₁₁≤−20 dB，功率容量0.35 MW，阵列口径效率0.68，可在±45°范围内扫描，最大增益下降3 dB。

提出了一种新型高功率微波宽带紧耦合偶极子阵列天线。在常规的紧耦合偶极子阵列天线的基础上，该阵列天线通过采用全金属结构设计、天线匹配层和密封层一体化设计以及调节天线结构的手段，获得了宽带高功率性能。仿真结果显示，在0.8～4.0 GHz的范围内，天线未扫描时的驻波比小于2；在16 mm×32 mm单元尺寸内和1个大气压的SF₆气体中，功率容量达到0.12 MW；以该单元天线组成10×10阵列，100个单元总尺寸仅为160 mm×320 mm，在1个大气压的SF₆气体中，功率容量可以达到12 MW，另外，该天线可实现45°的宽角扫描。该阵列天线的提出为实现高功率微波宽带天线的宽频带、大角度扫描、紧凑化、小型化以及低剖面化提供了参考。

Indefinite metacavities (IMCs) made of hyperbolic metamaterials show great advantages in terms of extremely small mode volume due to large wave vectors endowed by the unique hyperbolic dispersion. However, quality (Q) factors of IMCs are limited by Ohmic loss of metals and radiative loss of leaked waves. Despite the fact that Ohmic loss of metals is inevitable in IMCs, the radiative loss can be further suppressed by leakage engineering. Here we propose a mirror coupled IMC structure which is able to operate at Fabry–Pérot bound states in the continuum (BICs) while the hyperbolic nature of IMCs is retained. At the BIC point, the radiative loss of magnetic dipolar cavity modes in IMCs is completely absent, resulting in a considerably increased Q factor (>90). Deviating from the BIC point, perfect absorption bands (>0.99) along with a strong near-field intensity enhancement (>1.8×104) appear when the condition of critical coupling is almost fulfilled. The proposed BICs are robust to the geometry and material composition of IMCs and anomalous scaling law of resonance is verified during the tuning of optical responses. We also demonstrate that the Purcell effect of the structure can be significantly improved under BIC and quasi-BIC regimes due to the further enhanced Q factor to mode volume ratio. Our results provide a new train of thought to design ultra-small optical nanocavities that may find many applications benefitting from strong light–matter interactions.

基于多光束干涉光谱成像原理，研究一种高空间分辨率甲烷气体点源探测方法。首先，介绍了甲烷气体探测仪的工作原理和探测方案，详细设计法布里-珀罗干涉仪的系统参数，并建立甲烷气体探测正演模型。然后，分析了干涉信号和甲烷浓度之间的对应关系，以及仪器参数对探测灵敏度的影响。最终，迭代优化得到各光学结构参数的最优取值。结果表明，在甲烷探测波段为1 630~1 675 nm，自由光谱范围为12.5 nm，光谱分辨率为0.1 nm，法布里-珀罗标准具腔长为0.08 mm，腔内反射率为97.5%，截止滤光片范围为（1 630±4）nm~（1 675±4）nm时，探测源25%浓度变化对应的干涉信号相对变化量范围为［0.65%，4.30%］，探测灵敏度较好。研究结果可为高精度碳监测提供理论依据和技术支撑。