针对兆伏每米（MV/m）强脉冲电场的测量需求，设计并研制了基于集成光学的共路干涉仪（CPI）小体积宽带脉冲电场传感器。基于电光效应及电光调制原理，建立了传感器的幅度和频率响应传递函数，分析了集成光学探头的接收特性，并推导了探头灵敏度和带宽随波导长度的关系。设计了适用于MV/m量级脉冲电场测量的纯光学非金属CPI传感器，提出了利用晶体宽度对测量灵敏度调控的方法，使得设计的半波电场提高了2倍以上。研制的无源探头体积小于20 mm×10 mm×5 mm、理论带宽大于4 GHz、最大测量幅度大于1.2 MV/m。研制的传感器在高空电磁脉冲（HEMP）、雷电电磁脉冲（LEMP）及脉冲功率等领域具有应用前景。

Fast and stable phase control is essential for many applications in optics. Here, we propose an all-fiber all-optical phase modulation scheme based on a Fabry–Perot interferometer (FPI) and an Er/Yb co-doped fiber (EYDF). By using the EYDF as an F-P cavity via rational design, a phase shift with a modulation sensitivity of 0.0312π/mW is introduced to the modulator. The phase shifts in the EYDF consist of a thermal phase shift and a nonlinear phase shift with a ratio of 19:1, and the corresponding temporal responses of the modulation are 204 ms and 2.5 ms, respectively. In addition, the compact FPI is encapsulated to provide excellent stability for the modulator.

We present a novel noncontact ultrasound (US) and photoacoustic imaging (PAI) system, overcoming the limitations of traditional coupling media. Using a long coherent length laser, we employ a homodyne free-space Mach–Zehnder setup with zero-crossing triggering, achieving a noise equivalent pressure of 703 Pa at 5 MHz and a -6 dB bandwidth of 1 to 8.54 MHz. We address the phase uncertainty inherent in the homodyne method. Scanning the noncontact US probe enables photoacoustic computed tomography (PACT). Phantom studies demonstrate imaging performance and system stability, underscoring the potential of our system for noncontact US sensing and PAI.

光栅干涉仪位移测量系统作为测量领域中最精密的测量仪器之一，由于在测量过程中光栅的姿态位置无法保证完美装配，使得光栅的光栅矢量方向与运动矢量方向之间出现偏差，导致位移测量结果出现周期性非线性误差。文中针对在光栅干涉仪位移测量过程中出现的光栅与位移台以及读数头之间的姿态位置误差进行分析，通过分别建立位移坐标系及光栅坐标系，参考惯性导航领域中飞行器姿态表示方法，利用一维光栅的横滚、俯仰和偏航角共同描述一维光栅相对于位移台的装配状态。通过基于矢量衍射理论分析光栅干涉仪位移测量时三个维度的角度偏差量，对可能产生的位移测量误差进行了分析说明。基于广义一维光栅方程，探究出了一个更为普遍的结论，为后续装置的改进提供理论依据，以提高系统的测量精度。

We demonstrate a high-performance acousto-optic modulator-based bi-frequency interferometer, which can realize either beating or beating free interference for a single-photon level quantum state. Visibility and optical efficiency of the interferometer are (99.5±0.2)% and (95±1)%, respectively. The phase of the interferometer is actively stabilized by using a dithering phase-locking scheme, where the phase dithering is realized by directly driving the acousto-optic modulators with a specially designed electronic signal. We further demonstrate applications of the interferometer in quantum technology, including bi-frequency coherent combination, frequency tuning, and optical switching. These results show the interferometer is a versatile device for multiple quantum technologies.

The velocity interferometer system for any reflector (VISAR) coupled with a streaked optical pyrometer (SOP) system is used as a diagnostic tool in inertial confinement fusion (ICF) experiments involving equations of state and shock timing. To validate the process of adiabatically compressing the fuel shell through precise tuning of shocks in experimental campaigns for the double-cone ignition (DCI) scheme of ICF, a compact line-imaging VISAR with an SOP system is designed and implemented at the Shenguang-II upgrade laser facility. The temporal and spatial resolutions of the system are better than 30 ps and 7 μm, respectively. An illumination lens is used to adjust the lighting spot size matching with the target size. A polarization beam splitter and λ/4 waveplate are used to increase the transmission efficiency of our system. The VISAR and SOP work at 660 and 450 nm, respectively, to differentiate the signals from the scattered lights of the drive lasers. The VISAR can measure the shock velocity. At the same time, the SOP system can give the shock timing and relative strength. This system has been used in different DCI campaigns, where the generation and propagation processes of multi-shock are carefully diagnosed.

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。