针对不同结构的微光学元件的波前相位检测，传统数字全息三维场重建方法不能有效重建物光波的部分频谱分量，导致微光学元件的相位测量精度不高。本文提出了一种基于频域稀疏采样的压缩感知相位重建方法，该方法在数字全息的再现过程中结合压缩感知的稀疏特性，对全息图的频谱信息进行稀疏减采样，并利用小波变换域内的多尺度特性，实现物光波有效频谱信息的压缩重建，再经过傅里叶逆变换得到重建物光波的相位分布。最后，通过微透镜阵列及相位分辨率板的测试对该方法进行验证，实验结果表明：该方法稀疏减采样的同时能够实现波前相位的精确测量，与传统数字全息的相位重建结果进行残差估计，残差的峰谷值和均方根值分别降低了26.97%和15.04%。

具有高品质因子（Q 值）的光学谐振腔能够长时间将光束缚在较小的模式体积内，极大地增强了光与物质的相互作用，成为集成光学器件中具有重大潜力的重要组成部分。聚焦于目前广泛应用于集成非线性光学领域的氮化硅材料平台，为了解决大尺寸氮化硅微环腔由拼接误差、表面粗糙等因素导致的散射损耗较大的问题，进行了一系列的工艺改进以提高大尺寸氮化硅微环腔的品质因子。结果表明：通过薄膜再沉积工艺可以有效降低氮化硅波导的散射损耗，半径为560 μm的大尺寸氮化硅微环腔的本征Q值得到了平均26% 的提升。得益于提高的微腔Q 值，在氮化硅微环腔中实现了重复频率40 GHz 的光学频率梳。

液晶空间光调制器的空间不均匀性和边缘场效应导致调制后相位存在畸变，为提高基于液晶空间光调制器的相移数字全息显微系统的测量精度，提出了二次相位标定相移数字全息的测量方法。首先，基于斐索干涉系统，以反射式液晶空间光调制器为被测对象，对其灰度与相移量的关系进行一次标定，并测量畸变波前相位；然后，利用二维图像插值算法及灰度化算法，设计出与液晶空间光调制器分辨率相等的畸变相位共轭灰度图；最后，将共轭灰度图加载在液晶空间光调制器上，获得理想调制相位，达到二次相位标定的目的。构建基于液晶空间光调制器的相移数字全息显微测量系统，对微透镜阵列进行测量实验，结果表明：二次标定前后微透镜阵列纵向矢高的相对测量误差由3.08%减少到1.15%，证明该方法能够有效提高相移数字全息的测量精度。

The microresonator-based soliton microcomb has shown a promising future in many applications. In this work, we report the fabrication of high quality (Q) Si3N4 microring resonators for soliton microcomb generation. By developing the fabrication process with crack isolation trenches and annealing, we can deposit thick stoichiometric Si3N4 film of 800 nm without cracks in the central area. The highest intrinsic Q of the Si3N4 microring obtained in our experiments is about 6×106, corresponding to a propagation loss as low as 0.058 dBm/cm. With such a high Q film, we fabricate microrings with the anomalous dispersion and demonstrate the generation of soliton microcombs with 100 mW on-chip pump power, with an optical parametric oscillation threshold of only 13.4 mW. Our Si3N4 integrated chip provides an ideal platform for researches and applications of nonlinear photonics and integrated photonics.

Dissipative Kerr solitons offer broadband coherent and low-noise frequency combs and stable temporal pulse trains, having shown great potential applications in spectroscopy, communications, and metrology. Breathing solitons are a particular kind of dissipative Kerr soliton in which the pulse duration and peak intensity show periodic oscillation. Here we have investigated the breathing dissipative Kerr solitons in silicon nitride (Si3N4) microrings, while the breathing period shows uncertainties of around megahertz (MHz) order in both simulation and experiments. This instability is the main obstacle for future applications. By applying a modulated signal to the pump laser, the breathing frequency can be injection locked to the modulation frequency and tuned over tens of MHz with frequency noise significantly suppressed. Our demonstration offers an alternative knob for the control of soliton dynamics in microresonators and paves a new avenue towards practical applications of breathing solitons.

The dissipative sensing based on a self-interference microring resonator composed of a microring resonator and a U-shaped feedback waveguide is demonstrated experimentally. Instead of a frequency shift induced by the phase shift of the waveguide or the microcavity, the dissipative sensing converts the phase shift to the effective external coupling rate, which leads to the change of linewidth of the optical resonance and the extinction ratio in the transmission spectrum. In our experiment, the power dissipated from a microheater on the feedback waveguide is detected by the dissipative sensing mechanism, and the sensitivity of our device can achieve 0.22 dB/mW. This dissipative sensing mechanism provides another promising candidate for microcavity sensing applications.