针对不同项目研制过程中碲镉汞线列光导器件在筛选测试和应用中出现的失效模式进行了归纳和总结，并综合碲镉汞材料参数、器件结构尺寸、器件物理、器件制备工艺和器件测试等几个方面因素对器件失效的可能原因进行了分析，首次提出碲镉汞线列光导器件的优值因子作为失效判据，为进一步理解碲镉汞线列光导器件的物理机理以及更好优化器件的筛选过程提供了参考，为碲镉汞线列光导器件应用中出现的失效问题提供了分析和解决的方向。

微腔光频梳在光谱测量、微波光子学、光学原子钟和相干光通信等领域具有重要的应用。宽禁带氮化物半导体材料，如氮化铝（AlN）和氮化镓（GaN）等属于非中心对称晶体，具有二阶和三阶光学非线性系数，宽带的透明窗口以及与蓝宝石衬底较高的折射率差，使其成为研究非线性光子器件的理想平台。文中介绍了氮化物微腔的特性，同时对基于氮化物微腔光梳的相关研究进展，包括AlN微腔中的宽谱光频梳产生和光学参量振荡、GaN微腔中的孤子光频梳产生等进行了介绍和展望。

超宽带单行载流子（UTC）光电探测器因其仅需快速的电子输运过程，较传统PIN探测器具有明显宽带优势，是6G宽带无线通信、太赫兹成像、超宽带噪声发生器等亚太赫兹频段系统中的核心光电子器件之一。面向亚太赫兹频段光电转换需求，针对UTC探测器中大带宽与高饱和功率之间的矛盾问题，分别研究并突破了光生载流子高速输运机理、感性共面波导器件（CPW）结构等关键技术，研制成功带宽106 GHz、饱和输出功率7.3 dBm的双漂移层结构MUTC探测器芯片，和带宽超过150 GHz的超宽带MUTC探测器芯片。

A novel thin-film lithium niobate (TFLN) electro-optic modulator is proposed and demonstrated. LiNbO3-silica hybrid waveguide is adopted to maintain low optical loss for an electrode spacing as narrow as 3 µm, resulting in a low half-wave-voltage length product of only 1.7 V·cm. Capacitively loaded traveling-wave electrodes are employed to reduce the microwave loss, while a quartz substrate is used in place of a silicon substrate to achieve velocity matching. The fabricated TFLN modulator with a 5-mm-long modulation region exhibits a half-wave voltage of 3.4 V and a merely less than 2 dB roll-off in an electro-optic response up to 67 GHz.

An equivalent circuit model including multi-section distributed parameters is proposed to analyze wideband photodiodes (PDs) with coplanar waveguide (CPW) electrodes. The model helps extract CPW parameters as well as intrinsic bandwidth parameters so that the influence of the CPW structure can be investigated, making it valuable for the design of high-performance PDs. PDs with an inductive 115 Ω impedance CPW are fabricated, and the 3 dB bandwidth is improved from 28 GHz to 37.5 GHz compared with PDs with a conventional 50 Ω impedance CPW.