Ultra-High-Q Integrated Optical Microresonators for Frequency Comb Generation

集成光子学是一个主要的新兴技术领域，对生物医学、安全、国防、运输、电信和其他部门具有巨大影响的潜力。具体来说，集成的高q光学微谐振器可以构成大量新设备的基础，包括手持式光学时钟、微量气体探测器、超精密激光雷达、窄线宽激光器、低噪声微波源、生物传感器、陀螺仪和光学数据发射器。该项目解决了实现这类设备的两个主要挑战：实现超高q波导环形谐振器，并将其与半导体激光器集成在同一芯片上。该项目将重点开发Q因子接近108及以上的氮化硅波导环形谐振器，采用最新最先进的沉积、纳米光刻和蚀刻技术，并对波导几何形状进行建模，以优化色散。然后，谐振器将用于频率梳的产生，重点是光学时钟和双梳光谱学的自参考八度跨越梳。若时间允许，学生亦会研究将III-V半导体激光器与氮化硅谐振器的硅平台整合的技术，以实现独立的单片器件。该项目产生的新知识将使我们更接近商业化一系列令人兴奋的片上超高q微谐振器技术。

ntegrated photonics is a major emerging technological field with the potential for massive impact on the biomedical, security, defence, transportation, telecoms and other sectors. Specifically, integrated high-Q optical microresonators could form the basis for a vast array of new devices including handheld optical clocks, trace gas detectors, ultraprecise lidar, narrow-linewidth lasers, low-noise microwave sources, biosensors, gyroscopes and optical data transmitters. This project addresses two of the main challenges in bringing such devices to fruition: achieving ultra-high-Q waveguide ring resonators and integrating these with semiconductor lasers on the same chip.The project will focus on developing silicon nitride waveguide ring resonators with Q factors approaching 108 and above, building upon the latest and most advanced techniques for deposition, nanolithography and etching, and modelling the waveguide geometry to optimise dispersion. The resonators will then be used for frequency comb generation, with emphasis on self-referenced octave-spanning combs for optical clocks and dual-comb spectroscopy. Time permitting, the student will also research techniques to integrate III-V semiconductor lasers with the silicon platform of the silicon nitride resonators in order to realise self-contained monolithic devices.The new knowledge generated by this project will bring us closer to commercialising a range of exciting on-chip ultra-high-Q microresonator-based technologies.