Yu, Mengjie2018-10-232020-08-222018-08-30Yu_cornellgrad_0058F_10930http://dissertations.umi.com/cornellgrad:10930bibid: 10489824https://hdl.handle.net/1813/59728The development of a spectroscopy device on a chip that could realize real-time, label-free and high-throughput detection of trace molecules presents one of the biggest challenges in sensing. This is particularly challenging in the mid-infrared (mid-IR) domain where strong and characteristic molecular absorption occurs but optical sources are still in full development. In the past decade, there has been a remarkable development of a miniaturized optical frequency comb source using parametric nonlinear interactions in microresonators. Such integrated devices present as unique tools for direct generation of broadband mid-IR light and ultrafast acquisition speed of molecular absorption information. In this thesis, we address the microresonator technology for the generation of a broadband modelocked frequency comb in the mid-IR. The properties of such microcombs can be precisely controlled, tuned, and characterized. We show that microresonator-based combs is not only an ideal testbed for studying a variety of nonlinear dynamics but, more importantly, can be used to realize a silicon-based platform for vibrational spectroscopy. We demonstrate two different types of mid-IR microcomb-based spectroscopy, dual-comb spectroscopy, and scanning comb spectroscopy which are suitable for condensed phase study and trace gas sensing, respectively.en-USAttribution 4.0 InternationalApplied physicsintegrated opticsmid-infrared opticsnonlinear photonicsoptical frequency combsInfrared SpectroscopySilicon PhotonicsOpticsdissertation or thesishttps://doi.org/10.7298/X4N8780W