Chip-based spectroscopy using microresonator frequency combs
The 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.
Applied physics; integrated optics; mid-infrared optics; nonlinear photonics; optical frequency combs; Infrared Spectroscopy; Silicon Photonics; Optics
Rana, Farhan; Gaeta, Alexander L.
Electrical and Computer Engineering
Ph. D., Electrical and Computer Engineering
Doctor of Philosophy
Attribution 4.0 International
dissertation or thesis
Except where otherwise noted, this item's license is described as Attribution 4.0 International