Design and Applications of Super-Continuum Lasers and Time-of-Flight Camera in Spectroscopy and Healthcare

Like the Tricorder fantasized in the Star Trek series, being able to characterize a subject without physical contact has always been one of the holy grails in fields such as material characterization, industrial inspection, or even medical diagnosis. The work in this dissertation is focused on the development of technologies that could advance optical contactless measurement techniques. The dissertation consists of two parts: 1. Design of an innovative long-wave supercontinuum (SC) laser and its applications in spectroscopy for contactless quality inspection. 2. Applications of indirect Time-of-Flight (ToF) camera in contactless physiological parameter monitoring for health care application.

For SC source development and application, we design and demonstrate a 417mW supercontinuum spectrum ranging from 1.57 to 12μm with near-diffraction-limited beam quality using a cascade of soft glass fibers. (e.g., As₂Se₃). We also discuss how fiber parameters, such as numerical aperture, core size, and core/cladding composition, affects the generated SC spectrum. We then discuss the application of such SC sources in remote inspection of processed food samples.

In terms of the contactless monitoring of physiological parameters, we develop a Contactless Vital Sign Measurement (CVSM) system that measures heart rate (HR), respiratory rate (RR) with an indirect ToF camera. We show ToF camera significantly improves the reliability of HR and RR measurements compared to a conventional 2D near-infrared camera and demonstrate the feasibility of using such a system for active driver monitoring.

Chair: Professor Mohammed N. Islam