BROAD RANGE RADIATION DETECTOR BASED ON SPECTRUM SHIFTS OF OPTO-MECHANICAL MICROCAVITY

This SBIR Phase I proposal is aimed at the development of the ultra-sensitive detector for the far infrared (FIR) and terahertz (THz) bands of electromagnetic radiation. The device is inherently optical, operates at room temperature and of submillimeter size. The proposed technology is based on coupling the radiation to be measured to the mechanical degree of freedom of an optical microcavity and using the optical degree of freedom to get the information about the radiation field out. That is, the mechanical response of the microcavity to the incident radiation drives changes in its optical mode field. These changes manifest themselves as frequency shifts of the cavity optical resonances commonly known as Whispering Gallery Modes (WGM) which are measured using a tunable diode laser and a photoreceiver. In the Phase I research, measurements of FIR-THz radiation will be accomplished using microspherical and microtoroidal resonators, and the sensor operational model will be developed. Utilization of radiation pressure backaction cooling of the cavity to reduce local temperature and further increase sensitivity of detection is envisioned for the continuing research. Our goal is to demonstrate robust, field capable, ultra high sensitivity miniature FIR-THz detectors operating in room temperature environment.