Portable Terahertz Imaging System

Period of Performance: 10/11/2002 - 06/10/2003


Phase 1 SBIR

Recipient Firm

Spire Corp.
One Patriots Park
Bedford, MA 01730
Principal Investigator


This Phase I SBIR proposal describes a development program aimed at designing and fabricating a semiconductor terahertz quantum cascade (QC) laser, and demonstrating its operation in a proof-of-concept system for biological imaging. QC lasers have demonstrated coherent emission at and above room-temperature at wavelengths beyond 10 microns, and have recently also demonstrated terahertz emission at cryogenic temperatures. This suggests the possibility of small and efficient terahertz laser sources. The potential for room-temperature terahertz emission makes this laser an excellent candidate for portable terahertz imaging applications. Phase I will deal with the design, fabrication, and testing of a terahertz laser, the selection and use of a terahertz imaging detector, and preliminary demonstration of general imaging capability using paper envelopes and grocery-purchased chicken organs. Spire will collaborate with the Optics and Quantum Electronics Group, Research Laboratory of Electronics at MIT, which has a collaborative effort with Sandia National Laboratory on terahertz laser development. The QC laser will be fabricated and tested at MIT, and a pyroelectric detector imaging array will be specified and used in a proof-of-concept demonstration. During Phase II, Spire will develop and fabricate a prototype, portable biological imaging system and work towards commercialization of the technology. The commercial availability of a portable terahertz imaging system would greatly benefit the scientific, military, medical, veterinary, dental, agriculture, textile, law-enforcement, anti-terrorism, and industrial communities. This region of the electromagnetic spectrum has been largely unavailable due to a lack of small, affordable sources. The ability of terahertz electromagnetic fields to penetrate materials while being strongly absorbed by metals and polar molecules such as water, will make it possible to detect objects hidden beneath surfaces. This enabling technology both supplements and complements harmful x-ray techniques.