Development of Terahertz focal plane arrays and handy camera

Abstract

Uncooled Terahertz (THz) focal plane array (FPA), 320x240 format-23.5 μm pitch, and THz imager were developed. There are two types of THz-FPAs, i.e., broad-band type and narrow-band type. Since broad-band type THz-FPA was developed, a couple of modifications have been made to improve Noise Equivalent Power. The narrow-band type THz-FPA has such a new structure that Si cover is put above thermal isolation structure of broad-band type THz-FPA at a distance of half of wavelength of interest. Measurements on responsivities of narrow-band type FPAs show enhancement by a factor of ca. 3. Lock-in imaging technique has been developed, which increases signal-to-noise ratio as a function of square root of the number of frames of integration. Both passive and active THz imaging experiments were finally described.