Terahertz frequency domain spectrometer with integrated dual laser module

摘要

An apparatus for analyzing, identifying or imaging a target including an integrated dual laser module coupled to a pair of photoconductive switches to produce CW signals in the range of frequencies from 100 GHz to over 2 THz focused on and transmitted through or reflected from the target; and a detector for acquiring spectral information from signals received from the target and using a multi-spectral homodyne process to generate an electrical signal representative of some characteristics of the target with resolution less than 250 MHz. The photoconductive switches are activated by laser beams from the dual laser module. The lasers in the module are tuned to different frequencies and have two distinct low frequency identification tones respectively that are used in conjunction with a stable optical filter element to permit precise determination of the offset frequency of the lasers.