Patent ID: 8604433

Claim:
An apparatus for analyzing, identifying or imaging a target, comprising: a first housing including first and second lasers having tunable frequencies and coupled to first and second optical fibers respectively, said first laser to produce a first output beam and said second laser to produce a second output beam, said first output beam and said second output beam having different frequencies, wherein a first portion of said first output beam and a first portion of said second output beam are to produce a first composite output beam configured to be swept over a frequency band as the frequencies of at least one of the lasers is swept, wherein the first housing further comprises: a frequency shifting element coupled to a reference oscillator and positioned to receive a second portion of said first output beam to controllably shift the frequency of said second portion of said first output beam; and a beam combiner coupled to the output of the frequency shifting element and to a second portion of the second output beam to produce a second composite output beam; a second housing including (i) a first photoconductive switch activated by the second composite output beam for producing electromagnetic radiation in a range of frequencies greater than 100 GHz, and (ii) a radiator for directing said radiation to a target; and a third housing including (i) a receiver for acquiring electromagnetic radiation in a range of frequencies greater than 100 GHz from the target, and (ii) a second photoconductive switch activated by the first composite output beam and coupled to the electromagnetic radiation from the receiver and functioning to generate an electrical signal representative of some characteristic of the target.