Patent ID: 6844552

Claim:
A system for emitting and detecting one or more terahertz frequency electromagnetic pulses, the system comprising: a single transceiver device for both emitting and detecting the pulses; an optical source and related optics for providing: (a) a plurality of pump pulses to excite the transceiver to emit a corresponding plurality of terahertz output pulses, and (b) a plurality of probe pulses timed to illuminate the transceiver simultaneously with a corresponding plurality of reflected terahertz pulses; a chopper for modulating the terahertz output pulses by alternately transmitting and reflecting the pulses at a first frequency, the chopper having a clock output and positioned between the transceiver and an object such that terahertz output pulses reflected by the chopper have a polarity opposite terahertz output pulses reflected by the object; and a lock-in amplifier, having a reference input connected to the chopper clock output and auto-locked to the first frequency, for receiving and reducing noise in a plurality of electrical signals, each signal carrying information proportional to a corresponding reflected terahertz pulse as detected by the transceiver.