Progress towards an ultracompact cw terahertz spectrometer

A cw terahertz spectrometer operating without optical amplifiers and without mechanical delay line is presented. Fiber-coupled 1.5 μm DFB lasers in a “butterfly” housing drive a photodiode emitter, which provides 5 μW output at 0.5 THz. A coherent photoconductive receiver yields an SNR up to 75 dB.