Multi-channel homodyne detection of continuous-wave terahertz radiation

We demonstrate the principle of multichannel spectral data capture using an all-optoelectronic terahertz photomixing system. Two independent laser diodes, each emitting in multiple longitudinal modes, are used to generate and detect over ten terahertz frequencies simultaneously. The spectral composition can be altered by tuning the lasers, and filtering is achieved through the use of resonant antennas and tunable photonic crystal filters. Potential applications include gas phase spectroscopy and explosives detection.