Widely tunable quantum cascade laser-based terahertz source

摘要

A compact, tunable, ultranarrowband terahertz source, Δv ～ 1 MHz, is demonstrated by upconversion of a 2.324 THz, free-running quantum cascade laser with a THz Schottky-diode-balanced mixer using a swept, synthesized microwave source to drive the nonlinearity. Continuously tunable radiation of 1 μW power is demonstrated in two frequency regions: v_(Laser) ± 0 to 50 GHz and v_(Laser) ± 70 to 115 GHz. The sideband spectra were characterized with a Fourier-transform spectrometer, and the radiation was tuned through CO, HDO, and D_2O rotational transitions.