Abstract

Terahertz radiation bears great potential in imaging and spectroscopy. One established method of generating tunable continuous-wave (cw) terahertz light is optical heterodyning: a photomixer is irradiated with two near-infrared lasers of adjacent wavelengths, and an antenna emits an electromagnetic wave at the terahertz difference frequency [1]. We developed an all-fiber-based cw terahertz spectrometer, which combines distributed feedback (DFB) diode technology and precise interferometric frequency control. This allows us to stabilize the laser frequency to arbitrary values within the diode's tuning range, achieving a frequency resolution on the 1 MHz level and a long-term stability of about 20 MHz, yet maintaining a tuning range of > 1 THz.

© 2009 IEEE