HIGHLY SELECTIVE TERAHERTZ OPTICAL FREQUENCY COMB GENERATOR

Using a 10.5-GHz resonant electro-optic modulator placed inside a reso nant optical cavity, we generated an optical frequency comb with a spa n wider than 3 THz. The optical resonator consists of three mirrors, w ith the output coupler being a thin Fabry-Perot cavity with a free spe ctral range of 2 THz and a finesse of 400. Tuning this filter cavity o nto resonance with a particular high-order sideband permits efficient output coupling of the desired sideband power from the comb generator, while keeping all other sidebands inside for continued comb generatio n. This spectrally pure output light was then heterodyne detected by a nother laser with a frequency offset of the order of 1 THz. (C) 1997 O ptical Society of America.