THz-dual-frequency Yb3+:KGd(WO4)2 laser for continuous wave THz generation through photomixing

A diode-pumped KGd(WO/sub 4/)/sub 2/ Yb/sup 3+/ doped laser has been developed for CW-THz generation. The frequency difference between the two modes is step tunable from DC to 3.1 THz. A maximum total optical output power of 120 mW CW has been obtained with a beat note linewidth narrower than 30 kHz.