6–34 GHz offset phase-locking of Nd:YAG 1319 nm nonplanar ring lasers

We report offset phase-locking of two Nd:YAG nonplanar ring lasers by electronic feedback. The difference frequency is continuously tunable in three bands from 6 to 34 GHz and exhibits a hold-in range and linewidth of 82 MHz and <1 mHz, respectively.