Patent ID: 7539221

Claim:
A Gigahertz (GHz) source, comprising: a GHz generator head including a nonlinear optic (NLO) material; a first Q-switched fiber laser configured to generate a first pulsed laser output at a frequency ω 1 ; a second Q-switched fiber laser configured to generate a second pulsed laser output at a frequency ω 2 that at least partially temporally overlaps said first pulsed laser output; and a beam combiner configured to combine the first and second laser outputs and routes the combined output to the GHz generator head where a nonlinear interaction process in the NLO material generates GHz radiation between 30 and 300 GHz that is output from the head, where each said first and second Q-switched fiber laser comprises a polarization-dependent resonant cavity including a fiber chain having a gain medium between narrowband and broadband fiber gratings, a pump source that couples energy into the fiber chain to pump the gain medium and a modulator that applies stress to the fiber chain to induce birefringence and switch the cavity Q-factor to alternately store energy in the gain medium and then release the energy of the laser output in a laser pulse.