Two-octave polarized supercontinuum generated from a Q-switched laser pumped doubly resonant parametric oscillator

We report broadband polarized supercontinuum generated from a doubly resonant parametric oscillator with a lithium triborate gain crystal installed in a noncritical phase-matching condition. The parametric oscillator is pumped by a Q-switched frequency-doubled Nd:YAG laser at a repetition rate of 20 Hz, producing a polarized spectrum with a width more than 324 THz or a wavelength range between 0.6 and 1.7 μm. The laser output is further extended to the blue part of spectrum via temperature-tuned second-harmonic generation in the same crystal.