A laser system includes a laser resonator having a laser resonator volume and a gain block disposed therein, the gain block being configured to emit light at a predetermined laser wavelength, and an OPO unstable resonator having an OPO unstable resonator volume, the OPO unstable resonator optically coupled to the laser resonator and configured to receive light therefrom, wherein a portion of the OPO unstable resonator volume is situated with respect to the laser resonator volume so as to form an overlapping volume.