Patent ID: 8599474

Claim:
An apparatus comprising: an optical resonator comprising two or more mirrors arranged to support one or more resonant optical modes at a specified signal wavelength or a specified idler wavelength; a nonlinear optical medium positioned within the resonator and arranged to provide optical parametric gain at the specified signal and idler wavelengths when optically pumped at a specified pump wavelength; and a positioning mechanism arranged to translate the nonlinear optical medium in a transverse direction relative to a longitudinal direction of propagation of the resonant optical modes through the nonlinear optical medium, wherein: the nonlinear optical medium comprises a nonlinear optical material arranged for odd-order, quasi-phase-matched optical parametric conversion of radiation at the specified pump wavelength into radiation at the specified signal and idler wavelengths; the nonlinear optical medium comprises two or more transversely distinct, longitudinally extending regions within the medium; at least one of the regions differs from that of another of the regions with respect to their respective odd orders of quasi-phase-matching of the optical parametric conversion; and the positioning mechanism is arranged to translate the nonlinear optical medium so that the resonant optical modes propagate through any chosen one among two or more of the regions.