Simultaneous quasi-phase-matching in OP-GaAs

To our knowledge, simultaneous quasi-phase-matching of two non-linear interactions within a single orientation-patterned GaAs (OP-GaAs) grating was experimentally demonstrated for the first time. When pumped by the signal (2.74 μm) and idler (8.77 μm) output beams of a ZGP-based optical parametric oscillator, the designed aperiodic OP-GaAs grating produces a 2.09-μm and a 3.99-µm output with power levels of several milliwatts via the sum-frequency generation and difference-frequency generation, respectively, of the beams involved. This research opens up new possibilities for the development of engineered single OP-GaAs gratings which can simultaneously produce multiple wavelengths in the whole infrared spectrum.