Fabrication of a quasi-phase-matching stack of 53 GaAs plates for high-power mid-infrared wavelength conversion by use of room-temperature bonding

Using the room-temperature-bonding technique, we have succeeded in fabricating a quasi-phase-matching (QPM) stack of 53 GaAs plates with each thickness of 106 μm and aperture of 5.5 × 5.0 mm for second-harmonic generation of a CO2 laser at 10.6 μm. An improved process was applied which realized fine alignment of the GaAs plates on the translation stage. The fabricated 5.6 mm long, 53 plate-stacked GaAs-QPM device generated 20 times higher secondharmonic power than the previously fabricated 0.95 mm long QPM stack of nine GaAs plates.