Integrated QPM sum-frequency generation interferometer device for ultrafast optical switching

An all-optical switching device consisting of a LiNbO
₃
waveguide Mach-Zehnder interferometer with a quasi-phase-matched (QPM) sum-frequency generation (QPM-SFG) section, and a thermooptic phase shifter in the arms was designed and fabricated. Picosecond gate switching of signal wave by control pulses both in 1.5-μm wavelength band is demonstrated in a device having a QPM-SFG section of 5-mm length.