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Tunable second harmonic generation devices with an integrated micro-heater

We present design, fabrication and characterization of a novel integrated device for tuning the wavelength of quasi-phase matched (QPM) second harmonic generation (SHG) in a periodically poled lithium niobate (PPLN) wavelength converter. A Cr/Pt/Au thin film layer is deposited on a PPLN device with a polymer buffer layer to work as a micro-heater. Wavelength tuning is achieved by applying current to the micro-heater, which changes the effective period of QPM grating and thus the QPM wavelength through the thermal optics effect (TOE). In contrast to the conventional temperature tuning method based on a bulky oven, the proposed device has excellent characteristics such as compact, fast tuning speed and low power consumption.