Electro-optically tunable second-harmonic-generation gratings in ion-exfoliated thin films of periodically poled lithium niobate

The authors demonstrate that thin, single-crystal films fabricated by ion exfoliation of a bulk periodically poled LiNbO3 (PPLN) crystal reduced the tuning voltages for electro-optically tunable harmonic generation in PPLN devices. The tuning voltage of ±150V resulted in 0.5nm total tuning of the second harmonic signal in the authors’ 10-μm-thick device, compared to an order of magnitude higher tuning voltage value needed in a comparable bulk device.