Electro-optic modulation in crystal-ion-sliced z-cut LiNbO3 thin films

Electro-optic modulation is demonstrated in 10-μm-thick single-crystal ${\mathrm{LiNbO}}_{\mathrm{3}}$ films obtained by crystal ion slicing. This technique uses ion implantation of single-crystal bulk samples followed by selective etching. The measured electro-optic response of these films is comparable, within experimental error, to that of single-crystal bulk ${\mathrm{LiNbO}}_{\mathrm{3}}$ and is superior to previously reported values for epitaxial polycrystalline thin films. The product of half-wave voltage and modulator length, $V_{\pi }\mathrm{L,}$ is 8 V cm. Post lift-off annealing is shown to be of key importance in improving the modulator extinction ratio.