Thin-film channel waveguide electro-optic modulator in epitaxial BaTiO3

Abstract

We report on a thin-film channel waveguide electro-optic modulator fabricated in epitaxial ${\mathrm{BaTiO}}_{\mathrm{3}}$ on MgO. Films had an effective dc electro-optic coefficient of $r_{\mathrm{eff}}$ ∼50±5 pm/V and $r_{\mathrm{eff}}$ ∼18±2 pm/V at 5 MHz for λ∼1.55 μm light. Extinction ratios of 14 dB were obtained. The electro-optic effect decreases to ∼60% of the dc value at 1 Hz, 50% of the dc value at 20 kHz, and ∼37% of the dc value at 5 MHz.