DC-stable electro-optic modulators using thin-film lithium tantalate

We demonstrate telecommunication-wavelength Pockels electro-optic modulators in thin-film lithium tantalate (TFLT) with superior DC stability compared to equivalent thin-film lithium niobate (TFLN) modulators. Less than 1 dB output power fluctuation for quadrature-biased TFLT is measured compared to 5 dB with TFLN over 46 hours with 12.1 dBm input power. Our TFLT modulators maintain properties similar to those in TFLN: 3.4 Vcm half-wave voltage length product, 39 dB extinction ratio, flat RF electro-optic response from 3-50 GHz, and 0.35 dB on-chip loss. We also show low error-rate data modulation over 0-70°C with TFLT modulators and optical loss of 9 dB/m.