Electro-optic coefficients of lithium tantalate at near-infrared wavelengths

The unclamped linear electro-optic coefficients r13 and r33 for lithium tantalate are known at only one wavelength, 632.8 nm, whereas the clamped coefficients are also known at 3.39 μm. In the unclamped mode the effects of mechanical changes caused by piezoelectric and elasto-optic effects are accounted for in the electro-optic coefficient. We demonstrate a novel technique that uses a ferroelectric domain micropatterned electro-optic deflector to measure the unclamped linear electro-optic coefficients r13 and r33 at any wavelength. Using this method, we have determined these values for lithium tantalate at 980, 1330, and 1558 nm.