Periodically poled stoichiometric lithium tantalate:A new approach for a new material

"This Small Business Innovation Research Phase I project will investigate a promising new technique for fabricating periodic domain gratings in stoichiometric lithium tantalate(SLT). The key innovation in this SBIR effort is the use of externally mountedmicro-electrodes to electrically pole the material. This poling technique, made possible because of the low coercive field found in SLT, will significantly reduce the complexity of the poling setup and thus result in lower fabrication costs and higheroutput yields than has previously been possible. In addition, this technique should make it possible to periodically pole SLT wafers up to 5 mm thick. Periodically poled stoichiometric lithium tantalate, because of its increased ultra-violet(uv)transparency and high resistance to optical and photorefractive damage, will enable highly efficient, quasi-phase matched, nonlinear optical frequency conversion of high power continuous wave and pulsed laser radiation. The anticipated results of the PhaseI effort include a demonstration of periodic poling using the micro-electrode technology and a preliminary assessment of the effect different sample thicknesses have on the quality of the grating period. In the Phase II effort, the poling technology willbe refined and grating structures suitable for MDA specifc applications will be fabricated. The ability to engineer customized domain gratings in thick wafers of SLT will greatly expand its functio