External resonator BaWO_4 crystal Raman laser

BaWO4 crystals with high optical quality were grown along a-axis and c-axis by Czochralski pulling method,the largest crystal with size of 22 mm×80 mm and weight of 213 g was obtained.The transmission spectrum of BaWO4 crystal was measured by a spectrophotometer,and the results showed that the short-wave limit was 260 nm and the long-wave limit was larger than 3 200 nm.It was indicated that BaWO4 crystal can realize Raman frequency shifting in a wide wave band.Using a mode-locked Nd:YAG laser with pulse width of 40 ps as the pump source,the Raman output properties of BaWO4 crystal in an external resonator were studied.For a 30 mm crystal sample with c-cut,the total conversion efficiencies for multi-wavelength output reached 58%,and the largest output energy was 2.46 mJ.The highest conversion efficiencies for the first Stocks Raman output of 1 181 nm were 41%,and the largest output energy was 0.92 mJ.For a 50 mm crystal sample with a-cut,the highest conversion efficiencies for the second Stocks Raman output of 1 325 nm were 23%,and the largest output energy was 0.69 mJ.The experimental results show that BaWO4 crystal is a kind of excellent near-infrared Raman laser material.