Beta-barium Borate as a Pockels Cell for Excimer Lasers

一种新型的非线性晶体--β-硼酸钡(BB0)，建议用作248 nm准分子激光器的普克尔盒，以产生高峰值强度。目前，现有商用普克尔电池的各种材料相关问题已将其应用限制在300 nm以下。量子技术公司的研究人员种植了他们自己的BB0晶体，这些晶体将用于实验。它具有低至190 nm的良好透射率，高达4GW/cm2的损伤阈值，并可在1064 nm处处理高达100瓦的平均功率。将利用R11电光系数在248 nm处设计一个BBO Pockels池。晶体将被定向，以使磁场沿(100)方向施加，并且光束将沿(001)方向传播。目前可用的BBO晶体的最大长度限制在10毫米。在晶体尺寸为5×5×10 mm~3的情况下，理论半波电压预计为14千伏。然而，通过采用两个相同的晶体在光学上串联和电上并联，14KV的半波电压将在248 nm处降至7KV。在QTI生长的BBO晶体将用于这项工作。一个BBO Pockels电池将被组装并完全表征为在248 nm处使用。

A novel nonlinear crystal, beta- barium borate (BB0), is proposed to be used as a Pockels cell for excimer lasers operating at 248 nm for the generation of high peak intensities. At present, a variety of material related problems of existing commercial Pockels cells have limited their use below 300 nm. The researchers at Quantum Technology Inc. grow their own BB0 crystals, and these crystals will be used in the experiments. It has good transmission down to 190 nm, has a high damage threshold of 4 GW/cm2 and can handle average powers up to 100 watts at 1064 nm. A BBO Pockels cell will be designed at 248 nm utilizing the r11 electro- optic coefficient. The crystal will be oriented such that the field is applied along (100) and the beam will propagate along (001). The maximum length of BBO crystals presently available is limited to 10 mm. With a crystal dimension 5 x 5 x 10 mm3, the theoretical half-wave voltage is expected to be 14 KV. However, by employing two identical crystals optically in series and electrically in parallel, the half- wave voltage of 14 KV will be reduced to 7 KV at 248nm. BBO crystals grown at QTI will be used in this work. A BBO Pockels cell will be assembled and completely characterized for use at 248 nm.