Femtosecond Optical Parametric Oscillators and UV Sources and Ultrafast Processes in Semiconductors

飞秒激光和光学技术已经成功地应用于研究光学材料中的各种超快过程。然而，这些实验大多是用罗丹明6G染料激光在可见光630纳米左右进行的。显然需要将飞秒源扩展到紫外和红外，并实现广泛的可调性。我们最近首次成功地展示了315 nm的连续波紫外飞秒源和第一个深红色到近红外波段的宽可调谐飞秒光学参量振荡器（OPO）。OPO可在720 nm至4.5 uM范围内连续调谐。虽然我们最初的实验已经证明了这些装置的惊人潜力，但要实现这些潜力还有很多工作要做。概述了一项研究计划，以开发、表征和优化紫外飞秒源和固体激光源泵浦的红外宽可调谐光学参量振荡器。此外，我们建议应用这些独特的源来研究砷化镓及其相关化合物和量子阱结构中非平衡电子和空穴的弛豫动力学。

Femtosecond lasers and optical techniques have been used with great success to study a variety of ultrafast processes in optical materials. Most of these experiments are, however, performed with the Rhodamine 6G dye laser around 630 nm in the visible. There is a clear need to extend the femtosecond sources to the uv and to the ir and to achieve wide tunability. We have recently succeeded in demonstrating for the first time a cw uv femtosecond source at 315 nm and the first broadly tunable femtosecond optical parametric oscillator (OPO) in the deep red to near ir. The OPO is potentially continuously tunable from 720 nm to 4.5 uM. Although our initial experiments have demonstrated the spectacular potentials of these devices, much work remains to realize these potentials. A program of research to develop, characterize, and optimize femtosescond sources in the uv and broadly tunable optical parametric oscillators in the ir pumped by solid state laser sources is outlined. In addition, we propose to apply these unique sources to study the relaxation dynamics of nonequilibrium electrons and holes in GaAs and related compounds and quantum well structures.