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用于研究光学材料中的各种超快过程。然而，这些实验中的大多数都是在可见光下使用罗丹明6G染料激光器进行的，波长约为630 nm。显然需要将飞秒源扩展到UV和IR，并实现宽可调谐。我们最近首次成功地展示了315 nm的连续紫外飞秒光源和第一个从深红色到近红外的宽可调飞秒光学参量振荡器(OPO)。OPO有可能从720 nm到4.5微米连续可调。虽然我们的初步实验已经证明了这些器件的惊人潜力，但要实现这些潜力还有很多工作要做。概述了研制、表征和优化紫外光中的飞秒光源和固体激光泵浦的红外宽调谐光学参量振荡器的研究计划。此外，我们还建议将这些独特的源应用于研究非平衡电子和空穴的弛豫动力学以及相关化合物和量子阱结构。

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.