关键词：电子信息；半导体；激光器；面发射
摘 要：Almost a decade since the first report of a sub-500-fs mode-locked VECSEL we see a rapid growth of interest in this field, with many new results; shorter pulses, enhanced power levels, new spectral regions, improved device structures, and steady growth of physical insight. However, it is worth noting how much is still not understood. The SESAM structures used with these lasers vary over a huge range in material and design: so that mechanisms and techniques tested for mode-locked VECSELs in one material system may not be applicable to devices in another. With so few data points, even now, it is difficult to draw conclusions that are either firm or general.