Optical frequency combs from ultrafast solid-state and semiconductor lasers

Abstract

A fully stabilized optical frequency comb provides equally spaced frequencies for a precise ruler in optical frequency metrology. This talk will review recent progress in single and dual comb generation from diode pumped solid-state and vertical emitting semiconductor lasers. A modelocked integrated external-cavity surface-emitting laser (MIXSEL) integrates both the gain and the saturable absorber layer within the same semiconductor wafer which simplifies the laser geometry to a linear straight cavity with excellent noise performance. In dual-comb operation, the initially unpolarized beam is split with an intracavity birefringent crystal. A dual-comb MIXSEL has been used for molecular spectroscopy without the need of any additional stabilization. Novel concepts solved the Q-switching problem for gigahertz femtosecond solid-state lasers and enabled stable dual-comb generation as well.