Large-area broad band saturable Bragg reflectors using oxidized AlAs in the circular and inverted mesa geometries

摘要

A semiconductor Saturable Bragg Reflector (SBR) is a mirror structure comprising alternating layers of high and low refractive index materials with an incorporated saturable absorber. SBRs can be used to initiate and sustain ultra-short pulses in various laser systems. In order to form ultra-short pulses, SBRs with high reflectivity over a broad wavelength range are required. Furthermore, large-area SBRs facilitate easy integration in a laser cavity. One of the key elements for the realization of broad band SBRs is the development of the thermal oxidation process that creates buried low-index Al_xO_y layers over large areas. The design, fabrication, characterization, and implementation of broad band, high index contrast Ⅲ-Ⅴ/Al_xO_y SBRs in the form of circular mesas, as well as inverted mesa structures, is presented.