Saturable Bragg reflectors and their use in mode-locked lasers

摘要

A saturable Bragg reflector for use in mode locking a laser comprises a stack alternately of layers of a high index of refraction and layers of a low index of refraction. The layers of high index all have optical thicknesses of about one quarter the operating wavelength of the laser. The layers of low index, except for the pair of uppermost layers, have optical thicknesses of a quarter the operating wavelength but that pair have a thickness of about one eighth of a wavelength. A quantum well is located near the center of the layer of high index between the pair of one eighth wavelength. Such a reflector is used as one end of a resonant cavity that houses a gain medium. <IMAGE>