Controlling spatial hole burning in lasers using anisotropic laser mirrors

摘要

The concept of the twisted-mode laser operation, which suppresses spatial hole burning and produces single-mode operation in a standing-wave resonator, is revisited for the case of optically anisotropic laser mirrors presenting arbitrary birefringent and dichroic properties. Our analysis clarifies the relationship between the mirrors' optical properties and the proximity of the polarization states of the counterpropagating waves, which determines the contrast of the standing-wave pattern inside the resonator. The intensity of the principal mode and the population of the upper laser level as a function of the pumping rate are then determined analytically, which enables estimates of the slope efficiency and threshold of multimode emission for a given contrast value of the standing wave. The inversion density is found to reach an upper bound as a function of the pumping rate for every value of the contrast except unity. The design rules for anisotropic mirrors to produce single-frequency operation are provided that are less strict than those to achieve pure twisted-mode operation. (C) 2019 Optical Society of America