Abstract

Recently, mode selecting mirrors have been used to establish tailored fundamental modes in semiconductor laser arrays,¹ CO₂ lasers,² and Nd:YAG lasers.³ The laser mode profile can be chosen to be any real function by proper design of the mode selecting mirror. In addition, the cavity can be optimized to simultaneously provide small fundamental mode loss and large discrimination against higher-order modes. The modal discrimination is influenced by the chosen fundamental mode shape, the length of the cavity, and the placement of aperture stops. Optimization studies on super-Gaussian mode shapes show that the discrimination is maximized when the cavity length is approximately one Rayleigh range of the super-Gaussian. For large mode cross-sections, (ω₀ > 0.6 mm), this can require excessively long cavities (greater than one meter).

© 1994 Optical Society of America