Design of distributed Bragg reflector structures for transverse-mode discrimination in vertical-cavity surface-emitting lasers

An angular spectrum of plane-wave representation is employed to calculate the discrimination between the fundamental and higher order transverse modes in step-index-guided vertical-cavity surface-emitting lasers. The effect of material composition and number of layer pairs in the distributed Bragg reflectors, as well as mode size and structure, are examined with the goal of optimizing the mode discrimination for better mode stability and higher single-mode power. In particular, it is shown that decreasing the width of the distributed Bragg reflector stopband, by means of controlling the material composition, improves significantly the mode discrimination.