Formulations for calculating the eigenmodes of vertical-cavity laser arrays

Laser resonators, with laterally patterned end mirrors, are considered, and their modes are calculated based on two different approaches. In one approach, developed recently, the modes of individual cavities are coupled via mirror perturbations to yield the array modes. An alternative approach employs the mirror's background reflectivity to construct a background cavity. The background cavity eigenmodes, or any complete set of functions in this structure, are used to find the eigenmodes and eigenvalues of the vertical-cavity laser array. The advantages and disadvantages of the various methods are discussed.