Coupled-mode analysis of phase-locked injection laser arrays

Abstract

A coupled‐mode analysis has been developed to describe the output of phase‐locked injection laser arrays. We show that an array of emitters with weak coupling can only operate in a set of discrete modes determined by the number and the spacing of the emitters. The interaction between emitters leads to a splitting of the common frequency of operation that can be estimated from the coupling strength. The coupled‐mode analysis is compared to calculations based on simple diffraction theory. A consequence of the analysis is an explanation for the commonly observed discrepancy between experimentally observed far‐field lobe(s) widths and those predicted by simple diffraction theory.