Mode Engineering in Linear Coherently Coupled Vertical-Cavity Surface-Emitting Laser Arrays

The supermode tuning of coherent 3 × 1 vertical-cavity surface-emitting laser arrays are characterized and simulated. The array elements are resonantly tuned to achieve coherent operation using selective current injection. Depending on the electrical bias, multiple coherent supermodes are observed above threshold. An effective index model is developed to account for the variable current injection and to simulate the supermodes of the linear array. Agreement between experimental near-field and far-field coherent modes and our model simulations are found both at and above lasing threshold.