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The modal characteristics of dual-element coupled vertical cavity surface emitting laser (VCSEL) arrays are analyzed numerically and experimentally. A photonic crystal pattern etched into the top mirror optically defines the two elements of the array that are independently electrically biased. Using a two-dimensional complex waveguide analysis, we incorporate the effects of varying temperature and electron plasma-induced index suppression arising from asymmetric injection. The simulations are compared to experimental characterization of output power, lasing spectra, and far-field beam profile as a function of the two independent injection currents. Three distinct operating regimes are identified for the arrays: single independent local mode; a region of two modes that are primarily localized into a specific cavity; and a region of two supermodes whose fields extend across both elements. This analysis provides a physical intuition for the behavior of the dual-element coupled VCSEL array across its full operating range for emerging applications.

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The optical coupling between dual elements of photonic crystal vertical cavity surface emitting laser arrays is characterized. The optically coupled microcavity lasers have independent bias injection currents. Output power and beam analysis measurements are used to quantify the effects of optical coherence in nominally 850 nm emitting arrays. Modelling and experiment show how the optical coupling is influenced by photonic crystal lattice period and the independent current injection into the elements.

Effective engineering and exploitation of coherently coupled vertical cavity surface emitting laser arrays will benefit from simple and fast characterization of the optical coupling and coherence. We propose a Fourier method of analyzing beam profiles as an alternative to the prior beam visibility analysis and show that the mode suppression ratio and phase between a pair of supermodes can be extracted. Our analysis enables fast quantitative determination of the array coherence and supermode characteristics.