Analysis and Characterization of Photon-Photon Resonance in Coupled Dual-Element Photonic Crystal Vertical Cavity Surface Emitting Laser Arrays

We report a photonic resonance at the frequency difference between non-degenerate modes of dual-element photonic crystal vertical cavity surface emitting laser arrays. The evolution of modes in coupled dual-element laser arrays biased in the coherently coupled region is examined through theory and experimentation. A complex waveguide simulation predicts two supermodes for operation along the coherently coupled region which results in increased output power, visibility, and a photon-photon resonance frequency above the carrier-photon resonance frequency. Experimental analysis of number of spectral peaks, far-field beam profile, spectral linewidth, and noise frequency response along the coherently coupled region as a function of input current shows that the two supermodes must lase simultaneously within the coherently coupled region. The two supermodes are nearly degenerate and the resulting beating between the supermodes creates a photon-photon resonance. For the nominally 850 nm arrays characterized, we identify the photon-photon resonance at approximately 20 GHz for operation along the coherently coupled region.