Photonic crystal vertical cavity surface emitting laser arrays

Coherent coupling of 2×1 photonic crystal (PhC) vertical cavity surface emitting laser (VCSEL) arrays is studied. It is found that the relative phase between lasing defects, also known as the phase angle of the complex degree of coherence, varies with injection current. The amplitude of the complex degree of coherence also depends on current. Additionally, it is shown that the magnitude of the complex degree of coherence between defects is maximized near in-phase and out-of-phase conditions.