Vertical cavity photonic crystal coupled-defect lasers for optical interconnects

Optical interconnects may play an important role in future spacecraft applications. Single mode laser sources are critical for high performance. Vertical cavity surface emitting lasers (VCSELs) are viable candidates for space-based optical interconnects. A VCSEL with a two-dimensional photonic crystal (PhC) structure has been investigated for single lateral mode operation By controlling design parameters of the photonic crystal pattern, we have produced PhC VCSELs that operate in the fundamental defect mode. The transverse modal behavior is consistent with the predictions of a theoretical model in which the etching depth dependence of the air holes of the photonic crystals is considered. Photonic crystal patterns containing two defects were also fabricated within a VCSEL. By designing effective refractive index changes in the region between the two defects via cavity shifts caused by photonic crystals, we are also able to coherently couple laser light output from the defects. ¹².