Multi-point defect single-fundamental-mode photonic crystal vertical cavity surface emitting laser

A seven-point-defect photonic crystal (PhC) vertical cavity surface emitting laser (VCSEL) operating with high single-fundamental-mode of 2.3 mW and low threshold current of 1.2 mA was demonstrated and its performance was analyzed. The single-fundamental-mode emission aperture (central defect area) was enlarged to achieve high output power. Furthermore, suitable refractive index step due to the photonic crystal structure was obtained to overcome the external index perturbations, which can be attributed to stable single-fundamental-mode operation even at saturation current. The transverse mode confinement characteristics by photonic crystal was analyzed based on the effective index model and showed good agreement with the experiment results.

► Seven-point-defect PhC-VCSEL operating at 2.3 mW and low threshold current of 1.2 mA in single-fundamental-mode was fabricated.
► Single mode emission aperture was enlarged.
► Suitable refractive index reduction was obtained to overcome the external index perturbations.
► Stable single-fundamental-mode operation was obtained even at saturation current.
► The transverse mode confinement characteristics were analyzed based on the effective index model.