Parametric study of proton-implanted photonic crystal vertical-cavity surface-emitting lasers

Photonic crystals with single- and seven-point defects are used to achieve single-fundamental-mode operation of proton-implanted vertical-cavity surface-emitting lasers. The holes are etched at a variety of depths for various photonic crystal designs to investigate the influence on single-mode emission. Because proton-implantation provides weak transverse confinement in the form of thermal lensing, selective loss is not required to suppress lasing of extended photonic crystal modes. We show that etching the photonic crystals to shallow depths provides the ability to scale to large aperture sizes, while etching deeply allows single-mode emission of small diameter devices. Optimized designs exhibit a net reduction in loss relative to unetched control devices, as evidenced by a reduction in device threshold current.