This specification discloses a VCSEL (Vertical-Cavity Surface-Emitting
Laser) device with single-mode output and optionally single polarization
output. This device is given by lateral mode confinement by the PBG
(Photonic Band-Gap) effect by shallow etching in a partial VCSEL top
mirror. The PBG area encircles a MS-region (Mode-Shaping region), which
is characterized by large longitudinal mode losses. The MS-region
encircles the LA-region (Light Aperture region), which is characterised
by low longitudinal mode losses. The MS-region does not contribute to the
lateral mode-confinement to the LA-aperture, and the lateral modes
confined by the PBG area. The VCSEL is thus optimized for single
fundamental mode operation.