V

VCSEL (vertical cavity surface emitting laser)

Semiconductor lasers usually resonate light in a direction parallel to the substrate surface and emit the light in that direction. In VCSEL however, light resonates in a direction perpendicular to the substrate surface and is emitted perpendicular to the substrate. Therefore, the resonant cavity can be formed and laser characteristics can be tested without cleaving the substrate during the manufacturing process. This fact makes VCSEL suitable for high volume production. Compared to edge-emitting lasers, VCSEL can be manufactured at a lower cost and can be easily arrayed in two dimensions. Other features include low threshold current, high-speed modulation at low current, and small temperature dependence.