Edge emitting laser device

Abstract

An edge emitting laser (EEL) device includes a substrate, an n-type buffer layer, a first n-type cladding layer, a grating layer, a spacer layer, a lower confinement unit, an active layer, an upper confinement unit, a p-type cladding layer, a tunnel junction layer and a second n-type cladding layer sequentially arranged from bottom to top. The tunnel junction layer can stop an etching process from continuing to form the second n-type cladding layer into a predetermined ridge structure and converting a part of the p-type cladding layer into the n-type cladding layer to reduce series resistance of the EEL device. Therefore, the optical field and active layer tend to be coupled at the middle of the active layer, the lower half of the active layer can be utilized effectively, and the optical field is near to the grating layer to achieve better optical field/grating coupling efficiency and lower threshold current.

Dependencies are inferred from the claim text.