In various aspects, a semiconductor light emitting device provided between
a first edge and a second edge opposite to the first edge and emitting
laser from the first edge, may include: a first clad layer of a first
conductivity type having a nitride semiconductor; an active layer
provided on the first clad layer and having a nitride semiconductor; a
second clad layer of a second conductivity type provided on the active
layer having a nitride semiconductor and a ridge waveguide, the ridge
waveguide having an activation region and a first edge region which is
adjacent to the activation region and is extended from the first edge in
a direction from the first edge to the second edge; an upper electrode
provided on the ridge waveguide in the activation region; and a
dielectric layer provided on a side surface of the ridge waveguide in the
activation region, wherein the ridge waveguide in the first edge region
has a lower activation ratio of a second conductivity type impurity than
the ridge waveguide in the activation region.