This semiconductor laser device has the same structure as the conventional
broad-area type semiconductor laser device, except that both side regions
of light emission areas of active and clad layers are
two-dimensional-photonic-crystallized. The two-dimensional photonic
crystal formed on both side regions of the light emission area is the
crystal having the property that 780 nm laser light cannot be wave-guided
in a resonator direction parallel to a striped ridge within the region.
The light traveling in the direction can exist only in the light emission
area sandwiched between two photonic crystal regions, which results in
the light laterally confined by the photonic crystal region. The optical
confinement of the region suppresses the loss in the light at both edges
of the stripe serving as the boundary of the optical confinement, which
reduces the curve of wave surface and uniforms the light intensity
distributions of NFP and FFP.