Semiconductor light emitting device

A semiconductor light emitting device comprising a first cladding layer of a first conductivity type, an active layer formed on the first cladding layer, and a second cladding layer of a second conductivity type formed on the active layer, having a center portion of the second cladding layer forming a ridge structure, and comprising a stripe-shaped current injection structure, wherein:

• the second ridge structure is formed on the second cladding layer on at the two sides of the stripe portion formed on the second cladding layer via a ridge separation portion formed with a thickness of the stacking direction of the first cladding layer, active layer, and second cladding layer thinner than that of the ridge structure,
• the waveguide stripe width at the center is constant, and
• the width in the direction perpendicular to the stacking direction of the ridge separation portion is set so as to be narrow at the center portion in the resonator direction and broader than that at the center portion near the end surface.

A semiconductor light emitting device comprising a first cladding layer of a first conductivity type, an active layer formed on the first cladding layer, and a second cladding layer of a second conductivity type formed on the active layer, having a center portion of the second cladding layer forming a ridge structure, and comprising a stripe-shaped current injection structure, wherein:

• the second ridge structure is formed on the second cladding layer at the two sides of the stripe portion formed on the second cladding layer via the ridge separation portion formed with a thickness in the stacking direction of the first cladding layer, active layer, and second cladding layer thinner than that of the ridge structure,
• the waveguide stripe width at the center is constant, and
• the width in the direction perpendicular to the stacking direction of the ridge separation portion is set so as to be wide at the center portion in the resonator direction and narrower than that at the center portion near the end surface.

A semiconductor light emitting device comprising a first cladding layer of a first conductivity type, an active layer formed on the first cladding layer, and a second cladding layer of a second conductivity type formed on the active layer, having a center portion of the second cladding layer forming a ridge structure and comprising a stripe-shaped current injection structure, wherein:

• a waveguide mechanism comprises an index guide area formed at one of a position near a light emitting front end surface for emitting a laser beam and a position near a rear end surface and having a built-in refractive index difference for the waveguide in a lateral direction perpendicular to a resonator length direction and a gain guide area formed in the region except the index guide area and not having the built-in refractive index difference.