| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor laser using nitride based III-V compound semiconductor which can easily realize decrease of a driving voltage, stabilization in transverse mode, increase of a divergence angle of beams in the horizontal direction of a far field pattern, prevention of deterioration of laser characteristic which is to be caused by irregularity of the form of a resonator end surface, and improvement of noise characteristic. SOLUTION: In a GaN based semiconductor laser of a refractive index waveguide type in which SiO2 current constriction layers 11 absorbing no lights from a GaInN active layer 5 are formed on both sides of a ridge part 9 composed of an upper layer of a P-type AlGaN clad layer 7 and a P-type GaN contact layer 8, tapered regions 9a whose width decreases from the central part of the resonator lengthwise direction toward both ends of the resonator lengthwise direction are formed in both end parts of the ridge 9 in the resonator lengthwise direction. The central part of the ridge 9 in the resonator lengthwise direction is made a straight region 9b halving a constant width. The width W1 of both ends of the ridge 9 in the resonator lengthwise direction is made at most 3 μm. The width W2 of the central part of the ridge 9 in the resonator lengthwise direction is made at least 4 μm. |
