| 摘要 |
PROBLEM TO BE SOLVED: To provide a group III nitride semiconductor laser element which can reduce an operating current required for obtaining an intended optical output.SOLUTION: In a group III nitride semiconductor laser element 11, a first reflection film 43a of an optical resonator is formed to have a reflectance of less than 60% and a second reflection film 43b of the optical resonator is formed to have a reflectance of 85% and over. Because of this, deterioration in oscillation characteristic due to increase in threshold current can be inhibited and the occurrence of spatial ununiformity in an optical density in the optical resonator can be prevented. When reflectances on both end faces 26, 28 are too low, the threshold current is increased due to increase in mirror loss. When reflectances on both end faces 26, 28 are too high, a laser gain is decreased due to generation of spatial ununiformity in an optical concentration in the optical resonator. Due to the occurrence of optical concentration ununiformity (spatial hole burning), not only a phenomenon where a kink is observed in I-L characteristics exists but power-light output conversion efficiency is decreased. |
