| 摘要 |
PROBLEM TO BE SOLVED: To reduce a variation in a time and spacial lateral mode caused by a large variation of current distribution from a change in temperature, modulation and the like, and to restrict mode noise caused by the difference of transmission characteristics for each mode at a high-speed signal transmission time. SOLUTION: This vertical cavity type surface emitting laser element for generating a laser beam along a laminated direction includes a first DBR reflective mirror 2, a light emitting region layer 4 containing an active layer, a transparent buffer layer 5, and a second DBR reflective mirror 7 on a semiconductor substrate 1. The active layer 4-1 has an optical gain capable of laser oscillation and a concentric circular structure which is separated by an inactive layer 4-2 with non-light emission or a low optical gain. The buffer layer 5 is set to a thickness for separating 0-th diffracted light and primary diffracted light spatially for diffracted light in a concentric circular structure. The second reflective mirror 7 is selectively set to a range for reflecting the 0-th diffracted light and not reflecting higher order diffracted light. COPYRIGHT: (C)2004,JPO
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