| 摘要 |
PROBLEM TO BE SOLVED: To make a void small to prevent the absorption of laser light. SOLUTION: In a p-GaAs cap layer 38, a width W3 of its upper surface is made smaller than a width W2 of its lower surface in sectional shape. Furthermore, the width W2 and a width W1 of the upper surface of a mesa part 41 have a relation of W1<W2<W1×2.5, and A height H of the mesa part 41, W1 and W2 have a relation of 0<(W2-W1)/2<0.8×H, and a width of a canopy part 42 represented by (W2-W1)/2 is sufficiently made smaller as compared with W1 and H. Therefore, when forming an n-AlGaAs current block layer 43, an air under the canopy part 42 can escape upward as the current block layer 43 grows, and a void 49 produced under the canopy part 42 can be significantly made small. As a result, a laser light rising within the void 49 is prevented from being absorbed, and especially differential efficiency can be improved in a high output oscillation area of 50 mW or more, reducing both driving current and operation voltage.
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