| US 7,609,739 B2 | ||
| Semiconductor laser device | ||
| Akira Tanaka, Kanagawa-ken (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on Sep. 06, 2007, as Appl. No. 11/850,939. | ||
| Claims priority of application No. 2006-241938 (JP), filed on Sep. 06, 2006. | ||
| Prior Publication US 2008/0063019 A1, Mar. 13, 2008 | ||
| Int. Cl. H01S 5/00 (2006.01) | ||
| U.S. Cl. 372—45.01 [372/43.01] | 20 Claims |
| 1. A semiconductor laser device, comprising:
an active layer having a single or multiple quantum well structure including a well layer of InwGa1-wN (0.08≤w≤0.2) and a barrier layer of InbGa1-bN (0.01≤b≤0.05);
a cladding layer of AlyGa1-yN (0≤y≤0.1) provided on the active layer, the cladding layer including a ridge portion extending like a stripe in axial direction
of an optical cavity and a non-ridge portion located on both sides of the ridge portion; and
an overflow blocking layer of AlzGa1-zN (y<z) provided between the active layer and the cladding layer,
a thickness of D (μm) of the non-ridge portion and an axial length of L (μm) of the optical cavity satisfying formulas
L≧750−400×(D/0.01)
and
0<D≤0.01,
wherein a full width at half maximum of a horizontal far field pattern of a beam emitted from the active layer has a width
of not less than 9.2 degrees.
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