| US 7,577,173 B2 | ||
| Semiconductor laser device having a low reflection film of stable reflectance | ||
| Kazushige Kawasaki, Tokyo (Japan); Yasuyuki Nakagawa, Tokyo (Japan); and Hiromasu Matsuoka, Hyogo (Japan) | ||
| Assigned to Mitsubishi Electric Corporation, Tokyo (Japan) | ||
| Filed on Nov. 13, 2007, as Appl. No. 11/938,845. | ||
| Claims priority of application No. 2007-045253 (JP), filed on Feb. 26, 2007. | ||
| Prior Publication US 2008/0205468 A1, Aug. 28, 2008 | ||
| Int. Cl. H01S 5/00 (2006.01) | ||
| U.S. Cl. 372—43.01 [372/49.01] | 4 Claims |
| 1. A semiconductor laser device comprising:
a GaN substrate;
a semiconductor layer laminated on said GaN substrate;
a resonator having front and rear facets which are in face-to-face relation to each other in a direction perpendicular to
said semiconductor layer laminated on said GaN substrate; and
a reflection film on said front facet of said semiconductor laser device from which laser light generated within said semiconductor
laser is emitted, wherein said reflection film
has a reflectance within a range of 5-17% at an oscillation wavelength λ of the laser light generated within said semiconductor
laser device,
includes an even number of alternating first and second dielectric films of respective different materials, laminated from
said front facet of said semiconductor laser device,
includes a total number of said first and second dielectric films not less than four,
each of said first dielectric films has a refractive index and thickness of, respectively, n and d, each of said second dielectric
films has a refractive index and thickness of, respectively, n′ and d′, and (nd+n′d′) is within a range of pλ/4±10%, wherein
p is an integer, and
the dielectric constant n of said first dielectric film is larger than the dielectric constant n′ of said second dielectric
film.
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