The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 1994
Filed:
Dec. 01, 1992
Kimio Shigihara, Itami, JP;
Toshitaka Aoyagi, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor optical device includes a semiconductor laser having an effective refractive index n.sub.c, a first film having a refractive index n.sub.1 and a thickness d.sub.1, a second film having a refractive index n.sub.2 and a thickness d.sub.2, and a third film having a refractive index n.sub.3 and a thickness d.sub.3. The first to third films are successively disposed on a facet of the semiconductor laser. In this structure, the refractive indices and thicknesses of the first to third films are determined so that a characteristic matrix Xa of the three films is equal to a characteristic matrix Y of a single film whose refractive index n.sub.f is the square root of the effective refractive index n.sub.c of the semiconductor laser and whose thickness is obtained by dividing an oscillation wavelength .lambda. of the semiconductor laser by 4n.sub.f as represented by the following equation ##EQU1## where .phi.1=2.pi.n.sub.1 d.sub.1 /.lambda., .phi.2=2.pi.n.sub.2 d.sub.2 /.lambda., and .phi.3=2.pi.n.sub.3 d.sub.3 /.lambda.. Therefore, a non-reflection film having no reflectivity at the oscillation wavelength of the semiconductor laser is attained, and the production of the non-reflection film is simplified.