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:
Sep. 30, 2003
Filed:
Mar. 14, 2001
Makoto Okada, Ichikawa, JP;
Koichi Gen-Ei, Ichikawa, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A monolithic two-wavelength semiconductor laser device includes a front end face film on a resonator front end face , and a high-reflectivity end face film as a multilayered film on a resonator rear end face . The front end face film is formed using a low-refractive-index material, and the film thickness is so set that the reflectivity is 20%. The high-reflectivity end face film is formed by alternately stacking thin films of low- and high-refractive-index materials, and the film thickness is so set that the reflectivity is 80%. The film thickness of each of these two end face films is calculated by an optical length d=(¼+j)×&lgr;m by using a mean value &lgr;m=(&lgr;1+&lgr;2)/2 of the oscillation wavelengths of the two semiconductor laser diodes. This makes it possible to obtain an end face film having a desired reflectivity and capable of being formed at once, and to fabricate a two-wavelength semiconductor laser device having high reliability, meeting the required performance, and also having high productivity.