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:
Jun. 18, 2002
Filed:
Nov. 23, 1999
Keisuke Asami, Tokyo, JP;
Ando Electric Co., Ltd., Tokyo, JP;
Abstract
An external cavity type light source which has a semiconductor laser ( ) coated on one end ( ) with a reflection prevention film ( A), wherein emitted light from the end face of the semiconductor laser 1 on the reflection prevention film side is converted into collimated light and the collimated light having a wavelength selected through a diffraction grating ( ) is fed back into the semiconductor laser ( ), and wherein emitted light from an opposite end ( ) of the semiconductor laser ( ) is converted into collimated light and the collimated light is gathered and output to an optical fiber ( ). An unpolarized light splitter (light branch element) ( ) is placed between the diffraction grating ( ) and the semiconductor laser ( ), and the diffracted light fed back into the semiconductor laser from the diffraction grating is made to branch through the unpolarized light splitter ( ) and one branch light is taken out as output light through an optical fiber ( ).