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. 19, 2010
Filed:
Nov. 08, 2004
Naoki Hayamizu, Tokyo, JP;
Yutaka Ohki, Tokyo, JP;
Hideo Aoyagi, Tokyo, JP;
Takeshi Koiso, Sodegaura, JP;
Yuji Yamagata, Sodegaura, JP;
Kiyofumi Muro, Chiba, JP;
Naoki Hayamizu, Tokyo, JP;
Yutaka Ohki, Tokyo, JP;
Hideo Aoyagi, Tokyo, JP;
Takeshi Koiso, Sodegaura, JP;
Yuji Yamagata, Sodegaura, JP;
Kiyofumi Muro, Chiba, JP;
The Furukawa Electric Co., Ltd., Tokyo, JP;
Abstract
A laser module includes a semiconductor laser element and a feedback optical component forming an external cavity with the semiconductor laser element. Even if a ratio of a current threshold of the laser module changing according to a polarized state of returned light from the feedback optical component to a current threshold of the semiconductor laser element is in an arbitrary range within a predetermined range, a total value of a relative intensity noise occurring between a first frequency determined according to a cavity length of the external cavity and at least equal to or more than a frequency band of using a laser light and a second frequency calculated by multiplying the first frequency by a predetermined number is equal to or more than −40 dB.