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. 14, 2011
Filed:
Mar. 07, 2008
Naoki Fujiwara, Atsugi, JP;
Hiroyuki Ishii, Atsugi, JP;
Hiromi Oohashi, Atsugi, JP;
Hiroshi Okamoto, Atsugi, JP;
Naoki Fujiwara, Atsugi, JP;
Hiroyuki Ishii, Atsugi, JP;
Hiromi Oohashi, Atsugi, JP;
Hiroshi Okamoto, Atsugi, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
An object is to provide a wavelength tunable semiconductor laser device, a controller for the same and a control method for the same, which prevent wavelength drifts. The wavelength tunable semiconductor laser device includes an active region for oscillating a laser beam, and a wavelength tuning region for shifting a wavelength of the laser beam. In this device, a thermal compensation region for converting most of the inputted electric power to heat is provided adjacent to the wavelength tuning region, and the sum of an electric power inputted into the wavelength tuning region and an electric power inputted into the thermal compensation region is always kept constant.