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:
Aug. 20, 1991
Filed:
Apr. 25, 1989
Kabushiki Kaisha Topcon, Tokyo, JP;
Abstract
An output power and wavelength stabilizing apparatus of a semiconductor laser has an injection current supplying source adapted to supply injection current to a single-mode semiconductor laser, a first light receiving portion adapted to receive a part of the output power of the semiconductor laser through a first optical element with varying spectral characteristics in the wavelength area of the semiconductor laser and to output a first signal, a second light receiving portion adapted to receive a part of the output power of the semiconductor laser through a second optical element with varying spectral characteristics opposite to that of the first optical element and to output a second signal, a wavelength fluctuation detecting portion for producing a difference signal related to the first signal and the second signal and obtaining a fluctuation of the wavelength of the semiconductor laser based on the difference signal, an output fluctuation detecting portion for producing a signal related to the sum of the first and the second signals and obtaining the fluctuation of output power of the semiconductor laser based on the sum signal, and a temperature control portion for controlling the temperature of the semiconductor laser to a predetermined operating temperature based on the fluctuation of the output power of the semiconductor laser obtained by the output power fluctuation detecting portion so that the output power of the semiconductor laser can be maintained constant. The injection current supplying source is used to control the wavelength of the semiconductor laser based on the fluctuation of the wavelength of the semiconductor laser obtained by the wavelength fluctuation detecting portion such that the wavelength remains constant.