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:
Jul. 18, 1995
Filed:
Oct. 08, 1993
Julie E Fouquet, San Carlos, CA (US);
David M Braun, Santa Rosa, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
The invention increases the tuning range of a laser by altering the output coupler reflectivity. In a first embodiment of the invention, the tuning range of an external cavity laser is increased by applying a substantially spectrally flat reflective coating to the front facet of a semiconductor laser which has higher reflectivity than the uncoated front facet. In addition to increasing the tuning range, the increased reflectivity of the front facet reduces the laser threshold current for all laser wavelengths. In a second embodiment of the invention, various complex coatings were applied to the output coupler to generate reflective characteristics that change according to wavelength. The complex coatings enhance reflectance at the edges of the laser tuning curve without adversely affecting the output power at the center wavelengths. This further increases the tuning range of the laser while simultaneously maintaining high output power for each selected output wavelength.