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. 11, 1995
Filed:
Apr. 15, 1994
David A King, Palo Alto, CA (US);
William F Carlsen, Oakhurst, CA (US);
Damien F Gray, Austin, TX (US);
Richard J Pittaro, San Carlos, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A semiconductor laser power build-up system includes a semi-conductor laser. An optical resonance cavity is defined between at least two reflective elements and has an intracavity light beam along an intracavity beam path. A return light beam, which is a portion of the intracavity light beam, is transmitted through one of the reflective elements and is coincident with but oppositely directed relative to the incident beam. The laser is wholly optically locked to the cavity and the intracavity beam passes substantially without loss within the cavity. In a preferred application, a sample is placed in the cavity and a detector is provided to sense chemicals in the sample by, for example, detecting Raman-scattered light. A wavelength-determining element such as a grating or an etalon is preferably in the incident beam path between the laser and the cavity. The reflective elements can have very low transmission losses, an emission facet of the laser can have very low reflectivity, and feedback into the laser may be strong, for example, above 3%. When the laser is a diode laser, the invention provides for driving the diode laser with a current that is less than its bare-diode threshold current.