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:
Feb. 09, 1993
Filed:
Feb. 18, 1992
David F Welch, San Jose, CA (US);
Robert G Waarts, Palo Alto, CA (US);
Spectra Diode Laboratories, Inc., San Jose, CA (US);
Abstract
Arrangements for efficiently coupling light between a laser diode and a second-harmonic generator which feature external resonant cavities that include a feedback grating fabricated on the second-harmonic generator. The feedback grating reflects light of a first frequency that matches the frequency doubling band of the second-harmonic generator, thereby establishing stable laser oscillation at that first frequency. Preferably, the second-harmonic generator has a periodically-poled waveguide formed in the surface of the nonlinear material body. The laser diode may be butted against the harmonic generator or coupling optics may be positioned between the two. In one arrangement, a polarizer is placed in the resonant cavity, either between an external back reflector and the back facet of the laser diode or between the antireflection coated front facet of the laser diode and the harmonic generator, to provide loss to the TE polarization mode and enhance oscillation in the TM polarization mode. In another arrangement, a half-wave plate is positioned between the antireflection coated front facet of the laser diode and the input end of the harmonic generator to cause TE mode oscillation in the laser diode, while coupling TM polarized light into the harmonic generator. The laser diode may be a monolithic laser diode array with multiple emitters, with the second-harmonic generator having multiple waveguides for receiving and doubling the frequency of light received from a corresponding diode emitter. The diode array may be a multiple wavelength array.