Abstract: Disclosed is a laser (10) comprising a lasing cavity with a lasing medium and primary optical feedback means in the form of a facet (17) at either end of the cavity, the laser cavity defining a longitudinally extending optical path; and secondary optical feedback means formed by a plurality of refractive index perturbations (16, 22) in the laser cavity, each perturbation defining two interfaces (20, 21); characterized in that, for at least one perturbation, only one of the two interfaces contributes to optical feedback along the optical path. The present invention relaxes the lithographic tolerances for making single longitudinal mode devices and improves performance characteristics.
Type:
Grant
Filed:
January 9, 2006
Date of Patent:
March 2, 2010
Assignee:
Eblana Photonics Limited
Inventors:
John A. Patchell, Brian J. Kelly, James C. O'Gorman
Abstract: The present invention relates in general to semiconductor light emitting devices and in particular to methods of altering the spatial emission patterns of such devices. A known problem with these prior art light emitting devices (and laser diodes in general) is that their far-field emission patterns are elliptical and astigmatic in nature. The present invention addresses this problem by refractive index perurbations in the semiconductor device aligned in a direction substantially transverse to the light emission direction to achieve a desired spatial distribution of the emission.
Type:
Application
Filed:
September 5, 2005
Publication date:
August 14, 2008
Applicant:
EBLANA PHOTONICS LIMITED
Inventors:
James C. O'Gorman, Brian J. Kelly, John A. Patchell
Abstract: This invention generally relates to semiconductor devices, for example lasers and more particularly to single frequency lasers and is directed at overcoming problems associated with the manufacture of these devices. In particular, a laser device is provided formed on a substrate having a plurality of layers (1,2,3,4,5), the laser device comprising at least one waveguide (for example a ridge) established by the selective removal of sections of at least one of the layers. Wherein alignment features are provided on the device to facilitate subsequent placement.