A LASER

摘要

A laser comprising first and second feedback elements defining a laser cavit y, and a gain medium within the laser cavity, the gain medium having first and second facets (5, 6) and an optical waveguide (8) for guiding optical radiation between said first and second facets, wherein the second feedback element is wavelength selective, and the optical waveguide (8) is configured to direct optical radiation at an angle .theta. to the normal of the second facet (6).