Apparatus comprising an optical gain device, and method of producing the device.

摘要

Disclosed is apparatus comprising an optically pumped optical gain device that comprises a rare earth (RE)-doped planar waveguide (12) with non-uniform dopant distribution in the core of the waveguide. The RE ions are advantageously distributed such that the ions are concentrated in a core region in which the mode intensity of both signal radiation and pump radiation is relatively high. In preferred embodiments of a single mode planar waveguide (12) according to the invention the RE ions are substantially concentrated in the central core region (122). A method of making the disclosed apparatus is also disclosed. The method involves implantation of RE ions into the core region. <IMAGE>