Polarisation asymmetric active optical waveguide, method of its

Abstract

A method of producing an active optical waveguide having asymmetric polarization, said method comprising the steps of (a) providing an active optical waveguide (10) comprising: (i) a transverse refractive index profile (21) comprising a guiding region (11), an intermediate region (13), and a non-guiding region (12); (ii) a transverse photorefractive dopant profile (31) comprising a constant or graded photorefractive dopant concentration within at least one of the guiding, non-guiding and intermediate regions, except that the photorefractive dopant is not located solely in the guiding region; and (iii) exhibiting in said guiding region, intermediate region, or both, light guiding modes having different polarizations; and (b) exposing at least a part (10a, 10b) of the active optical waveguide to an effective transverse illumination of light (20) reacting with the photorefractive dopant and modifying said transverse refractive index profile; said part of the active optical waveguide being exposed to a fluence selectively suppressing the propagation of the light guiding modes having different polarizations so that the propagation of one mode is less suppressed than the propagation of the other mode(s). Such an active optical waveguide, single polarization mode optical waveguide lasers and multi-wavelength single polarization mode optical waveguide lasers comprising such an active optical waveguide, methods of their production, and their uses in telecommunications, in spectroscopy, in sensors and in absolute calibrated laser light sources.