Active stripe waveguides produced by electron beam lithography in LiF single crystals

Photo-luminescent colored stripes have been fabricated by electron beam lithography in lithium fluoride crystals, and their guiding properties are demonstrated for the first time. An increase of refractive index ?n larger than 5 × 10-3, suitable for light confinement, was achieved by irradiation with a 12 keV electron beam. This single-step process, that induces at the same time the waveguiding structure and the photo-luminescent color centers, offers good perspectives for the development of color-center integrated optical lasers tunable in the visible.