New perspectives of coloured LiF for optoelectronic devices

Colour centre lasers (CCL) based on LiF crystals have been operating at room temperature (RT) in the visible and in the near infrared since many years. On the other hand little is known about LIF films treated by low energy electrons, which are promising candidates for the realisation of miniaturised broad band active optical devices, like waveguide and microcavity amplifiers and lasers. The high concentration of defects produced in these optically confined active structures does not seem to affect appreciably the numerical value of the gain coefficients, although complex mechanisms of losses should be taken into account. Interactions among several types of defects in extremely coloured samples should be further investigated in crystals and films. The formation of different kind of centres could be controlled by a careful choice of irradiation conditions and growth parameters in the polycrystalline films. (C) 2001 Elsevier Science B.V. All rights reserved.