Design and fabrication of optical microcavities based on F 2 colour centres in lithium fluoride films

Abstract

The current search for novel materials with active optical properties has demonstrated the relevance of the emission characteristics of laser active colour centres in lithium fluoride (LiF) to design new miniaturized solid-state light sources. We adapted a simple theoretical model, based on vacuum-field modes, to calculate the angular-resolved photoemission spectra of F 2 colour centres, produced in a LiF thin film by 6 keV electron irradiation, both in free space and embedded in a symmetric planar optical microcavity constituted by two Bragg mirrors. The predictions of the theoretical model reproduced with very good accuracy the photoemission intensity distribution measured for such structures under optical pumping. The peculiar role of the spatial distribution of F 2 centres along the LiF film depth was also pointed out.