A narrow band, green-red colour centre laser in LiF fabricated by femtosecond laser pulses

Recent advances in high-intensity femtosecond (fs) laser pulses have made it possible to encode non-erasable functional micro-structures inside almost any type of photo-insensitive transparent materials. We focus our attention on bulk lithium fluoride (LiF) because of its broad emission band from the green-to-red spectral range under excitation of a single absorption band at about 450 nm. Here a room temperature, visible laser action in LiF from a distributed-feedback laser with embedded fine-pitched gratings written by fs pulses and from a laser-active colour centre laser with multilayer dielectric mirrors has been demonstrated. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.