1.3-/spl mu/m emission of Nd:LaF/sub 3/ thin films grown by molecular beam epitaxy

摘要

The 1.3-/spl mu/m emission of Nd/sup 3+/-doped LaF/sub 3/ thin films grown on LaF/sub 3/ and CaF/sub 2/ [111] substrates by molecular beam epitaxy is reported. The waveguide behavior of the heteroepitaxial layers has been demonstrated and the refractive indexes measured. Guided spectra have been obtained from these layers using a prism-coupling technique. The 1.3-/spl mu/m emission corresponding to the 4F/sub 3/2//spl rarr//sup 4/I/sub 3/2/ transition has been characterized as a function of Nd/sup 3+/ concentration and temperature. The relative efficiencies of different excitation bands were compared. The optimum concentration for Nd/sup 3+/ dopant has been found to be about 1 at.%. A narrowing of the emission lines is observed in the homoepitaxial layers compared to the heteroepitaxial layers. The decay of the luminescence of the /sup 4/F/sub 3/2/ level measured at room temperature is similar for homoepitaxial and heteroepitaxial layers.