Theoretical study of population inversion in active doped MIR chalcogenide glass fibre lasers (invited).

S Sujecki,K Scholle,Z Tang,A Oladeji,E Barney,T M Benson,A Phillips,D Furniss,Ł Sójka,P Furberg,S Lamrini,E Bereś-Pawlik,H Sakr,A B Seddon

doi:10.1007/s11082-014-0086-x

Abstract

We study the mechanism of the population inversion in mid-infrared fibre lasers based on a chalcogenide glass host doped with active lanthanide ions. Three lanthanide dopant ions are considered: terbium, dysprosium and praseodymium. We predict the relevant trivalent ion level populations and gain. The simulation parameters were obtained by fabricating and optically characterising a series of trivalent ion doped chalcogenide glass samples. We also provide simple analytical expressions that aid the design of the cascade lasing process.

Highlights

Mid-infrared (MIR) coherent light sources find application in medicine, environmental monitoring, the pharmaceutical industry and defence (Seddon 2011; Steinmeyer and Skibina 2014)
Core-clad, lanthanide-doped chalcogenide glass fibres (Sojka et al 2014), including small-core (Tang et al 2014) have been recently demonstrated various active lanthanide ions have been considered for the realisation of MIR fibre lasers (Shaw et al 2001; Sojka et al 2012)
The population inversion for the idler wave in the case of Pr3+ doped glass cannot be achieved since β32 ×τ3 < τ21

Summary

Introduction

Mid-infrared (MIR) coherent light sources find application in medicine, environmental monitoring, the pharmaceutical industry and defence (Seddon 2011; Steinmeyer and Skibina 2014). Lanthanide-doped fibre lasers are well established in the visible and near-infrared part of the optical spectrum These sources rely on the classical three and four level pumping scheme. For reaching wavelengths significantly longer than 2 μm, other host glass materials need to be applied This is necessary due to the large phonon energy of silica-glass. The most promising glass host for the realisation of longer wavelength MIR fibre lasers appears to be the chalcogenide glasses. Core-clad, lanthanide-doped chalcogenide glass fibres (Sojka et al 2014), including small-core (Tang et al 2014) have been recently demonstrated various active lanthanide ions have been considered for the realisation of MIR fibre lasers (Shaw et al 2001; Sojka et al 2012). We define the theoretical conditions of lasing in MIR spectral range

Theory

Results

Conclusions