Active mid-IR emissions from rare-earth doped tellurite glass ceramics for bioapplications

Abstract

Promising bio based applications such as bloodless surgery, non-invasive blood constituents monitoring or high sensitivity tracing of green house gases could be designed starting form optically active materials working within the 2.0-2.3 μm wavelength window. For this purpose, room temperature operated high power devices are entering the market of which rare-earth (RE) doped devices hold a prominent place. But such devices are based today on 3+ rare-earth doping of thulium and holmium. Though Er has an active 2.0 μm transition to achieve broad emission bandwidth, it is usually quenched in an amorphous matrix and hence rarely reported in glasses or any other 3+ as the active ion backbone would leverage efforts and investments done in the telecom industry to non-telecom applications which would allow a quick progression. This work successfully reports the engineering of the base glass matrix to produce the key 2.0 μm emission. This was obtained by specific selection of precursors and custom-designed heat treatment of an Er doped fluorotellurite glass.