Spectroscopic properties and frequency upconversion of Er3+-doped 0.8CaSiO3–0.2Ca3(PO4)2 eutectic glass

In this work we report the spectroscopic properties of the infrared emission at 1.5 μm and the infrared to visible upconversion processes in Er3+-doped glasses with the 0.8CaSiO3–0.2Ca3(PO4)2 eutectic composition. Intense upconversion green emissions at 529 and 550 nm have been observed under infrared excitation at 800 nm in the 4I9/2 level and attributed to a two photon upconversion process. The possible excitation mechanisms responsible for this upconversion luminescence are discussed in terms of excitation spectrum and time evolution of the upconverted luminescence. The time evolution of the green emission from the 4S3/2 level indicates that an ETU process is responsible for the upconversion luminescence.This work has been supported by the Spanish Government (Ref.: MAT2005-06508-C02-02) and the Basque Country Government (IT-331-07).Peer reviewe