Fluorescence lifetime enhancement of Nd3+-doped sol–gel glasses by Al-codoping and CO2-laser processing

We studied the effect of aluminum co-doping and CO2-laser treatment on the fluorescence lifetime of neodymium-doped sol–gel derived silica with respect to the enhancement of the dopant’s fluorescence lifetime. The combination of host material modification and thermal treatment offers a possibility to overcome the limitations set on the fluorescence lifetime of Nd3+-doped silica by clustering, concentration quenching, and phonon quenching. Our study focuses on the fluorescing behavior of the produced samples contingent on different methods of thermal annealing and host material modification. We show that neodymium doped sol–gel derived silica glasses, co-doped with aluminum and treated with a CO2-laser exhibit a fluorescence lifetime of several hundred microseconds even at high dopant concentrations (e.g. 280 ± 6 μs for a Nd3+-concentration of 1.1 × 1021 cm−3).