<title>Nd<formula><sup><roman>3+</roman></sup></formula>-doped sol-gel glasses: enhanced fluorescence lifetime by Al-codoping and CO<formula><inf><roman>2</roman></inf></formula>-laser processing</title>

The influence of aluminum co-doping and CO₂-laser processing on the fluorescence lifetime of neodymium doped sol-gel derived silica glasses has been studied. 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 depending on different methods of thermal annealing and host material modification. We show that neodymium doped sol-gel derived silica glasses, modified with aluminum and treated with a CO₂-laser exhibit a fluorescence lifetime of several hudnred microseconds at high dopant concentrations (e.g. 280±6μs for a Nd³⁺-concentration of 1.1×10²¹ cm^-3).