Arrayed DBR waveguide lasers for the ITU grid

We have successfully demonstrated an array of monolithic, single-frequency DBR waveguide lasers that operate near 1536 nm. Single transverse mode waveguides in the 1500 nn telecommunications band were fabricated in a commercially available phosphate glass that was codoped with 1/spl times/10/sup 20/ Er/sup 3+/ ions/cm/sup 3/ and 4/spl times/10/sup 20/ Yb/sup 3+/ ions/cm/sup 3/. Phosphate glass is a very good host compared to silica for erbium ions since the sensitization efficiency is nearly unity and large doping concentrations are possible before the onset of concentration quenching. We have performed waveguide laser simulations correlated to experimental results that indicate the Yb-Er energy transfer efficiency is greater than 95% in this glass. Waveguides are formed by potassium for sodium thermal ion-exchange. We have also used a field assisted process to form waveguides in codoped phosphate glass. Tests of thermal ion exchanged Fabry-Perot lasers without DBR gratings have shown that slope efficiencies of 28% are possible with thresholds as low as 25 mW of coupled 980 nm pump power, Similar results have been achieved using field assisted ion exchanged waveguides. We have also shown these lasers can be tuned from 1525 to 1595 nm.