Role of alkali ions on persistent hole burning in Pr^3+-doped germanate glasses

The effect of a Na2O network modifier on the persistent spectral hole burning of Pr^3+ ions has been investigated in (GeO2)1 – x-(Na2O)x glasses for x=0-0.35. The homogeneous linewidth increased twice by adding 35 mol% Na2O. The hole burning efficiency was found to increase about 8 times by adding the same amount of Na2O. These observations are interpreted by considering coupling of the optical centers with the TLS introduced by Na2O doping.

T. Suemoto, M. Namiki1 and K. Koyama
Institute for Solid State Physics, The University of Tokyo, Roppongi, Minato-ku, Tokyo 106, Japan