LITTLE KNOWN FACTS ABOUT ER:YB:YAB CRYSTAL.

The nonradiative changeover premiums Adhere to the system WNR = W (0) exp(-alphap), wherever p is the amount of phonons matching the energy gap. The nonradiative changeover rates of Er3+ show temperature dependence in keeping with the multiphonon relaxation concept. In Tm3+ the temperature dependence of nonradiative rest premiums is complicated thr