Optical absorption and multiphonon relaxation of Nd3+ ions in ZnCl2-based glass

Optical absorption and multiphonon relaxation have been investigated for Nd3+-doped ZnCl2-based glass. The intensity parameters for radiative transitions of Nd3+ were determined to be Omega(2) = 4.97 x 10(-20) cm(2), Omega(4) = 7.39 x 10(-20) cm(2) and Omega(6) = 5.12 x 10(-20) cm(2). All of the Omega(t) parameters, especially Omega(4), of Nd3+ in the ZnCl2-based glass were large compared with those reported for oxide and fluoride glasses. Multiphonon relaxation rates for three emission levels of Nd3+ were determined from lifetime measurements. The multiphonon relaxation rates in the ZnCl2-based glass were extremely low, because of the low-phonon-energy of the matrix. Values were found to obey the energy-gap law in the same manner as the values in Er3+-doped ZnCl2-based glasses. (C) 1998 American Institute of Physics.