TIME-RESOLVED SPECTROSCOPY OF NI-DOPED FLUOROZIRCONATE GLASSES

Optical absorption, time-resolved luminescence and fluorescence decay measurements of Ni2+-doped fluorozirconate glasses are reported. Time-resolved luminescence measurements have been taken exciting the samples at different wavelengths. The position of the green emission band (the 1T2g(D) --> 3A2g(F) transition) moves slightly to the blue when the excitation is changed to higher energies. For a fixed excitation wavelength, the emission moves also to the blue when the time of measurement after the laser pulse increases. The fluorescence decays are non-exponential and depend on the detection wavelength. They are slower for the shorter detection wavelengths. The results show a distribution of Ni2+ sites with different 'crystal field' environments.