Time resolved photoluminescence (PL) has been performed on Ge-doped silica preform in the temperature range 10 to 295 K. Under pulsed KrF laser (5 eV) the well known c~ and [3 emissions have been recorded at different delays from excitation. An accurate analysis of the time resolved spectra taken at different temperatures has shown the composite property of the two PL structures. At room temperature cx components (c~ ], ~2) are peaked at 4.09 and 4.26 eV with a decay time of about 10 ns. The peak energies of [3j and 132 components are calculated at 3.03 and 3.21 eV with lifetimes of 111 and 94 ~s, respectively. As temperature is decreased, a l and o~ 2 display the normal behaviour increasing in intensity down to 125 K; on the contrary, in the same temperature range, 13 n and [32 undergo a quenching of their intensities. Taking into account their mutual spectral characteristics, ~ has been correlated to [31 and c~ 2 to [32. The two sets of emission bands are tentatively attributed to a single center stabilized in different environments of the glassy matrix.
Low temperature time resolved photoluminescence of the 3.1 and 4.2 eV emission bands in Ge-doped silica
ANEDDA, ALBERTO;CARBONARO, CARLO MARIA;CORPINO, RICCARDO;
1997-01-01
Abstract
Time resolved photoluminescence (PL) has been performed on Ge-doped silica preform in the temperature range 10 to 295 K. Under pulsed KrF laser (5 eV) the well known c~ and [3 emissions have been recorded at different delays from excitation. An accurate analysis of the time resolved spectra taken at different temperatures has shown the composite property of the two PL structures. At room temperature cx components (c~ ], ~2) are peaked at 4.09 and 4.26 eV with a decay time of about 10 ns. The peak energies of [3j and 132 components are calculated at 3.03 and 3.21 eV with lifetimes of 111 and 94 ~s, respectively. As temperature is decreased, a l and o~ 2 display the normal behaviour increasing in intensity down to 125 K; on the contrary, in the same temperature range, 13 n and [32 undergo a quenching of their intensities. Taking into account their mutual spectral characteristics, ~ has been correlated to [31 and c~ 2 to [32. The two sets of emission bands are tentatively attributed to a single center stabilized in different environments of the glassy matrix.
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