Study of defects in fused silica via a Franck-Condon analysis.

We present a spectroscopic study of defects in fused silica (SiO 2) samples, showing their signatures in photoluminescence (PL) excitation and emission spectra, PL decay rate, and Fourier-transform infrared and Raman spectra. Using the multi-transition Franck-Condon (FC) analysis, we were able to characterize phonon coupling with oxygen-deficient centres (ODC) in fused silica. Four observed FC emission bands, located at 2.8, 3.2, 4.2, and 4.4 eV were identified as singlet-singlet and singlet-triplet transitions in two different types of ODC defect. This model was confirmed by PL decay data and allowed us to describe different emission pathways of ODC defects. • A spectroscopic study of the defects in fused silica (SiO2) has been investigated, by measuring photoluminescence excitation and emission spectra, PL decay rate, and Fourier-transform infrared and Raman spectra. • A model based on multi-Franck–Condon (FC) progression has been used to analyze the photoluminescence (PL) spectra and to study oxygen-deficient centres (ODC) defects presented in fused silica, and their different emission pathways. • A PL decay time measurement a have been used to confirm the utility of the multi-FC progression to study the defects and track their different radiative transitions. [ABSTRACT FROM AUTHOR]