Observation of ⁴F_3/2→⁴I_15/2 radiative transition in Nd³⁺ ions in GaLaS glass using frequency‐resolved PL spectroscopy

Abstract

The photoluminescence (PL) emission band corresponding to 4F3/2→4I15/2 transition has been revealed using a double lock‐in technique and quadrature frequency resolved spectroscopy (QFRS) at room temperature in Nd3+ in a GaLaS glass. The band is centred around 1840 nm and has a lifetime ∼77 μs, which seems to be the same for all four radiative transitions 4F3/2→4IJ (J = 9/2, 11/2, 13/2 and 15/2). The branching ratios βJ of the four above transitions have been estimated from the PL data and agree well with the results of Judd‐Ofelt (JO) analysis. In addition to the 1840 nm band, we have observed another PL band appearing around 1580 nm and having a dominant lifetime ∼3.8 μs. This band may be identified with the radiative transition from the doublet (4F5/2, 2H9/2) to the 4I15/2 manifold. The short lifetime ∼3.8 μs may be caused by effective multiphonon relaxation from the doublet to the 4F3/2 manifold. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Reappraising the Luminescence Lifetime Distributions in Silicon Nanocrystals

“…The QFRS method is rather sparsely reported in the literature, mainly limited to a few studies of rare-earth-doped glasses [ 26 – 28 ] and amorphous silicon [ 29 – 31 ]. The basis of the technique is to excite the sample with a sine-wave-modulated pump beam of angular frequency ω and to measure the phase and amplitude of the luminescence as it attempts to track the excitation.…”