Resolve the charge-transfer excitation spectrum

Resolve the detailed charge-transfer excitation spectrum in Yb-containing oxides and determine whether representing its lowest contribution by a single effective charge-transfer state accurately describes the reverse-parametric-fluorescence source amplitude.

Background

The source calculation represents the broad charge-transfer absorption band of YbAlO3 by a single effective state at 5.5 eV. This state supplies the virtual intermediate level for both electric-dipole couplings.

Because the detailed charge-transfer level structure has not been resolved, the effective-state approximation may conceal multiple poles, linewidths, and interference effects. Spectroscopic resolution of the charge-transfer manifold is therefore needed to establish the validity and accuracy of the microscopic source estimate.