Anomalous optical dephasing in crystalline Y 2O 3: Eu 3+

Abstract

Sample dependent optical dephasing is observed for the 7F 0⇔ 5D 0 transition of Eu 3+ in Y 2O 3 crystals prepared by flame fusion, arc imaging and laser heated pedestal growth techniques. Two pulse photon echo measurements at 1.4K show that the homogeneous line widths over nearly two orders of magnitude in them different samples (Г H = 0.8 to 42 kHz), and are uncorrelated with the Eu 3+ concentration. The temperature dependence of Г H is nearly linear in temperature (1-12 K), similar to that observed for disordered systems. The measured line widths may be associated with limited disorder in the crystalline state. We also report on the line width of optical holes burned in the 7F 0 ⇔ 5D 0 transition of a MOCVD Y 2O 3 film containing ≈ 2 at.% Eu 3+_. We find Г H = 12 MHz at 1.4K, about 10 3 times larger than that measured in the bulk crystals, and it is also linearly dependent on temperature.