Anomalous optical dephasing in crystalline Y₂O₃: Eu³⁺

Sample dependent optical dephasing is observed for the 7F0⇔ 5D0 transition of Eu3+ in Y2O3 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 (G{cyrillic}H = 0.8 to 42 kHz), and are uncorrelated with the Eu3+ concentration. The temperature dependence of G{cyrillic}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 7F0 ⇔ 5D0 transition of a MOCVD Y2O3 film containing ≈ 2 at.% Eu3+_. We find G{cyrillic}H = 12 MHz at 1.4K, about 103 times larger than that measured in the bulk crystals, and it is also linearly dependent on temperature. © 1994.