Room-temperature persistent spectral hole burning in Eu 3+-doped inorganic glasses: the mechanisms

Abstract

High-temperature persistent spectral hole burning (PSHB), up to room temperature, has been observed in a Eu 3+-doped aluminosilicate glass and in a lanthanum-aluminosilicate one. The emphasis here is on trying to understand the mechanism(s) leading to such a process and the effects due to changes in glass composition. Spontaneous refilling measurements show that at least two mechanisms, a very slow one and a faster one, are involved. The “faster” or “easy” component may correspond to a local structural rearrangement of the host and/or to photoreduction of the Eu 3+ ions. We suggest that the slow component, leading to very stable photoproducts, corresponds to transfer of an electron over a sizable distance through a multi-step process. PSHB in the lanthanum-aluminosilicate sample requires larger irradiation doses but leads to more stable spectral holes. This observation is discussed, which leads us to raise the question as to whether there should be a trade-off between easiness and stability.