PHOTON GATED HOLE BURNING IN THE ⁷F₀ ? ⁵D₂ ABSORPTION OF BaCIF : Sm²⁺

Abstract
Spectral hole burning in solids is a selective bleaching of a small portion of an inhomogeneously broadened optical transition by a laser. In the photon gated holeburning process spectral holes are burned in two steps. The first is provided by a narrow band laser resonant with the inhomogeneously broadened transition and the second (gating) can be initiated by a broad band light source. Photon gated spectral hole burning was reported recently in ⁷F₀→⁵D₀ and ⁷F₀→⁵D₁ absorption lines of Sm²⁺ in BaClF⁽¹⁾. In this poster we report on the spectral holeburning behaviour of ¹F₀→⁵D₂ transition. We found that even in absence of additional light source for gating, permanent holes can be burned. This self gating behaviour is consistent with the observation that the optimum frequency following ⁵D₀ excitation is ≈ 22 000cm^-1 so that two photons of energy ⁵D₂ - ⁷F₀ are sufficient to produce photoionisation. We have analysed the light intensity dependance of hole area and a simple model indicate that the electron transfer following the photoionisation is strongly dependant on the ion - electron trap distance.