Luminescence-induced photorefractive spatial solitons

We report the observation of spatial confinement of a pump beam into a photorefractive solitonic channel induced by luminescence (luminescence induced spatial soliton , LISS). Trapped beams have been obtained in erbium doped lithium niobate crystals at concentrations as high as 0.7 mol % of erbium. By pumping at 980 nm, erbium ions emit photons at 550 nm by two-step absorption, wavelength which can be absorbed by lithium niobate and originates the photorefractive effect. The luminescence at 550 nm generates at the same time the solitonic channel and the background illumination reaching a steady-state soliton regime.