Optical spectroscopy of trivalent chromium in sol-gel lithium niobate

Abstract

We report on the characterization of sol-gel derived lithium niobate via trivalent chromium probe ions, a study that is motivated by recent reports on the synthesis of high quality sol-gel lithium niobate (LiNbO${}_3$). In order to assess the quality of sol-gel derived LiNbO${}_3$, we incorporate Cr${}^{3+}$ during the hydrolysis stage of the sol-gel process. A comparison of the Cr${}^{3+}$ emission and photo-excitation data on both sol-gel and melt-grown LiNbO${}_3$ shows that the sol-gel derived material is highly stoichiometric.