This paper presents a new method of laser-stimulated oxidation of a porous silicon layer with pore sizes of 5-10 nm that uses the strong-absorption effect of radiation by a semiconductor. The results of a study of the optical properties of a thin film of laser-oxidized porous silicon of various morphologies, doped with erbium or ytterbium ions, are presented. The transmittance of the layer of interest in the wavelength range from 1.2 to 2.0 μm was at least 66%.