We have observed grating-based morphological hole burning in Sm2+-doped glass powders at room temperature. When photobleaching on the 4f(6)-4f(5)5d transition Of Sm2+ is combined with multiple light scattering, holes are produced in frequency and wave-vector domains. The hole profile depends on the amount of light absorption Of Sm2+; it sharpens as the absorption decreases. The variation of the hole shape is explained theoretically based on a diffusion approximation. (C) 2003 Optical Society of America.