We report the luminescence properties of undoped and 10% -doped nanopowders under the infrared excitation of 975-nm laser diode. A broadband white light (WL) emission is observed in the undoped powder, and its intensity becomes stronger with increasing excitation power. A blue emission centered at is observed below the excitation power of in the -doped sample. The blue emission intensity dependence on the excitation power suggests that this emission is a two-photon absorption process known as the cooperative luminescence of ions. When the excitation power is increased above 2 W, a broadband “white” emission extending from blue into the near infrared appears while the blue cooperative emission band of ions disappears. The excitation power dependence of the WL intensity at 758 nm is due to a multiphoton process that may be attributed to the thermal radiation mechanism. The International Commission on Illumination coordinates for the WL emission in the -doped nanocrystalline sample is found to be (0.4503, 0.3999) and (0.5035, 0.4096) for 2.005- and 3.68-W excitation powers, respectively. These values lie in the yellowish region and correspond to the color temperature value of 5030 K, with a color rendering index of 85.