Abstract: An apparatus and method is provided for irradiating a portion of a patient's scalp with light. The apparatus includes a source of light including one or more wavelengths in a range of about 630 nanometers to about 1064 nanometers. The apparatus further includes an output optical element in optical communication with the source. The output optical element includes an emission surface configured to emit a light beam having a cross-sectional area greater than about 2 cm2 at the emission surface of the output optical element and having a time-averaged irradiance in a range of about 10 mW/cm2 to about 10 W/cm2 across the cross-sectional area. The apparatus further includes a thermally conductive portion configured to be placed in thermal communication with the irradiated portion of the patient's scalp and to remove heat from the irradiated portion of the patient's scalp at a rate in a range of about 0.1 Watt to about 5 Watts.