The output power of incoherent light sources can be measured using power meters or radiometers, which can quantify the total power or the power density of the emitted light. The measurement can be done either directly, by placing the sensor in the path of the light beam, or indirectly, by measuring the irradiance or illuminance of the light on a surface of known area. The output power of incoherent sources can vary depending on the input power, the efficiency of the light-generating process, and the losses in the optical system. The measurement of the output power of incoherent sources is important for applications such as photometry, radiometry, and laser safety.