An optical power meter gauges the light intensity of an optical signal. It is used to measure energy loss during transmission, monitor laser power in the generation of an optical signal, and assess the electronics of a signal receiver.
Optical power meters are typically composed of a photodiode, or photodetector, that transforms light into an electric current, an amplifier that transforms the current into voltage, and a converter that changes the voltage into a digital signal. Most optical power meters rely on semiconductor detectors, such as silicon, indium-gallium-arsenide and germanium, because of their sensitivity to light at wavelengths frequently used in fiber optics.