A typical optical power meter consists of a calibrated sensor, a measuring amplifier and a display. In this article, learn: What is an optical power meter? An optical power meter (OPM) measures the power levels of light signals in devices that transmit data or power using. An optical power meter (OPM) is a device used to measure the power in an optical signal. Other general purpose light power measuring devices are usually called radiometers, photometers, laser power. Below are general answers on typical components of an optical power meter product from the list of GAO Tek's optical power meter.