This unit is designed for optical power measurement in FTTH and other passive optical networks (BPON, EPON, GPON) that use 1490 nm to downstream data and 1550 nm to downstream video. 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. FS offers a range of fibre optic power meter, choose from a variety of cost-effective optical power meters. TIA standard test FOTP-95 covers the measurement of optical power.