PON OPMs measure signal levels of individual wavelengths specific to the PON technology/service being deployed – miniature embedded filters, enabling wavelength selective measurements, is what diferentiates PON OPMs from ordinary, broadband OPMs. Measuring optical power is one of the most important measurements in optical networks, performed using optical power meters. Optical. The optical power meter is a kind of instrument to test the strength of laser signal in optical cable, it is generally used with laser light source, or can be used alone (one end of the light terminal machine). (optical network terminal) and OLT (optical line terminal) are. Passive Optical Networks (PONs) are a fundamental component of most Fiber-to-the-Home (FTTH) broadband networks worldwide. While FTTH/PON. tor to charge the unit. Any sufficiently rated AC-to-USB power adapter can be used, though an AC adapter with a current rating below 2.