Optical power abnormalities often indicate deeper issues such as fiber degradation, connector contamination, excessive attenuation, or equipment malfunction. Stable optical power is the foundation of every high-capacity optical transport system. Even minor deviations—whether too high, too low, or unstable—can impact signal integrity, trigger service alarms, or interrupt traffic on DWDM, OTN, or long-haul optical line systems. Optical networks rely on precise power balance—too much power can damage receivers or distort signals, while insufficient. An optical power meter, often shortened to OPM, is the instrument used for that job. You use it to measure the strength of light signals in fiber optic cables.