An optical power meter (OPM) measures the strength of light signals in fiber optic systems. At its heart, an OPM uses a photodiode. For light power measurements outside the field of. 📦 For purchasing, use the RP Photonics Buyer's Guide for optical power meters. It provides an expert-curated supplier directory, buyer-focused technical background information, and structured selection criteria to support professional procurement decisions. Beginners may find it complex, but understanding its function makes it.