Silicon (Si): Si sensors can detect very low power levels (nanowatts to tens of milliwatts), but their wavelength range is restricted to around 1,100 nanometers (nm). 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. 📦 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. Newport's 1936/2936-R Series Optical Power Meters are among the most versatile power meters in the market, and the. Optical power meters are a key element in the optimization and maintenance of such optical networks and of their components.