In some examples, a multi-wavelength power meter may include a first coupler to separate optical signals from an optical line terminal and an optical network terminal to ascertain a reduced percentage of total power related to the optical signals. A second coupler may receive the separated optical signals, combine the separated optical signals, and output the combined optical signals to an optical fiber. A filter may be communicatively connected to the optical fiber to isolate at least one specified wavelength or wavelength range of the combined optical signals. A photodiode may be communicatively connected to the filter for power measurement of the at least one specified wavelength or wavelength range.