This reports the optical power of the specific wavelength channel selected on a coherent receiver, which can differ from the port's total received power when multiple channels arrive together. It lets an admin isolate the power of just the channel of interest on a DWDM line receiving several wavelengths at once. For example, on a port receiving a full C-band comb, this value tells the admin the power of the one channel actually being demodulated, separate from the aggregate power across all wavelengths.