Systems and apparatus for a wirelessly-powered passive optical power meter device. In one aspect, an optical power meter device comprises a power circuit connected to one or more antennas, the circuit including an RF to DC converter that generates a DC power signal that provides a DC power source for the optical power meter from an RF signal received by the one or more antennas, a photodetector that generates a power measurement signal that measures the power of the optical input signal, and a communication circuit that is connected to the one or more antennas, the photodetector, and the power circuit that when powered by the DC power source generates a modulation signal that is responsive to the power measurement signal and that causes the one of the one or more antennas to convey the power measurement signal to a reader device that is transmitting the RF signal.