An RF optical modulation technique for multiplexing and self-referencing a number of fiber optic intensity sensors is described. The optical transducers are incorporated into recirculating optical fiber loops connected in parallel between transmit and receive optical fibers. A linear RF ramped optical signal is coupled into the system and the detected optical signal is electronically mixed with the input. Beat signals are produced in the frequency domain in the form of pulse trains that characterize the output of each sensor module. The relative magnitudes of the frequency components are insensitive to varying optical loss characteristics between the sensor modules and the signal processing location. The theoretical basis of the technique is presented and experimental results are given.