Remote sensor with waveguide optics telemetry

A system for measuring electrical current flowing in an electrical conductor, comprising:

• a signal source/detection module;
• a telemetry optical fiber having a first end optically coupled to the signal source/detection module;
• a conversion module optically coupled to a second end of the telemetry optical fiber, the conversion module including an interferometer having a pair of optical paths and an optical waveguide arranged to be included in each one of the optical paths of the interferometer, the interferometer being arranged to produce an interference pattern to indicate the phase relationship of optical signals input to the pair of optical paths from the signal source/detection module;
• an apparatus arranged to phase modulate optical signals guided by the optical waveguide;
• and
• an electrical current sensor connected to the phase modulating apparatus and arranged to provide a modulating signal to the phase modulating apparatus such that the interference pattern indicates the magnitude of the electrical current.