A novel bulk-glass optical current transducer having an adjustable multiring closed-optical-path

This paper describes a new design of a bulk-type Faraday effect-based optical current transducer. The sensing element is a four-piece bulk optic structure which enables the polarized light to circulate around the conductor a number of times and increases the sensitivity several times. The design makes for ease of manufacturing and alignment. The number of closed-optical-paths can be changed easily by adjusting the incident point of light. The principle of the design is described and the simulation and experimental results are presented.