New design of optical electric-current sensor for sensitivity improvement

A new design of optical electric-current sensor based on the Faraday effect is proposed and demonstrated experimentally. The sensor probe is a precise ly cut glass prism with a high reflection coating on the base surface at th e far end, Inside the prism, the light beam is allowed to bounce up and dow n at the critical angle and retrace its path back by the reflection coating . The sensor demonstrated offers a sensitivity of six times higher as compa red with conventional designs and suffers from fewer optical losses. The de sign can also reduce the package size of the sensor probe.