A typical noiseless Pockels E field sensor.

A new practical Pockels E field sensor has been demonstrated. By combining a ferroelectric liquid crystal and a polarization-maintaining optical fiber with the sensor, it is theoretically found that almost all of the optical and electronic noise produced in the system can be completely eliminated. This fact has been experimentally proven not only under the conditions of a uniform electric field but also those of a nonuniform electric field and with ac voltages applied to a stabilized corona discharge. It is shown that if with the new Pockels E field sensor, the smallest detectable phase change was set to be 10(-5) rad, the minimum measurable E field in the electrical discharge could be reduced from 10(2) to 10(-1) kV/m. This technique should be useful not only for the field of electrical discharge studies but also for other optical measurement applications such as length, temperature, and pressure using appropriately configured transducers.