Slab Coupled Optical Fiber Electric Field Sensors

In order to create a non-intrusive electric field sensor, an all dielectric electric field sensor is developed. This sensor is based on resonant coupling between a D-shaped optical fiber and a slab of non-linear optical material. A laser is tuned to have a wavelength on the edge of one of the resonant dips. The non-linear crystal causes a shift in the resonance, which causes the incident electric field to be converted into a change in the optical power transmitted through the SCOS. The SCOS is fabricated to have a size of 0.2 mm x 0.2 mm x 1.2mm and tested to have a sensitivity of 60 mV/m HZ^1/2. The SCOS is used to measure the electric field inside of an X-band waveguide and is fabricated into an array using KTP and LiNbO₃ as the non-linear optical crystals.