Electro-optic electric field sensor utilizing Ti:LiNbO 3 symmetric Mach-Zehnder interferometers

Abstract

The use of a Ti:LiNbO 3 symmetric Mach-Zehnder interferometric intensity modulator with a push-pull lumped electrode and a plate-type probe antenna to measure an electric field strength is described. The modulator has a small device size of 46×7×1 mm and operates at a wavelength of 1.3 μm. The output characteristic of the interferometer shows the modulation depth of 100% and 75%, and V π voltage of 6.6 V, and 6.6 V at the 200 Hz and 1 KHz, respectively. The minimum detectable electric field is ~1.84 V/m, ~3.28 V/m, and ~11.6 V/m, corresponding to a dynamic range of about ~22 dB, ~17 dB, and ~6 dB at frequencies of 500 KHz, 1 MHz and 5 MHz, respectively.