Electro-optic electric-field sensors utilizing Ti:LiNbO3 1 x 2 directional coupler with dipole antennas

Abstract

We have demonstrated a Ti:LiNbO3 electro-optic electric-field sensor based on 1 x 2 directional optical waveguide coupler. The symmetric geometry of the 1 x 2 directional coupler provided the sensor with unique characteristics of intrinsic 3-dB operating point and two complementary outputs. A DC switching voltage of similar to 12 V and an extinction ratio of similar to 8.1 dB were observed with the coupler at a wavelength of 1.3 mu m. The minimum detectable electric fields are similar to 0.99 and similar to 1.67 V/m corresponding to a dynamic range of similar to 29.5 and similar to 25 dB at frequencies of 20 and 50 MHz, respectively. The sensors exhibit almost linear response for the applied electric-field intensity from 0.29 to 29.8 V/m. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)