An integrated photonic Mach-Zehnder interferometer with no electrodes for sensing electric fields

Abstract

A new configuration for a Mach-Zehnder interferometric electric field sensor device utilizing the electrooptic effect is reported. The lithium niobate device uses no metallic electrodes and operates solely by immersion in an electric field. Reverse poling of one arm of the interferometer provides opposing optical phase changes in the two interferometer arms when placed in an electric field. One fabricated device exhibits a measured minimum detectable field of 0.22 V/m/spl radic/Hz and a frequency response of greater than 1 GHz. Theoretical calculations show that detection of 0.11 V/m/spl radic/Hz is attainable while the upper frequency limit can exceed 6 GHz.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>