Lithium Niobate (LiNbO3) Photonic Electric-Field Sensors

Abstract

This study comprehensively reviewed four types of integrated-optic electric-field sensors based on titanium diffused lithium-niobatewaveguides: symmetric and asymmetric Mach-Zehnder interferometers, 1×2 directional couplers, and Y-fed balanced-bridge Mach-Zehnder interferometers. First, we briefly explain the crystal properties and electro-optic effect of lithium niobate and the waveguidefabrication process. We theoretically analyzed the key parameters and operating principles of each sensor and antennas. We also describeand compare the design, simulation, implementation, and performance tests: dc and ac characteristics, frequency response, dynamicrange, and sensitivity. The experimental results revealed that the sensitivity of the sensor based on the Y-fed balanced bridge Mach-Zehnder interferometer (YBB-MZI) was higher than that of the other types of sensors.