Sensitive, highly linear lithium niobate interferometers for electromagnetic field sensing

Abstract

An asymmetric Mach–Zehnder interferometer in Ti:LiNbO3 has been demonstrated to have a 84 dB linear dynamic range and 1.1 μV sensitivity, for a 3 kHz detection bandwidth and a 50 Ω resistance, at the 1.3 μm wavelength. This device is useful for electric and magnetic field sensing. Optimum linearity is achieved with a 90° intrinsic phase bias. The dependence of dynamic range and sensitivity on optical power, phase bias, and modulation voltage is reported. The reasons for, and magnitudes of, deviations from optimum linear behavior are described for many fabricated interferometers.