Design and Analysis of Multilayer Solenoid Coil for Faraday Modulator

School of Instrumentation Science & Opto-Electronics Engineering, Beihang University, Beijing 100191, PR China

^a Corresponding author: mb@buaa.edu.cn

Abstract

A well-designed polarimeter is integral to the realization of the highly sensitive atomic magnetometer. Amongst various detection schemes, optical polarimetry based on Faraday modulator is most commonly used owing to its angular sensitivity at low-frequency range. The multilayered solenoid coil is the key component of Faraday effect based optical detection system. This paper primarily deals with design and analysis of multilayered coil of Faraday modulator. All deterministic parameters that affect the optimum design have been identified and analyzed. Mathematical expressions have been obtained for axial field homogeneity; modulation depth and power dissipation manifesting direct dependence on coil geometry. The design parameters of the coil are optimized with respect to axial magnetic field homogeneity over region of interest and reduced power losses with suitable geometric construction. The influence of different geometrical and electromagnetic parameters on optimum design has been highlighted and guidelines for design procedure are given. Theoretical results have been compared with simulation and experimental results. The mathematical formulation could be implemented in a computer program for recurrence design and to assist the realization of an optimized design of Faraday modulator coil.