Green function for radiation and propagation in helicoidal bianisotropic mediums

Radiation by prescribed sources in a helicoidal bianisotropic medium (HBM) is investigated. The Oseen transformation and spatial Fourier transforms are used to obtain an inhomogeneous, first-order, matrix differential equation with nonconstant coefficients. As these coefficients are analytic functions of z and can be expanded as polynomials in that variable, the solution of an auxiliary homogeneous differential equation is explicitly and simply obtained. On using this auxiliary equation´s solution, the radiated fields are determined and an appropriate Green function is formulated as a 4×4 matrix. Novel results apply to thin-film HBMs as well as to chiral liquid crystals