Non-transverse electromagnetic fields in micro- and nano-fibers

We present an analytical and numerical study of electromagnetic modes in micro- and nano-fibers (MNFs) where the electric and magnetic fields of the modes are not necessarily orthogonal to each other. We first investigate these modes for different fiber structures including circular- and rectangular-core fibers as well as photonic crystal fibers. We then discuss two specific applications of these modes: (1) generation of hypothetical axions that are coupled to the electromagnetic fields through the dot product of electric and magnetic fields of a mode, E→⋅B→, and (2) a new type of optical trap (optical tweezers) for chiral atoms with magneto-electric cross coupling, where the confining potential again is proportional to E→⋅B→.