Dispersions of robust optical vortices in multihelicoidal fibers with torsional mechanic stress

Abstract

We study the structure of higher order modes in multihelicoidal optical fibers (MHFs) in the presence of torsional mechanic stress (TMS). We show that at some values of pitch such modes present circularly polarized nondegenerate optical vortices robust to external perturbations of the cross-section’s form. Based on analytical expressions for the propagation constants of such vortex modes, we investigate polarization, topological, and hybrid dispersions of vortex modes. We also demonstrate that, based on MHF with TMS, one can implement a universal CCNOT logic gate, which is also known as a Toffoli gate. This property could be useful for classical emulation of quantum computations.