Simulation of the speckle pattern rotation in an absorbing optical fiber under the change of sign of the circular polarization of propagating light

The effect of rotation of a speckle pattern of circularly polarized light outgoing from a few-mode absorbing optical fiber under the change of sign of the circulation is numerically simulated on the basis of the wave approach. The theoretically predicted parabolic dependence of the value of the angle of rotation of the speckle pattern on the fiber length is discussed. Optical fibers with power-law refractive index profiles are considered.