SPIN-ORBIT INTERACTION IN THE FIELD OF AN OPTICAL VORTEX OF A FEW-MODE FIBER

A quantum-mechanical analog of the spin-orbit interaction operator (V) over cap is constructed for the fields of optical CV vortices and TE and TM modes in an optical fiber. It is shown that the polarization co rrection delta beta to the propagation constant, which is the mean val ue of this operator, is a measure of the ''level splitting'' of the pr opagation constant <(beta)over tilde> in the scalar case. The differen ce in the operation of the individual parts of the operator (V) over c ap on the fields of CV vortices and on the fields of TM and TE modes i s indicative of the presence of two different physical processes - cir cular and linear birefringence in the locally isotropic optical fiber. The conversion of the ''scalar'' field (e) over tilde to a vector fie ld e(1) as a consequence of the spin-orbit interaction operator can be regarded as resulting from a re-radiation of the additional field e(1 ) by the vortex field (e) over tilde, which rotates around the optical axis of the fiber. In this picture the additional field e(1) can be r egarded as being a ''relativistic'' correction to the vortex field for the distortions of the main field (e) over tilde and arising as a res ult of the rotation of the field of the optical vortex in the medium o f the few-mode fiber. (C) 1998 American Institute of Physics. [S1063-7 850(98)03010-9].