The effects of spin-orbit interaction of a photon and their analogues in mechanics

Influence of the helical shape of a fibre waveguide on the propagation of light

“…The plane of polarisation of linearly polarised light is rotated in the course of its propagation through a single-mode [1] or a multimode [2] fibre waveguide twisted to form a helix. When the tangents to the entry and exit ends of the fibre are parallel, the angle of rotation \\i (in radians) of the plane of polarisation is numerically equal to the solid angle Q (in steradians) formed on a unit sphere in the space of the tangents [3][4][5][6].…”

“…1 shows the apparatus schematically. Linearly polarised radiation from an He-Ne laser(7) of wavelength X = 0.63 um was focused on the entry of a fibre (3) by a lens (2). Light transmitted by the fibre was observed on a screen (4).…”

“…2that such a change in the pitch rotated the speckle pattern by (p ~ 90°. If the fibre had conserved linear polarisation, then the plane of polarisation would have rotated by the same (in respect of the sign and magnitude) angle[2].…”