Influence of imperfections in gradient-index waveguides on Talbot effects

On the basis of the unitary transformation and the Lie algebra decomposition technology widely used in quantum mechanics, we obtain the analytical propagator for light beams propagating through an imperfect gradient-index (GRIN) waveguide. The results show that, unlike in the straight GRIN waveguide widely studied, in an imperfect GRIN waveguide, self-imagining phenomena can result in two new effects: one is a phase shift including a global one and a local one, in which the local one results in a change of direction of the light beam propagating through the imperfect GRIN waveguide; the other is a transverse shift of self-image. The transverse deviation occurring in the imperfect GRIN waveguide is also calculated.