Talbot effect in optical lattices with topological charge.

We studied the interference resulting from the superposition of optical lattices, which are non-diffracting fields propagating in free space, and showed a Talbot self-imaging effect. These lattices are formed by spatially Fourier transforming a "quasi"-orbital angular momentum (OAM) state. We experimentally observed that although the Talbot images change, the Talbot length is insensitive to the topological charge of the "quasi"-OAM state. Our findings can be useful for laser-written photonic lattices.