The transmission of structured light fields in uniaxial crystals employing the Laguerre-Gaussian mode spectrum

In the plane-wave angular-spectrum representation, we derive the analytical expressions for any order Laguerre-Gaussian beams propagating along the optical axis of uniaxial crystals. We further prove the orthogonality of propagating modes inside the uniaxial crystals, and investigate the energy efficiency as well as the behavior of spin-orbital coupling. Based on the analytical solutions, we propose a scheme for the transmission of structured light fields through the uniaxial crystals, which firstly decomposes the input fields into LG spectrum and then superposes all OAM components inside crystals to obtain the propagating optical fields. We use the trefoil image as an example to demonstrate the effectiveness of our scheme. The evolution of optical fields and spectra of trefoil image are also studied.