THz Bessel Beams Generated by BOEs

Diffractive optical elements (DOEs) are designed for producing Bessel beams at THz frequencies in this paper. To lessen the computational burden and therefore improve the design efficiency, the design tool, which is to connect a microgenetic algorithm (MCA) for optimal design of DOEs with a body-of-revolution finite-difference time-domain (BOR-FDTD) method for rigorous analysis the fields diffracted by DOEs, has been adopted to acquire the profiles of the DOEs. Simulation results show that the field distributions generated by the designed DOEs are in good agreement with those of the desired on the output plane.