Enhanced transmission and beaming of light from a photonic crystal waveguide via two collimation lenses

Directional emission of light passing through a subwavelength photonic crystal waveguide (PCW) with the help of two collimation lenses is researched. The collimation lens is another photonic crystal with a self-collimation effect. Four different configurations of PCW and collimation lens are studied by the finite-difference time-domain (FDTD) method. Simulation results show that this collimation lens method can not only achieve a high transmission and low divergence light beam but also provide a wide band width of Δω/ω = 5% (where, ω is the angular frequency), which is better than the mechanism of interference of surface modes.