Theoretical investigation on Bessel beam transmission through a polygonal binary amplitude diaphragm

We propose a new kind of polygonal binary amplitude diaphragm(PBAD), which is employed to suppress intensity oscillations of propagating Bessel beams in free space. With exact mathematical deductions, we obtain equivalent amplitude transmission coefficient formulas of the PBAD. Through optimizing the Bessel beam axial intensity, we get the optimum set of structure parameters of the PBAD. Numerical simulation results based on the complete Rayleigh-Sommerfeld method reveal that the optimized PBAD suppresses intensity oscillations of the propagating Bessel beam very well, either along the axial direction or in the cross-sectional planes. Compared with the gradually varying amplitude diaphragm or the cardioid binary amplitude diaphragm in present literatures, the proposed PBAD shows superiorities in easy fabrication and low cost. Our research results will provide important guidance value for wide application of Bessel beams in practical optical systems.