Minimizing the Bright/Shadow Focal Spot Size with Controlled Side-Lobe Increase in High-Numerical-Aperture Focusing Systems

Table 2

Results of numerical simulation for the radially polarized beam with a first-order phase vortex (𝑚=1).

Transmission function, 𝐵(𝜃,𝜙)	Transverse intensity in the focus, 3𝜆×3𝜆 (total and 𝑧-component)	Transverse intensity profile: total (solid line) and 𝑧-component (dashed line)
exp(𝑖𝜙)	FWHMz = 0.352λ
exp(𝑖𝜙),  𝛿=0.05	FWHMz = 0.3λ
𝜌𝜀=0.1𝜆,; 𝜌Δ=2𝜆,  𝜇=0.3	FWHMz = 0.308λ
𝜌𝜀=0.2𝜆,; 𝜌Δ=1.2𝜆,  𝜇=0.9	FWHMz = 0.28λ, FWHMz = 0.28λ