Tight Focusing of Partially Coherent Vortex Beams

Figure 4

Degree of polarization along π/4 in focal plane of an aplanatic lens with NA=0.9 of uniformly polarized vortex beams 𝜇_𝑜=0.5, 𝛽=𝜋/2, for m (a) 0 (b) 1, and (c) 2.