Intensity distribution at the focus of a 1.20 NA water-immersion objective with aperture radius R = 4 mm for an x-polarised Gaussian beam with beam waist (a) w0 = 4 mm and (b) w0 = 2 mm, and for (c) a radially polarised and (d) an azimuthally polarised cylindrical vector beam. All beams have wavelength λ0 = 632 nm and the full laser power after the aperture is 10 mW. The iso-intensity surfaces correspond to I(x,y,z)=50, 20, 10, 5 GW/m2.
Fig. 4.13 — Focal fields