Fig. 2.

Shape of the initial electric field ψ₀. Modulus of the electric field PSF calculated by Fourier transform of the pupil using a uniform beam profile (A) or with a truncated Gaussian beam (B). (C) Field profiles at y = 0 through the uniform (black line) and truncated Gaussian pupil fields (red line). For both, λ = 543 nm and D = 5.85 mm. The Gaussian function of the truncated field had a 1/e width of 4.75 mm (1/e² width for the intensity). Both fields are normalized to their peak value. The intensity full-width half-maxima were 1.6 µm for the uniform beam and 2.0 µm for the truncated Gaussian beam.