Comparison To Gaussian Beam Focus
A circular laser beam with uniform intensity profile, focused by a lens, will form an Airy pattern at the focal plane of the lens. The intensity at the center of the focus will be where is the total power of the beam, is the area of the beam ( is the beam diameter), is the wavelength, and is the focal length of the lens.
A Gaussian beam with diameter of D focused through an aperture of diameter D will have a focal profile that is nearly Gaussian, and the intensity at the center of the focus will be 0.924 times .
Read more about this topic: Airy Disk
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