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odak.wave.rayleigh_resolution

Definition to calculate rayleigh resolution limit of a lens with a certain focal length and an aperture. Lens is assumed to be focusing a plane wave at a focal distance.

Parameter

diameter : float Diameter of a lens. focal : float Focal length of a lens, when focal length is provided, spatial resolution is provided at the focal plane. When focal length isn't provided angular resolution is provided. wavelength : float Wavelength of light.

Returns

resolution : float Resolvable angular or spatial spot size, see focal in parameters to know what to expect.

Source code in odak/wave/__init__.py
def rayleigh_resolution(diameter, focal=None, wavelength=0.0005):
    """
    Definition to calculate rayleigh resolution limit of a lens with a certain focal length and an aperture. Lens is assumed to be focusing a plane wave at a focal distance.

    Parameter
    ---------
    diameter    : float
                  Diameter of a lens.
    focal       : float
                  Focal length of a lens, when focal length is provided, spatial resolution is provided at the focal plane. When focal length isn't provided angular resolution is provided.
    wavelength  : float
                  Wavelength of light.

    Returns
    --------
    resolution  : float
                  Resolvable angular or spatial spot size, see focal in parameters to know what to expect.

    """
    resolution = 1.22*wavelength/diameter
    if type(focal) != type(None):
        resolution *= focal
    return resolution

See also