odak.wave.linear_grating

A definition to generate a linear grating.

Parameters:

Name	Type	Description	Default
nx	int	Size of the output along X.	required
ny	int	Size of the output along Y.	required
every	int	Add the add value at every given number.	2
add	float	Angle to be added.	3.14
axis	string	Axis eiter X,Y or both.	'x'

Returns:

Type	Description
ndarray	Linear grating term.

Source code in odak/wave/lens.py

def linear_grating(nx, ny, every=2, add=3.14, axis='x'):
    """
    A definition to generate a linear grating.

    Parameters
    ----------
    nx         : int
                 Size of the output along X.
    ny         : int
                 Size of the output along Y.
    every      : int
                 Add the add value at every given number.
    add        : float
                 Angle to be added.
    axis       : string
                 Axis eiter X,Y or both.

    Returns
    -------
    field      : ndarray
                 Linear grating term.
    """
    grating = np.zeros((nx, ny), dtype=np.complex64)
    if axis == 'x':
        grating[::every, :] = np.exp(1j*add)
    if axis == 'y':
        grating[:, ::every] = np.exp(1j*add)
    if axis == 'xy':
        checker = np.indices((nx, ny)).sum(axis=0) % every
        checker += 1
        checker = checker % 2
        grating = np.exp(1j*checker*add)
    return grating

See also

• Computer Generated-Holography