slmsuite.holography.toolbox.phase.bahtinov#

bahtinov(grid, radius=0.001, angle=0.17453292519943295, grating=<function binary>)[source]#

Returns a Bahtinov mask, commonly used for focusing telescopes. When the farfield pattern resulting from this mask is symmetric, the system is in focus.

Parameters:

grid (Union[Tuple[ndarray, ndarray], object]) – \(\vec{x}\). Meshgrids of normalized \(\frac{x}{\lambda}\) coordinates corresponding to SLM pixels, in (x_grid, y_grid) form. These are precalculated and stored in any SLM, so such a class can be passed instead of the grids directly.
radius (float) – Radius of the diffraction pattern in normalized \(\frac{k_x}{k}\) units. See convert_radius(). Defaults to a milliradian.
angle (float) – Angle of the right two quadrants from the left two quadrants in radians. Defaults to 10 degrees.
grating (Callable) – Type of grating to use for the mask. Must have a vector= argument. Defaults to binary().

Return type:

ndarray

Returns:

The phase for this function.