slmsuite.holography.toolbox.phase.lens

lens(grid, f=(inf, inf))

Returns a simple thin parabolic lens. When f is isotropic,

\[\phi(\vec{x}) = \frac{\pi}{f}|\vec{x}|^2\]

Otherwise,

\[\phi(x, y) = \pi \left[\frac{x^2}{f_x} + \frac{y^2}{f_y} \right]\]

Parameters

• grid ((array_like, array_like) OR SLM) – 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.

• f (float OR (float, float)) – Focus in normalized \(\frac{x}{\lambda}\) units. Scalars are interpreted as a non-cylindrical isotropic lens. Future: add a convert_focal_length method to parallel convert_blaze_vector() Defaults to infinity (no lens).

Returns

The phase for this function.

Return type

numpy.ndarray