Patent ID: 9454809
Filing Date: 2016-09-27
CPC Classification: G02B,G06T

Claim Text:
1. A phase derivative module comprising: a. a first lens for creating, in a Fourier plane, a field corresponding to a 2D spatial Fourier transform in a spatial frequency domain of an image field of a sample; b. an amplitude mask disposed in the Fourier plane, the amplitude mask transmitting a transmitted field characterized by a central axis, the amplitude mask characterized by a transmission amplitude having a minimum value at the central axis such that a subsequent Fourier transform of the transmitted field results in a function of a phase component of the image field of the sample having a term proportional to a power of a derivative of the phase component of the image field; c. a second lens for transforming the transmitted field back to an image domain showing the derivative of the phase component at a focal plane of a detector array disposed at an image plane.