US Patent 11709132 Modulus-enforced probe

Apparatus and methods for forming an image of an object which involves focusing partially to fully spatially-coherent radiation onto a sample and collecting the resulting scattered radiation (the “standard data set”) on an array detector. In addition to the standard dataset, an additional measurement or plurality of measurements is made of a relatively-unscattered beam, using the array detector, which comprises the “modulus enforced probe (MEP) dataset”. This MEP dataset serves as an extra constraint, called the MEP constraint, in the phase retrieval algorithm used to reconstruct the image of the object.