Enabling aberration retrieval of microlenses with the Extended Nijboer-Zernike (ENZ) diffraction theory

We propose a measurement approach that allows the determination of aberrations of a microlens by analyzing the through-focus intensity image it produces when the object is a point source. To simulate image formation by a microlens we apply the extended version of the Nijboer-Zernike diffraction theory (ENZ) that uses the Debye diffraction integral to compute the image point-spread function. Due to the aperture size of the microlens and the finite dimensions of the pixels of the electronic detector the Debye diffraction integral should be adapted according to the Li-Wolf scaling rules to yield correct results. In addition to this we also discuss the experimental requirements posed by this characterization approach and derive from this a suitable experimental setup.