An exposure tool includes an illumination source, a blazed phase grating reticle, a reticle stage holding the blazed phase grating reticle, a lens system including at least one adjustable lens element, a wafer stage holding a sample, and a controller. The controller is configured to control the illumination source and the position of the blazed phase grating reticle and the lens system relative to the wafer stage to expose the sample to generate a blazed phase grating sample. The controller is configured to adjust the at least one adjustable lens element to compensate for aberrations of the lens system based on feedback generated from analyzing images of the blazed phase grating sample.