We propose a novel computational imaging system that enables the generation of Point Spread Functions (PSFs) of userspecified geometry. Key ingredient of our system is a phase-coded aperture which manipulates the phase distribution of the pupil function by inserting a phase modulator. We use a reflective phaseonly liquid crystal-based Spatial Light Modulator (SLM) for phase modulation. Via encoding a grayscale image on the SLM, the refractive index of each cell can be altered. Phase patterns of PSFs with different shapes are optimized by the Gerchberg-Saxton algorithm. A number of non-trivial, complex shaped PSFs has been captured. We further demonstrate how such a system can realize refocusing through encoding a Fresnel lens phase pattern to shift the focal plane.
Jieen Chen, Michael Hirsch, Rainer Heintzmann, Bernhard Eberhardt, Hendrik P. A. Lensch, "A Phase-coded Aperture Camera with Programmable Optics" in Proc. IS&T Int’l. Symp. on Electronic Imaging: Computational Imaging XV, 2017, pp 70 - 75, https://doi.org/10.2352/ISSN.2470-1173.2017.17.COIMG-426