Figure 1 : Schematic of our 3D super-resolution microscope using a phase mask.

From: Generalized recovery algorithm for 3D super-resolution microscopy using rotating point spread functions

Figure 1

FL is the focal lens. For a typical wide field microscope, the detector is placed at the focal point after FL. Lens 1 and Lens 2 are two identical lenses forming a 4f system. The phase mask is mounted in the Fourier plane, which is the center plane between Lens 1 and Lens 2. The detector is placed after the 4f system. The phase mask is made of transparent materials with different thicknesses generating different phase delays. The simulated phase mask pattern shown approximates the double helix phase mask reported elsewhere61, and the commercially available phase mask (Double Helix LLC) used in the experimental portions of the current work.