Double-Helix Point Spread Function phase mask
Matlab code about how to create a DH-PSF phase mask using GL mode of light.
Referenceļ¼Rafael Piestun, Yoav Y. Schechner, and Joseph Shamir, "Propagation-invariant wave fields with finite energy," J. Opt. Soc. Am. A 17, 294-303 (2000)