title: Adjustable spiral phase plate.
abstract: A spiral phase retarder phi(r, theta) = mtheta has been constructed with use of a deformed cracked plexiglass plate. By changing the degree of deformation, the retarder can be adjusted for use at any wavelength, and the value of the phase step 2pim at theta = 2pi can be chosen.
authors.affiliation: Department of Physics, Technion-Israel Institute of Technology, 32000 Haifa, Israel.
authors.forename: Carmel
authors.initials: C
authors.lastname: Rotschild
authors.forename: Shachaf
authors.initials: S
authors.lastname: Zommer
authors.forename: Shulamit
authors.initials: S
authors.lastname: Moed
authors.forename: Oren
authors.initials: O
authors.lastname: Hershcovitz
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Lipson