title: Point diffraction interferometer with a liquid crystal monopixel.
abstract: In this work a novel point diffraction interferometer based on a variable liquid crystal wave plate (LCWP) has been implemented. The LCWP consists of a 3x3 cm(2) monopixel cell with parallel alignment. The monopixel cell was manufactured such that the electrode covers the entire surface except in a centered circular area of 50 μm of diameter. This circle acts as a point perturbation which diffracts the incident wave front giving rise to a spherical reference wave. By applying a voltage to the LCWP we can change the phase of the wave front that passes through the monopixel, except at the center. Phase shifting techniques are used in order to calculate the amplitude and phase distribution of the object wave front. The system allows a digital hologram to be obtained, and by using the Fresnel diffraction integral it is possible to digitally reconstruct the different planes that constitute the three dimensional object.
authors.affiliation: Depto. Física, Universidad Autónoma Barcelona, 08193 Bellaterra, Spain.
authors.forename: Claudio
authors.initials: C
authors.lastname: Ramírez
authors.forename: Eva
authors.initials: E
authors.lastname: Otón
authors.forename: Claudio
authors.initials: C
authors.lastname: Iemmi
authors.forename: Ignacio
authors.initials: I
authors.lastname: Moreno
authors.forename: Noureddine
authors.initials: N
authors.lastname: Bennis
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Otón
authors.forename: Juan
authors.initials: J
authors.lastname: Campos
mesh_terms: D004574:Electromagnetic Fields; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007368:Interferometry / Q000295:instrumentation*; D050866:Liquid Crystals / Q000737:chemistry* / Q000528:radiation effects*; D012031:Refractometry / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*