title: Polarization-controlled contrasted images using dye-doped nematic liquid crystals.
abstract: We explore the polarization dependence of the nonlinear response of a planar nematic liquid crystal cell doped with 1% wt of methyl red dye. The results obtained show that the refractive index change can be switched from a positive value to a negative one as the polarization of the beam changes from parallel to perpendicular with respect to the rubbing direction. This property is exploited in a phase contrast system, where a dynamic phase filter is photoinduced in a liquid crystal cell placed in the system's Fourier plane. Real-time contrast inversion in the resulting images is demonstrated.
authors.affiliation: Departmento de Optica, Instituto Nacional de Astrofisica, Optica y Electronica, Apartado Postal 51 y 216 72000Puebla, Pue. Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Porras Aguilar
authors.forename: J C
authors.initials: JC
authors.lastname: Ramirez-San-Juan
authors.forename: O
authors.initials: O
authors.lastname: Baldovino-Pantaleon
authors.forename: D
authors.initials: D
authors.lastname: May-Arrioja
authors.forename: M L
authors.initials: ML
authors.lastname: Arroyo Carrasco
authors.forename: M D
authors.initials: MD
authors.lastname: Iturbe-Castillo
authors.forename: D
authors.initials: D
authors.lastname: Sánchez-de-la-Llave
authors.forename: R
authors.initials: R
authors.lastname: Ramos-Garcia