title: Zeroth-order phase-contrast technique.
abstract: What we believe to be a new phase-contrast technique is proposed to recover intensity distributions from phase distributions modulated by spatial light modulators (SLMs) and binary diffractive optical elements (DOEs). The phase distribution is directly transformed into intensity distributions using a 4f optical correlator and an iris centered in the frequency plane as a spatial filter. No phase-changing plates or phase dielectric dots are used as a filter. This method allows the use of twisted nematic liquid-crystal televisions (LCTVs) operating in the real-time phase-mostly regime mode between 0 and p to generate high-intensity multiple beams for optical trap applications. It is also possible to use these LCTVs as input SLMs for optical correlators to obtain high-intensity Fourier transform distributions of input amplitude objects.
authors.affiliation: Department of Research and Development, Holophotonics Equipamentos Opticos e Eletrônicos Ltda-ME, Avenida Araraquara 863, 13566-770 São Carlos-SP, Brazil.
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Pizolato
authors.forename: Giuseppe Antonio
authors.initials: GA
authors.lastname: Cirino
authors.forename: Cristhiane
authors.initials: C
authors.lastname: Gonçalves
authors.forename: Luiz Gonçalves
authors.initials: LG
authors.lastname: Neto