Polarization changes at Lyot depolarizer output for different types of input beams

Abstract

Lyot depolarizers are optical devices made of birefringent materials used for producing unpolarized beams from totally polarized incident light. The depolarization is produced for polychromatic input beams due to the different phase introduced by the Lyot depolarizer for each wavelength. The effect of this device on other types of incident fields is investigated. In particular two cases are analyzed: (i) monochromatic and nonuniformly polarized incident beams and (ii) incident light synthesized by superposition of two monochromatic orthogonally polarized beams with different wavelengths. In the last case, it is theoretically and experimentally shown that the Lyot depolarizer increases the degree of polarization instead of depolarizes.

Liquid crystal depolarizer based on photoalignment technology

“…A depolarizer is another depolarization approach, which decreases the degree of polarization (DOP) in space or wavelength domain. The commonly available devices are wedge [9], the Loyt type [10,11], and microretarder array [12] depolarizers, respectively. However, these devices are polarization dependent or mainly effective for broadband light.…”

Longitudinal polarization periodicity of unpolarized light passing through a double wedge depolarizer

“…The use of optical devices that reduce the degree of polarization (DOP) of light is necessary for removing undesired polarization effects that could affect the performance of many optical systems, [1][2][3][4][5][6][7]. Approaches for reducing the DOP are based on scrambling states of polarization either in time, wavelength or space domain.…”

Polarization characteristics of light beams at the output of anisotropic depolarizing prism

“…Normalmente se requiere información global acerca de las características de polarización del haz, para lo cual se suele emplear el grado de polarización estándar [12,13]: (5) con (6) Por otro lado, un sistema óptico queda representado por su matriz de Müller de modo que el vector de Stokes a la salida del sistema óptico vendrá dado por [14]:…”

“…Estos dispositivos pueden llegar a tener comportamientos muy distintos dependiendo del estado de polarización, lo cual da lugar a efectos indeseados que llevan a una degradación en la aplicabilidad de tales sistemas. Una forma de resolver estos problemas es reducir el grado de polarización de la luz empleada utilizando los denominados pseudodespolarizadores ópticos [1][2][3][4][5][6][7]. Una clase de estos, son los llamados pseudo-despolarizadores espaciales que producen una variación continua y rápida del estado de polarización en la sección transversal del haz dando lugar a una distribución de la polarización inhomogénea de modo que el grado de polarización estándar resulta próximo a cero.…”