Customized depolarization spatial patterns with dynamic retardance functions

David Marco,Ángel Lizana,Ignacio Moreno,María Del Mar Sánchez-López,Guadalupe López-Morales,Juan Campos

doi:10.1038/s41598-021-88515-x

David Marco, Ángel Lizana + Show 4 more

Open Access

https://doi.org/10.1038/s41598-021-88515-x

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Abstract

In this work we demonstrate customized depolarization spatial patterns by imaging a dynamical time-dependent pixelated retarder. A proof-of-concept of the proposed method is presented, where a liquid–crystal spatial light modulator is used as a spatial retarder that emulates a controlled spatially variant depolarizing sample by addressing a time-dependent phase pattern. We apply an imaging Mueller polarimetric system based on a polarization camera to verify the effective depolarization effect. Experimental validation is provided by temporal integration on the detection system. The effective depolarizance results are fully described within a simple graphical approach which agrees with standard Mueller matrix decomposition methods. The potential of the method is discussed by means of three practical cases, which include non-reported depolarization spatial patterns, including exotic structures as a spirally shaped depolarization pattern.

Highlights

In this work we demonstrate customized depolarization spatial patterns by imaging a dynamical time-dependent pixelated retarder
Controlling the polarization of light is an essential aspect in many different optical techniques[1], and its detection is the basis of polarimetry and ellipsometry[2]
We have demonstrated a spatially controlled depolarization emulator based on a liquid–crystal on silicon (LCOS)-spatial light modulators (SLM) that is addressed with a time-varying gray level pattern, encoding a time-varying pixelated linear retarder

Summary

Introduction

In this work we demonstrate customized depolarization spatial patterns by imaging a dynamical time-dependent pixelated retarder. If the detector integration area is much greater than the SoP spatial variation, the resulting beam presents an effective depolarization effect This is the case of the cholesteric LC wedge depolarizer[18] or the LC depolarizers designed with randomly distributed optical axes[19,20]. The second strategy considers using optical modulators to generate a fast temporal variation of the SoP In this case, if the detector integration time is much greater than the SoP temporal variation, again the result is an effective depolarization effect. If the detector integration time is much greater than the SoP temporal variation, again the result is an effective depolarization effect This effect was noticed originally in liquid–crystal on silicon (LCOS) d isplays[21,22], where it was perceived as a negative effect that reduced the image contrast or the diffraction efficiency of patterns displayed onto these devices.

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