Simple method to evaluate the pixel crosstalk caused by fringing field effect in liquid-crystal spatial light modulators

Ignacio Moreno,María Del Mar Sánchez-López,Jeffrey A Davis,Don M Cottrell

doi:10.1186/s41476-021-00174-7

Abstract

In this work we provide a simple experimental method to measure and evaluate the pixel crosstalk in phase-only liquid-crystal displays caused by the fringing field effect. The technique is a reverse engineering method that does not require information about the microscopic physical parameters of the liquid-crystal material or details of the fabrication and electronics of the display. Instead, it is based on the overall effect on the diffraction efficiency of displayed binary phase gratings as a function of the addressed gray level. We show how the efficiency of the zero (DC) and first diffraction orders provides valuable information enough to identify and quantify the pixel crosstalk. The technique is demonstrated with a modern phase-only liquid-crystal on silicon (LCOS) spatial light modulator (SLM), illustrating the limitations that this effect imposes to the spatial resolution of the device and providing quantitative measurement of the impact on the diffraction efficiency.

Highlights

Spatial light modulators (SLM) are opto-electronic micro-displays capable to modulate the amplitude, the phase, or the state of polarization of light waves in space and in time [1]
This paper presents an approach that is important for users of LC-SLMs to quantify fringing-field effects based on diffraction efficiency experiments with displayed binary phase gratings with different periods
The goal of the method is not to determine the cause of the pixel crosstalk but to specify the overall response and its impact in terms of diffraction efficiency and spatial resolution, parameters that are relevant for users of the devices

Summary

Introduction

Spatial light modulators (SLM) are opto-electronic micro-displays capable to modulate the amplitude, the phase, or the state of polarization of light waves in space and in time [1]. As it is shown all these effects can be explained by the roundness of the phase profile of the displayed binary diffraction grating caused by the fringing effect on the SLM.

Results

Conclusion