Multi-spectral random illumination using a liquid crystal spatial light modulator

Xiao Chen,Zhiguang Shi,Weidong Hu

doi:10.1186/s41476-018-0088-6

Abstract

BackgroundUsing phase-only liquid crystal spatial light modulator (LC-SLM) to generate random illumination is always used in phase-retrieval and single pixel imaging as it have high energy efficiency. While the methods were only used to generate monochromatic illumination. This paper aims to use LC-SLM generating the multi-spectral random illumination.MethodsThe method requires only one SLM; multiple laser beams are simultaneously used to illuminate the entire SLM. Random voltages designed with a probability density function (PDF) are applied to modulate the random phases in the multi-spectral emitted light beam, leading to random amplitude spots in the far field. By optimize the PDF, the random illumination spot can be close to uniform distributed with high efficiency.ResultsThe average intensities of the random light spots are almost uniformly distributed within the range of the first diffraction order. And the zero-order beam is eliminated. The proposed method has a high energy efficiency and refresh rate and does not require the SLM to have an excessive modulation range.ConclusionThis paper provides a method to generate multi-spectral random illumination using a LC-SLM, which can be used in phase-retrieval and single pixel imaging.

Highlights

Using phase-only liquid crystal spatial light modulator (LC-SLM) to generate random illumination is always used in phase-retrieval and single pixel imaging as it have high energy efficiency
The generation of random phase illumination by an SLM has been used in many applications such as phase retrieval [1] and microscopic imaging [2, 3]
In summary, we have developed a method to generate multi-spectral random illumination by a piece of an SLM whose modulation range is a slightly greater than 1λ

Summary

Introduction

Using phase-only liquid crystal spatial light modulator (LC-SLM) to generate random illumination is always used in phase-retrieval and single pixel imaging as it have high energy efficiency. This paper aims to use LC-SLM generating the multi-spectral random illumination. A pure-phase spatial light modulator (SLM) is a diffractive optical device with a high energy efficiency. The generation of random phase illumination by an SLM has been used in many applications such as phase retrieval [1] and microscopic imaging [2, 3]. In single-pixel imaging [4] and structured illumination imaging [5, 6] applications, an SLM may be used to generate random amplitude patterns. SLMs are generally used only for a single-wavelength beam. As the LC-SLM technology is mature and cheap, it is the most

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Discussion

Conclusion