Spatial LIGHT Modulators
BUYER ' S GUIDE
SPATIAL LIGHT MODULATORS
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Aurélie JULLIEN Institut de Physique de Nice( INPHYNI), Université Côte d’ Azur, CNRS, Nice, France * aurelie. jullien @ inphyni. cnrs. fr
Spatial light modulators are mature yet evolving optoelectronic devices enabling dynamic control of light’ s amplitude, phase, or polarization. This buyer’ s guide reviews the principles, performance trade-offs, and major families of liquid-crystal-based spatial light modulators, with emphasis on recent breakthroughs. https:// doi. org / 10.1051 / photon / 202614071
This is an Open Access article distributed under the terms of the Creative Commons Attribution License( https:// creativecommons. org / licenses / by / 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Spatial light modulators( SLMs) are two-dimensional optoelectronic devices enabling the dynamic and programmable modulation of the amplitude, phase, or polarization, of an incident light beam [ 1 ]. They belong to the broader family of microdisplays, devices capable of dynami cally encoding spatially structured images, alongside digital micromirror devices( DMDs) and other programmable optical components. SLMs are generally classified according to their addressing scheme( electrical or optical), their operating geometry( reflective or transmissive), and the optical parameter they modulate. Among the various technologies available, liquid-crystal-based SLMs( LC-SLMs, hereby just SLMs) are by far the most widely used in scientific and industrial applications, and will be the focus of this buyer’ s guide [ 2 ]. Although SLMs present intrinsic limitations( required polarized light, moderate refresh rates operation, wavelength-dependent response), they have reached a high level of technological maturity, underpinned by decades of development initially driven by the display industry. Today, this maturity is reflected both in the broadness of their applications, and in their progressive adoption in demanding environments: for instance, LC-based devices are now being qualified for space instrumentation, enabling compact polarimetric and spectroscopic instruments aboard satellites and stratospheric balloon observatories [ 3 ]. In general, the global LC-SLM market is steadily expanding, with annual growth rates reported in excess of 20 % in recent years, driven by the rapid development of applications in laser material processing, microscopy, and quantum technologies.
APPLICATIONS SLMs have become ubiquitous tools in modern photonics, serving both scientific research and industrial applications across an exceptionally broad range of fields( Figure 1). In imaging, microscopy and biomedicine, SLMs are routinely used in adaptive optics systems to correct wavefront aberrations and optimize the point spread function, enabling diffraction-limited performance in biological imaging. They are central to structured illumination microscopy, light-sheet microscopy, and holographic optical tweezers for single-cell manipulation. A particularly convincing biomedical application is optogenetics, where SLMs generate spatially patterned light stimuli with single-cell resolution and millisecond-range temporal precision to photo-activate neuronal activity [ 4 ]. In a closely related domain, SLMs are the central tool to focus and control light propagating
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