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BUYER ' S GUIDE Spatial LIGHT Modulators

standard devices( Figure 4), and firmly establish high-power LCoS SLMs as viable components for industrial laser beam shaping. However, to date, no characterization data for these new high-power products under femtosecond-pulsed operation have been published.

PERSPECTIVES Despite the maturity of SLM technology, several directions are actively explored that could complement the capabilities of current commercial devices. While LC-SLMs remain the dominant commercial technology, several emerging approaches now demonstrate that programmable phase modulation no longer requires liquid crystals, pointing toward a more diverse landscape for phase control. Optically addressed light valves with wide-bandgap photoconductors extend the OASLM concept to high-power applications. Thermo-optically addressed SLMs( TOA-SLMs) modulate the LC refractive index purely through a photothermal effect, with no electrode or photoconductor, making this pixelfree architecture uniquely suited to ultrabroadband pulse shaping. Dielectric metasurfaces offer a radically different approach to phase modulation, with subwavelength spatial resolution, however, challenges remain in scaling large area. Finally, high-speed piezoelectric SLMs based on silicon nitride resonant waveguide gratings address the fundamental speed limitation of LC devices, enabling single-pixel modulation bandwidths exceeding 10 MHz and scalable to the GHz regime.

CONCLUSION Liquid-crystal spatial light modulators have reached a high level of technological maturity, dominated by the LCoS architecture, a technology optimized for specific wavelength ranges, resolution requirements, and operating conditions. The most significant recent advances concern the damage threshold, now exceeding 1 kW CW in dedicated high-power products,

REFERENCES

[ 1 ] A. Jullien, Photoniques 101( 2020) [ 2 ] Y. Yang et al., Opto-Electron. Sci. 2, 230026( 2023). and the extension of the operating spectral range, from the near-UV to the SWIR. Several performance criteria must be considered jointly when selecting a device for a given application, as they reflect interdependent design trade-offs. The supplier table provided herein offers an updated overview of the main commercial offerings. Looking ahead, dielectric meta-surfaces, high-speed piezoelectric modulators, wide-bandgap OASLMs, and thermo-optically addressed SLMs each target specific limitations of current LC technology, pointing toward a diversifying landscape for programmable phase control in the coming years.

[ 3 ] A. Alvarez-Herrero, Proc. SPIE PC14103, Liquid Crystals Optics and Photonic Devices II( 2026)

[ 4 ] V. Emiliani et al., Nat. Rev. Methods Primers 2, 55( 2022) [ 5 ] S. Gigan et al., Nat. Phys. 18, 980 – 985( 2022) [ 6 ] C. He et al., Light Sci. Appl. 11, 205( 2022) [ 7 ] Y. Shen et al., J. Opt. 25, 093001( 2023) [ 8 ] R. Martin-Hernandez et al., Ultrafast Sci. 6, 0161( 2026)

[ 9 ] M. Piccardo et al., « Trends in relativistic laser – matter interaction: the promises of structured light », Optica 6, 732( 2025).

[ 10 ] C. Mauclair et al., Opto-Electron. Sci. 5, 250002( 2025).

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