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Updated: Apr 16, 2026

Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator
Published on: January 28, 2019
Engineering the phase front of light with phase-change material based planar lenses
Yiguo Chen1, Xiong Li2, Yannick Sonnefraud3
11] The Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom [2] Department of Electrical and Computer Engineering, National University of Singapore, 117576, Singapore.
Abstract:
A novel hybrid planar lens is proposed to engineer the far-field focusing patterns. It consists of an array of slits which are filled with phase-change material Ge2Sb2Te5 (GST). By varying the crystallization level of GST from 0% to 90%, the Fabry-Pérot resonance supported inside each slit can be spectrally shifted across the working wavelength at 1.55 µm, which results in a transmitted electromagnetic phase modulation as large as 0.56π. Based on this geometrically fixed platform, different phase fronts can be constructed spatially on the lens plane by assigning the designed GST crystallization levels to the corresponding slits, achieving various far-field focusing patterns. The present work offers a promising route to realize tunable nanophotonic components, which can be used in optical circuits and imaging applications.
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