Fig. 1. Phase modulation model of allosteric unit.(a) Elliptic cylindrical anisotropic unit for phase modulation; (b) global coordinate system and local coordinate system

Fig. 2. Schematics of Elliptical pillar units. (a) Elliptical pillar unit of amorphous GSST ; (b) elliptical pillar unit of crystalline GSST

Fig. 3. Schematisc of dual-channel erasable holographic imaging. (a) Amorphous GSST; (b) crystalline GSST

Fig. 4. Refractive indexes and extinction coefficients of GSST in crystalline and amorphous states

Fig. 5. Phase-coded maps

Fig. 6. Transmission phases of 36 elliptic cylindrical structures and corresponding cross polarization and co-polarization transmissivity values

Fig. 7. Normalized near-field holographic phases. (a) “LCP” pattern; (b) “RCP” pattern

Fig. 8. Schematics of constructed holographic metasurfaces. (a) Amorphous GSST; (b) crystalline GSST

Fig. 9. Simulation results of far-field holographic imaging

Fig. 10. Dual-channel parabolic phase distributions with focal lengths of 25 μm and 30 μm

Fig. 11. Two-dimensional disk structure of bifocal lens

Fig. 12. Intensity and corresponding phase distributions of amorphous-GSST superlens

Fig. 13. Intensity and corresponding phase distributions of crystalline-GSST superlens