Fig. 9
From: Planar metasurface-based concentrators for solar energy harvest: from theory to engineering
(a) Diagram of a broadband achromatic deflector (I) and its corresponding phase compensation profile (II). (III) Optical image (top) and SEM image (bottom) of fabricated meta-lens. (IV) Measured focused images at different focal planes. Insets show one-dimensional (1D) counterparts. (V) Simulated and measured FL as a function of wavelength for achromatic meta-lens (top) and chromatic meta-lens (bottom). (VI) Measured focusing efficiency (data points distributed in three-dimensional space) and FWHM (projection in the bottom plane) as a function of wavelength for three achromatic meta-lenses. (b) (I) Circularly polarized conversion efficiency (red curves) and phase profile (blue curve) of IRUEs with phase compensation of 1050° (top) and 1080° (bottom). Normalized magnetic energy for phase compensation of solid (II) and inverse nanostructures (III). (IV) Measured operation efficiency as a function of incident wavelength obtained for three achromatic meta-lenses. (a) Reproduced with permission [202]. Copyright 2017, NPG. (b) Reproduced with permission [165]. Copyright 2018, Wiley-VCH