Fig. 13: Metalenses for light concentrating.

a–c Top views of designs 1, 2, and 3 of metalens-based concentrators respectively. The center dashed square indicates the intended detector on the opposite side of the substrate onto which the concentrators focus light. d–f SEM images of fabricated metalenses of designs 1, 2, and 3 respectively. g Measure and simulated signal enhancement at the substrate surface for all designs. The black dotted horizontal line indicates the optical signal without any optical concentrators. h Schematic illustration of metalens integrated OLED, metalens embedding between the glass substrate and ITO anode. i The EQE of different sizes of OLEDs without pattern, with grating, metalens, RCL, and QRSL. j Schematic of the sub-pixel 2 × 2 metalens focusing into its corresponding SPAD. k The expected number of detected photons of the experimental value without and with the metalens as a function of applied overvoltage. l The expected number of detected photons of the experimental value without and with the metalens as a function of the angle of incidence. m Photograph of the 40×40 metalens array with a magnified view, a blank area on the center of the metalens that corresponding to the through-silicon via area of the SiPM. n Photograph of the 40×40 SPADs of the SiPM with a magnified view. o Measured number of detected events with and without metalens as a function of the x-position. The black solid line shows the Gaussian fit curve. p Schematic of the axicon metalens for CMOS imaging sensor light harvesting. q Transmission spectra of the metalens along the x-direction, x = 0 indicates the center of the HSI lens and x = 6 indicates 6 pixels (on the HSI system) away from the center of the lens. a–g Reprinted with permission from²²⁴. Copyright 2021 American Institute of Physics Publishing. (h–i) Reprinted with permission from²²⁵. Copyright 2021 John Wiley and Sons. j–l Reprinted with permission from²²⁷. Copyright 2022 John Wiley and Sons. m–o Reprinted with permission from²²⁸. Copyright 2021 American Chemical Society. p, q Reprinted with permission from²²⁹. Copyright 2023 De Gruyter