A Broadband Metalens Exhibiting Superior Focusing Efficiency and Polarization Insensitivity

In this paper, we propose a broadband metalens that demonstrates efficient operation across the wavelength range of 1270 to 2070 nm and exhibits polarization insensitivity. Compared to no metalens, the metalens can enhance incident light transmissivity by approximately 10%. In the operational wavelength range, the average focusing efficiency of the metalens is 56%, with a maximum focusing efficiency of 70.7%. The average full width at half maximum (FWHM) of this structure measures
$0.5526\mu \mathrm{m}$