Figure 2

(a,b) Measured cross-sections of the focal spots of the conventional metalens and the BLM, respectively. The two inserts are the corresponding images of focal spot captured by CCD. (c,d) Images of 1951 USAF resolution test chart taken from the conventional metalens and the BLM with white light illumination (scale bar = 7 μm). The two inserts are the corresponding results of monochromatic images after 630 nm-wavelength filter, respectively.