Figure 5.

Electrically tunable active imaging using the bifocal metalens combined with LCs. a) Schematic of the optical setup to image the negative 1951 USAF resolution target. b) Captured images of negative 1951 USAF resolution targets at the focal plane of (i) and (ii) f ₁, and (iii) and (iv) f ₂ with an electrical bias of 1.1 and 1.3 V, to produce LCP and RCP, respectively. c) Schematic of the optical setup to image two positive 1951 USAF resolution targets. d) Captured images of positive 1951 USAF resolution targets at the focal planes of i) f ₁ and ii) f ₂, with applied electrical biases of 1.1 and 1.3 V, respectively.