Patent ID: 9482796
Filing Date: 2016-11-01
CPC Classification: G02B,G02F,G03B,Y10T

Claim Text:
1. An optical device, comprising: a substrate; a first metasurface disposed over the substrate, the first metasurface comprising a first high-contrast pattern operable for modifying, over a first phase profile, a phase front of a collimated narrow-band light beam incident to the first metasurface; a second metasurface disposed over a plane parallel to the first metasurface, the second metasurface comprising a second high-contrast pattern operable for shaping, over a second phase profile, the phase front of the modified phase front of the incident light beam into a converging spherical phase front; and a spacer layer in which the modified phase front of the incident light beam diffracts, the spacer layer disposed in a controllable separation between the first metasurface and the second surface, the separation relating to a position of a focus point of the converging spherical phase front beyond the second metasurface, in relation to the first metasurface in a direction of propagation of the incident light beam, wherein controllably changing the separation between the first metasurface and the second metasurface by a first distance correspondingly changes the position of the focus point of the converging spherical phase front by a second distance, wherein the second distance exceeds the first distance to a significant degree.