Frequency-Selective Optical Metalens Filters

A frequency-selective optical filter, comprising:

• a two-dimensional array of subwavelength unit cells, wherein each subwavelength unit cell comprises:
• an optically transmissive medium;
• and
• an array of passive deflector elements with varying diameters arranged within the optically transmissive medium,
• wherein interelement on-center spacings of the passive deflector elements are selected to:
• reflect optical radiation within a target bandwidth to a focal point, and
• deflect or pass optical radiation at frequencies outside of the target bandwidth to locations other than the focal point,
• wherein the array of passive deflector elements of each subwavelength unit cell is configured for a multi-frequency response with the interelement on-center spacings of a first set of the passive deflector elements selected as a function of a first operational wavelength, the interelement on-center spacings of a second set of the passive deflector elements selected as a function of a second operational wavelength of the optical metalens, and the interelement on-center spacings of a third set of the passive deflector elements selected as a function of a third operational wavelength of the optical metalens.

A frequency-selective optical filter, comprising:

• a two-dimensional array of subwavelength unit cells, wherein each subwavelength unit cell comprises:
• an optically transmissive medium;
• and
• an array of passive deflector elements with varying diameters arranged within the optically transmissive medium,
• wherein interelement on-center spacings of the passive deflector elements are selected to:
• reflect optical radiation within a target bandwidth to a focal point, and
• deflect or pass optical radiation at frequencies outside of the target bandwidth to locations other than the focal point.