DESCRIPTION: A flat lens focuses light by imparting an instantaneous phase shift to the light instead of working like a conventional lens by changing the distance traveled through a higher index of refraction material.  Such a lens offers numerous advantages over conventional lens.  It does not impart aberrations upon the light including spherical aberration, astigmatism, and coma.  Additionally, wide-angle lens will not exhibit the fish-eye effect that occurs with conventional wide-angle lens.  The resulting image or signal will not require complex corrective techniques.  Such a lens will exhibit a large reduction in weight, greater than 90 percent depending upon the diameter and focal length.  Additionally, this lighter weight lens would only need lighter weight holders, and weight savings for the holder is estimated to be greater than 50 percent.  This would have a large reduction in the weight of optical and infrared sensors and would require less delta v for satellites utilizing such sensors.  Fresnel Lens are a type of flat lens, but suffer from serious deficiencies in the image quality due to varying width of the rings that make up the lens.  A flat lens would not experience such deficiencies as the phase shift is instantaneous.  Recently it was reported by Aieta et al. (2015) that a multi-color flat lens was demonstrated in the laboratory.
 

PHASE I: Assess the feasibility of developing a flat lens that works across a broader region of the spectrum than around a particular laser wavelength.  Investigate methods of color correction for such flat lenses.
 

PHASE II: Build and test that a flat lens that will focus light and has reduced aberrations compared to conventional lenses.
 

PHASE III DUAL USE APPLICATIONS: Numerous potential applications exist. Any optical device could be made much lighter. Military devices include ultra light optics for: cameras (satellites, drones), binoculars, and lasers. Commercial applications include telecom, camera lenses, prescription glasses, or optical implants.
 

REFERENCES:

1. Aieta, F., et. al. "Aberration-Free Ultra thin Flat Lenses and Axicons at Telecom Wavelengths Based on Plasmonic Metasurfaces," dx.doi.org/10.1021/nl302516v, Nano Letters, 2012, 12, 4932-4936.
 

2. Aieta, F., A. Kats, M. A., Genevet, P., and Capasso, F.  Multiwavelength achromatic metasurfaces by dispersive phase compensation.  Science 20 March 2015:  347 (6228), 1342-1345.Published online 19 February 2015 [DOI:10.1126/science.aaa2494].