All-dielectric subwavelength metasurface focusing lens.
We have proposed, designed, manufactured and tested low loss dielectric micro-lenses for infrared (IR) radiation based on a dielectric metamaterial layer. This metamaterial layer was created by patterning a dielectric surface and etching to sub-micron depths. For a proof-of-concept lens demonstration, we have chosen a fine patterned array of nano-pillars with variable diameters. Gradient index (GRIN) properties were achieved by engineering the nano-pattern characteristics across the lens, so that the effective optical density of the dielectric metamaterial layer peaks around the lens center, and gradually drops at the lens periphery. A set of lens designs with reduced reflection and tailorable phase gradients have been developed and tested, demonstrating focal distances of a few hundred microns, beam area contraction ratio up to three, and insertion losses as low as 11%.
Paul R
PR
West
James L
JL
Stewart
Alexander V
AV
Kildishev
Vladimir M
VM
Shalaev
Vladimir V
VV
Shkunov
Friedrich
F
Strohkendl
Yuri A
YA
Zakharenkov
Robert K
RK
Dodds
Robert
R
Byren
D017076:Computer-Aided Design; D004867:Equipment Design; D007909:Lenses; D008420:Manufactured Materials; D012031:Refractometry / Q000295:instrumentation*; D055053:Terahertz Radiation