US 12,392,929 B2
Zero-index photonic crystals for visible and near infrared applications
Shizhao Liu, Troy, NY (US); and Joel L. Plawsky, Albany, NY (US)
Assigned to Rensselaer Polytechnic Institute, Troy, NY (US)
Appl. No. 17/265,063
Filed by RENSSELAER POLYTECHNIC INSTITUTE, Troy, NY (US)
PCT Filed Aug. 1, 2019, PCT No. PCT/US2019/044628
§ 371(c)(1), (2) Date Feb. 1, 2021,
PCT Pub. No. WO2020/028642, PCT Pub. Date Feb. 6, 2020.
Claims priority of provisional application 62/713,690, filed on Aug. 2, 2018.
Prior Publication US 2021/0311226 A1, Oct. 7, 2021
Int. Cl. G02B 1/00 (2006.01); G02B 5/18 (2006.01)
CPC G02B 1/005 (2013.01) [G02B 5/1857 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A two dimensional (2D) photonic crystal (PhC) structure comprising:
a substrate; and
a periodic grating structure formed on the substrate, the periodic grating structure comprising a plurality of gratings having a grating period, a, each pair of adjacent gratings separated by air, each grating having a grating width, d, and comprising a plurality of alternating layers of a first material and a second material, the first material corresponding to a high index material, the second material corresponding to a low index material, a ratio of a first refractive index of the first material to a second refractive index of the second material greater than or equal to two, each first material layer having a first thickness, t1, each second material layer having a second thickness, t2, wherein the 2D PhC structure has a structure refractive index at or near zero for a range of frequencies.