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Title: Generation of over 1000 Diffraction Spots from 2D Graded Photonic Super-Crystals
For the first time, we are able to generate over 1000 diffraction spots from a graded photonic super-crystal with a unit super-cell size of 12a × 12a where a is the lattice constant and hole radii are gradually changed in dual directions. The diffraction pattern from the graded photonic super-crystal reveals unique diffraction properties. The first order diffractions of (±1,0) or (0,±1) disappear. Fractional diffraction orders are observed in the diffraction pattern inside a square with vertices of (1,1), (1,−1), (−1,−1) and (−1,−1). The fractional diffraction can be understood from lattices with a period of a. However, a dual-lattice model is considered in order to explain higher-order diffractions. E-field intensity simulations show a coupling and re-distribution among fractional orders of Bloch waves. There are a total of 12 × 12 spots in E-field intensity in the unit supercell corresponding to 12 × 12 fractional diffraction orders in the diffraction pattern and 12 × 12 fractional orders of momentum in the first Brillouin zone in k-space.  more » « less
Award ID(s):
1661842
PAR ID:
10163102
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Photonics
Volume:
7
Issue:
2
ISSN:
2304-6732
Page Range / eLocation ID:
27
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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