Parity time symmetry in two dimensional chiral optical lattice, via positive and negative refraction.

The parity time symmetry and positive/negative refraction is investigated in chiral optical lattice. Significant parity time symmetry is reported in five level chiral optical lattice which satisfied the conditions R e (n r (±) (x , y)) = R e (n r ∗ (±) (− x , − y) and I m (n r (±) (x , y)) = − I m (n r ∗ (±) (− x , − y) for left and right circularly polarized beams. The related group indices, phase shifts and divergent angle are also satisfied the parity time symmetry conditions n g (±) (x , y)) = n g ∗ (±) (− x , − y) , ϕ (±) (x , y)) = ϕ ∗ (±) (− x , − y) and θ d , g (x , y) = θ d , g ∗ (− x , − y) for left and right circularly polarized beams. Maximum negative group index is calculated to − 25000. The maximum phase and group divergent angles are reported to 0.001 radian and − 0. 9 radian. The phase shifts in LCP and RCP beams are investigated to ± 0. 004 radian at a length L = 10 λ. The modified results have potential application in nanotechnology. [ABSTRACT FROM AUTHOR]