“…In Optics, the refractive index of the medium must satisfied a relation of the same nature n (x) = n * (−x) [7][8][9][10][11][12][13] and ε (x) = ε * (−x) for dielectric permittivity in Metamaterials [14][15][16][17]. The notion of Parity-Time Symmetry is also extended to many order fields such as Photonics [7][8][9][10][11][12][13], Mechanics [18][19][20], Optomechanics [20][21][22][23], Acoustics [24][25][26] and Electronics [27][28][29][30][31] just to name few. In 2010, Reuter realized the first experimental demonstration of PTsymmetry in Optics by coupling two waveguides having equal amount of gain and loss [7].…”