2D photonic crystals

2D PHOTONIC CRYSTALS

A 2D photonic crystal is a two-dimensional virtual medium whose refractive index is periodically modulated in two dimensions.

Example: The Holey fiber or photonic crystal fiber is made by taking cylindrical rods of glass in hexagonal lattice. Then heating and stretching the rods, the triangle-like airgaps is extended between the glass rods. These holes confine the modes.

A dielectric material dug with a periodic lattice containing deep and parallel cylindrical holes are formed. The wave propagation is being considered along directions normal to the holes.

A cross-section of such a 2D periodic lattice, with discrete triangular transitional symmetry, is shown in figure 5.31.

Two of the three vectors aj (j = 1, 2, 3) in figure 5.31 for a complete description of symmetry properties of the 2D photonic crystal in real space. In particular, the permittivity of the periodic medium is given by

Note

A periodic lattice with spacing between points are in the order of wavelength of light (500 nm).