1d photonic crystals

1D PHOTONIC CRYSTALS

A (1D) photonic crystal is a one-dimensional virtual medium, whose refractive index has periodic modulation (Fig. 5.30).

Thin film layers of materials of different dielectric constant are periodically deposited. This structure leads to a band gap in a particular propagation direction (as normal to the surface).

A Bragg grating is an example of this type of photonic crystal. The 1D photonic crystals can also include layers of non-linear optical material. The non-linear behavior provides field enhancement at wavelengths near degenerate band edge. This field enhancement (intensity) can reach N2 where N is the total number of layers.

Applications

• A graphene-based Bragg grating (one-dimensional photonic crystal) supports excitation of surface electromagnetic waves in the periodic structure by using He-Ne laser 633 nm as the light source.

• A ID graphene-dielectric photonic crystal can act as a far-IR filter. It can support low-loss surface plasmons for waveguide and sensing applications.

• 1D photonic crystals doped with bio-active metals (i.e. silver) can be used as sensing devices for bacterial contaminants.

• A planar 1D photonic crystals made of polymers is used to detect volatile organic compounds vapors in atmosphere.