Applications

Some of important applications of the Photonic Crystals.

Perfect dielectric mirror

The reflectivity of photonic crystals derives from their geometry and periodicity, not a complicated atomic-scale property (unlike metallic components mirror). The only demand we make on our materials is that for the frequency range of interest, they should be essentially lossless. Such materials are widely available all the way from
the ultraviolet regime to the microwave.

Nonlinear effects

Using of the materials with non-linear properties for construction of photonic crystal lattices open new  possibilities for molding the flow of light. In this case the dielectric constant is additionally  depend on intensity of incident electromagnetic radiation and any non-linear optics phenomena can appeared.

Resonant cavities

   

 Transmission Response for Perfect 2D Photonic Crystals.

 

Transmission Response for Defect 2D Photonic Crystals.

For the defect lattice we have some spikes appearing inside the region where there is normally zero transmission. This is expected behavior as we have broken the periodicity of the crystal and created a defect state.

Lasing

Cross section through the middle of the photonic crystal microcavity. A defect is formed in the 2D photonic crystal by removing a single hole, thus forming an energy well for photons similar to that for electrons in a quantum wire structure. Photons are also localized vertically by TIR at the air-slab interface. The combination of Bragg reflection from the 2D photonic crystal and TIR from the low-index cladding (air) results in a three-dimensionally confined optical mode.

-- Photon trap volume: ~ 2.5 (wave_length/2)^3~0.03mkm.
-- wave_length_pump=830 nm, wave_length_lasing=1504 nm.
-- Active region: indium gallium arsenic phosphide (InGaArP).

Waveguides and junctions

The existence of guided modes with different parities is an important factor that deeply influences the
transmission through the Y junction.  For the a/wave_length=0.26 we observe that the cavity is filled with a mode that has odd symmetry with respect to the axes of the output arms. At this frequency the PhC waveguide supports only the even mode. As a result, no field is transmitted from the input to the output arms of the Y junction.
A different behavior is observed for the a/wave_length=0.24. The cavity now produces a skewed field that can be understood as a superposition of modes with odd and even parities.



(a) Contour plot of the modulus of the magnetic field amplitude for wavelength a/wave_length=0.26. (b) Real part of the magnetic field along the dashed line in (a). (c) Same as in (a), with a/wave_length=0.24. (d) Same as in (b), with a/wave_length=0.26.