products     news     technology     partners     about us     careers     contact us     home   
 
 
pharmaceutical
homeland security
forensics
medical diagnostics
analytical chemistry
support & performance

 

 

Introduction to photonic crystals 

Photonic crystals are created when a strong periodic modulation of refractive index in a material causes photons to be localised in discrete energy states, giving rise to a photonic band structure.

This band structure is analogous to the electronic band structure of semiconductor materials, but is created using man-made periodic structures, rather than natural crystal structures.  We are therefore free to use patterns that do not occur in nature and fabricate these in well understood materials such as silicon.

Photonic crystals are not crystals in the sense that sapphire or diamonds are crystals. Photonic crystals can be made of many materials into which a periodic structure or strong refractive index modulation is fabricated.

One feature of photonic crystals is the ability to form a photonic band gap (PBG) region.  This represents a range of energies where no permitted states are allowed and the light of a wavelength residing within is forbidden to propagate.

The periodicity of a photonic crystal can be 1, 2 or 3 dimensional.  Two-dimensional photonic crystals can be fabricated in two different forms:

• Photonic crystal fibres which have air-holes running along their length
• Planar photonic crystals, of the type designed and manufactured by Mesophotonics, that contain arrays of holes each a couple of hundred nanometers deep

 

 

 




Illustrative planar photonic crystal structure and associated SEM micrographs of fabricated structures.


Simplified band gap structure.


 

a technology platform
photonic crystals in SERS
photonic quasicrystals
benefits of silicon
size reduction
photonic crystal links