Optical devices having controlled nonlinearity

An optical device comprising:

• a solid state nonlinear material comprising a nanostructured extent, in at least one dimension, that is less than about 10 nm, and having an electronic band gap, EGap, that is at least about twice as large as an energy of a photon with a wavelength, λ, equal to an operational wavelength of the device, such that:
• E
• Gap
• ≥
• 2
• ⁢
• hc
• λ
• ,
• where h is Plank's constant, c is the speed of light, and λ is the operational wavelength of the optical device, the nonlinear material further being characterized by a switching figure of merit, ξ, having a value that is at least about 2π, such that:
• ξ=Reχ(3)/Imχ(3)≧2π,
• where Reχ(3) is nonlinear susceptibility real part and Imχ(3) is a nonlinear susceptibility imaginary part;
• a dielectric structure around at least one dimension of the nonlinear material in a geometric arrangement having a characteristic photonic band gap that at least partially overlaps the electronic band gap of the nonlinear material;
• and
• at least one waveguide disposed at the dielectric structure in sufficient proximity with the nonlinear material for coupling light to the nonlinear material and including input and output ports for directing incident light to the nonlinear material and for directing processed light away from the nonlinear material.