Monday, July 17, 2006

US Patent 7076138 - Quantum Dots Embedded in Bandgap Medium for Nanophotonics

All optical photonics is being experimented with at various levels to get around the attenuation effects that occur in electronics. Several opportunities (and dangers) exist if this technology is successful such as massively parallel processing computation (which may mean an end to many current cryptography methodologies used in data encryption for secure banking and internet transactions). The problem with photonics in general is that the optical amplifiers that have been built are difficult to scale down. This patent proposes one route to nanophotonics using an arrangement of quantum dots in a frequency bandgap medium. Claim 1 reads:

1. A nonlinear optical and electro-optical material for optical signal processing, spectral and spatial filtering, light amplification or generation comprising a frequency bandgap medium exhibiting at least one photonic bandgap forbidden for electromagnetic modes of the light propagating in at least one direction, a set of quantum systems including at least one atom, molecule or quantum dot having at least two degenerate or non-degenerate discrete energy levels with at least one working transition between the energy levels interacting with the light, wherein said set of quantum systems is embedded into said frequency bandgap medium, and frequency of said at least one working transitions between the energy levels of the quantum systems lies inside the said photonic gap of the frequency bandgap medium developing a photonic passband inside the photonic bandgap and ensuring efficient suppression of spontaneous decay of the upper energy state of the working transition.