Figure 1.

Schematic representation of the photonic double quantum well heterostructure. a Cross-sectional view of the photonic crystal arrangement in the heterostructure. The circles represent the air spheres imbedded in each crystal, which may have different sizes as indicated. The backbone material of each crystal is shaded differently to represent a possible variation in the dielectric constant of that material. b Energy band structure of the double quantum well. The dashed line represents the energy of a possible resonant state

Cox and Singh Nanoscale Research Letters 2010 5:484-488   doi:10.1007/s11671-010-9546-9