Image Number 5 for United States Patent #6404789.
A chiral laser apparatus comprises a layered structure configured to produce a photonic stop band, the layered structure including a upper chiral material layer, a middle excitable light-emitting layer, and a lower chiral material layer and an excitation source that, when applied to the layered structure, causes the middle light-emitting layer to emit electromagnetic radiation, such that polarized lasing at a lasing wavelength occurs in a direction perpendicular to the layered structure. The middle light-emitting layer may be configured to produce a defect such that lasing advantageously occurs at a wavelength corresponding to a localized photonic state within the photonic stop band. The excitation source may be an electrical power source connected to the layered structure via two or more electrodes. In another embodiment of the invention, the layered structure is replaced with a homogeneous chiral material doped with a light-emitting material. Excitation sufficient to cause lasing is provided by the electrical power source via a pair of electrodes connected to the chiral material. In yet another embodiment of the invention, the excitation source may be an electromagnetic wave source that applies an electromagnetic wave to the middle light-emitting layer to excite the middle layer sufficiently to cause lasing.