Abstract: An infrared emitter, which utilizes a photonic bandgap (PBG) structure to produce electromagnetic emissions with a narrow band of wavelengths, includes a semiconductor material layer, a dielectric material layer overlaying the semiconductor material layer, and a metallic material layer having an inner side overlaying the dielectric material layer. The semiconductor material layer is capable of being coupled to an energy source for introducing energy to the semiconductor material layer. An array of holes are defined in the device in a periodic manner, wherein each hole extends at least partially through the metallic material layer. The three material layers are adapted to transfer energy from the semiconductor material layer to the outer side of the metallic material layer and emit electromagnetic energy in a narrow band of wavelengths from the outer side of the metallic material layer.

Abstract: An infrared emitter, which utilizes a photonic crystal (PC) structure to produce electromagnetic emissions with a narrow band of wavelengths, includes a semiconductor material layer, a dielectric material layer overlaying the semiconductor material layer, and a metallic material layer having an inner side overlaying the dielectric material layer. The semiconductor material layer is capable of being coupled to an energy source for introducing energy to the semiconductor material layer. An array of surface features are defined in the device in a periodic manner or quasi-periodic. The emitter device is adapted to emit electromagnetic energy having spectral characteristics determined by parameters of the periodically distributed surface features, the parameters including shape, size, depth, distribution geometry, periodicity, material properties and defects.

Abstract: An absorption spectroscopy apparatus including a sample cell having a central axis, and a side wall coaxially positioned about the axis. The side wall defines a generally circular cross-section of the cell as taken along a plane extending perpendicular to the axis, wherein the generally circular cross-section of the sample cell has an average radius. The side wall includes a plurality of light reflective segments arrayed about the axis, wherein each reflective segment has a cross-section taken along a plane extending perpendicular to the axis of the cell that is concave with respect to the axis. The concave cross-section of each segment has an average radius that is unequal to the average radius of the generally circular cross-section of the sample cell. Among other aspects and advantages, the apparatus of the present disclosure is able to use incoherent, non-collimated light sources while maintaining high optical throughput efficiencies.