Hot Dielectrics as Light Sources for TPV Devices and Lasers

Experiments have demonstrated the feasibility of using flame-heated refractory dielectric solid bodies as wavelength-selective sources of light for special applications; in particular, for powering thermophotovoltaic (TPV) devices and for pumping lasers. A refractory dielectric material suitable for this purpose is one that, when heated by a flame, emits intense light with a spectral peak or peaks at one or more visible and/or infrared wavelengths. For a given laser or TPV application, one would choose such a material with an emission peak or peaks to match the corresponding laser absorption or TPV response peak(s). The emissive material can be in the form of a mantle or a felt, or it can be one of the chemical constituents of a solid crystal. To increase the effectiveness of a light source of this type, one can join a crystalline rod containing the emissive material with another rod (which serves as an optical waveguide) to form a device called a "superemissive light pipe" (SELP).