Abstract: Systems and methods that use a single-crystal boule SiC sharpened into a cutting tool for ultra-precision machining of ferrous alloys are disclosed. Conventional ultra-precision machining uses single-crystal natural diamond. Despite the exceptional mechanical properties of diamond, its chemical properties have inhibited the extension of ultra-precision machining to iron-containing (ferrous) alloys. A single-crystal SiC cutting tool can be used to cut many materials for which diamond cutting tools are conventionally used. Additionally, a single-crystal SiC cutting tool can be used to cut materials for which diamond cutting tools are inappropriate, such as ferrous metals or nickel.

Abstract: Far infrared light is detected using semiconductor devices having at least two doped layers with adjacent doped layers separated by undoped layers. The technique includes doping to levels which establish work functions at interfacial barriers between the doped and undoped layers approximately equal to the photon energy of far infrared light of the longest wavelength to be detected. The devices are forward biased, cooled to a temperature at which thermal excitation of carriers in the doped layers is less than the work function, and exposed to far infrared light of a band width including the selected longest wavelength. Photo current produced by excitation of carriers over the interfacial barriers is then measured. The method can be applied to existing p-i-n diodes and superlattice structures as well as devices fabricated to respond to specific far infrared wavelength bands.