Mid-IR Lens Incorporates Waste Sulfur
TUCSON, Ariz., April 21, 2014 — Thin, inexpensive plastic lenses for IR imaging devices can be manufactured from waste sulfur generated by refining fossil fuels.
The plastic is transparent to wavelengths from 3 to 5 µm, have a refractive index between 1.865 and 1.745, and have high optical focusing power, according to researchers from the University of Arizona. Most polymers have refractive indices below 1.6 and transmit much less midrange IR, the researchers said.
Inexpensive sulfur lenses can be...