title: Optical constants of far infrared materials. 2: crystalline solids.
abstract: The far infrared optical constants of four crystalline materials at room temperature and at 1.5 K are reported. The materials are crystal quartz, sapphire, germanium, and silicon. The first two of these are birefringent (uniaxial) and both sets the range from 30 cm(-1) to 350 cm(-1).
authors.forename: E V
authors.initials: EV
authors.lastname: Loewenstein
authors.forename: D R
authors.initials: DR
authors.lastname: Smith
authors.forename: R L
authors.initials: RL
authors.lastname: Morgan