Reflection and transmission measurements over the 800-33-cm-1 (12.5–300-µm) region are presented for several materials. Data include the spectral reflectance of ADP, KDP, NaCl, KBr, CsBr, CsI, TIBr, TlCl, and KRS6. Curves of the external transmittance of samples of Kel-F, Teflon, germanium, Millipore filters, and a Kodak Wratten filter are included. Data are given on the fundamental absorption frequencies of MgO, LiF, TiO2, KBr, TlCl, and TlI.
D. E. McCarthy, "Reflection and Transmission Measurements in the Far Infrared," Appl. Opt. 10, 2539-2541 (1971)