Thin-film 28-μm and 38-μm absorption in single-layer films

Abstract

A systematic study was made of thin-film absorption at 2.8microm and 3.8 microm for a wide variety of transparent coating materials. The extinction and absorption coefficients were measured using HF/DF chemical laser calorimetry in single-layer films of PbF(2), LiF, YbF(3), NaF, ThF(4), As(2),S(3), As(2),Se(3), Si, MgO, ZnSe, and Al(2),O(3), on CaF(2), substrates. The lowest absorbing film materials were the As glasses, ZnSe, and some fluorides. In these cases, high-purity starting material led to the lowest loss films.

Are Silicon Nanoparticles an Interstellar Dust Component?

“…For glassy we take m@@ from Palik (1985) for 0.01 SiO 2 , km \ j \ 7 km, but with one modiÐcation : for 0.15 km \ j \ 3.6 km, we set m@@ \ 1.0 ] 10~4 based on the absorption coefficient measured by Harrington, Rudisill, & Braunstein (1978). For 7 km \ j \ 500 km, we take m@@ from Henning & Mutschke (1997) for a glassy sample SiO 2 at 100 K (the optical properties of glassy are not SiO 2 sensitive to temperature ; see Henning & Mutschke 1997).…”

Magnesium Oxide (MgO)

“…Harrington et al [69] used a laser calorimeter to measure the aborption in electron-beam evaporated MgO films. They tried to minimize extrinsic absorption by using high-purity starting material.…”