Infrared optical constants of CO and CO2 thin icy films

被引:126
作者
Baratta, GA [1 ]
Palumbo, ME [1 ]
机构
[1] Osservatorio Astrofis Catania, I-95125 Catania, Italy
来源
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION | 1998年 / 15卷 / 12期
关键词
D O I
10.1364/JOSAA.15.003076
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
We derived the optical constants (n, k) of carbon monoxide (CO) and carbon dioxide (CO2) cryofilms (T = 12 K) in the 4400-400-cm(-1) (2.27-25-mu m) infrared spectral range. Icy films were accreted on a silicon substrate inclined at an angle of 45 deg with respect to the infrared beam of the spectrometer. Transmittance spectra were taken at different thicknesses (0.05-3 mu m) with the electric vector parallel (p polarized) and perpendicular (s polarized) to the incidence plane. Optical constants were derived, with a nonlinear least-squares method, in a way such that they satisfy the Kramers-Kronig relation and give the best agreement with the transmittance spectra at oblique incidence for p and s polarizations measured at different thicknesses. We showed that this procedure can clearly separate the contribution of n and k to the spectrum. This is essential for deriving optical constants of ices where strong transitions occur. The optical constants derived can be found at the website http://www.ct.astro.it/lasp/optico.html. (C) 1998 Optical Society of America [S0740-3232(98)00612-7].
引用
收藏
页码:3076 / 3085
页数:10
相关论文
共 13 条
[1]  
Bohren C F., 1998, Absorption and Scattering of Light by Small Particles
[2]  
deGraauw T, 1996, ASTRON ASTROPHYS, V315, pL345
[3]   DETERMINATION OF OPTICAL-CONSTANTS OF THIN-FILM COATING MATERIALS BASED ON INVERSE SYNTHESIS [J].
DOBROWOLSKI, JA ;
HO, FC ;
WALDORF, A .
APPLIED OPTICS, 1983, 22 (20) :3191-3200
[4]  
Ehrenfreund P, 1997, ASTRON ASTROPHYS, V328, P649
[5]   The 2140 cm(-1) (4.673 microns) solid CO band: The case for interstellar O-2 and N-2 and the photochemistry of nonpolar interstellar ice analogs [J].
Elsila, J ;
Allamandola, LJ ;
Sandford, SA .
ASTROPHYSICAL JOURNAL, 1997, 479 (02) :818-838
[6]   MIDINFRARED AND FAR-INFRARED SPECTROSCOPY OF ICES - OPTICAL-CONSTANTS AND INTEGRATED ABSORBANCES [J].
HUDGINS, DM ;
SANDFORD, SA ;
ALLAMANDOLA, LJ ;
TIELENS, AGGM .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1993, 86 (02) :713-870
[7]  
Macleod H. A., 1986, THIN FILM OPTICAL FI
[8]  
Teixeira TC, 1998, ASTRON ASTROPHYS, V330, P711
[9]   INTERSTELLAR SOLID CO - POLAR AND NONPOLAR INTERSTELLAR ICES [J].
TIELENS, AGGM ;
TOKUNAGA, AT ;
GEBALLE, TR ;
BAAS, F .
ASTROPHYSICAL JOURNAL, 1991, 381 (01) :181-199
[10]  
TROTTA F, 1996, THESIS U J FOURIRER