P7 - Background-Corrected Determination of Optical Properties in the Far Infrared Range up to 1 mm
- Event
- AMA Conferences 2013
2013-05-14 - 2013-05-16
Nürnberg - Band
- Proceedings IRS² 2013
- Chapter
- IP - Poster Session
- Author(s)
- M. Kehrt, C. Monte - Physikalisch-Technische Bundesanstalt (PTB), Berlin (Germany)
- Pages
- 121 - 123
- DOI
- 10.5162/irs2013/iP7
- ISBN
- 978-3-9813484-3-9
- Price
- free
Abstract
The optical properties transmittance and reflectance of materials are defined as the flux of radiation reflected from or transmitted through a sample with respect to the incident flux. Usual measurement approaches for these quantities follow these definitions and determine the quotient of the reflected or transmitted flux with respect to the incident flux. However, in the Mid and Far Infrared Range (MIR and FIR) this approach might easily lead to wrong results because background radiation sources including the sample itself and temperature gradients inside the spectrometer are not correctly considered in this way. The observed deviations are particularly significant when working with cooled detectors. By carefully temperature stabilizing the spectrometer, by measuring at two flux levels of incident radiation and by using an appropriate evaluation scheme the transmittance and reflectance can be determined in the range from 25 μm up to 1000 μm with largely reduced systematic deviations.