Long-wave infrared absorption measurement of undoped germanium using photothermal common-path interferometry
Abstract
Germanium is one of the most commonly used materials in the longwave infrared ( λ ∼ 8 − 12 µ m ), but ironically, its absorption coefficient is poorly known in this range. An infrared photothermal common-path interferometry system with a tunable quantum cascade pump laser is used to measure the absorption coefficient of > --> 99.999 % pure undoped germanium as a function of wavelengths between 9 and 11 µm, varying between about 0.15 and 0.45 c m − 1 over this range.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 09, 2020
- Source ID
- 10.1364/ao.390374
Entities
People
- Avijit Das
- Joseph J. Talghader
- Merlin L. Mah
- Yu-jen Lee
Organizations
- Army Research Office
- Office of Naval Research