
Raman spectrometer for high precision temperature sensing of atmospheric gases
Author(s) -
Carter Mashburn,
Jacek Borysow
Publication year - 2021
Publication title -
applied optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.668
H-Index - 197
eISSN - 2155-3165
pISSN - 1559-128X
DOI - 10.1364/ao.419882
Subject(s) - analytical chemistry (journal) , materials science , chemistry , chromatography
We present a highly accurate Raman spectrometer capable of measuring changes in atmospheric temperature as small as 0.75 K with high spatial and temporal resolution. The spectrometer is based on a laser diode tuned to the resonant absorption line of the 85 R b isotope near 780.0 nm. A heated glass cell containing Rb atoms was used as an ultranarrowband atomic absorption notch filter with 0.3 c m -1 bandwidth and optical density as high as four. This filter was placed in front of the spectrograph and blocked up to 99.99% of the elastically scattered laser light, which made it possible to resolve the pure-rotational Raman spectra of molecular atmospheric gases. The relative intensities of pure-rotational Raman transitions were then used to infer atmospheric temperature changes.