Spontaneous Raman scattering at trace gas concentrations with a pressurized external multipass cavity

Autor: Andreas Muller, Juan Gomez Velez
Rok vydání: 2021
Předmět:
Zdroj: Measurement Science and Technology. 32:045501
ISSN: 1361-6501
0957-0233
DOI: 10.1088/1361-6501/abd11e
Popis: A setup is described with which the spontaneous Raman scattering rate from pressurized gas samples is greatly enhanced inside a near-concentric optical cavity. The pump source is a high power multimode semiconductor laser diode that receives optical feedback from the cavity by way of a volume Bragg grating, resulting in a linewidth of 80 pm and circulating power close to 100 W. Under pressurization (up to 8 bar) a limit of detection below 100 parts-per-billion was obtained for gaseous hydrogen, measured in ambient air and in breath. Furthermore, isotopic trace detection is demonstrated by headspace measurements of semiheavy water.
Databáze: OpenAIRE