Continuous wave Doppler-free spectroscopy on the 𝐀 𝟐𝚺+ ← 𝐗 𝟐𝚷𝟑/𝟐 transition in thermal nitric oxide

Abstract

The framework of this thesis is given by the development of a laboratory prototype for a new kind of gas sensing scheme to detect smallest quantities of nitric oxide in a large background of other gases. This thesis presents the underlying concepts of the sensing principle and some of the technical aspects developed for its investigation. In addition, the technique of Doppler-free saturated absorption spectroscopy, which is a standard technique in atomic physics, was applied to thermal nitric oxide molecules. It enabled direct resolution of the hyperfine structure and the determination of the corresponding hyperfine constants for the involved excited state. The results show the capabilities of the application of this technique to thermal molecules and in addition prove that saturation on the investigated transition is possible. This is an important result in terms of the overall goal the development of the trace gas sensor prototype.