Differential noise-immune cavity-enhanced optical heterodyne molecular spectroscopy for improvement of the detection sensitivity by reduction of drifts from background signals

Gang Zhao, Thomas Hausmaninger, Weiguang Ma, Ove Axner

Research output: Contribution to journalArticle

5 Citations (Scopus)


The detection sensitivity of noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) is often limited by background signals that bring in drifts. A novel realization of NICE-OHMS, termed differential NICE-OHMS, that both reduces such drifts and enlarges the molecular signal is presented. It is based on simultaneous detection of NICE-OHMS signals in reflection and transmission, followed by a subtraction of the former (properly weighted) from the latter. An Allan plot analysis shows that the instrumentation could demonstrate a noise equivalent absorption per unit length (NEAL) of 4.7 × 10−14 cm−1, obtained for an integration time of 170 s.

Original languageEnglish
Pages (from-to)29454-29471
Number of pages18
JournalOptics Express
Issue number23
Publication statusPublished - 13 Nov 2017
MoE publication typeA1 Journal article-refereed


Cite this