Systematic errors in dual-comb spectroscopy stemming from non-linear pulse interaction in common fiber

Published

May 20, 2024

Author(s)

Mathieu Walsh, Nathan Malarich, Scott Egbert, Ryan Cole, Esther Baumann, GREGORY RIEKER, Ian Coddington, Kevin Cossel, Nathan Newbury, Jerome Genest

Abstract

Systematic errors are experimentally observed in dual-comb spectroscopy when pulses from the two comb sources travel in a common fiber before interrogating the sample of interest. When interrogating a molecular gas these errors can varyingly distort both the observed molecular lineshapes and retrieved concentration. Simulations of the dual-comb interferograms based on a generalized non-linear Schrodinger equation highlight two sources for these systematic errors. First, self-phase modulation changes the spectral content of the field that interrogates the molecular response while not modifying the baseline interferogram accordingly. This effect leads to line intensity errors. Second, cross-phase modulation induces a pulse interaction that modifies the relative inter-pulse delay between combs, thus introducing interferogram sampling errors and creating a characteristic asymmetry on spectral lines. A quantitative understanding of these effects is critical for precise and accurate dual-comb spectroscopic measurements of gases, including greenhouse gases.

Citation

Optics Express

Volume

32

Issue

11

Pub Type

Journals

Download Paper

https://doi.org/10.1364/OE.523623

Local Download

Citation

Walsh, M. , Malarich, N. , Egbert, S. , Cole, R. , Baumann, E. , Rieker, G. , Coddington, I. , Cossel, K. , Newbury, N. and Genest, J. (2024), Systematic errors in dual-comb spectroscopy stemming from non-linear pulse interaction in common fiber, Optics Express, [online], https://doi.org/10.1364/OE.523623, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956543 (Accessed March 14, 2026)