Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Dual comb spectroscopy with tailored spectral broadening in nanophotonic Si3N4



Esther Baumann, Edgar Perez, Gabriel M. Colacion, Fabrizio Giorgetta, Kevin Cossel, Gabriel Ycas, David Carlson, Kartik Srinivasan, Scott Papp, Ian Coddington, Nathan R. Newbury


Spectral broadening of compact robust Er+: fiber combs is demonstrated with tailored Si3N4 waveguides to obtain spectrally-smooth broadened light in the 2 μm 2.5 μm atmospheric water window for gas spectroscopy. This successfully extends the Er+ spectrum to longer wavelengths not accessible with silica-based fiber systems. To verify the broadband source performance, spectra are acquired with a CO2 and CO gas cell and compared, with excellent agreement, to database line shape models. The dual-comb spectroscopic figure of merit for the new source is 6x106/√Hz, roughly equivalent to that of all-fiber dual comb setups around 1.6 μm. This spectroscopic performance shows that the high coherence between the two combs is retained in the broadening process.
Optics Express


dual-comb spectroscopy, spectral broadening, SiN waveguides


Baumann, E. , Perez, E. , Colacion, G. , Giorgetta, F. , Cossel, K. , Ycas, G. , Carlson, D. , Srinivasan, K. , Papp, S. , Coddington, I. and Newbury, N. (2019), Dual comb spectroscopy with tailored spectral broadening in nanophotonic Si3N4, Optics Express (Accessed July 17, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created April 15, 2019, Updated April 10, 2023