Interleaved Electro-Optic Dual Comb Generation to Expand Bandwidth and Scan Rate for Molecular Spectroscopy and Dynamics Studies near 1.6 μm

Published

October 11, 2021

Author(s)

Jasper Stroud, James Simon, Gerd Wagner, David Plusquellic

Abstract

A chirped-pulse interleaving method is reported for generation of dual optical frequency combs based on electro-optic phase modulators (EOM) in a free-running all-fiber based system. The interleaving scheme effectively separates the EOM's (+) and (-) sidebands and any number of orders in the down-converted intermediate frequency (IF) region. The method has been demonstrated to 4th-order thereby extending the frequency coverage to 120 GHz. Two different methods are demonstrated that share the same experiment configuration and require simple changes to the programmed waveforms of an arbitrary waveform generator. The first method is based on a segmented scan approach to acquire the complex transmission spectrum of 4 lines of CO2 near 1.6 μm with 50 kHz resolution and > 1 million comb lines. At 87% fractional transmission over a 2.2 m optical path, the signal-to-noise ratio of >500:1 and the noise equivalent absorption of 9.4x10 8 cm-1 Hz-1/2 is observed for the 3rd-order spectra in a 40 sec integration period. The second method is based on a dual chirped scheme to achieve much faster spectral scan rates at the expense of fewer comb lines. Rapid passage effects in the complex transmission line shape of CO2 are shown at scan rates up to 43.5 MHz ns-1 and analyzed using the Maxwell-Bloch formalism. Both methods are well-suited for applications in the areas of remote sensing, molecule reaction dynamics and sub-Doppler high-resolution studies across the wide spectral coverage available to EOMs.

Citation

Nature Photonics

Volume

29

Issue

21

Pub Type

Journals

Download Paper

https://doi.org/10.1364/OE.434482

Local Download

Keywords

Interleaving, Arbitrary waveform generators, Electro-optic phase modulators, Dual optical frequency comb methods, Molecular dynamics, Remote sensing, Spectroscopy

Citation

Stroud, J. , Simon, J. , Wagner, G. and Plusquellic, D. (2021), Interleaved Electro-Optic Dual Comb Generation to Expand Bandwidth and Scan Rate for Molecular Spectroscopy and Dynamics Studies near 1.6 μm, Nature Photonics, [online], https://doi.org/10.1364/OE.434482, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932662 (Accessed March 8, 2025)