Interleaved difference-frequency generation for microcomb spectral densification in the mid-infrared
Abstract
With their compact size and semiconductor-chip-based operation, frequency microcombs can be an invaluable light source for gas spectrcoscopy. However, the generation of mid-infrared (mid-IR) frequency combs with gigahertz line spacing as required to resolve many gas spectra represents a significant challenge for these devices. Here, a technique referred to as interleaved difference-frequency generation (iDFG) is introduced that densifies the spectral line spacing upon conversion of near-IR comb light into the mid-IR light. A soliton microcomb is used as both a comb light source and microwave oscillator in a demonstration, and the spectrum of methane is measured to illustrate how the resulting mid-IR comb avoids spectral undersampling. Beyond demonstration of the iDFG technique, this work represents an important feasibility step towards more compact and potentially chip-based mid-IR gas spectroscopy modules.
Additional Information
© 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement. Received 12 November 2019; revised 3 March 2020; accepted 5 March 2020 (Doc. ID 382992); published 8 April 2020. The authors thank Scott Diddams, Christian Frankenberg, Neil Fromer, Qi-Fan Yang, and Xu Yi for helpful discussions. The content of the information does not necessarily reflect the position or the policy of the federal government, and no official endorsement should be inferred. Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. C. B. gratefully acknowledges postdoctoral fellowship support from the Resnick Sustainability Institute at Caltech. Funding: Defense Threat Reduction Agency (HD-TRA11810047); Air Force Office of Scientific Research (FA9550-18-1-035); Resnick Sustainability Institute for Science, Energy and Sustainability, California Institute of Technology, and the Kavli Nanoscience Institute. The authors declare no conflicts of interest.Attached Files
Published - optica-7-4-309.pdf
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Additional details
- Eprint ID
- 103199
- Resolver ID
- CaltechAUTHORS:20200514-130155611
- Defense Threat Reduction Agency (DTRA)
- HD-TRA11810047
- Air Force Office of Scientific Research (AFOSR)
- FA9550-18-1-0353
- Resnick Sustainability Institute
- Kavli Nanoscience Institute
- Created
-
2020-05-14Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Kavli Nanoscience Institute, Resnick Sustainability Institute