Retrieval of phase relation and emission profile of quantum cascade laser frequency combs

ABSTRACT Recently, the field of optical frequency combs experienced a major development of new sources. They are generally much smaller in size (on the scale of millimetres) and can extend

frequency comb emission to other spectral regions, in particular towards the mid- and far-infrared regions. Unlike classical pulsed frequency combs, their mode-locking mechanism relies on

four-wave-mixing nonlinear processes, yielding a non-trivial phase relation among the modes and an uncommon emission time profile. Here, by combining dual-comb multi-heterodyne detection

with Fourier-transform analysis, we show how to simultaneously acquire and monitor over a wide range of timescales the phase pattern of a generic (unknown) frequency comb. The technique is

applied to characterize both a mid-infrared and a terahertz quantum cascade laser frequency comb, conclusively proving the high degree of coherence and the remarkable long-term stability of

these sources. Moreover, the technique allows also the reconstruction of the electric field, intensity profile and instantaneous frequency of the emission. Access through your institution

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COMBS FOR PRECISION METROLOGY AND ATTOSECOND SCIENCE Article 28 January 2021 TOWARDS PHASE-STABILIZED FOURIER DOMAIN MODE-LOCKED FREQUENCY COMBS Article Open access 17 August 2022

FEMTOSECOND PULSES FROM A MID-INFRARED QUANTUM CASCADE LASER Article 22 November 2021 DATA AVAILABILITY The data that support the plots within this paper and other findings of this study are

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financial support from the Ministero dell’Istruzione, dell’Università e della Ricerca (project PRIN-2015KEZNYM NEMO), the European Union’s Horizon 2020 research and innovation programme

(Laserlab-Europe Project, grant no. 654148; CHIC Project, ERC grant no. 724344; ULTRAQCL Project, FET Open grant no 665158; Qombs Project, FET Flagship on Quantum Technologies grant no.

820419), the Italian ESFRI Roadmap (‘Extreme Light Infrastructure’—ELI Project) and the Swiss National Science Foundation (SNF200020-165639). AUTHOR INFORMATION Author notes * These authors

contributed equally: Francesco Cappelli, Luigi Consolino. AUTHORS AND AFFILIATIONS * CNR-INO – Istituto Nazionale di Ottica, Florence, Italy Francesco Cappelli, Luigi Consolino, Giulio

Campo, Iacopo Galli, Davide Mazzotti, Annamaria Campa, Pablo Cancio Pastor, Roberto Eramo, Paolo De Natale & Saverio Bartalini * LENS – European Laboratory for Non-Linear Spectroscopy,

Sesto Fiorentino, Italy Francesco Cappelli, Luigi Consolino, Giulio Campo, Iacopo Galli, Davide Mazzotti, Annamaria Campa, Pablo Cancio Pastor, Roberto Eramo, Paolo De Natale & Saverio

Bartalini * ppqSense Srl, Campi Bisenzio, Italy Iacopo Galli, Davide Mazzotti, Pablo Cancio Pastor & Saverio Bartalini * ASI – Agenzia Spaziale Italiana, Contrada Terlecchia, Matera,

Italy Mario Siciliani de Cumis * Institute for Quantum Electronics, ETH Zurich, Zürich, Switzerland Markus Rösch, Mattias Beck, Giacomo Scalari & Jérôme Faist Authors * Francesco

Cappelli View author publications You can also search for this author inPubMed Google Scholar * Luigi Consolino View author publications You can also search for this author inPubMed Google

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publications You can also search for this author inPubMed Google Scholar * Roberto Eramo View author publications You can also search for this author inPubMed Google Scholar * Markus Rösch

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this author inPubMed Google Scholar CONTRIBUTIONS F.C. and S.B. conceived the experiment. L.C., F.C., G.C., I.G., M.S.d.C., A.C., P.C.P. and R.E. performed the measurements. F.C., G.C., R.E.

and S.B. analysed the data. L.C. and F.C. wrote the manuscript. G.C., D.M., M.S.d.C., P.C.P., R.E., S.B., G.S., J.F. and P.D.N. contributed to manuscript revision. J.F., G.S., M.R. and M.B.

provided the quantum cascade lasers. L.C., F.C., D.M., P.C.P., R.E., S.B., G.S., J.F. and P.D.N. discussed the results. All work was performed under the joint supervision of P.D.N. and S.B.

CORRESPONDING AUTHORS Correspondence to Francesco Cappelli or Luigi Consolino. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing interests. ADDITIONAL INFORMATION

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L., Campo, G. _et al._ Retrieval of phase relation and emission profile of quantum cascade laser frequency combs. _Nat. Photonics_ 13, 562–568 (2019).

https://doi.org/10.1038/s41566-019-0451-1 Download citation * Received: 24 July 2018 * Accepted: 29 April 2019 * Published: 17 June 2019 * Issue Date: August 2019 * DOI:

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