Abstract
Single-mode frequency-tuneable semiconductor lasers based on monolithic integration of multiple cavity sections are important components, widely used in optical communications, photonic integrated circuits and other optical technologies. To date, investigations of the ultrafast switching processes in such lasers, essential to reduce frequency cross-talk, have been restricted to the observation of intensity switching over nanosecond-timescales. Here, we report coherent measurements of the ultrafast switch-on dynamics, mode competition and frequency selection in a monolithic frequency-tuneable laser using coherent time-domain sampling of the laser emission. This approach allows us to observe hopping between lasing modes on picosecond-timescales and the temporal evolution of transient multi-mode emission into steady-state single mode emission. The underlying physics is explained through a full multi-mode, temperature-dependent carrier and photon transport model. Our results show that the fundamental limit on the timescales of frequency-switching between competing modes varies with the underlying Vernier alignment of the laser cavity.
Original language | English (US) |
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Article number | 3076 |
Journal | Nature communications |
Volume | 9 |
Issue number | 1 |
DOIs | |
State | Published - Dec 1 2018 |
Funding
We acknowledge the support from: the Engineering and Physical Sciences Research Council (EPSRC), UK (\u2018COTS\u2019 and \u2018HyperTerahertz\u2019 programmes, EP/J017671/1 and EP/P021859/1); European Union FET-Open grant ULTRAQCL 665158; the European Cooperation in Science and Technology (COST) Action BM1205; Centre National de la Recherche Scientifique (CNRS), France; and a Royal Society International Exchange grant (IE120898). E.H.L. and A.G.D. are grateful for support from the Royal Society and Wolfson Foundation.
ASJC Scopus subject areas
- General Chemistry
- General Biochemistry, Genetics and Molecular Biology
- General Physics and Astronomy