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arXiv · 1804.04162

Evidence of Linear Chirp in Mid-Infrared Quantum Cascade Lasers

Matthew Singleton·Pierre Jouy·Mattias Beck·Jérôme Faist
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Abstract

We measure the inter-modal phase relation of a quantum cascade laser frequency comb operating at 8 um using a coherent beatnote spectroscopy. We find these phases to be reproducible after cycling the power of the device, and to be smoothly varying with driving current. Moreover, these phases describe a comb state exhibiting a simple, linear chirp, which in fact corresponds to the lowest state of chirp to minimise the amplitude modulation, as required for combs driven by four wave mixing in a gain medium with a short gain recovery lifetime.

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Matthew Singleton, Pierre Jouy, Mattias Beck, Jérôme Faist. 2018-04-11. Evidence of Linear Chirp in Mid-Infrared Quantum Cascade Lasers. https://arxiv.org/abs/1804.04162

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