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Updated: Dec 24, 2025

Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
NQontrol: An open-source platform for digital control-loops in quantum-optical experiments
Christian Darsow-Fromm1, Luis Dekant1, Stephan Grebien1
1Institut für Laserphysik und Zentrum für Optische Quantentechnologien der Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
Abstract:
In this paper, we present NQontrol, a digital feedback-control solution based on the ADwin platform that delivers eight simultaneous feedback loops running with 200 kHz sampling frequency and offers five second-order filtering sections per channel for flexible shaping of the feedback loop. With this system, we demonstrate a Pound-Drever-Hall lock of an optical resonator and compare its performance to an analog reference implementation. A comprehensive support package written in Python, together with a web-based graphical user interface, makes the system quick to setup and easy to use, while maintaining the full flexibility of open-source platforms.
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