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Updated: Mar 24, 2026

Construction and Characterization of External Cavity Diode Lasers for Atomic Physics
Published on: April 24, 2014
Note: Differential configurations for the mitigation of slow fluctuations limiting the resolution of digital lock-in
M Carminati1, G Gervasoni1, M Sampietro1
1Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano 20133, Italy.
Abstract:
The resolution of digital lock-in amplifiers working with a narrow bandwidth (<100 Hz) is limited by slow fluctuations, which can be two orders of magnitude larger (μV range) than the noise of the input amplifier (tens of nV). In order to tackle this issue, affecting state-of-the-art laboratory instrumentation and here systematically quantified, three differential sensing configurations are presented. They adapt to different setup conditions and are based on manual and automatic tuning of dummy references, allowing a 25-fold resolution improvement for enhanced long-term tracking of impedance sensors.
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