Wiegand B, Leykauf B, Jördens R, Krutzik M
Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.
QUARTIQ GmbH, Rudower Chaussee 29, 12489 Berlin, Germany.
Rev Sci Instrum. 2022 Jun 1;93(6):063001. doi: 10.1063/5.0090384.
We present a user-friendly and versatile tool for laser frequency stabilization. Its main focus is spectroscopy locking, but the software is suitable for lock-in techniques in general as well as bare proportional-integral-derivative (PID) operation. Besides allowing for sinusoidal modulation (up to 50 MHz), triangular ramp scanning, in-phase and quadrature demodulation (1-5 f), infinite impulse response, and PID filtering, Linien features two different algorithms for automatic lock point selection; one of them performs time-critical tasks completely on field-programmable gate arrays. Linien is capable of autonomously optimizing spectroscopy parameters by means of machine learning and can measure the error signal's power spectral density. The software is built in a modular way, providing both a graphical user interface as well as a Python scripting interface. It is based on the RedPitaya STEMLab platform but may be ported to different systems.
