Related Experiment Video
Updated: Sep 6, 2025

Fabrication and Testing of Microfluidic Optomechanical Oscillators
Published on: May 29, 2014
Linien: A versatile, user-friendly, open-source FPGA-based tool for frequency stabilization and spectroscopy
B Wiegand1, B Leykauf1, R Jördens2
1Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.
We developed Linien, a versatile software tool for precise laser frequency stabilization and spectroscopy locking. It uses machine learning for autonomous optimization and offers both graphical and Python interfaces for broad accessibility.
Area of Science:
- Physics
- Engineering
- Computer Science
Background:
- Laser frequency stabilization is crucial for high-resolution spectroscopy.
- Existing methods can be complex and require manual tuning.
- A need exists for user-friendly, automated solutions.
Purpose of the Study:
- To introduce Linien, a versatile software tool for laser frequency stabilization.
- To provide a user-friendly platform for spectroscopy locking and general lock-in techniques.
- To enable autonomous optimization of spectroscopy parameters using machine learning.
Main Methods:
- The Linien software utilizes sinusoidal modulation (up to 50 MHz) and triangular ramp scanning.
- It incorporates in-phase and quadrature demodulation (1-5 f), infinite impulse response, and PID filtering.
- Two automatic lock point selection algorithms are implemented, with one leveraging field-programmable gate arrays for time-critical tasks.
Main Results:
- Linien demonstrates capability in spectroscopy locking and proportional-integral-derivative (PID) operation.
- Machine learning enables autonomous optimization of spectroscopy parameters.
- The software measures the error signal's power spectral density.
Conclusions:
- Linien offers a user-friendly and versatile solution for laser frequency stabilization.
- Its modular design, with graphical and Python interfaces, enhances accessibility.
- The software, based on the RedPitaya STEMLab platform, is adaptable to different systems.
Related Concept Videos
Linear Approximation in Frequency Domain
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
Load-frequency control
Aliasing
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original...
Time and frequency -Domain Interpretation of Phase-lag Control
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
Time and frequency -Domain Interpretation of Phase-lead Control
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
Linear Approximation in Time Domain
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length,...

