Freiburg 2024 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 57: Poster VIII
Q 57.10: Poster
Thursday, March 14, 2024, 17:00–19:00, Aula Foyer
Noise cancelling in solid-state lasers — •Thomas Konrad1, Tobias Steinle1, Roman Bek2, Michael Scharwaechter2, Matthias Seibold2, Andy Steinmann1, and Harald Giessen1 — 14th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart — 2Twenty-One Semiconductors GmbH, Allmandring 3, 70569 Stuttgart
Ultra-low-noise laser sources are key for fast and precise measurements, for instance in the fields of bioimaging, near-field optical microscopy, and gravitational wave detection. Besides efficient detection, the laser noise figure is the dominating factor that should be exploited to the fundamental limit demarked by the shot noise. Higher laser noise can be compensated by longer averaging, but the penalty in measurement time scales with the square of the excess noise. Especially with biological samples a significant longer measurement time can alter the results. Therefore, noise reduction of the system itself is more beneficial than longer measurement durations.
In this work we investigate an active noise cancelling scheme in solid state lasers, which are commonly used in many high precision applications. Instead of reducing the noise after the laser, we investigate approaches to reduce the laser noise at its source, namely the laser cavity itself. Due to a resonant coupling between the lifetime of the gain medium and the intracavity laser field, relaxation oscillations are one dominating noise phenomenon in solid-state lasers. Our approach is to actively modulate the absolute gain in a solid-state laser against the relaxation oscillations to achieve wide-band ultra-low intensity noise.
Keywords: solid-state laser; laser noise