Open AccessCavity length control for Fourier domain mode locked (FDML) lasers with µm precision
Author(s) -
Simon Lotz,
Christin Grill,
Madita Göb,
Wolfgang Draxinger,
Jan Philip Kolb,
Robert Huber
Publication year - 2021
Publication title -
biomedical optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.362
H-Index - 86
ISSN - 2156-7085
DOI - 10.1364/boe.422898
Subject(s) - optics , optical coherence tomography , laser , mode locking , fourier domain , time domain , dispersion (optics) , materials science , physics , computer science , computer vision
In highly dispersion compensated Fourier domain mode locked (FDML) lasers, an ultra-low noise operation can only be achieved by extremely precise and stable matching of the filter tuning period and light circulation time in the cavity. We present a robust and high precision closed-loop control algorithm and an actively cavity length controlled FDML laser. The cavity length control achieves a stability of ∼0.18 mHz at a sweep repetition rate of ∼418 kHz which corresponds to a ratio of 4×10 -10 . Furthermore, we prove that the rapid change of the cavity length has no negative impact on the quality of optical coherence tomography using the FDML laser as light source.