Microcontroller-based locking in optics experiments

K Huang (1, 2) , H Le Jeannic (2) , J Ruaudel (2) , O Morin (2) , J Laurat (2)

1 ECNU - East China Normal University [Shangaï]
2 LKB (Jussieu) - Laboratoire Kastler Brossel

Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments.

Domaines: Optique [physics.optics]; Systèmes et contrôle [cs.SY]

K Huang, H Le Jeannic, J Ruaudel, O Morin, J Laurat. Microcontroller-based locking in optics experiments. Review of Scientific Instruments, 2014, 85 (12), pp.123112. ⟨10.1063/1.4903869⟩. ⟨hal-03269656⟩