Title
| Feedback Control Of Dynamical Instabilities In Classical Lasers And Fels |
Author(s)
| Bielawski, S ; Bruni, C ; Szwaj, C |
Affiliation
| (PhLAM/CERCLA, Villeneuve d'Ascq Cedex CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette ELETTRA, Basovizza, Trieste Universita di Firenze, Florence UVSOR, Okazaki ENEA C.R. Frascati, Frascati (Roma) Nagoya University Graduate School of Engineering, Nagoya) |
Publication
| 2005 |
In:
| 27th International Conference on Free Electron Lasers, Palo Alto, CA, USA, 21 - 26 Aug 2005, pp.391 |
Subject category
| Accelerators and Storage Rings |
Abstract
| Dynamical instabilities lead to unwanted full-scale power oscillations in many classical lasers and FEL oscillators. For a long time, applications requiring stable operation were typically performed by working outside the problematic parameter regions. A breakthrough occurred in the nineties [1], when emphasis was made on the practical importance of unstable states (stationary or periodic) that coexist with unwanted oscillatory states. Indeed, although not observable in usual experiments, unstable states can be stabilized, using a feedback control involving arbitrarily small perturbations of a parameter. This observation stimulated a set of works leading to successful suppression of dynamical instabilities (initially chaos) in lasers, sometimes with surprisingly simple feedback devices [2]. We will review a set of key results, including in particular the recent works on the stabilization of mode-locked lasers, and of the super-ACO, ELETTRA and UVSOR FELs [3]. |