Self-induced laser line sweeping in rare-earth-doped fiber lasers

Year: 2012

Pavel peterka

Cooperation: ORC University of Southampton, UK, a FJFI ČVUT

Rare-earth doped fiber lasers are prone to various instabilities that can lead to damage of their components. An interesting self-pulsing regime accompanied with laser line drift with time is the so called self-induced laser line sweeping. In fiber lasers, such a laser wavelength drift with time was firstly mentioned in literature in 2009, with a relatively broad span of about 1076 –1084 nm in ring ytterbium-doped fiber lasers by our team. The main characteristic of the self-sweeping is the sweeping of the laser line over the interval of several nanometers, and instantaneous bounce backward. The sweeping rate is usually slow, of the order of nm/s. This effect was attributed to spatial-hole burning caused by standing-wave in the laser cavity [2, 3]. Although the typical scanning direction is from shorter to longer wavelength, we have reported also the reverse direction [3, 4]. We have also reported the self-sweeping in erbium-doped fiber laser tunable in the range 1557-1567 nm. The laser was built in Fabry-Perot configuration according to Fig. 1. The sweeping took place within about 0.5 nm spectral interval defined by the spectral filter, see Fig. 2. The sweeping rate was dependent on the filter and polarization controller settings and varied in the range 0.8-12.5 nm/s.

The turning-up of self-sweeping in fiber lasers may help laser designer to find source of possible parasitic reflections and sources of instabilities. Although the self-sweeping is an undesired effect in ytterbium-doped fiber lasers intended for CW mode of operation, it may find useful applications, e.g., in interrogation of optical fiber sensor systems.

1. Peterka, P. - Navratil, P. - Dussardier, B. - Slavik, R. - Honzatko, P. - Kubecek, V.: Self-induced laser line sweeping and self-pulsing in double-clad fiber lasers in Fabry-Perot and unidirectional ring cavities. Laser Sources and Applications, Proc. of SPIE. Sv. 8433, (2012), 843309.
2. Peterka, P.- Navratil, P.- Maria, J.- Dussardier, B.- Slavik, R.- Honzatko, P. - Kubecek, V.: Self-induced laser line sweeping in double-clad Yb-doped fiber-ring lasers. Laser Physics Letters Sv. 9, č. 6 (2012), s. 445-450.
3. Honzátko, P. - Vojtíšek, P. - Navrátil, P. - Peterka P.: Self-induced laser line sweeping in tunable erbium-doped fiber laser. Proc. 5th EPS-QEOD Europhoton conf., WeP.28, 26-31 August 2012, Stockholm, Sweden.