A research topic on high-power fiber lasers was initiated in 2017 in the framework of the Fast-Mir project funded by the EMC3 labex. This new topic focuses on the study of Raman fiber lasers in order to develop high-brightness laser sources between 1.6 µm and 2 µm. We have developed several fiber Raman laser sources with diffraction-limited beam quality, high laser efficiency and facility of use due to the "all-fiber" nature of the sources. In particular, a wavelength close to 1680 nm was used for the optical pumping of crystalline laser materials doped with Tm3+ ions, in the framework of the Fast-Mir project. The results obtained in CW regime demonstrated a maximum output power of 6.3 W at 1655 nm and emission wavelength tunability between 1615 nm and 1690 nm. We have also developed a pulsed Raman laser based on a MOPA pulsed pump source synchronized on the frequency of the Raman cavity. This configuration allows simultaneous laser oscillation at the wavelengths of the first two Raman Stokes at 1660nm and 1800nm. The maximum conversion efficiency of the pump to Stokes 2 is close to 35%.
We also demonstrate a first-order random Raman fiber laser near 1650 nm pumped by an Erbium fiber laser source. The highest output power is 9.6 W at 1650 nm with a conversion efficiency of 78% and a spectral purity of 98.2% for Stokes 1.
Linearly-polarized high-power Raman fiber lasers near 1670 nm
R. Thouroude, H. Gilles, B. Cadier, T. Robin, A. Hideur, A. Tyazhev, R. Soulard, P. Camy, J-L. Doualan and M. Laroche
Laser Phys. Lett. 16 025102 (2019)
doi : https://doi.org/10.1088/1612-202X/aaf6a4