Hybrid fiber/bulk laser source designed for CO<sub>2</sub> and wind measurements at 2.05 µm
Julien Lahyani, Mathys Thiers, Fabien Gibert, Dimitri Édouart, Julien Le Gouët, Nicolas Cézard
Abstract
and wind monitoring using differential absorption LIDAR (DIAL) and coherent detection at 2.05 µm. This source features a master oscillator power amplifier (MOPA) architecture made of four fiber stages and one single-pass, end-pumped, bulk amplifier. This Letter focuses on the single-pass bulk amplifier performance and on the hybrid architecture benefits for DIAL and coherent detection. The bulk material is a holmium-doped YLF crystal that provides high efficiency amplification at 2.05 µm. This laser offers an energy breakthrough as compared to the classical stimulated Brillouin scattering (SBS) limit encountered in a fiber laser without compromising robustness, thanks to very few free-space optical elements and a small optical path. It delivers pulse energy and repetition frequency of 9.0 or 1.2 mJ/20 kHz with 200 ns quasi Fourier-transform limited pulses.