Large stimulated Brillouin scattering amplification in gases

We exploit backward stimulated Brillouin scattering in gases to achieve unprecedented nonlinear optical amplification in fibers. The gain coefficient is 10 times larger than any reported nonlinear gain in gas-filled HC-PCF and 6 times larger than the largest nonlinear gain in standard silica single-mode fiber (SMF). Furthermore, our system can work at any wavelength from vacuum ultraviolet to mid-infrared thanks to the nature of stimulated Brillouin scattering. This massive gain enables us to realize a single-pass gas Brillouin laser with 140 mW threshold power over 50 m of fibre. This platform opens new avenues in gas Brillouin lasing, all-optical signal processing and high performance distributed fiber sensing.