Efficient, watt-level, tunable 1.7 µm fiber Raman laser in H2-filled hollow-core fibers

Abstract

We report here an efficient watt-level tunable 1.7 µm fiber gas Raman laser. Pumped by a homemade pulsed fiber amplifier around 1.5 µm wavelength, a tunable laser ranging from 1687 to 1723 nm is demonstrated in a hydrogen-filled hollow-core photonic crystal fiber (HC-PCF). A maximum average power of ∼ 0.8 W (pulse energy of ∼ 1.6 µ J ) is achieved on a 20-m-long HC-PCF filled with 16 bar of hydrogen gas, corresponding to a maximum Raman power conversion efficiency of 60%. A steady-state model of the rotational stimulated Raman scattering in hydrogen-filled HC-PCF, considering the pump pulse shape, is also established. The predicted output power and pulse shapes of the pump and Stokes waves are in good agreement with the experimental results. Our system offers an elegant solution for realizing efficient, tunable, and high-power fiber lasers operating at 1.7 µm wavelength range.