Efficient, Tunable 1.7-μm All-Fiber Pulsed Raman Laser Pumped by L-Band DSR Pulses

We demonstrate a highly efficient, wavelength-adjustable 1.7-μm all-fiber Raman pulse laser, utilizing dissipative-soliton-resonance (DSR) rectangular pulses as the pump. A 50-m GeO ₂ -doped silica fiber serves as the Raman gain medium. When pumped at 1580.2 nm, the 1st-order Raman pulse at 1698.5 nm exhibits a spectral purity as high as 97.7% and a Raman optical conversion efficiency of 59.4%, marking the highest levels ever achieved in a 1.7-μm all-silica-fiber pulsed Raman laser, to the best of our knowledge. The output Raman pulses exhibit a pulse width of approximately 10 ns and achieve a maximum average power of 325.3 mW. By adjusting the central wavelength of DSR pulses, the Raman laser can be continuously tuned across a range of 31.5 nm (1676.4~1707.9 nm). This is the widest tunable range yet reported for an all-silica-fiber pulsed Raman laser operating at 1.7 μm. Our system offers a simple and attractive solution for the realization of efficient, tunable all-fiber pulse lasers within the 1.7-μm band.