Noise-like pulse generation in an Nd-doped single-mode all-fiber mode-locked Raman laser operating at 0.93 µm

Based on the Nd-doped single-mode fiber (SMF) as the gain medium and SMF as the Raman medium, an all-fiber mode-locked Raman laser operating at 0.93 µm waveband was demonstrated for the first time. A mandrel with a diameter of 10 mm was employed to introduce bending losses to suppress the dominant emission of Nd-doped fiber at 1.06 µm. A noise-like pulse with a pulse width of 194.70 fs, a repetition rate of 1.73 MHz and a single pulse energy of 2.03 nJ was obtained in the mode-locked Raman laser with a Stokes wavelength of 932.59 nm. Such an ultrafast all-fiber Raman laser operating at 0.93 µm has the advantages of low cost, simple structure and compactness, and can be used as an ideal light source for the two-photon microscopy.