▎ 摘　　要

The continuous wavelength tunable passively mode-locked Er-doped fiber laser (PML-EDFL) from C-band around 1544 nm to L-band around 1574 nm has been demonstrated in combination with graphene oxide (GO) nanoplatelets and the nonlinear polarization rotation (NPR) mechanism. The preparation of GO nano-platelets was based on the liquid phase exfoliation and then mixed with a PVA solution to produce the GO/PVA film. The PMLEDFL was operated at the fundamental mode-locked state in the longer wavelength regime (>1565 nm) and was turned into the fourth harmonic mode-locked state in the shorter wavelength regime. The wavelength tuning mechanism is attributed to the invisible filter by means of the in-line polarizer inside laser cavity, which can be verified from the emission peaks of the dual wavelengths mode-locked state. The relatively stable operation of tunable PML-EDFL at certain wavelength, disregarding environmental perturbations, has been confirmed to reveal promising commercial applications in the near future.