Wavelength-tunable spatiotemporal mode-locked fiber laser

We report a wavelength-tunable spatiotemporal mode-locked (STML) fiber laser based on nonlinear polarization rotation (NPR). Benefiting from both the saturable absorption and tunable filtering effect of the NPR, not only the multimode continuous wave (MM CW) but also fundamental spatiotemporal dissipative soliton pulse and its harmonic mode-locking (HML) can realize wavelength adjustment with the maximum adjustable range of 39 nm by simply adjusting the waveplates. Moreover, the maximum output power of the laser can reach 42.2 mW, 115.3 mW, 164.2 mW, and 151.5 mW for MM CW, fundamental, 2nd, and 3rd order HML spatiotemporal dissipative soliton, respectively. This work provides a new platform for exploring wavelength-tunable STML fiber lasers.