Synthesis of one-dimensional selenium nanowires for ultrafast fiber lasers in different bands

One-dimensional (1D) semiconductor materials, frequently manifested as nanowires, nanotubes, and nanorods, exhibit exceptional electronic and optical characteristics due to the confinement of their constituent atoms within a single spatial dimension. Furthermore, they possess remarkable nonlinear optical response properties, harboring immense potential for use in ultrafast optics. Nevertheless, the exploration of their nonlinear optical properties remains inadequate and necessitates further investigation. Here, we report on a saturable absorber (SA) featuring what we believe to be novel 1D selenium (Se) nanowires (NWs) synthesized via the hydrothermal method and its nonlinear optical properties have been studied. It is found that the Se NWs SA has a low saturation intensity of 1.3 MW/cm 2 , suggesting a significantly reduced self-starting mode-locked threshold power. Employing the Se NWs SA, we successfully achieved an Er-doped fiber laser with a pulse width of 556 fs and a Tm-doped fiber laser with a predicted pulse width of 1.4 ps, respectively. Our results not only underscore the significant potential of 1D Se nanowires for utilization in broadband ultrafast fiber lasers but also contribute to the enhancement and diversification of research into the nonlinear optical properties of 1D semiconductor materials.