Preparation of tellurium nanowires and its application in ultrafast photonics

As a kind of semiconductors, tellurium has attracted much attention due to its superior optical, electrical, and thermoelectric properties. In particular, a lot of research on low-dimensional tellurium has been performed in recent years, but with relatively few work on its applications in ultrafast photonics. In this work, a femtosecond fiber laser was realized using the prepared tellurium nanowires as the saturable absorber. Tellurium nanowires were synthesized by the hydrothermal method and then deposited on the tapered optical fiber to form the tellurium saturable absorber (Te-SA). The saturable absorption property of Te-SA was tested by the two-arm balance detection method, the saturation intensity and modulation depth were determined to be 8.9 MW/cm2 and 27.0%, respectively. Then, Te-SA was applied in the erbium-doped fiber laser and a stable mode-locked fiber laser with a pulse width of 621 fs was achieved. The results indicate the great potential application of tellurium nanowires in ultrafast photonics.