Platinum ditelluride-based saturable absorber and preparation method and application thereof

The invention relates to a saturable absorber based on platinum ditelluride and a preparation method and application thereof. The preparation method comprises the following steps: S1, depositing a platinum metal film on a substrate to obtain a platinum metal film-substrate; s2, the platinum metal film-substrate is placed in tellurium steam at the temperature of 420-500 DEG C, heat preservation is conducted for 50-60 min, and a platinum ditelluride film-substrate is obtained; and S3, stripping the platinum ditelluride thin film from the platinum ditelluride thin film-substrate, and transferring the platinum ditelluride thin film to a tapered region of a tapered optical fiber to obtain the saturable absorber based on platinum ditelluride. The platinum ditelluride-based saturable absorber prepared by the preparation method has good air stability, and the erbium-doped mode-locked fiber laser prepared by the preparation method can generate stable femtosecond-level mode-locked pulse, has high pulse intensity and sh