Passively Q-switched ytterbium-doped fiber laser using the evanescent field interaction with bulk-like WTe₂ particles

The potential of bulk-like WTe₂ particles for the realization of a passive Q-switch operating at the 1 μm wavelength was investigated. The WTe₂ particles were prepared using a simple mechanical exfoliation method together with Scotch tape. By attaching bulk-like WTe₂ particles, which remained on the top of the sticky surface of a small segment of the Scotch tape, to the flat side of a side-polished fiber, a saturable absorber (SA) was readily implemented. A strong saturable absorption was then readily obtained through an evanescent field interaction with the WTe₂ particles. The modulation depth of the prepared SA was measured as ~2.18% at 1.03 μm. By incorporating the proposed SA into an all-fiberized ytterbium-doped fiber ring cavity, stable Qswitched pulses were readily achieved.