Vector Soliton Bunching in Thulium-Holmium Fiber Laser Mode-Locked With PbS Quantum-Dot-Doped Glass Absorber

Saturable absorber based on PbS quantum-dot-doped glasses exhibiting bi-temporal recovery dynamics provides effective means for control of vector soliton bunching in 2-μm spectral range. The slow response of absorption creates an attractive force between pulses, and a bunch of tightly bounded vector solitons propagates in a cavity as an entity. Subjected to the joint action of attractive and repulsive forces, the solitons tend to oscillate within the bunch.