title: Thulium/holmium-doped fiber laser passively mode locked by black phosphorus nanoplatelets-based saturable absorber.
abstract: By coupling black phosphorus (BP) nanoplatelets (NPs) with a fiber-taper evanescent light field, a saturable absorber (SA) based on the BP NPs has been successfully fabricated and used in a thulium/holmium-doped fiber laser as the mode locker. The SA had a modulation depth of ∼9.8% measured at 1.93 μm. A stable mode-locking operation at 1898 nm was achieved with a pulse width of 1.58 ps and a fundamental mode-lock repetition rate of 19.2 MHz. By increasing the pump intensity, phenomena of multi-pulsing operations, including harmonic mode-locked states and soliton bunches, were obtained in the experiment, showing that the BP NPs possess an ultrafast optical response time. This work suggests that the BP NPs-based SA is potentially useful for ultrashort, pulsed laser operations in the eye-safe region of 2 μm.
authors.forename: Hao
authors.initials: H
authors.lastname: Yu
authors.forename: Xin
authors.initials: X
authors.lastname: Zheng
authors.forename: Ke
authors.initials: K
authors.lastname: Yin
authors.forename: Xiang'ai
authors.initials: X
authors.lastname: Cheng
authors.forename: Tian
authors.initials: T
authors.lastname: Jiang
mesh_terms: D004867:Equipment Design; D006801:Humans; D053844:Lasers, Solid-State; D055100:Optical Fibers; D055620:Optical Phenomena; D010758:Phosphorus; D045663:Quantum Dots; D013932:Thulium
chemical_list: D010758:Phosphorus; D013932:Thulium