Actively mode-locked Tm^3+-doped silica fiber laser with wavelength-tunable, high average output power

Abstract

A diode-pumped, actively mode-locked high-power thulium (Tm³⁺)-doped double-clad silica fiber laser is demonstrated, providing an average output power in mode-locked (continuous wave) operation of 53 W (72 W) with a slope efficiency of 34% (38%). Mode-locking in the 6th-harmonic order was obtained by an acousto-optic modulator driven at 66 MHz without dispersion compensation. The shortest measured output pulse width was 200 ps. Owing to a diffraction grating as cavity end mirror, the central wavelength could be tuned from 1.95 to 2.13 μm. The measured beam quality in mode-locked and continuous wave operation has been close to the diffraction limit.

Tunable SESAM-Based Mode-Locked Soliton Fiber Laser in Linear Cavity by Axial-Strain Applied to an FBG

“…This type of fiber lasers have been experimentally demonstrated as an alternative to solid-state lasers because of their low cost, compact cavity structure, heat dissipation properties, free-alignment and overall high stability [5][6][7][8][9]. Furthermore, active mode-locked fiber lasers also require additional switching electronics and complex driven modulators [10][11][12]. Particularly, the capability of passively mode-locked fiber lasers to generate ultrafast solitons are of important interest in practical applications such as optical fiber sensing, biomedical diagnostics, material processing, nonlinear optics, terahertz generation and ultrahigh speed communications [13][14][15].…”

Yb‐fiber‐based, high‐average‐power, high‐repetition‐rate, picosecond source at 2.1 µm

“…There has been substantial effort to develop various conventional laser technologies near 2 µm. In particular, the wide gain spectrum of the rare‐earth‐doped bulk and fiber gain media based on thulium (Tm) over 1.8‐2.1 µm, and holmium (Ho) across 2.05‐2.15 µm, are attractive for the development of ultrafast lasers in the 2‐µm wavelength range . A survey of the state‐of‐the‐art ultrafast lasers with picosecond and sub‐picosecond pulse duration operating near 2 µm, showing the output pulse energy as a function of repetition rate, is presented in Fig.…”

“…On the other hand, Tm‐fiber lasers operating at 1930 nm, providing 3.4 mW of output power in 1.32 ps pulses at 37 MHz repetition rate , and 2.5 mW in 3.6 ps at 6.5 MHz operating at 1940 nm , have also been demonstrated. In another report, Tm‐doped silica fiber laser at 2032 nm, providing 53 W of average output power in 200 ps pulses operating at 66 MHz was realized by active mode‐locking using an acousto‐optic modulator . Tm‐Ho co‐doped fiber lasers have also extended the lasing wavelength to 2060 nm with 10 mW of output power in 1.1 ps at 24.4 MHz repetition rate , while deploying Ho‐fiber has enabled tunable generation in the 2030–2100 nm range with a maximum average power of 60 mW in 0.89 ps pulses at 15.7 MHz repetition rate .…”

2 μm mode-locking laser performances of sol-gel-fabricated large-core Tm-doped silica fiber

“…As the launched pump power increased, the CW output power linearly increased with slope efficiencies of 12.80%, 16.39%, and 18.85% for 2, 3, and 4 m fiber, respectively. The slope efficiencies were smaller than those of fiber lasers with mature commercial Tm-doped silica fiber [24] , which could be attributed to a larger optical loss in the present SGTS fiber [19] . The results show that the 4 m length LC double-cladding SGTS fiber has the best laser performance among them, which is attributed to a larger absorption of the pump light for the longer fiber.…”