High power resonant pumping of Tm-doped fiber amplifiers in core- and cladding-pumped configurations

Abstract

We have demonstrated ultra-high efficiency amplification in Tm-doped fiber with both core- and cladding-pumped configurations using a resonant tandem-pumping approach. These Tm-doped fiber amplifiers are pumped in-band with a 1908 nm Tm-doped fiber laser and operate at 1993 nm with >90% slope efficiency. In a core-pumped configuration, we have achieved 92.1% slope efficiency and 88.4% optical efficiency at 41 W output power. In a cladding-pumped configuration, we have achieved 123.1 W of output power with 90.4% optical efficiency and a 91.6% slope efficiency. We believe these are the highest optical efficiencies achieved in a Tm-doped fiber amplifier operating in the 2-micron spectral region.

Pulsing mechanism based on power adiabatic evolution of pump in Tm-doped fiber laser

“…Since the corrugated sections of the Bragg reflector is much shorter than the fiber length, the pump reflector is assumed to be located at z = L. Thus, the boundary conditions of pump power described by rate Eqs. (9), (10), (14), (15), (21) and (22) are as follows…”

Tandem-pumped, tunable thulium-doped fiber laser in 21 μm wavelength region

“…Alternatively, Tm-doped fiber lasers were also pumped at around 1565 nm ( 3 H 6 → 3 H 4 transition) by Er-doped fiber lasers with a diffraction-limited beam [15,[19][20][21], with the advantages of high Stocks efficiency and hence low quantum-defect-induced heat generation. A Tm-doped fiber laser could also be tandempumped by another Tm: fiber laser at > 1900 nm, since the absorption band of a Tm-doped silica fiber related to the 3 H 6 → 3 H 4 transition extends up to > 1900 nm [12], thus allowing for higher Stocks efficiency and further reduction of quantum-defect-induced heat generation [22][23][24][25]. Indeed, tandem-pumping scheme was widely employed in kW-level Yb-doped fiber lasers to minimize the quantum-defect-induced heat generation, thus enabling high-power operation of fiber lasers [26,27].…”

“…Indeed, tandem-pumping scheme was widely employed in kW-level Yb-doped fiber lasers to minimize the quantum-defect-induced heat generation, thus enabling high-power operation of fiber lasers [26,27]. Recently, Creeden et al used a 1908-nm source to in-bandpump a Tm-doped fiber laser operating at 2005 nm, demonstrating >90% slope efficiency and a potential of power-scaling to 2 kW [22,23]. Similarly, Jin et al used a 1940-nm source to resonantly-pump an ultra-fast Tm-doped fiber amplifier at 1970 nm, with an inherent Stokes efficiency up to 98.5%, achieving a slope efficiency of 87% [25].…”

Widely tunable multi-wavelength thulium-doped mode-locked all-fiber laser

“…2 shows the measured transition cross sections, including absorption and emission cross section of Ho-doped and Tm-doped fiber[82][83][84], which emit at the eye-safe regime. For each kind of fiber, the transition cross section varies a little with different dopants and different doping concentrations.…”

“…The transition cross section of (a) holmium-doped silica fiber and (b) Tm-doped silica fiber[82][83][84].…”