Fig. 1. Layout of 10/130 TFL system (PD, photo diode; CPS, cladding power stripper; HRG, high reflection grating; TDF, Tm3+-doped fiber; COM, combiner; LD, laser diode; OG, output grating; ISO, isolator; WDM, wavelength division multiplexer).

Fig. 2. Experimental and theoretical output curves of 10/130 Tm:fiber amplifier. (A 4.5 wt.% Tm3+ concentration is adopted in the theoretical simulation, which is credible from Coherent-Nufern.)

Fig. 3. (a) Simulated laser power distribution, (b) three-dimensional and (c) longitudinal temperature distributions along the length direction of the amplifier Tm:fiber. [The heat transfer coefficient at the boundary between fiber coating and the water-cooling copper sink was set as 50W/(m2·K).]

Fig. 4. Laser stability measurements of output power at (a) 52 W, (b) 65 W, and (c) 87 W.

Fig. 5. (a) Blue light emission spectrum with the 658 nm LD exciting; (b) a detailed energy structure of a silica Tm:fiber.

Fig. 6. (a) Typical laser spectrum, (b) beam quality measurement, and (c) laser stability measurement at the maximum output of air-cooling TFL.