We demonstrate the first 60 W Tm<sup>3+</sup>-doped all-fiber laser with single-mode 10/130 fiber and compact air-cooling thermal management way at 1945 nm. The overall optical conversion efficiency reaches 42.2%. High laser power stability of <1.5% is obtained during a continuous test time of >15 hours. The spectra linewidth at maximum output is evaluated as only 0.19 nm. Meanwhile, its direct bonding applications on kinds of transparent plastics are presented.
We demonstrate the bleaching characteristics of Cr<sup>2+</sup>: CdSe (Cr: CdSe) crystal around 2 μm and prove that Cr: CdSe crystal is an effective saturable absorber to obtain Q-switched pulsed output in Tm<sup>3+</sup>-doped fiber laser pumped Ho: YAG system. The saturable absorption property of Cr: CdSe is investigated with a pulsed source at 2090 nm. The laserinduced damage threshold of uncoated Cr: CdSe is estimated around 9.92 J/cm<sup>2</sup> at 2090 nm with the pulse duration of 30 ns. With the measured bleaching curve, the estimated pulse saturation fluence is around 1.06 J/cm<sup>2</sup>, and the estimated ground-state absorption cross section is 8.97×10<sup>-20 </sup>cm<sup>2</sup>, which is very close to the experimental value. The preliminary laser experiments are all finished with an antireflection coated Cr: CdSe crystal to reduce the insertion loss. The maximum output pulse energy is about 1.8 mJ with repetition frequency of 685 Hz, pulse duration of 15.4 ns, and pulse peak power of 115 kW. The pulsed laser wavelength is measured to be 2090.2 nm.