Our study reveals results from an all-polarization-maintaining Ho-doped fiber laser that is passively modelocked, consisting of both an oscillator and an amplifier. A stable, self-starting, noise-like mode-locked pulse is achieved in the Ho-doped fiber laser oscillator based on a nonlinear optical loop mirror at a wavelength of 2.05 mu m. The mode-locked oscillator achieves a peak output power of 20.2 mW, generating pulses with a duration of 284 ps and exhibiting a coherence peak at 690 fs. Moreover, with the use of Ho-doped fiber amplifier, the mode-locked pulse can reach a peak output of 1.05 W while maintaining a power stability of 1.43 % over the course of an hour. The highest pulse energy reaches approximately 333.6 nJ, which equates to a peak power of 1.18 kW. The polarization extinction ratio is approximately 24.9 dB.

We demonstrate a high power, Er:LuAG single-longitudinal-mode laser in an anti-misaligned resonator. Based on the Faraday effect, a 1.61 W single-longitudinal-mode (SLM) laser is obtained with the double corner-cube-retroreflector (CCR) structure, and the tunable wavelength is 1649.2–1650.3 nm. Additionally, we investigate the anti-misalignment characteristics when the CCR moves and rotates along the optical axis. Furthermore, by utilizing the Er:LuAG amplifier, the maximum 2.32 W single-longitudinal-mode laser at 1649.6 nm is achieved. The beam quality factors M2 of the 2.32 W Er:LuAG single-longitudinal-mode laser are 1.23 and 1.25 along the horizontal (x) and vertical (y) directions, respectively.

We demonstrate a single-longitudinal-mode thulium-doped fiber laser operating at 1.94 mu m. Stable singlelongitudinal mode operation is contingent upon the synergistic filtering effect of multiple narrow-bandwidth filters of varying types. By inserting dynamic Bragg grating with unpumped thulium-doped fiber, fiber Bragg grating and sub-ring filters into the thulium-doped laser cavity to enhance longitudinal mode selection capability, the maximum single-longitudinal-mode laser power reaches 544 mW. The time-domain root mean square (RMS) value of laser power is calculated to be 0.41 %. The wavelength tuning from 1940.02 to 1941.12 nm is also demonstrated by varying the temperature of the Fiber Bragg Grating.

We demonstrate a continuously operating Er:YAG single-longitudinal-mode laser and its amplifier with a corner cube retroreflector based on the Faraday effect. A maximum power of 1.02 W, the central wavelength of 1645.46 nm, Er:YAG single-longitudinal-mode laser with a line-width of 204 kHz has been realized. The slope efficiency is 9.38% and the beam quality factors M2 are 1.16, 1.05 in the x and y directions. Additionally, the singlelongitudinal-mode laser is amplified to 1.86 W by the double-pass amplifier. The results indicate that the unidirectional operation ring laser in combination with the corner cube prism provides a 1.6 & mu;m continuous-wave single-longitudinal-mode laser with high-power and stability.