A power-scaled laser operation of Pr:YLiF₄ (YLF) crystal at 720.9 nm pumped by a 443.6 nm laser diode (LD) module was demonstrated. The 20 W module was used to pump the Pr:YLF crystal, and a maximum output power of 3.03 W with slope efficiency of 30.04% was obtained. In addition, a 5 W blue LD was also used to pump the Pr:YLF laser, and a maximum output power of 0.72 W was obtained at room temperature. The output power was limited by the wavelength mismatch between the single-emitter LD and the absorption peak of the crystal.

Over the last years, there has been tremendous progress with compact pulsed lasers based on various solid-state gain media, such as crystals and glasses doped with laser-active ions. With the integration of increasingly diverse saturable absorber materials, these small sources are capable of delivering stable pulses with durations as short as femtoseconds and repetition rates exceeding 10 GHz. These promising sources are known as solid-state waveguide lasers, which have become synonymous with miniaturization, integration, and functionality. This article overviews the progress in the development of passively Q-switched and mode-locked solid-state waveguide lasers employing diverse saturable absorbers. The most commonly used laser configurations, state-of-the-art waveguide fabrication techniques, and experimental demonstrations of pulsed waveguide lasers are summarized and reviewed. Selected well-noted topics, which may shape the future directions in this field, are also presented.

We demonstrate a femtosecond Cr:YAG laser mode-locked by a carbon nanotube saturable absorber mirror (CNT-SAM) at a repetition rate of 550 MHz. By employing the CNT-SAM, which exhibits a modulation depth of 0.51% and a saturation fluence of 28 μJ/cm2 at 1.5 μm, we achieved a compact bulk Cr:YAG laser with self-starting mode-locked operation near 1.5 μm, delivering an average output power of up to 147 mW and a pulse duration of 110 fs. To our knowledge, this system provides the highest repetition rate among reported CNT-SAM mode-locked Cr:YAG lasers and the shortest pulse duration among saturable absorber mode-locked Cr:YAG lasers with repetition rates above 500 MHz.

A high pulse repetition frequency (PRF), high energy Ho:YAG laser directly pumped by a Tm-doped fiber laser and its application to a mid-infrared ZnGeP2 (ZGP) optical parametric oscillator (OPO) is demonstrated. The maximum polarized 2.09 μm laser pulse energy is 13.46 mJ at a PRF of 1 kHz. The corresponding peak power reaches 504 kW. In a double-resonant ZGP-OPO, a maximum mid-infrared laser pulse energy of 1.25 mJ, corresponding to a peak power of 79 kW, is accomplished at a PRF of 3 kHz. The nonlinear conversion efficiency reaches 41.7%. The nonlinear slope efficiency reaches 53.3%.

We present a hybrid adaptive optics system for a kW-class solid-state slab master oscillator power amplifier laser that consists of both a low-order aberration corrector and a 59-actuator deformable mirror. In this system large defocus and astigmatism of the beam are first corrected by the low-order aberration corrector and then the remaining components are compensated by the deformable mirror. With this sequential procedure it is practical to correct the phase distortions of the beam (peak to valley up to 100 μm) and the beam quality β is successfully improved to 1.9 at full power.

A high-power, high-energy Ho:YAG oscillator resonantly pumped by a Tm-doped fiber laser is presented. A maximum continuous output power of 38 W with a slope efficiency of 51.9% is achieved at the wavelength of 2.09 μm, and M2≈1.48. In the Q-switching regime, the maximum pulse energy of 12.8 mJ, corresponding to a 514.5 kW peak power, is obtained at the pulse repetition frequency of 1 kHz. Furthermore, the thermal lens effect of the system is studied theoretically, and the radius of the transverse electromagnetic (TEM00) mode of the laser crystal under different pump powers is given.