Wireless power transmission has become a research hotspot in the field of energy transmission, in which laser power transmission is one of the best methods for long-distance wireless transmission. Since laser has the advantages of high directivity, high energy density and no electromagnetic interference, laser power transmission technology can be applied to the energy supply of unmanned aerial vehicles (UAVs), micro-vehicles, airships and other flight systems. Long-distance laser power transmission can enable high-altitude flight systems to operate continuously without the need to return to the base station for charging, im-proving their operational efficiency. Therefore, high-altitude flight systems have a demand for laser power transmission. However, the commonly used lasers in laser power transmission are semiconductor lasers and fiber lasers, which are only suitable for short-distance transmission of about 1 km. In this paper, taking high-flying UAVs as an example, the transmission efficiency of different lasers used for laser power transmission is analyzed theoretically, and the results show that the diode pumped alkali vapor laser (DPAL) has a high transmission efficiency in high-power long-distance laser power transmission. The transmission efficiency of rubidium lasers which is 1.5 to 4 times that of other lasers can reach 21.94%, which illustrates that DPAL is expected to become a new type of laser source in laser power transmission technology.

A frequency-tunable and single-longitudinal-mode master oscillator power amplifier system based on a radio-frequency (RF)-excited waveguide CO ₂ laser with three-stage amplification was demonstrated. The continuous tuning range of 0.29 GHz within one longitudinal mode spacing of the RF-excited waveguide CO ₂ laser was realized by adjusting the cavity length in closed loop. The linewidth of the CO ₂ laser was 3.9 MHz, and the maximal output power was 23.7 W at the center frequency of 9P (20) (9.56 μm). An amplification factor of 17 was obtained by adopting three RF-excited seven-channel folded-waveguide CO ₂ amplifiers. This laser system will be a good candidate for coherent detection lidar.

A novel double-cycle alternating-flow diode-pumped potassium vapor laser is proposed, theoretically modeled and simulated. The results show that the optical-to-optical efficiency of the laser increases with increasing gas flow rates, although at high flow rates the rate of increase in efficiency decreases. The optical-to-optical efficiency reaches 74.8% at a pump power density of 30 kW/cm² and a gas flow rate of 50 m/s. The optical-to-optical efficiency of the laser is greater with a narrow linewidth pump and high buffer gas pressure. The optical-to-optical efficiency of a flow gas cell is higher than that of a static gas cell. There is an optimal gas cell length that provides the highest optical-to-optical efficiency. At higher pump power densities, higher flow rates are required to obtain higher optical-to-optical efficiencies.

Extending diode-pumped alkali lasers (DPALs) toward high-repetition-rate, high-peak-power burst-mode operation broadens their application potential. Here we report the first experimental demonstration of burst-mode operation in DPALs enabled by high-repetition-rate electro-optic cavity dumping under pulsed optical pumping. The cavity-dumping repetition rate reaches up to 1.2 MHz, representing the highest cavity-dumping repetition rate reported to date for DPALs. The cavity-dumped pulses with a FWHM of 11 ns are generated, delivering a maximum peak power of 96 W. At the highest repetition rate, up to 277 pulses are extracted within a single 250 µs pump period, yielding a maximum total burst energy of 322 µJ. These results verify the feasibility of burst-mode cavity dumping in DPALs and highlight its potential for generating high-peak-power, temporally structured laser outputs.

In this study, we analyzed the spatiotemporal distribution of annealing temperature using a dual-beam dynamic scanning annealing technique based on a CO₂ laser (10.6 μm) and a 785 nm laser, and the effects of laser energy density, scanning speed, and preheating temperature on the resulting temperature. We systematically examined the influence of key process parameters, including laser energy density, scanning speed, and preheating temperature, on the annealing temperature. Our aim was to optimize annealing conditions to enhance the electrical properties of the materials, as indicated by reduced sheet resistance, controlled diffusion depth of doped ions, and higher activation rates. This approach ensured high activation rates of doped ions while limiting dopant re-diffusion to merely 3.6 nm in the depth direction, as confirmed by concentration profile analysis. Furthermore, based on temperature distribution, deformation of the wafer surface was analyzed. The results indicate that under the employed process parameters, no significant adverse effects on wafer flatness or structural integrity were observed.

Diode-pumped alkali vapor lasers (DPALs) offer high quantum efficiency, low thermal loading, excellent beam quality, and emission wavelengths matched to important application scenarios. Extending DPALs toward pulsed regimes is of particular interest for applications such as lidar, free-space optical communication, and precision material processing, where high peak power and flexible temporal control are required. This review surveys the key technologies underlying DPAL systems and summarizes the progress in pulsed-generation approaches. The pulsed techniques reported to date are systematically reviewed, including pump modulation, intracavity modulation, cavity dumping, and mode-locking, together with a comparison of their performance. The current status indicates that pulsed DPALs remain at an early stage, with limitations in parameter space exploration and performance scaling. Future developments are expected along several directions, including further exploration of mode-locked DPALs, burst-mode pulse generation for structured temporal output, power scaling through MOPA architectures, and spectral extension via nonlinear frequency conversion. These directions collectively define the pathway toward high-performance pulsed DPAL systems.