常规高功率激光器以连续或者长脉冲方式工作，与物质作用主要是依靠单一“加热”模式，针对其对复杂目标作用能力有限的问题， 提出一种连续和脉冲激光同时输出，脉宽、重频可调的新体制高功率激光技术，激光放大链路以特殊时域模式工作，即高重频脉冲与连续运转同时输出，在重频10 kHz时，实现输出功率4800 W，其中连续激光功率3600 W，脉冲激光功率1200 W，脉冲宽度为3.6 ns；在重频100 kHz时，实现输出功率4920 W，其中连续激光功率3100 W，脉冲激光功率1820 W，脉冲宽度为7 ns，光束质量4.8倍衍射极限 。

We demonstrate a high-efficiency and high-power quasi-three-level laser based on a trapezoidal composite slab architecture with a 270 μm-thick Yb-doping surface. The design of a surface-doped slab architecture, temperature effects, laser oscillator model, and laser oscillator experiments with a surface-doped slab as a laser host medium have been presented. By theoretical calculation, the temperature rise in the surface-doped slab is only one seventh of that in the bulk-doped slab at the same maximum pump power of 30 kW. Finally, in the laser oscillator experiments, an output energy of 21.6 J is obtained when the pump energy is 48 J with a repetition rate of 5 Hz and a pulse width of 1 ms. The optical-optical efficiency is 45%.