In order to achieve laser-micro-engraving, the pulse width of the laser beam should be at about several nanoseconds level and its peak power should also be at dozens of megawatt level.

• 要实现激光内雕，激光束必须具有数个纳秒量级窄脉宽、数十兆瓦高峰值功率，同时也要具有发散度恒定不变、大深径比的环状聚焦光束。