Laser system

The invention relates to a laser system. The laser system includes: a laser operable to generate a laser beam; an optical system including a first optical element and a second optical element; and the laser beam leaves the output end of the laser system; the laser, the optical system and the output are arranged such that the laser beam sequentially travels to the first optical element, the second optical element and the output; wherein the first optical element has a first focal length, the second optical element has a second focal length equal to the first focal length, and the second optical element is spaced apart from the first optical element by a distance that is twice the first focal length. 本公开涉及激光系统。激光系统包括：可操作以生成激光束的激光器；包括第一光学元件和第二光学元件的光学系统；以及激光束离开激光系统的输出端；激光器、光学系统和输出被布置为使得激光束依次行进到第一光学元件、第二光学元件和输出端；其中第一光学元件具有第一焦距，第二光学元件具有与第一焦距相等的第二焦距，并且第二光学元件与第一光学元件被间隔开第一焦距的两倍的距离。