自从激光器和全息术出现以来,人们对采用全息图作光学系统的衍射元件产生了强烈兴趣。这类元件有时称为全息光学元件(HOEs),它很像普通全息图,用两激光束干涉方法产生。一般情况下,全息光学元件的功能与透镜类似。当激光束被它们折射时,衍射光束的波前 Since the advent of lasers and holograms, there has been a strong interest in diffractive elements that employ holograms as optical systems. These elements, sometimes referred to as holographic optical elements (HOEs), resemble ordinary holograms and are produced by two laser beam interference methods. In general, the holographic optical element functions like a lens. When the laser beams are refracted by them, the wavefront of the diffracted beam is diffracted