激光显示中散斑的抑制

文章首先概述了散斑的形成机理,接着简述了在近场条件下通过降低激光的时间或空 间相干性来抑制散斑的许多方法,并具体分析了仅通过降低激光的相干性来减弱激光显示中散斑的缺陷。提出一种在远场条件下减弱散斑的两维扫描复面转镜,且详细说明了该转镜的工作原理,当合成的激光束通过旋转的复面镜时,移动的干涉条纹在屏幕上产生“沸腾”的散斑图样。最后以红光为例,说明了合成光束通过转镜时显示屏幕上散斑对比度的降低,显示了二维转镜有效地抑制了激光显示中的散斑现象。

Speckle Suppression in Laser D isplay

Firstly it summarizes how laser speckle is formed, then speckle supp ression is simp lified in the near field by reducing or eliminating temporal or spatial coherence of the laser, and disadvantages are detailed to reduce speckles only by changing the coherence properties of laser in the far field such as in laser TV.Rotating polygonmirrorwith two-dimensional scanningwhich can decrease speckles in the far field is proposed and how rotating polygon mirror is illuminated in detail. When combined laser beams go through rotating polygon mirror with two-dimensional scanning, moving interference fringes produce \" boiling\" speckle patterns in the screen. Finally speckle contrast is explained when combined laser beams pass rotating polygon by taking example for red beam, which effectively reduce speckles in laser display owning to rotating polygon mirrorwith two - dimensional sanning.