激光显示中散斑的减弱

Speckle contrast reduction in laser display

为减弱激光显示中散斑的影响,在对散斑对比度进行理论分析的基础上,提出了一种利用位相光学元件减弱散斑的方法。实验以绿光为光源,让激光束通过位相光学元件,再经过CCD相机和图像处理系统处理,得到屏幕上散斑对比度和光强的变化。实验结果表明:散斑的对比度降低到3.7%,可满足激光显示中对散斑减弱的要求。该方法具有简单易行、成本低、适合批量化生产等优点。

In order to weaken the influence of speckle on laser display system, a novel speckle reduction method utilizing pure phase pattern optical element was presented based on the theoretic analysis of speckle contrast. Then, by using green laser as source, the laser beam passed through the Diffractive Optical Element（DOE） in experiment. The changes of speckle contrast and light intensity on screen were obtained with the help of CCD camera and image processor. The experimental results indicate that the contrast of laser speckle is reduced to 3.7%, which meets the requirement of laser display. Proposed method has many advantages in simple practice, low cost and good manufacture in industry.