在物理光学实验(例如做小孔、单缝、双缝、光栅等衍射与干涉实验)和某些光学生产技术中(例如用氦氖激光检验激光毛细放电管的直度或校准研磨激光管管口的平行度与垂直度等工艺),常常用到光屏,以便显示激光的各种演示图象。通常光屏都是白色的,但对于以氦氖激光为光源的光屏来说,则以红色为佳。因为红色能更多更清晰地显示出演示图象。以小孔衍射为例,在相同的条件下,红色光屏能比白色光屏显示出更多的同心环图象,而且条纹更 In physical optics experiments (such as pinhole, single slit, double slit, grating and other diffraction and interference experiments) and in some optical manufacturing techniques (such as helium-neon laser inspection of the laser capillary tube straightness or calibration grinding laser tube Mouth parallelism and verticality and other processes), often used light screen, in order to display a variety of laser demonstration images. The light screens are usually white, but red is better for light screens with He-Ne laser as the light source. Because red can more clearly show the demo image. In the case of pinhole diffraction, under the same conditions, a red screen can show more concentric ring images than a white screen, and more stripes