通常,演示泊松亮斑用的“圆盘”(如大头针头、平板玻璃上的小黑点等)直径只有2mm左右,可见度小,泊松亮斑与黑暗背景对比度也差,演示效果差. 我们在室内改用“大圆盘”演示,现介绍如下. 实验器材:J2513—3型氦氖激光器、平面镜、铁架台、一枚直径为10mm的图钉(大圆盘)、一段直径约为0.2mm为的漆包线、光屏. In general, the “discs” (such as tack needles, small black dots on flat glass, etc.) used to demonstrate Poisson bright spots are only about 2mm in diameter, and the visibility is small. The contrast between Poisson bright spots and dark background is also poor, and the demonstration effect is poor. We use the “big disk” demonstration in the room as follows. Experimental equipment: J2513-3 helium neon laser, plane mirror, iron stand, a thumbtack (large disc) with a diameter of 10mm, a section of approximately 0.2 in diameter Mm for enameled wire, light screen.