The equivalent Fresnel numbers of the regular polygon and slit are calculated by using the radius of inscribe circle and half width of the slit as the feature length.

• 以正多边形的内切圆半径和狭缝的半宽度为特征尺度,给出了匀幅平面波入射时正多边形和狭缝的等效菲涅耳数。