用衍射方法测量微小直径

Diameter of a Thin Wire Measured by Diffraction

利用普通物理实验室的激光器,便可通过衍射方法来对各种细丝外径进行测量。He-Ne实验表明,这是一种高精度的非接触测量,它通过对衍射图像的检测来求细线的外径,其测量精度可达微米。0.

When a train of Laser light travels through a thin wire, it spreads out behind it, when a screen is placed in the diffracted light, there appear on the screen alternating bright and dark bands which are called diffraction fringes.By measuring the positions of the diffraction fringes, the diameter of the thin wire can be computed.