Influence of vibration on microdiameter measurements using a laser-charge-coupled device system

The influence of vibration on dynamic measurements of microdiameters using a laser diffraction-CCD detection system is studied. The theoretical analysis indicates that the influence of vibration on the diffraction pattern of a measured object introduces significant errors into its diameter measurement, and the improvement can be approached by using a TEM(00) Gaussian incident beam instead of the usual uniform beam. The experimental results of these cases are also presented and in good accordance with the theoretical analysis.