Parameters of structured lights of DMD used in confocal measurement

Parallel confocal measurement improves confocal measuring efficiency. However,the parameters of traditional optical divided devices(ODD)are fixed,which are not be suitable for different specimens.As the Digital Micromirror Device(DMD)is a flexible ODD and could produce different types of structured lights,this paper induces the DMDS into the confocal measurement system to improve the suitability of parallel confocal measurement devices.A modulation model of structured light produced by the DMD was analyzed,a confocal measurement device was constructed,and the effects of parameters of structured light from the DMD on the axial resolution,transverse resolution and the image contrast of measuring device were researched.The experiment results indicate that when the optical parameters are matched,the smaller the size of structured light is,the higher the measuring resolution is.Moreover,the DMD also could be applied as a flexible illuminatorto improve the image contrast caused by a smaller structured light size.All of these researches provide a strong support for multi-scale measurement based on DMDs.