Study Of Surface Technology Of MEMS On Reflecting Microscopic Measurement

Digital holography is a new measuring technique which combines the principle of digital holography with microscopic imaging principle. Only a single hologram is required to reconstruct phase information of the object wave, and then the surface topography of the objects can be obtained. It has the features of non-contact, high resolution and few measurement requirements, etc. This paper centers on the reflecting digital holographic microscopy. The main contents are as follows:1. A method for phase recovery from undersampled wrapped phase is presented. Both the simulation and experimental results prove that the improved method is valid. The method can not only vary the shearing direction and shearing times according to the undersampled wrapped phase flexibly to achieve the best result, but also retrieve the phase with high accuracy from the undersampled wrapped phase with weak noise.2. In this paper, three kinds of reflection type digital holographic microscope system are introduced, and run a comparison of their advantages to get the best one. Then, use the 1951 USAF resolution test target to make experiment to verify the validity of the system. The next task is conducting an experiment on the pressure sensor, and compensating the phase aberration, then the original phase information is obtained. Finally, use the adjustable magnification reconstruction algorithm to reconstruct the hologram to improve the total pixel utilization of off-axis digital holography.