Low-coherence interference microstructure rapid measurement method based on FPGA

Abstract

The invention discloses a low-coherence interference microstructure rapid measurement method based on an FPGA, and the method comprises the steps: enabling the FPGA to respectively receive image data and single-point light intensity data collected by a CMOS sensor and a photoelectric detector, and transmitting the two types of data to an FPGA chip internal memory; a parallel pipeline architecture of the FPGA is designed, so that interference pattern contrast can be calculated in real time and displacement point-by-point calculation can be completed while a series of image data and photoelectric detector interference analog signals are received, and the processing efficiency is remarkably improved; and calculating the position of an interference envelope peak value by adopting a gravity center method, completing three-dimensional shape detection of the microstructure, and realizing three-dimensional shape reconstruction. According to the method, the processing speed of low-coherence interference measurement can be effectively increased, the microstructure morphology can be restored at a high speed, and online detection application of low-coherence interference in the fields of semiconductor packaging, lithium battery manufacturing, ultra-precision machining and the like is facilitated.