FPGA-based Detection Module for the Chromatic Confocal Measurement Sensor

Chromatic confocal microscopy (CCM) has the advantages of high accuracy, strong anti-interference ability and sensitivity to objects with low reflectivity. Its disadvantage is that it needs to measure all points on the surface of the measured object, which is an inefficient measurement. Currently, domestic researches mostly focuses on the development of dispersed objective lens, the research on improving the measurement efficiency is not enough. This article introduces a method that can improve the efficiency of CCM measurement. It uses hardware to accelerate the calculation of the decoding algorithm, which not only speeds up the signal processing time but also reduces a lot of data transmission time. The hardware used for acceleration is a photo-detector driven by field-programmable gate array (FPGA). This paper also designed the optical path in front of the photo detector, which can make the photo detector receive accurate spectral information. Through calculation and simulation, our method can ensure accuracy and increase the measurement speed of CCM.