Research on micro displacement measurement technology based on chromatic confocal method

Compared with other non-contact displacement sensors, the chromatic confocal sensor, which based on wavelength-displacement modulation technique, has no special requirements on the material and texture of the measured surface, and suitable for measuring the displacement of objects whose size range from micro to macro with high precision. In this paper, the chromatic confocal method is applied to measure the micro displacement. A hyperchromats with a measurement range of 1.27mm and linear regression coefficient R-2 of 0.996 has been designed by using ZEMAX optical design software. The experimental system of chromatic confocal displacement measurement is set up. Through two miniature fiber optic spectrometers, the large measurement range and high precision spectrum detection are realized. The system error is calibrated synthetically. The measurement range of 1.2mm and linear regression coefficient R(2 )of 0.997 is realized. The research results are of great significance for the development of micro-nanometer displacement measurement technology.