Vision chromatic confocal sensor based on a geometrical phase lens

A vison chromatic confocal sensor used to monitor the location of a measured point is proposed and experimentally verified. To induce chromatic aberration of the sensor, a geometrical phase lens is adopted and is also used as a beam splitter. Near the geometrical phase lens, a focused beam is used for the chromatic confocal sensor, and a diverging beam is used for imaging of the specimen. In the experiment, the performance of the proposed system was verified with regard to distance sensing and the capability of monitoring the measured points. The measuring range was approximately 10 mm, and the repeatability was 0.4 µm when a geometrical phase lens with a 75 mm focal length was used.