Confocal micro-optical distance sensor for precision metrology

摘要

Increasing demands for controlling tolerances of small mechanical and optical components require improved measurement techniques. In particular, components with a complex geometry such as small holes or channels are difficult to access by classical tactile measurement systems. These systems are also limited in their measurement speed. Optical distance sensors do not have many of these disadvantages, but the sensor heads are normally too large to access e.g. small holes. Presented in this paper is a novel microoptical sensor concept using the chromatic confocal principle for distance gauging applications. This is used in high aspect ratio cavities with a diameter of about 2 mm. The distance resolution of the sensor is aimed to be in the sub-micrometer range.