Optical metrology includes both the science of how measurements with light work and the technology used to carry out the measurements.
The measurement itself can be of the light source and light emitted or of the objects that the light measures. There is no distinction between the two in the field of optical metrology, making it a vast study area with many changing advancements.
Metrology used to measure an object can create data on that object’s size, shape, temperature, roughness, and strain. It is not only very precise when performed with highly-calibrated light sources, but it also can be done quickly and with little to no damage to the surface of the object being measured.
Optical metrology is most commonly used for the inspection and measurement of objects using either laser triangulation through 3D laser mapping equipment or structured light technology. This type of optical metrology is also called 3D scanning.
3D laser mapping runs a laser along the surface of an object, acquiring data line by line. As each point along the surface is hit by the laser, a dot of data is mapped. Each of these dots is then assembled in a data program to recreate the picture of the object.
Structured light technology, on the other hand, uses DLP or LCD to project light at a close range onto the object. Within seconds, it triangulates and captures the full picture of the object. Because of the speed of structured light projection and image capture, it’s an ideal pick for industrial applications who need fast measurements in the production line.
Optical metrology has an almost unlimited number of applications, and because of its speed and ability to scan surfaces without damage to the object, it is trusted in highly-sensitive fields. It is also favored in automation and is growing in popularity among the automotive and health industries.
Currently, it’s an ideal choice for autobody sheet metal, surgical implants, and electronic parts. Optical metrology may also be used to scan areas and tell robots where and how to move, increasing their precision while maintaining automation benefits.
The more specific term for optical metrology is “frequency metrology.”