Optical metrology is the science and technology concerning measurements using light. These measurements may focus on the properties of light itself or other properties such as distance.
Research Using Optical Metrology
Global optics specialist, Olympus Corporation offers a wide range of optical measuring products, some of which have been used in breakthrough research studies.
Professor Robert Wood and his team working at the Harvard School of Engineering and Applied Sciences chose the Olympus LEXT OLS4000 Laser Scanning Confocal Microscope as their optical metrology tool over other measurement options such as the scanning electron microscope (SEM) and stylus profilometer.
The idea of using the SEM was dropped as it cannot measure height, and the stylus profilometer was not used because it cannot measure vital wall-like steep profiles as its square pyramid shaped stylus tip bumped against the side wall and could not reach the bottom.
The Olympus OLS4000’s ability to quickly and precisely measure deep cavities and 85° sloped walls with ease was perfect for the research team, which aimed to quantify the relationship between a natural insect wing, a micro-machined silicon mold and a fabricated wing. It was successfully used for morphological measurements in the creation of micromolds and fabricated insect wings.
Developments in Optical Metrology
Automation is taking over a major chunk of manual industrial processes world over. Companies are now catering to the needs of automation in processes of optical metrology as well.
GOM mbH is a company that develops and distributes optical measuring systems that focuses primarily on applications such as 3D coordinate measurements, 3D digitizing, deformation measurements and quality control. The company offers fully automated optical metrology solutions to automotive, aerospace and consumer goods industries as well as to research centers and universities.
GOM’s ATOS ScanBox is a plug-and-play measuring cell for fully automated 3D digitizing and inspection. The ScanBox is a combination of optimized industrial components, mobility and high levels of safety fitted in an off-the-shelf 3D measuring machine.
The ScanBox can be used in the following applications:
- 3D color digitizing
- FEA simulation verification
- Inspection of plastic components
- Quality control on fuel tank and turbine manufacturing
- Analysis of cast and forged components
- Surface verification and CFD analysis on space vehicle
- 3D metrology for reverse engineering on helicopters
- Control of shape and dimension of sheet metal parts
- Online calibration and validation of jigs, fixtures, and gauges
- Optical 3D measurements providing benefits to foundry processes
- Mobile optical metrology in injection molding.
Future of Optical Metrology
Optical sensors are being incorporated in to stationary and portable coordinate measuring devices, thereby enabling measurement and inspection operations to go beyond estimation of just size and location, and cover form and fit as well.
Similarly, optical digitizers and scanners are being adapted as precision optical measurement equipment. Micro and nanostructures are gaining wide publicity and are being developed for various industries. Measuring of these tiny structures offers a huge challenge to develop high resolution optical metrology.
International conferences help to showcase these kinds of innovative research and developments and discuss solutions for existing challenges. About 400 scientists, engineers, researchers and applications and product developers attended the SPIE Optical Metrology 2013 conference in Munich. A similar event is already being planned for June 2015.
Such events will hopefully help the field of fast, high precision, and non-destructive optical measurement to expand to greater heights in the coming years.
References and Further Reading