Laboratory for Optical Profilometry
Rapid, non-contact, standardized roughness determination
Optical profilometry is an analytical method for the non-contact characterization of surface topography. Newer devices for optical profilometry achieve depth resolutions of approx. 1 nm. Various measurement modes are available for the analytical work, which allow a determination of sample roughness in accordance with DIN EN ISO 4287. In our laboratory such analyses can be performed even on transparent media (e.g., glasses, optical fibers, ...) after appropriate sample preparation. Tascon GmbH offers optical profilometry for a variety of areas such as the automotive industry, medical technology or the semiconductor industry.
Details on optical profilometry
Physical principle - information gained - analytical possibilities
With optical profilometry analysis, the topography of a surface can be investigated without contact with a vertical resolution of up to one nm. The optical profilometer used by tascon GmbH allows both confocal and interferometric analyses.
In confocal microscopy, a monochromatic light beam is focused on a sample surface. The use of suitable diaphragms ensures that only the light reflected in the focal plane reaches the imaging CCD sensor. Thus, only the area that is illuminated in the focus of the incident light is imaged. By a computer-controlled, continuous variation of the distance between the sample surface and the optical system, corresponding individual images of the sample surface are obtained. These images are used to calculate a three-dimensional model of the sample surface.
In the interferometric analysis, the sample surface is irradiated with monochromatic or white light. During the measurement, the distance between the sample and the lens of the interferometer is increased in small increments. Due to the topography, for each point at the surface, different transit time differences between the reflected light beam and a reference light beam occur. The superposition of both light beams results in an interference pattern that moves across the surface during the fine step change in vertical distance to the sample. These sequences of interference images result in interferograms for each object point, from which the sample topography can be calculated.
The decision which of the measuring methods is used depends on the analytical question and the sample properties. All samples with reflective surfaces with height differences of max. 2 cm are suitable. Analyses of optically transparent sample systems (for example, mirrors, glasses, etc.) are only possible to a limited extent. For an accurate determination of topographic information, it is in some cases recommended to deposit a thin, reflective metal film on the surface of these systems.
Tascon - Your new partner for Optical Profilometry
If you want to know more about the different possibilities of optical profilometry and which examination method exactly fits your samples and your questions, please contact the experienced staff in the laboratory for optical profilometry. The experts at Tascon will be pleased to advise you on which profilometry methods can be used to answer your question. Please do not hesitate to contact us.