Laser scanning microscopy
Point by point to a detailed, precise 3D image. Whether large or invisible to the naked eye: Laser scanning microscopy captures tiny structures and assembles them with pixel precision.
Table of contents
- What is laser scanning microscopy used for?
- Quality analysis: laser scanning microscopy with a system
- How does laser scanning microscopy work?
- Entroduction of the image in laser scanning microscopy
- What is special about laser scanning microscopes?
- What other laser scanning microscopes are available?
- Laser scanning microscopes in practical use
- Briefly summarized: Laser scanning microscopy
What is laser scanning microscopy used for?
Laser scanning microscopy is suitable for analyzing a wide variety of materials—including metals, polymers, semiconductors, and multilayer systems. Surface topographies can be mapped in three dimensions down to the nanometer range, and surface roughness can be determined noncontact. For example, the method is used to characterize topographic structures, to non-destructively determine the thickness of coatings and thin films, and to comprehensively analyze materialographic samples. By generating precise 3D profiles, laser scanning microscopy provides detailed insights into the structure and properties of materials.
Laser scanning microscopy with system
at Quality Analysis
- 3D topographic measurement and analysis of surface roughness
- Layer thickness measurement and analysis of coatings
- Wear, defect and damage analysis
- Volume and depth measurements of indentations
- Geometry and profile analysis of microstructures
- Non-contact measurement of sensitive surfaces
- Examination of surfaces of additively manufactured components, ceramic materials, and polymer composites
How does laser scanning microscopy work?
Laser scanning microscopy is a method of light microscopy in which a sample is scanned point by point using a focused laser beam. Typically, confocal laser scanning microscopes (CLSM) are used for this purpose. The laser light is guided along a confocal optical path and filtered using a pinhole aperture so that only light from the focal plane is detected. This largely eliminates reflections from areas in front of or behind the focal plane, as well as interfering stray light. This produces high-resolution, high-contrast optical sections of the sample. These individual images are then used to create a three-dimensional image stack (3D stack), which enables a detailed analysis of the surface structure in three dimensions.
Entroduction of the image in laser scanning microscopy
In a laser scanning microscope, the image is not created by taking a complete image, but by scanning the specimen line by line. This process, which is measured in Hertz, varies in speed. In modern confocal laser scanning microscopy, speeds of 200 to 2,000 image lines per second are common. While the laser moves continuously within an image line, a scanned point on the sample surface is assigned to a specific pixel of the complete image via the so-called pixel dwell time. This means that a point is assigned to a specific pixel within a defined period of time. This precise control not only enables the creation of two-dimensional images, but also forms the basis for the generation of detailed and high-quality 3D images in laser scanning microscopy.
What is special about laser scanning microscopes?
One of the special features is the ability to create three-dimensional images, which enables precise analysis of the spatial structure of cells, tissues or other sample structures. The exceptionally high resolution allows the finest details to be made visible on the microscale, while at the same time high-precision measurements can be carried out on the nanometer scale.
A further advantage lies in the non-contact analysis, which ensures that sensitive samples have no physical contact with the microscope during the imaging process. The fast analysis speed, combined with the versatility in applicability, makes it possible to examine a wide variety of samples in real time. In addition, laser scanning microscopes are able to analyze objects with large height differences, which is particularly important in the study of uneven surfaces. Overall, laser scanning microscopes offer a comprehensive range of advanced imaging capabilities that provide valuable insights and knowledge in various scientific disciplines.
What other laser scanning microscopes are available?
In addition to the confocal laser scanning microscopes discussed here, there are other models. Only of historical importance are the flying spot microscopes, which also focus the light in a small spot over the sample, but are not equipped with a pinhole aperture. Today, there are several further developments of the conventional CLSM, which often do not exist as separate devices but are used as additional functions in CLS microscopes. STED and 4Pi microscopes should be mentioned here in particular. Both methods provide a better resolution than conventional laser scanning. The multiphoton microscope, on the other hand, works without pinhole apertures, without any loss of sharpness due to stray light.
The laser scanning microscopes in practical use
Defect Analysis:
Measurement of Wear Marks
Laser scanning microscopy is used in defect analysis to measure the depth of wear marks, for example. Laser scanning microscopy can also be used to determine the surface roughness of even the smallest tooth flank surfaces.
Material properties:
Optimization of materials
Laser scanning microscopy is also used in the investigation of surface topographies in the characterization of materials. By precisely capturing surface structures in 3D, detailed and high-resolution images can be generated that provide insights into the microscopic features of material surfaces.
Micro roughness:
Quality assurance of components
One example is the analysis of micro-roughness on metallic components. LSM enables the visual representation of roughness as well as the quantitative measurement of surface profiles. This allows the roughness value to be determined. This is important for the quality assurance of components, as the precise characterization of the surface topography at a microscopic level provides information about the manufacturing process and the material properties. By creating precise 3D images, laser scanning microscopy thus supports the development and optimization of materials for industrial applications.
Briefly summarized: Laser scanning microscopy
Laser scanning microscopy is a light microscopy method in which an object is scanned line by line by a laser. This and the use of pinhole apertures result in images with a particularly high resolution.