Applications for Glass

Biotechnology, Data Storage, AR/VR, Imprint Lithography, Glass Materials


Stains, or organic residue, are discolorations on the surface due to contamination or residue from the cleaning process. These contaminants not only impact cosmetic appearance, but may also affect the adhesion of coatings onto the substrate.

Residual Stress

Residual or internal stress is caused by tension or refractive index variation formed within glass and glass-ceramic materials during production. This can lead to striations, internal defects, and changes in the surface topography. Internal stress is known to impact the mechanical properties of these materials.


Particles on the surface of glass can be caused by many factors, usually during the cleaning or packaging phase. Lumina's systems are able to detect particles down to 150nm on glass surfaces. Controlling particles is critical for achieving high quality and yield. Identifying particles and being able to take action early in the manufacturing process will also help avoid wasting resources on downstream processes.

Inclusions and Particles

Inclusions are the result of contaminants incorporated within the glass during the melting phase. These can impact the optical and mechanical properties of the substrate.

There are two methods to detect inclusions:

  • Reflectivity: Detecting the residual stress pattern made by the inclusion
  • Dark Field: Detecting the double scattering event produced by the direct incident beam (a) and the secondary scattering event (b) due to the beam which reflects from the bottom surface of the glass.

Click here for a visual representation of the method to detect inclusions


These defects can be caused either during the manufacturing phase, cleaning phase, or due to rough handling of the glass. When layers are stacked, internal scratches may occur. Scratches impact the cosmetic and mechanical properties of the glass.