The technological most complex method to produce laser protection filters with very high optical density is the application of a reflective dielectric interference coating. At the laser wavelength where the laser safety filter blocks, a constructive multi-beam interference in the direction of the reflection occurs and nearly the entire laser power is reflected. By a special design of the interference layers also incident light at angles different from 90 deg will be completely reflected according to the required angular range of +/- 30° (according to norms EN207/208).
Using their own coating facility laservision is able to apply high reflection layers for laser protection filters on glass as well as on plastic substrates. Such reflection layers are usually applied on the laser side of absorbing glass filters in order to either optimize the wavelength blocking range or to further increase the protection effect of the absorbing filter. In case of a direct laser hit a significant part of the laser energy is reflected by the coating and does not enter the absorbing substrate. This technology provides exceptionally high protection levels for reflective coated laser safety filters.
Due to the angular dependence of the reflection effect of the coated filters only laser protection glasses with plane or slightly curved surface can be manufactured (laser protection spectacle frames R01, R02, R10, R14, and R17). As a large part of the protection effect is based on reflection every scratch on the coated surface must be avoided. As a service laservision offers to examine laser protection glasses in case of suspicion of damage to the coating.
Highlights
- Very high optical density
- Combinable with plastic and glass filters
- Best color view for IR and highest daylight transmission
- Available in miscellaneous forms of frames
- Brake-proof by special plastic structures
- Low weight and best carrying properties
