Your contact persons
Want to find out more? - Contact us for customised solutions!
Front surface mirrors
Front surface mirrors offer excellent reflectivity over wide wavelength ranges
The term ‘front surface mirror (VS)’ can basically be applied to any mirror whose first boundary surface is a mirrored surface. In contrast to a back surface mirror (mirroring of the second boundary surface), in which the passing beam is strongly reflected at the second boundary surface and slightly reflected at the first boundary surface, the double images resulting from this beam path are avoided in a front surface mirror. The task of a mirror coating is the reflection of radiation, adjustable for the UV, VIS and IR range.
Designs of surface mirrors
Front surface mirrors are usually realised by applying metallic layers, as these have a high reflectivity over a wide wavelength range. In addition, metal mirrors whose metal layers have a rather low strength can be reinforced with additional dielectric layers. Copper is also recommended as a reflective medium for infrared diodes. The reflection values of typical front surface mirrors are between 88 % and 92 % and can also reach 94 % to 99 % for highly reflective surface mirrors. Front surface mirrors are usually designed as aluminium mirrors and are sometimes also referred to as surface mirrors.
Advantages of surface mirrors
- Double image-free image reproduction, avoidance of multiple reflections
- High reflection effect and reflection values
- By selecting different mirroring materials, different wave-dependent reflectance values can be set.
- Spectral range: UV to IR (depending on the coating material)
- Angle of incidence can be adjusted
- Substrates: Float glass, borosilicate glass, glass ceramic, quartz and metal as well as plastics (polycarbonate, COC etc.)
Application examples for front surface mirrors
- Optics, optical device construction
- Optics for sensor technology / sensor systems, e.g. positioning systems, scanner technology, barcode recognition, etc.
- Optics for beam steering (deflecting mirrors)
- Illumination optics
- Laser applications / laser technology
- Medical technology / medical devices, e.g. with ultraviolet light sources
Possible designs of front surface mirrors (examples)
- Protected aluminium mirror: Broadband surface mirror with high UV reflection and a broad reflection spectrum of approx. 200 nm - 10 µm and very good optical properties
- Enhanced aluminium mirror: Aluminium Enhanced front surface mirror with a dielectric reinforcing layer over the aluminium layer and thus improved reflection without double images (ghost image effect); large-format dimensions also possible
- Mirrors with silver coating and gold coating are also possible
- Highly reflective (HR) coating
- More about other optical coatings
- Further mirror coatings
Dielectric protective coatings
- Typically, dielectric top layers are applied to increase the durability of the mirrors and protect the metallic reflective layer.
- The reflective properties of the metallic mirror layers are not affected.
- In order to increase reflectivity in certain areas, additional dielectric layer packages can be applied (e.g. UV or IR-enhanced).
- Further information on dielectric mirror coatings
FAQ - Frequently asked questions about front surface mirrors
A front surface mirror is a mirror whose first boundary surface is the mirrored surface. This prevents double images, which occur with rear surface mirrors.
With front-surface mirrors, the reflection is produced at the first interface, while rear-surface mirrors reflect at the second interface, resulting in double images.
Aluminum is often used, but copper, silver, gold, or dielectric layers can also be used.
Typical values range between 88% and 92%, with highly reflective versions even reaching 94%–99%.
They cover UV, VIS, and IR ranges, depending on the coating material.
- Double image-free image reproduction
- High reflection effect
- Adjustable reflection levels depending on material
- Suitable for different angles of incidence
Float glass, borosilicate glass, glass ceramics, quartz, metal, and plastics such as polycarbonate or COC.
In automotive, sensor technology, scanner technology, optical device manufacturing, lighting optics, laser technology, and medical technology.
- Protected aluminum mirrors
- Enhanced aluminum mirrors with dielectric reinforcement
- Mirrors with silver coating
- Highly reflective (HR) coatings
They increase durability and protect the metallic reflective layer without impairing the reflective properties. More about dielectric mirrors
