Your contact persons
Want to find out more? - Contact us for customised solutions!
AR-Coatings
We offer effective, high-quality anti-reflective coatings
Optical Coatings
Bte is your partner for designing and manufacturing high precision dielectric and metallic optical coatings using thin-film technology
Bte specialises in the design and production of high-precision optical coatings using advanced thin-film technology. Our expertise extends across various substrates, including glass, metal, plastic, and ceramic, allowing us to coat a wide range of surfaces to meet diverse industry needs. From individual mirrors and highly reflective coatings to various optical filters, beam splitters, metallic coatings and AR coatings, well-known suppliers from a wide range of industries rely on our solutions. We also offer ITO coatings. We customise our coatings precisely to your requirements, from individual layer design to series coating production. Additionally, we offer peripheral services such as glass cutting, measurement, and packaging solutions to ensure seamless integration into your manufacturing process. We are committed to providing innovative and high quality optical coating solutions tailored to your specific needs. Partner with us for reliable, highly accurate coatings that meet the demands of your applications.
Optical Coatings for different characteristics
Optical thin films play a pivotal role in altering the reflection or transmission characteristics of surfaces and optical components across various spectrums such as UV, IR, or VIS radiation. Among their diverse applications, they are commonly utilised for mirroring and anti-reflective coatings on surfaces, as well as in optical filters, where reflection is tailored based on wavelength selectivity.
These coatings can be broadly classified into metallic or dielectric coatings, depending on the materials employed. For instance, multilayer systems incorporating metals like aluminium or copper are used for applications such as reflectors and neutral density filters. On the other hand, dielectric coatings leverage a variety of materials to achieve precisely defined optical interference. This allows the incident radiation to be split into a transmitted and a reflected fraction.
The selection of coating material and technology is contingent upon specific application requirements, which encompass factors like thermal resistance, mechanical properties such as hardness and abrasion resistance, as well as resistance to solvents, UV radiation, weathering, and ageing. At Bte, we offer a broad range of different optical coatings for a great variety of applications.
Our Coatings
FAQ: Frequently asked questions about optical coatings
Optical coatings are extremely thin layers of transparent materials that are applied to optical components such as lenses, mirrors, or glass surfaces. Their main purpose is to specifically influence light transmission, reflection, or absorption, depending on the respective application.
Optical coatings serve several important purposes, depending on the application. The main functions are:
1. Reflection control
Anti-reflective coatings (AR) reduce unwanted reflections on surfaces such as eyeglass lenses, camera lenses, or displays. They improve light transmission and thus image quality or visibility. If light falls on an uncoated eyeglass lens, reflections occur on the front and back. This is visually disturbing because the person opposite us cannot see our eyes. It can also compromise safety: the reflection dazzles the eye and restricts vision. Anti-reflective coatings on the eyeglass lens minimize these disturbing effects.
2. Light management
Mirror coatings specifically increase reflection, e.g., in telescopes or laser systems.
Filter coatings allow certain wavelengths to pass through and block others (e.g., UV filters, infrared filters).
3. Protection
Optical coatings can also provide mechanical protection, for example, against scratches, moisture, or chemical influences. In industrial applications, they protect sensitive optical components.
4. Color and contrast optimization
In displays, sensors, microscopes, measuring instruments, or projectors, special coatings ensure better color reproduction and contrast ratios.
5. Performance optimization
In sensor technology, scanner technology, and laser technology, coatings are used to optimize performance, e.g., by increasing contrast, achieving high reflections at defined wavelengths, or minimizing reflections.
There are numerous applications in which thin optical coatings are used to achieve specific effects. Optical coatings are used, for example, in:
- Automation technology: In industrial sensors, such as light barriers or laser and barcode scanners, optical coatings ensure precise signal transmission while protecting against dust, moisture, and chemical influences.
- Displays and screens: Coatings reduce reflections and improve readability.
- Cameras and microscopes: Anti-reflective coatings improve image quality by minimizing distracting light reflections.
- Laser technology: Special coatings enable precise control of laser beams.
- Telescopes and scientific instruments: Optical coatings increase light efficiency and improve measurement accuracy.
The effect of optical coatings is based on the principle of interference. The behavior of light waves when they strike the surface is influenced by specific layer thicknesses and material selection. This allows certain wavelengths to be amplified or canceled out, depending on the desired effect.
Interference is a physical phenomenon that occurs when two or more waves overlap. The waves can reinforce or cancel each other out, depending on their relative phases. This principle applies to all types of waves, including light waves.
phenomenon that occurs in optically thin layers, such as soap bubbles, oil films on water, or special coatings.
- Light strikes the thin layer (e.g., a soap film or an anti-reflective coating).
- Part of the light is reflected at the upper interface, while another part penetrates the layer and is reflected at the lower interface.
- The two reflected light rays overlap.
- Depending on the thickness of the layer, the wavelength of the light, and the angle of incidence, constructive or destructive interference occurs:
- Constructive interference: The waves reinforce each other, making certain colors appear more intense.
- Destructive interference: The waves cancel each other out partially or completely, causing certain colors or reflections to disappear.
Example: Anti-reflective coating
Anti-reflective coatings involve applying an extremely thin layer that is calculated to cause destructive interference with light of a certain wavelength, usually in the visible range. This reduces reflection.
