Optical Coating
High performance optical coatings
High-end optical coatings in the spectral range from UV to near infrared for demanding products with reasonable delivery times and reliable service - that's optical coating made by asphericon. Equipped with state-of-the-art manufacturing and measuring technologies available on the market as well as an experienced team of technicians, we turn your ideas into reality.
Reflection-minimizing coatings, also referred to as anti-reflection coatings, are essential for maximum transmission of the lens. Depending on the desired application, we offer single layer coatings, broadband coatings and reflection-minimizing coatings specific for laser applications. It is possible to minimize the reflection to <0.1%, depending on the glass type.
Multiple Coatings (ARDD)
Absorption-free, stress-minimized mirrors optimized for various angles of incidence with reflections greater than 99% can be produced for various wavelength ranges with dielectric coatings.
Mirrors can be specialized for single wavelengths (Single High Reflection, or SHR), two wavelengths (Double High Reflection, or DHR) and over a broad spectral range (Broadband High Reflection, or BBHR). Our high-power coatings are optimized for high-performance laser applications.
Single High Reflection (SHR)/Broadband High Reflection (BBHR)
Metallic mirrors provide a constant level of reflection across a very wide wavelength range. The surfaces are based on metals (e.g. Al, Ag or Au). Metallic mirrors can be protected and their reflectivity enhanced by adding dielectric coatings.
For many applications, various wavebands can be separated with filter coatings. We offer short pass and long pass filters based on dielectric coatings.
Short pass filters allow short wavelengths to pass, while long wavelengths are reflected. In contrast, long pass filters transmit the long wavelengths and reflect the short wavelengths.
Short-pass Filter (KPF)
Long-pass Filter (LPF)
Coatings for beam splitters divide incoming light into a transmitted and a reflected part. Based on thermally very stable dielectric layers, we realize customer-specific desired splitting ratios, typically 50 % / 50 % (R/T) or 30 % / 70 % (R/T).
Beam Splitter (BS)
Specifications optical coating
| Electron Beam Evaporation | Ion Assisted Deposition | Magnetron Sputtering | |
|---|---|---|---|
| Substrate size (Diameter) | up to 300 mm | up to 300 mm | 15 mm - 250 mm |
| Spectral range | 190 - 5100 nm | 190 - 5100 nm | 380 - 5100 nm |
| Stability | good | very good | ultra-hard |
| Residual reflection | Rabs < 0.1% (V-Coating) | Rabs < 0.1% (V-Coating) | Rabs < 0.1% (V-Coating) |
| Feature | - | usage of plasma source | sputter-up technology |
| Applications | AR | ARBB, HR | ARSBB, HR, Filter |
| Fast-Lane Service (24/48h) | optional | optional | optional |
Coating technologies
Depending on individual properties of the material and the requirements of the optical system, we select the appropriate coating technology for your project. For this purpose electron beam evaporation, ion beam assisted deposition or sputtering can be used.
- Electron Beam Evaporation
- Ion Assisted Deposition
- Magnetron Sputtering
- Magnetron Sputtering
Electron Beam Evaporation
Electron beam evaporation (EBE) is a process, in which optical components are coated in a vacuum chamber by evaporation of a material located at the bottom. The energy required for evaporation is generated by an electron beam. The vapor particles of the heated material propagate almost linearly in the vacuum. They condense evenly when they hit the surface of the optical substrate held at upper part of the evaporation chamber, which is located on a rotating calotte.
- Coating: dielectric mirrors, anti-reflective and metal coatings
- Substrate size: up to a diameter of 300 mm
- Spectral range: 190 – 5100 nm
- Fast-Lane coating (24/48h delivery)
Electron Beam Evaporation
Schematic process
Ion Assisted Deposition
Ion Assisted Deposition is based on the electron beam evaporation process and used for most optical coatings at asphericon. In addition, a plasma source is used in this coating process to additionally densify the resulting layer by ion bombardment. The result is an even harder, more stable layer.
- Coating: dielectric mirrors, anti-reflective coatings
- Substrate sizes: up to a diameter of 300 mm
- Spectral range: 190 - 5100 nm
- Very high coating hardness and stability
- Good thermal conductivity
- Fast-Lane coating (24/48h delivery)
Ion Assisted Deposition
Schematic process
Magnetron Sputtering
In magnetron sputtering, high-energy ions are generated in a vacuum from an AR plasma, which are directly pushed against a solid-state target. This is achieved by applying an electric field. As a result, ions and atoms are knocked out of the target and accelerated in the direction of the substrate by the electric field. The atoms and ions of the target are deposited on the top-mounted substrate ("sputter-up") and thus form a high-quality and uniform optical coating. The layer growth can be monitored spectroscopically and thus ensures high process stability and reproducibility.
- Coating: dielectric mirrors, anti-reflective coatings
- Substrate sizes: 15 mm - 250 mm
- Materials: glass, quartz, crystals
- Spectral range: UV - NIR (380 - 5100 nm)
- Very dense and uniform coatings
- Higher sputter rates, separately loadable magazine sluices
Magnetron Sputtering
Schematic process
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