Special Optical Coatings
Capability
Diamond Coatings offer a wide range of special optical coatings in the optical and the infra red, using oxide and semiconductor layers (approximate wavelength range 300 nm – 20 microns). A flavour of the optical coatings we offer are given below, but if you can’t see your exact requirement then please contact us.
Available Optical Coatings
- All coatings are available in the Visible, Near Infra Red and Infra Red.
- Anti reflection coatings (V coats and Broadband AR), offering highly efficient AR with reflections of less than 0.5%.
- Beam splitters giving a range of Transmission/Reflection values (e.g., 50/50 or 70/30 +/- 1.5%)
- Front surface mirrors giving reflection of more than 99%
- Infra-red blocking filters (hot mirrors)
- Bandpass and edge filters
- Narrow band filters
Substrates Available Include
A wide range of glasses, sapphire, and optical polymers.
Anti-Reflection Coatings
‘V’ coat anti-reflection coatings
‘V’ coat AR coatings are usually used for specific laser wavelengths and can be designed for a range of incidence angles. Reflections of less than 0.1% can be obtained at a single wavelength for ‘V’ AR coatings.
‘V’ Coat Anti-Reflection Coating for 514nm AR Laser
Broadband Multilayer Anti-Reflection Coatings
Broadband multilayer AR coatings give less than 0.5% average reflectance over a wide wavelength range (in the UV, Visible and Infra-red regions). We can design multilayer AR coatings for a range of performances, substrates, wavelengths and incidence angles. This capability extends to design of dual band anti reflection coatings.
Broadband Visible AR Coat
Beamsplitters
Beamsplitters reflect a portion of the incident light and transmit the remainder.
Most often they are used at a 45º angle of incidence, but we have the capability to design beamsplitters for other angles of incidence.
For simple angular insensitive requirements, metal coatings can be used as long as a relatively large amount of absorption can be accepted. All dielectric designs can give spectrally flat transmittance and reflectance curves over about a 300nm bandwidth.
Infra-red 50:50 Beamsplitter
Edge Filters
Using a similar design to the all dielectric high reflectors, it is possible to achieve long wave or short wave pass filters for various angles of incidence.
These filters are used to reflect a portion of the incident spectrum and transmit another portion. They can be used to reflect the infrared and transmit the visible (commonly called ‘hot mirrors’) or transmit the infrared and reflect the visible (commonly called ‘cold mirrors’). They also find application as colour filters and ultraviolet light filters.
We have the capability to design and manufacture these filters for a range of incidence angles.
Near Infra-Red Blocking Filter
Durability
Dependent on design and specific deposition process, these coatings usually meet all durability and cosmetic requirements of the common optical specifications, including MIL-C-675 and MIL-M-13508.
