Starna Optical Coatings

Thin film coatings can be used to increase or reduce reflection from the surface of an optical component. They can be used to improve performance at a specific wavelength or over a broad wavelength band.
Optiglass now has a variety of optical coating equipment which includes electron bombarded sources with automated deposition control. In addition, the use of Thin Film Design Software enables Optiglass to offer a range of optical coatings which can be applied to any suitable optical surface. The main categories of coatings are as follows:

 

ANTI-REFLECTION COATING
Single Layer Anti-Reflection Coatings Laser Line Anti-Reflection Coatings(V-Coatings)
MgF2 Single Layer AR
V-Coat @ 633 Nm
MgF2 Single Layer AR

The coatings are a quarter wave optical thickness of magnesium fluoride and may be centered at any wavelength over the range 300 - 2500 Nm. Reflectance is reduced to 1.5% per surface at the centre wavelength.

 

V-Coatings provide very low reflectance at one specific wavelength.(typically less than 0.1% per surface at the specified wavelength)
V-Coatings are available centred at any wavelength over the range 400-1200 Nm.

 

Broadband Multilayer Anti-Reflection Coatings
Visible Broadband AR Cuvette Coating
some fluorescent applications require either or both the excitation and emission energy to be enhanced by applying a metallic mirror coating to the outside of adjacent windows opposite to the source and the detector windows. Similarly, anti-reflection coatings on the other windows reduce reflective losses.

 

This type of coating provides much lower reflectance than that obtained from a single layer of Magnesium Fluoride. This multilayer coating typically achieves less than 0.3% reflection per surface over the range 425-675 Nm.
The coating is available for other wavebands and for various refractive index of glass. In addition, dual-band coatings(e.g. visible and 1064 Nm) are available.
Type No.
Description
/AR
/MC
/AR/MC
Anti-reflection coating
Mirror coating
Anti-reflection & mirror coating
BEAM SPLITTER COATINGS
These coatings are partially reflecting and may be used where a light beam needs to be split into two. Two types of Beamsplitter are available from Starna.
Polka-Dot Beamsplitters Dielectric Beamsplitters
  50/50 Beamsplitter for 45 deg

These coatings are constructed from protected metal films and provide a constant reflection-transmission ratio over a very wide spectral range.

 

These are low absorption coatings and are useful over a more limited wavelength range. Typical reflection: transmission ratios are 50:50 and 40:60.

 

MULTILAYER INTERFERENCE FILTERS
Notch Filter for 633 Nm Laser beam Splitter
Notch Filter for 633 Nm
Laser beam Splitter
These can be used to pass certain regions of the spectrum while rejecting others.
The curve shown is for a Notch Filter designed for maximum reflectance at 633Nm and low reflectance in other spectral regions.

 
HIGH REFLECTANCE METAL COATINGS.
UV Aluminium Mirror Visible Aluminium Mirror
UV Aluminium Mirror Visible Aluminium Mirror

This provides reflection greater than 85% over the wavelength range 190-300 Nm.

 

This provides reflection greater than 85% over the wavelength range 400-700 Nm.

 

Enhanced Aluminium Mirror Coatings
Enhanced Aluminium
Toric Mirrors
Aluminium can be overcoated with dielectric layers which increase its reflection in certain regions of the spectrum.Typical reflection is 95% average over the wavelength region 450-650 Nm.
Mirrors
available in all Glass types & Fused Silica
with a variety of optical coatings.