21
Jan
PAT Roberts

How are custom optical thin film filters different?

Custom optical thin film filters are a bespoke product – but just what does bespoke mean in the case of optical thin film filters?

It’s not just about the wavelengths of light that are absorbed by the filter, although of course that is often the main need to be addressed.

But there are other factors too, such as the choice of substrate and the dielectric materials deposited on to that substrate to create custom optical thin film filters to order.

 

Substrate

At Envin Scientific we use a wide range of different substrates, including sheet materials, moulded substrates, ground and polished, fire-polished and diamond-turned materials – just check our Optical Thin Film Filters page for a full list of specific substrates available.

The choice of substrate can affect the optical properties of the finished filter, so getting the right substrate is not an insignificant part of the process when making bespoke optical thin film filters.

 

Dielectric

Dielectric materials deposited on to the substrate add the main optical capabilities to the filter, and this can range from a reflective or anti-reflective coating, to absorbing specific wavelengths from the light that passes through.

Laminated filters can layer different absorption bands on top of one another to create a single filter with multiple characteristics – another welcome ability in many bespoke optical thin film filters.

 

Shape

The shape of the substrate can be significant, and not all filters are flat. Some may be reflective and/or curved, directing or focusing the light into a specific direction and again removing the need to use a separate component to achieve this desired effect.

It may simply be a matter of needing a specific size – and many of the custom optical thin film filters we produce are primarily about fitting the desired dimensions, rather than the properties of the optical filter itself.

 

Absorption pattern

Finally, the overall absorption pattern of the filter is crucial, and all of the materials used, size and shape of the filter, and so on can have an effect on this when combined.

We use industry standard spectrophotometers in the range from 175 nm to 30 microns to measure and qualify every filter we produce, so you can rest assured that your bespoke optical thin film filters will always have the optical profile you need.

 

Are you in need of a bespoke-made optical thin film filter? Get in touch with us today. Explain your requirements to us and we’ll get back in touch as soon as possible to discuss your needs.