Story: 3D printed optics

3D printing has taken huge steps ahead in recent years. But what is the most fascinating to me is the development in 3D printed optical components.

The “normal” 3D printing – or additive manufacturing – is often putting melted material on some form and then let it cool down to make a solid structure. From the optics point-of-view this is rather inaccurate approach. Although the printed objects might look nice, the surfaces don’t have optical quality.

If optics components are required, typically the precision of the surface must be sub-micrometers. Sometimes approaching just a few tens of nanometers, or even less. For example, if a good quality lenses are needed, the magnitude of the surface roughness should be just some nanometers. Otherwise light will be scattered into unwanted directions making image blurry. And the system inefficient.

Recently we have managed to develop the 3D printed optics to achieve better quality. This work has been done together with a Dutch company Luxexcel. Although the lenses are not yet perfect, they still have nice optical quality.

It is more than just high quality that matters in optics. One big challenge is always the designing and prototyping of optical systems. Traditionally that has been a big challenge. I mean, if complicated optical system is properly designed and analyzed, it will take easily weeks.

Also, when the prototype of the lens is fabricated it can easily take weeks or even months. But with 3D printing this will change completely. Printing a prototype lens can be really fast. Just hours. So the prototyping will be considerably faster than before.

But this speed means also that the fabrication can be even faster than the designing the lenses. So, if the design of the lenses will not develop fast, we will have in future experimental designing of optical components: When a rough design is ready, the refinement can be done with 3D printing. Just print a selection of slightly different lenses and then check which works best, and that will be the correct design.

With 3D printing one also have a larger flexibility in lens making. One can easily make, e.g., asymmetric lenses. Or even lenses that are hollow.  Or print the lens and its frames or holders at once. Like those 3D printed eye-glasses I managed to test a couple of years ago.

So, the world is changing very fast also in optics…