Accuracies in the micrometer range thanks to center turning
Alignment turning enables us to manufacture mounted spherical, aspherical and cylindrical lenses with the highest accuracy.
In the first step, the optical axis of the lens and the mechanical stops of the mount are measured so that the mount surfaces can then be machined using the high-precision alignment system. As a result, the optical axis of the lens and the mechanical axis of the frame are perfectly aligned. The advantage for our assemblies is that the air gaps can also be precisely adjusted afterwards. This means that we can still achieve accuracies in the micrometre range even with very complex optical systems. The technology remains an all-rounder in use for different optical materials from UV to IR applications.
At a glance
| lens diameter | machinable material | Tilting error | Adjustable air gap tolerance |
| 20 – 200mm | Brass
Aluminium Invar Titanium Stainless Steel |
2 – 3µm | 3µm |
That`s what our expert says:
“Alignment turning is a technology that allows the alignment of optical and mechanical axis on lenses, beyond what is conventionally possible, to be reproducibly manufactured. The imaging quality of assemblies is significantly increased by improved centering. In the technology process, a lens of any glass is glued into a metallic mount, the optical axis is measured and adjusted to the spindle axis. Then the metal mount is turned on the diameter and two axial contact surfaces. Thanks to this technology, it is possible to build systems in which the error of tilting and displacement of the individual elements is only 2-3µm. The air gap tolerance between two elements can also be reduced to 3µm.
Using alignment turning, we at POG can manufacture lenses with diameters up to 200mm.
This technology was of great benefit in the development of an assembly for a lens for wafer inspection. Here, the imaging quality and stability could be significantly improved.”
Silvio
Process Engineer Optical Systems
