Optical production

Bertin Winlight has production workshops for the manufacturing of high-precision optical components. It manufactures components based on specifications as well as components integrated into complete systems.

Moreover, the polishing processes in our manufacturing workshops allow us to achieve polishing qualities with shape errors of just a few nanometers and roughness of a few angstroms. The automation of techniques also enables the production of increasingly aspheric parts (with several millimeters of deformation). Furthermore, to ensure the quality of optical manufacturing, Bertin Winlight has been equipped since its inception with high-performance metrology tools, primarily in interferometry, allowing very precise measurements of flat, spherical, aspheric, and even freeform parts.

Roughing and optical polishing

The components are initially machined using computer numerical control (CNC) machines with 3 to 5 axes, and then polished using various techniques available in the workshop:

• Traditional polishing on machine or pedal
• Traditional polishing on machine or pedal
• Robotic polishing
• Machining by MRF (magnetorheology)
• Machining by IBF (ionic machining)

These methods allow for the creation of very diverse optics:

• Spherical or aspherical lenses
• Doublets, triplets
• Plane, spherical, or aspherical mirrors
• Windows, prisms
• Assemblies by bonding or molecular adhesion

Aspherics & freeforms

Robotic processes for roughing and polishing enable the manufacturing of aspheric and freeform components. For aspherics, we produce mirrors and lenses:

• Centered
• Off-axis, created directly off-axis without going through the centered parent asphere. This method allows for the production of highly off-axis aspherics while reducing manufacturing costs.

For freeform optics, we create optics based on the definition provided by the client, which can be decomposed into Zernicke coefficients, for example. Non-revolution freeforms are produced directly without using a parent revolute piece.

Polishing of glasses, ceramics, crystals…

Thanks to proprietary technologies and processes, Bertin Winlight polishes a wide variety of optical materials, covering spectral ranges from X-ray mirrors to lenses for IR band 3, such as:

• Glasses (Schott, Ohara, Hoya…)
• Crystals (CaF2, Silicon, Germanium…)
• Low CTE materials (Silica, Zerodur®, Clearceram®…)
• Metals (Aluminum, Stainless Steel, Invar, Titanium…)
• IR materials (GaAs, ZnSe…)
• Ceramics (SiC…)

Mastery of superpolishing processes allows, depending on the materials and shapes, to achieve roughness levels as low as 0.1 nm RMS.

Optical metrology

All our components undergo 100% inspection. The optical checks include, in particular:

• Dimensional measurements (external dimensions and thickness)
• Measurement of radii of curvature or aspheric or freeform shapes
• Surface quality control measured by interferometry
• Roughness and appearance control

We are equipped with 8 ZYGO and 4D interferometers. We also have 2 interferometric stations dedicated to very large mirrors as well as aspheric and freeform mirrors. Finally, we have roughness control capabilities down to 0.1 nm RMS.