LIMO, a manufacturer of high-precision micro-optics for laser systems, has achieved a process engineering breakthrough in the production of FAC lenses for all types of diode-pumped laser sources. The Dortmund-based company has made it possible to mass-produce the lenses with very high precision.
FAC lenses are a key component in many technologies, for the aerospace industry, medical field, photovoltaics, display manufacturing and materials’ processing. Now, batch sizes are expected to see a major increase thanks to using these lenses in additive manufacturing (3D printing) and LIDAR systems (laser-based Light Detection and Ranging), which find applications in autonomous driving and harsh environments.

Aside from high quality, FAC lenses also need to deliver reliable operation with long-term stability. The only way to meet these requirements is with laser systems that use high-end glass micro-optics.
The component most critical to their quality is the fast-axis collimator lens (FAC lens), manufactured from high-grade glass and with acylindrical surface. However, current production methods have yet to demonstrate their ability to produce large quantities at a consistently high optical quality and at attractive prices.

LIMO has now achieved that with its new manufacturing process. Its FAC lenses are produced on 140mm x 140mm wafers, which allows several thousand lenses to be fabricated from high-grade glass in a single step. The unique feature of its method is that the glass lenses are produced at room temperature. The company was able to increase the wafer size while also reducing the cycle time per wafer to under 60 minutes. The advantage of this “cold” method is that, since the glass is processed at room temperature, a higher production rate has no adverse impact on the quality of the lenses. LIMO is the world’s only manufacturer to have mastered this technique in high-volume production.

It now plans even bigger wafer generation.