Precision Glass Molding: For Scalable Manufacturability Application Note

Chalcogenide material is gradually taking over Germanium in the broad IR regime. It performs especially well within the 8 to 12μm range due to its lowest absorption and dispersion in LWIR. The low dn/dT of Chalcogenide makes lens athermalization much simpler by removing the required mechanical compensation complexity. The Chalcogenide series of glasses can be processed by molding. While polished or machined glass lens requires more than 1 hour per piece, the molding process is reduced to 5 mins.
Operation Principle
The overall manufacturing capability is listed in Figure 1.
- A precision glass molding manufacturing recipe has been developed for both low and high-transition temperature glasses. With more than 10 years of experience in optics design, the capability could be extended to free-form optics design and microstructured optics design.
- The automatic lens inspection system will check the optical performance right after the molding process.
- Depending on the target applications, the versatile thin-film coating will be applied. Applications include broadband transmission, high-power lasers, automotive headlight diffusers, etc.

The key specifications of a typical precision glass molding machine can be found in Tables 1 & 2. For other general specifications such as coating and profile control, please refer to WOE laser optics/IR optics/ biomedical optics catalogs.
Ultra-low Tg glasses for Tg<400゜C
Glass Material | Infrared glass, PbO-based glass |
Mold Material | Stainless steel, Optical-grade Aluminum alloy, Electroless nickel |
Mold Machining | Aspherical Glass molding machine |
Mold Life | <1000 pieces |
Low Tg glass Tg<650゜C
Glass Material | Oxide-based glass |
Mold Material | Tungsten carbide |
Mold Machining | Ultra-precision grinding |
Mold Life | <10000 pieces |
Applications
With higher optical quality, high-temperature resistance and thermal stability, corrosion resistance, scratch resistance, and wide refractive index, precision molded glass could be used in various industry sectors as suggested in Figure 2.
