Molding Aspherical Glass Lens Manufacturing
With using conventional techniques by mechanical grinding and polishing ways to manufacture lens to specific shapes which called "cold manufacturing", A better quick method is optical engineers can manufacture lens through "thermal manufacturing", it is using precision lens molding through which preformed glass blanks would be placed in mold cavities, go through heating, pressing, annealing and cooling processing, then inspected and finally assembled.
The mold cavity has high surface quality and accuracy; it is configured to produce lens of predetermined shapes. The molded lenses have a high degree of repeatability and accuracy, because they are all determined by the surfaces in mold cavity. The molding process is much quicker than cold manufacturing, so the fabrication cost could be controlled to low level in large quantity production. Molding is especially popular in the field of aspheric and free-form optical lens manufacturing.
Not all optical glass materials are suitable for glass lens molding. A series of low Tg(Glass Transition Temperature ) optical glass materials are specially developed to meet the requirement of molding process. With refracting index range from 1.4 to 2, they can meet the needs of most optical system design and manufacturing.
The major disadvantage of glass lens molding is that they cannot be used to make lens in large diameter, mostly because of the difficulty of warm up and cool down big piece of glass parts in short period.
Molding Lens Specifications
ODM Optics provides glass molded lens with 1-25 mm in diameter. The surface irregularity of the lens surface can be controlled to less than 0.3 micron, lens decentration less than 1 arc-minute.
| Material | Optical Glass |
| Diameter | 1mm-25mm |
| Shape | >Aspheric/free-form |
| Decentration | <1 arc-minute |
| Surface irregularity | < 0.3 micron |
| Clear Aperture | >90% |
| Coating | Dielectric/Metallic film |
