Our series explains how Ross Optical can help you reduce lead time on your orders. This article will explain the three factors that most impact lead time for optical components:

• Choice of materials
• Method of fabrication
• Method of testing

While these three factors impact any manufacturing process, they present unique challenges in optical manufacturing.

Choice of Materials

Manufacturing optical materials is still an artisanal process, even with the use of computer controls and automation in modern glass manufacturing. The process of turning raw materials into optical-grade glass or crystal is intrinsically slow and requires constant, expert supervision. In many ways, facilities still resemble the one shown in this educational film reel from Bausch and Lomb, circa 1944.

The availability of a particular glass or crystal depends on the availability of raw materials and how often that glass or crystal is made. New environmental regulations also impact the availability of some glass types. At Ross Optical, we work with our suppliers to stay updated on projected material availability.

Method of Fabrication

Optical fabrication is the process of transforming glass into lenses, prisms; or mirrors. Similar to glass manufacturing, it is still an artisanal process. There are three major methods of fabrication:

• Traditional grinding and polishing of optical elements can be seen in the 1944 B&L video in the previous section. Although these processes are now automated, they are still time consuming.
• Molding molten glass allows fabricators to skip lengthy grinding and polishing processes. This technology enables mass fabrication, but it is generally best suited for small optical elements sold in high volumes, such as mobile phone cameras.
• CNC shaping uses computerized motion control to sculpt optical materials by passing them against a small grinding or polishing element. This method of shaping has revolutionized the optics industry by enabling the fabrication of aspherical lenses that can simplify or enhance an optical design. Like traditional grinding and polishing, though, CNC shaping is time consuming. At Ross we are well versed in our suppliers’ fabrication methods and can identify which products will best match a project’s schedule and budget.

Testing

In optics, “If you can’t measure it, you can’t make it.” An optical element is no good if there is no way to test that it performs correctly. The current measurement standard is laser interferometry, which can measure optical surfaces with nanometers of precision. This level of precision requires special vibration-resistant testing facilities that must be configured differently for different kinds of parts.

Developing the right test setup for an unusual optical element can be time consuming and expensive. At Ross we can tell you how testing requirements will be reflected in the cost and lead-time of a part.

Next, learn what Ross Optical can do to shorten lead times, and what you can do to “help us help you.”

Want more pointers? Download: 10 Tips for Reducing Lead Time for Optical Components