SPIE Optifab is shaping up to be a great event in Rochester, N.Y. next week. The sold-out exhibition will feature optical fabrication equipment and technologies from around the world. The show is best recognized for its educational track, though.

Ross Optical’s Charlie Metzger has worked in all aspects of optical fabrication, from equipment sales to production management to optical component sourcing, over the course of his career. In this post, Charlie and the Ross Optical team share their take on the latest trends in the optics industry.

3D printing is the headliner topic again this year. What are you seeing as this technology evolves?

While widely in use in other component industries, it’s still just emerging in optics. The few requests we’ve had for 3D printing of optics we’ve been able to redirect to the one or two providers that are actively using 3D printing to prototype optics.

We expect to see a lot of change in this area over the next few years. The demand is there for rapid prototyping of optics. Right now, though, given timeline, cost and quality demands, customers are turning to COTS, catalog off-the-shelf optics. Much of this push is ITAR-driven. As long as the lens or other optic is an off-the-shelf item, the optic can be sourced from anywhere in the world and customized to meet their needs.

If we don’t have the lens a customer requires in stock, we can find it and customize it to suit their application.

One of the topics featured is cost-conscious tolerancing. This is something you work on with customers every day. What are your top recommendations to customers in controlling costs?

I think this will be a very well-attended session at Optifab. Often, drawings for optical components are over-specified for their particular end-use. In working with customers to understand the application and what is really needed, we can suggest ways to drive out cost without noticeable impact on optical system performance.

For non-optical engineers, for example, specifying a 0.02 tolerance on a CNC metal part is easy. But this same tolerance can be quite costly in optics and may be unnecessary. We can help our customers understand feasibility and where some level of compromise may mean huge cost savings without a perceptible difference in how well a system operates.

Irregularity is another common tolerance; 1/20 wave radius tolerance may be needed for some types of instrumentation, but it sets a level that may be unnecessarily costly in other devices. 

In surface quality, 40/20 is the standard in the industry, and quite acceptable for many systems, but some designers just routinely spec 20/10 or 10/5. Unless an application is in the visible spectrum with a problem with scatter, or a lens in the focal plane, for example, the industry standard may be the more reasonable tolerance.

Inspection specifications can also drive costs. Applying MIL or ISO standards for scratch dig and other inspection standards can reduce your costs and speed the purchasing process for optics.

We like the wisdom of John Plummer, long time SPIE presenter. Faced with this issue, John would say, “In optics, you shouldn’t look at them, you look through them.” In other words, examine the optics in the way they’ll be used.

Inspection tolerances can drive costs at the customer’s assembly stage as well. Their assembly team can spend hours trying to meet or measure tolerances they simply don’t need.

We’re happy to work with customers to quote per specifications, as well as suggest ways they can drive down optics costs without impact to performance.

What are you hoping to learn at Optifab?

The course in optical inspection is a great one. We’ll be exploring the similarities and differences between the MIL and ISO standards, with hands-on learning. The Optifab show is also a great opportunity to catch up with long-time customers and colleagues. We hope to see you there!

Whether you're looking for custom optical lenses, a standard aspheric lens, micro optics, or optical assembly, Ross Optical can work with you to meet your needs. Contact Charlie Metzger to set up a meeting at Optifab.