Before making a decision, it’s important to analyze whether making or buying optical parts and components is the best approach for your team, budget, and business goals.

How to Approach Make Vs. Buy Decisions for Optic Assembly
How to Approach Make Vs. Buy Decisions for Optic Assembly

Paul Townley-Smith, Director of Design & Prototyping | ZYGO Electro Optics

It’s not enough for industrial manufacturers to simply deliver great products anymore. Every organization today is exploring a better approach to shorten their development cycle to remain ahead of competitors. Despite the natural inclination for manufacturers to keep as many product development steps as possible in house, this can be short-sighted when fabricating optical devices. Before making a decision, it’s important to analyze whether making or buying optical parts and components is the best approach for your team, budget, and business goals.  


Considerations When Making Optics

Even though in-house optics fabrication and assembly may provide more control over a product development process, it can be extremely costly and time consuming.  As a small industry, it can be challenging to locate the necessary personnel with the requisite amount of experience. Typically it will take months to purchase all the equipment necessary, but years to build up the know-how to master it. So unless your predicted volume is high, the reduced cost of internally produced optics will not cover the fixed costs of implementation. 

In addition, optical infrastructure is not useful for anything but optics, and so if the requirement for optics eventually wanes or no longer exists, the infrastructure cannot be repurposed.

There is a unique skillset required in the optics industry which is often not fully recognized. First, precision is critical. When making optics, the levels of precision are measured in microns and nanometers, well beyond anything found in a familiar and traditional machine shop. This requires a high level of hand-skill that is difficult to find. Often, the defects are so small that problems cannot actually be seen so they have to be inferred, and this takes a long time to learn. In-house development resources may be able to handle routine projects. However, today’s optical devices are increasingly demanding greater functionality, which often times increases the scope of projects.

Also fabricating optics is not interchangeable with fabricating metals. When manufacturing optics, you are handling and manipulating brittle and fragile materials which have to be kept clean and free from scratches. This requires the establishment of procedures and best practices to avoid costly fractures or cosmetic defects due to improper material handling.

There is a danger that manufacturers perceive optics in the same way as electronics and software, where base coding or hardware skills can be easily adapted to apply to a broad range of problems. However, with optical devices we are working with the physics of light, it is analog not digital, the math can be difficult, and conclusions reached are often seemingly counter-intuitive. These unique skills do not transfer well with other domains.

In addition, typically nanometer-level precision is required on the surfaces of optics which requires specialized production and test equipment, and extreme temperature controls. Processes are continuously drifting as grinding and polishing tools and compounds wear. It takes years to learn how to manage and control such process drift effectively.

If deciding to make rather than buy, the infrastructure for optics fabrication and assembly is significantly  different from traditional manufacturing. You will need to invest in clean rooms, vibration isolation tables, expensive optical testing equipment, and the means to maintain extreme product cleanliness. Optics fabrication is a dirty and messy process, and it needs to be undertaken directly next to optical coating—a process which has to be handled in a pristine clean environment. It is a challenge to manage these competing needs under the same roof.


Considerations When Buying Optics

The motivation to make rather than buy optics is influenced by a number of factors, including: 

•  the ability to avoid the potential margin that an optics vendor will add to the price; 

•  a discernable long term need for a high volume of optics; 

•  the loss of control over schedules if production is out-sourced; or 

•  the product contains intellectual property that needs to be maintained within the company. 


In some of these cases, the high investment for in-house production could pay off. 

However, except in a minority of cases, these perceived benefits will typically be out-weighed by the considerable advantage of buying from an established vendor rather than making optics. With a buy decision, you are minimizing up-front investment and speeding up time to market, meaning a faster and more predictable program, and shorter time to revenue for your product.

In the area of costs, the considerable capital investment required to secure the space, equipment, and personnel required for internal optics fabrication and assembly can be avoided when outsourcing. This is particularly important when the future is uncertain in terms of volumes and demand for optics moving forward. In addition, outsourced costs are bounded and predictable, (the vendor eating any overruns), and even when your demand is for low volumes, you can benefit from the fact that the vendor is geared up for high volume across a range of products and has high efficiency processes in place. 

Optics manufacturing is characterized by continuous evolution of fabrication and metrology technological solutions which rapidly depreciates investments. Buying optics from a vendor that is continuously investing in and improving its tools creates compounding returns that are hard to compete with in a small internal shop.

When it comes to scheduling advantages, when you are buying rather than making you are outsourcing to specialists who will no doubt have done what you require before (or something similar) and therefore can get product to market more quickly as there is no steep learning curve to traverse. Experience also means that vendors can design and develop quickly with greater confidence and minimize costly and time-consuming mistakes, particularly important when the level of design sophistication is high. 

For instance, glass lenses take a long time to fabricate. A small error in the design can add many months to the schedule if the error is not discovered until after the optics have been made. Also, and quite obviously, there are significant time savings working with a vendor that has the equipment and experienced team already in place rather than having to start to pull together the required optics manufacturing infrastructure from scratch.

Strategically, outsourcing optics manufacturing makes sense as often the optical part to be bought is not a critical enabling technology in the customer’s final unique end-use product, and so time and resources can remain focused on other more important and fundamental areas of the business. The vendor becomes a risk mitigator for your overall business, a reliable and efficient addition to the efforts of your internal teams focused on the core of your business.


Vendor Selection — When and Who?

If the decision has been made to buy rather than make your optics, it is important to engage at the right time in the product development process and to partner with a competent vendor.

Typically, it makes most sense to engage with a production vendor at the product implementation phase rather than at the early research / proof of concept phase. At the very early stage of product development, the key is to be agile, work quickly, iterate, and economize. At this stage, the key is getting the technical specifications right and defining the operating window for your product, which needs to be assessed through prototype testing. This early phase is typically best handled by internal resources and employing consultants who can provide full-time dedication to your project and do not carry the overhead of a production vendor. Companies tend to see their own research labor as a free component of their fixed costs, whereas a production vendor’s research team will be relatively expensive as it needs to cover fixed costs. 

For vendors such as ZYGO, the product implementation phase is where engagement with customers is optimal. At this stage proof of concept is complete, the concept for the final product is ready, and the product technical performance window is understood so an accurate specification can be made. Also, the system level specification of the product is well defined including size, weight, and power; optical requirements are known such as field of view, image or beam quality, numerical aperture, and radiometrics; and environmental requirements are defined. 

Essentially this is the first generation design of a product that will be shipped to a customer, which a vendor can optimize so that analysis proves it is fit for purpose, and also provide a predictable schedule for prototypes and initial low rate production.

When it comes to selection of a particular vendor when you are at the product implementation phase, there are some useful tips to consider. 

First of all, look for vendors that develop their own machines for making, assembling, and testing optics, as they will have much more leverage for compounding returns, and they will have a more profound knowledge of the product and how it can be made efficiently.

Next, assess whether the vendor has a history of making devices similar to the device you need. This will ensure that fulfilment will be quicker (as many lessons will have already been learned), and fewer mistakes/missteps will be made improving costs and adherence to schedule. Effectively, competent vendors have a supply chain ready to accept your product.

Finally, look for a vendor that can leverage its existing internal infrastructure to make your parts, which saves on your capital investment costs, and makes for more efficient production and lower costs.

About Paul Townley Smith
Paul Townley Smith is currently the Director of Design and Prototyping for ZYGO's Electro Optics Group, which designs and develops custom optical assemblies. He has been developing optical products for over 30 years covering a broad range of applications including space, lithography, AR/VR, telecommunications, medical imaging, laser surgery, machine vision, life sciences, and material processing.
The content & opinions in this article are the author’s and do not necessarily represent the views of ManufacturingTomorrow

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