By Frank Calcagni, Optical Filter Source
Imagine a world where the slightest component failure at 30,000 feet could have catastrophic consequences. In this high-stakes environment, reliability isn’t just a goal, it’s a lifeline. At Optical Filter Source, we specialize in developing optical components that not only meet but exceed the rigorous demands of the aviation industry. Here are some insights about our busbar technology and how it addresses the unique challenges faced by avionics systems.
Meeting the extreme challenges of aviation
Avionics systems face extraordinary environmental demands. From the intense heat of the tarmac to the frigid temperatures at 30,000 feet, these systems can experience temperature swings exceeding 100 degrees Celsius. Add in constant vibration, particularly during turbulence, and you have conditions that would quickly compromise inferior components. The potential consequences of coating failure in such conditions include signal loss, inaccurate readings, and display malfunction.
Our approach to these challenges is elegantly simple yet technically sophisticated. Our coatings are intimately connected to the surface of the window or optical component. Their mass is very light, and they adhere exceptionally well to the surface, whether it’s a camera window or a cockpit display. This intimate connection ensures our coatings withstand vibrations and temperature fluctuations without any degradation in performance.
The surprising role of gold in our busbar technology
When people think about gold in electrical components, they typically assume its primary purpose is conductivity. In reality, gold serves a much more critical function in our thin film coatings: passivation.
Gold passivates the surface and protects it from corrosion. When a wire or preform is soldered to a solderable coating, the gold diffuses into the solder, creating an alloy that enhances both performance and durability. This passivation is crucial for ensuring long-term reliability in mission-critical environments where human lives depend on flawless operation.
Reliability: The ultimate advantage
If I had to summarize the main advantage of our busbar solutions in one word, it would be “reliability.” Alternative technologies often create issues that require workarounds. Some may involve adhering components to the surface or using organic materials like polymers, which can degrade over time.
Our busbar technology uses exclusively inorganic materials, eliminating many common failure points. In avionics, where both aircraft safety and human lives are at stake, this reliability isn’t just a selling point; it’s an absolute necessity.
When we’re developing components at Optical Filter Source, we often ask ourselves: “Would you fly on the plane that contains this component?” It’s a simple but powerful standard that drives our commitment to excellence.
Real-world problem solving
One particularly interesting case study demonstrates the robustness of our technology.
A customer was testing our busbar coating combined with a transparent conductive oxide (TCO), a coating that allows electricity to flow through a completely transparent surface. They wanted to test the part to failure, so they attached wires, applied current, and continuously increased the heat.
When asked about the failure mode, they reported that they had heated the window so hot that the solder melted off the coating and the wires came off—but the coating itself remained intact and functional. We consider that a “successful failure,” demonstrating the extraordinary resilience of our technology under conditions far beyond normal operating parameters.
The white-glove collaboration process
All our customers receive meticulous attention, but our avionics clients require an especially high level of detail and documentation. From the initial quote phase through to delivery, we practice what I call “white-glove treatment.”
When we receive specifications from avionics customers, there’s typically extensive documentation to review. Every detail matters—sometimes right down to the precise wording of requirements, where the difference between “may” and “shall” can have significant implications.
We begin by engineering quality into the product from the very start. At the quote phase, we map out the entire process to ensure we can deliver exactly what’s needed. Once an order is received, we typically hold a kickoff meeting where our technical team collaborates with the customer’s engineers to clarify details and establish action items.
While substrates are being fabricated and tooling is being made, we maintain ongoing communication. Before coating begins, we conduct a final review of all specifications. Our quality team works alongside technicians during coating and performs another inspection afterward.
Even packaging receives the same level of attention, after all, what good is an expensive, perfectly-coated component if it’s damaged during shipping? Getting all the way to the finish line with an expensive substrate and expensive coatings, only to destroy it in packaging would be tragic.
Overcoming technical challenges
Every component presents its own unique challenges. Some might appear simple, such as circles or squares, but avionics customers often throw us curveballs: oddly shaped components that require creative solutions.
With busbars specifically, the main challenge lies in creating patterned coatings. We need to determine the best approach for each application, whether using mask technology or photolithography to create precise patterns on the component surface.
These challenges are our specialty. What might be insurmountable obstacles for companies new to this field are everyday problems for us. Problem-solving isn’t just part of our service, it’s central to everything we do.
Evolving with industry trends
The avionics industry evolves slowly by nature. We still see prints from the 1960s, 70s, and 80s specifying coatings that we would rather not produce because far better alternatives have since been developed. However, safety-critical industries necessarily move cautiously when adopting new technologies.
That said, we are seeing some newer developments. More airframes are now incorporating transparent conductive oxides for heating camera windows and providing EMI/RFI protection.
We’ve developed full in-house capabilities to address these requirements and can create custom components to each customer’s exact specifications.
Every print we receive is almost like a fingerprint, completely unique. Even the drawing style often tells us whether it originated from a U.S.-based avionics customer or a European one (perhaps from France, Germany, or further east). This variety of approaches keeps our work interesting and challenging.
Looking to the future
I believe optical coatings and components have a bright future in avionics. Classical optics aren’t going anywhere soon, and even newer technologies like LiDAR still rely on classical optical principles. These systems are appearing on more airframes and ground-based platforms—including autonomous vehicles, which depend on LiDAR for operation.
At Optical Filter Source, we’re not content to rest on our laurels. That’s why we’ve invested in capabilities like photolithography. While avionics may not experience disruptive change, requirements continually become more demanding. We’re constantly advancing our technology so that when a customer comes to us with a novel approach, we’re already prepared to meet that challenge.
Beyond busbars: Our complete optical capabilities
It’s important to note that busbars are just one part of our comprehensive optical coating capabilities. Between Optical Filter Source and our sister company North American Coating Laboratories, we offer a wide range of optical coatings including anti-reflective coatings, high reflectors, and beam splitters that differentiate between wavelengths.
We’re essentially a one-stop shop for customers across multiple industries: avionics, oil and gas, medical, and many others, all of whom require high-quality optical components for their specific applications.
In this business, the details matter. Whether it’s a high-stakes avionics application or any other precision optical need, our commitment to quality, reliability, and technical excellence remains unwavering.
Learn more about our advanced busbar technology and how it can enhance the reliability of your avionics systems, and beyond. Contact our team today for a consultation.
