Dr. David Biss, Senior Manager of Optical Engineering at Optikos Corporation, returns to the Photonics West stage this January with fresh insights for the life sciences sector. Drawn from years of hands-on experience solving complex optical challenges, his talk “Correlating final system performance metrics with design metrics of optical imaging systems in biomedical devices” addresses a persistent industry problem he has seen time and time again in his job: the disconnect between how optical systems are designed and how they are ultimately tested and qualified for production. This reality hits companies hard because of the costs involved, from time and money to sometimes even product viability.
We sat down with Dr. Biss before his flight to Photonics West 2026 to find out more about this silent issue that is shaping the MedTech world and how his talk could open up new perspectives.
What inspired you to tackle this particular topic?
David Biss (DB): Over my 12 years at Optikos, I’ve repeatedly encountered this fundamental disconnect in how optical systems are developed versus how they’re ultimately tested and qualified within the life sciences sector. We work extensively on optical system development—think lens design, optical engines, subsystems, you name it. What we’ve observed is that the performance metrics used by engineering teams during the design phase of a project don’t always translate into what quality control departments or regulatory bodies need at the end of the production line. And this is huge to know if you’re working for a life science company.
Let me give a concrete example. When engineering teams optimize against one set of metrics during design, say like wavefront error, but quality control departments need to verify completely different specifications, like encircled energy or spot size, the resulting miscommunication can lead to over-designed systems that miss cost targets, under-designed systems that fail performance requirements, or protracted back-and-forth cycles that delay time to market.
So, the topic of my talk at Photonics West isn’t just a theoretical problem.
Why is this issue particularly critical for medical devices?
DB: Medical devices face stringent regulatory requirements, and rightfully so. These devices often relate directly to human lives, whether through diagnostic outputs or actual interventions on patients. Because of these regulations, specifications and requirements for medical devices need to be extremely well-defined and justified.
The challenge is that typical optical metrology methods used during the design phase for these applications, like interferometry for wavefront measurement, aren’t always feasible or meaningful at the production stage. You might design against wavefront error because it’s mathematically convenient for optimization, but your end-of-line requirement might be irradiance uniformity or resolution, which can mean many different things depending on context. If you don’t bridge this gap properly, you risk either over-designing your system, which drives up cost and complexity, or under-designing it, which means it won’t meet actual performance requirements.
Can you give a concrete example of how this disconnect manifests?
DB: Sure, it’s related to what I’ve said in the beginning. One case involved a customer who insisted on diffraction-limited performance with specific wavefront requirements. But their real concern was encircled energy, which is what actually determines whether enough light hits the detector for good images. When we conducted tolerance analysis and Monte Carlo simulations, we discovered that if you’re looking at build yields and the manufacturing reality regarding practical constraints and variations, you could actually relax the wavefront requirements somewhat because the encircled energy specification was already being met. The customer was essentially holding their system to unnecessarily tight tolerances, which had direct implications for manufacturing costs and yields.
This happens because there’s often a language barrier between different parts of the organization that are involved in getting a product out the door of the factory. The optical design team speaks in terms of wavefront, aberrations, and point spread functions. The quality control department needs to measure things like spot size, uniformity, or resolution. The systems engineering team needs to flow down requirements from overall device performance to individual subsystems. If these groups aren’t communicating effectively about metrics, problems compound throughout the development cycle.
Who should attend your talk?
DB: Systems engineers would definitely benefit because they need to understand how end-of-line specifications flow down to individual components and subsystems. QC (quality control) personnel should attend because if someone starts handing you wavefront data but your actual performance requirement is encircled energy like I previously mentioned, you need to know how to interpret and convert that information meaningfully.
Optical designers and engineering managers working on medical devices or precision optical systems would also find this valuable. Anyone worried about over- or under-designing a system against specifications should care about understanding these relationships. Ultimately, people hire Optikos to get a job well done and because of these issues, we’re able to add even more value where most people wouldn’t. This tells me the knowledge about performance metrics isn’t as widely distributed as it could be. And that’s why I proposed this exact topic for this year’s Photonics West.
What can Optikos offer to help bridge this gap?
DB: We can support the entire production process actually. We help develop metrology approaches, create end-of-line test systems that measure actual performance, and provide design support that keeps these final requirements in view from the beginning. We do interferometry and traditional optical testing, but we also build custom test systems that measure real-world performance metrics. Our experience across microscopy, lidar, remote sensing, and projection displays gives us perspective on how these challenges manifest across different applications.
Finally, what are the key takeaways you want people to leave with after your presentation?
DB: First, I’d appreciate if people would start to recognize that a disconnect can exist between design criteria and end-of-line performance requirements. Second, understand that this disconnect, if not addressed, can cause both over-design and under-design depending on your system and how you’ve set up your metrics. Third, realize that metrology considerations matter enormously.
We’ve actually written white papers on microscopy metrology techniques that address some of these measurement challenges and gaps within the production process. The fundamental principle is that your end specifications need to be addressed first, then distilled into appropriate design metrics, with full awareness of the translation between the two.
After years of helping clients navigate these exact problems, I can say: the companies that get this right from the start save enormous amounts of time and resources downstream. They are the real winners at the end of the day.