Skip To Content

OSA Industry Member Profile - Delta Optical Thin Film

Samantha Hornback, Research & Program Development Coordinator, The Optical Society


OSA Industry Development Associates (OIDA) member Delta Optical Thin Film, Denmark, is the leading continuously variable filter manufacturer in the industry. Calling themselves “The Optical Filter Company,” Delta puts an emphasis on customization and the highest quality products. To learn more about Delta and what it’s up to now, OSA spoke with CEO Poul Svensgaard, CTO Henrik Fabricius and Director of Sales and Marketing Oliver Pust. What follows is an edited version of that conversation.

Tell me about your company and its primary market.

Delta Optical Thin Film develops and manufactures high quality components in high volumes for instrument builders like microscope vendors, manufacturers of microplate readers and other types of optical instrumentation that use optical interference filters, dichroics and beamsplitters. This is the founding idea of the company. Over the years, we have developed technology that allows us to control all aspects of design and manufacture of our components, while keeping prices low. Our history goes back to the 1960s, when the focus was mostly on interference filters for fluorescence microscopes. Today, we have a new focus on continuously variable filters in addition to the homogeneous ones we were founded upon.

Quite often, our clients are very skilled optical engineers, but they may not be aware of all the facets of integrating optical filters into an optical measurement chain. We can often assist and add value by simplifying an optical system. Clients requesting a very advanced optical filter sometimes submit drawings that are far too complicated. We can take that and make it feasible. Working very closely with clients’ development engineering teams is definitely a key to our success.

We are able to offer so much customization due to our own design and optical monitoring software (OMS). Not only can we design the filters, but we can also design and manufacture the tools needed to make those filters. This technology also enables us to make continuously variable filters, something commercially available coating machines simply cannot do. The area of proprietary software has been leading the way as an enabling technology for creating advanced filters at competitive prices.

What goals drive Delta?

We are very much focused on bringing benefit to the people of the globe and trying to make products that have an impact on people’s daily lives. Our goal is to sustain our business and continue its growth. It’s critical for us to stay competitive, to make sure that we are still a viable supplier and that we are able to drive innovation for our clients.

We work frequently in medical diagnostics, new medicines, drug discovery, food quality and, more recently, point-of-care instruments. We deliver small, inexpensive minifilters for point-of-care instruments, some of which can be used at home. Of course, in the current situation, there is growing interest and need for point-of-care instruments, particularly those that can deliver the results quickly. The interesting thing is that these kinds of applications are just as advanced as the big lab equipment used today. Automation drives the cost reduction for these complex, yet small, components. 

Beyond these types of applications, we have been expanding into the semiconductor industry, hyperspectral imaging and many others. Recently, we even received a request from NASA.

One other aspect that we find incredibly important is sustainability, not only for our employees, but for our customers as well. As a Danish company, we are already very fortunate that more than 50% of the country’s energy comes from wind turbines. At Delta, our new facility’s whole roof will be covered by solar panels, and we continually work toward being completely green. We don’t use any substances that cannot be directly poured into the sewer except for the oil for our vacuum pumps, and the water we use to clean our glasses before coating can be completely discharged without further cleaning. We as individuals strive to live sustainably, and we look after our employees and customers equally.

Where do you expect the company to be in 10 years?

We can tell you that we have been growing and almost doubling our profits in the last five years, and we expect similar growth to continue, especially within the medical market. From our own internal point of view, we are currently building a new facility that the whole company will move into this August. Based on trends in the industry, our new building will have greatly updated clean-room facilities, and we have expanded our capacity by acquiring new coating technology and sputtering machines. This will be a completely customized building, and the opportunities are very exciting.

We’ve talked a lot about how you work with your customers to make exactly what they need. How does your relationship with the customers influence your business?

We are a company that focuses on specific customers—original equipment manufacturers (OEMs). We are not a catalogue company where we have a plethora of filters that a customer can choose from. The relationship is best if we can get a deep insight into what our customers really need, not necessarily what they say or write down as specifications of what they want to have. It’s really a dialogue with the customer from the start.

What is the best decision that Delta has made?

We all agree that the best decision Delta has made was to become our own company. This happened five and a half years ago, and it was the right thing for us. Previously, the company was held by a public research institute that was a self-owned entity, almost like a foundation. That was acceptable initially for moving the technology out of the university level, but converting to a 100% commercial company has been critical to our success. This, coupled with Henrik’s development of  high-performance continuously variable filters, created the foundation of our success. 

Describe your career paths. What brought you all to where you are today?

Henrik and Poul both studied at the Technical University of Denmark. After completing his degree as M.Sc., Henrik went on earning a diploma as industrial researcher from the Academy of Technical Sciences and he worked on a number of different national research projects within optics. This made him receive the annual award of the Danish Optical Society in 1995 for his research in and realization of quasi inhomogeneous optical filters. His research and development of new optical coating techniques and technology for more than 30 years makes him a key stakeholder and enabler. Poul brings to Delta a more commercial focus. His career has mainly been with Danish companies, previously in acoustics and electronics. He joined Delta in 2008 and has focused on improving the customer experience and new technology. Oliver has a strong technical background as well. Before Delta, Oliver obtained a Ph.D. in laser optical measurement technology and worked in sales and product marketing. The opportunity to explore filters presented itself, and he made the switch.

Why did you decide to join OIDA, and what do you see as the value of that membership?

As a long-time individual member of OSA, Henrik advised the company that an OIDA membership would prove beneficial. We find that OIDA is an excellent platform with a good combination of all the scientific background but with an industrial reach that enables us to identify potential users of our technology. The recent webinars have been particularly valuable in times like these. Further, the workshops, market reports and the growing global outreach have helped our business greatly.

Image for keeping the session alive