Case Study: H₂0 Blocking Notch Filter

Case Study: Development of a Notch Filter for Imaging Applications

Customer Challenge: Our customer faced a challenge, when their legacy notch filter was discontinued by the previous supplier. It was a notch filter that blocked the H₂O absorption band at a centre wavelength (CWL) 950 nm ± 10 nm The filter needed to maintain less than 6% transmission at the CWL, to ensure optimal imaging performance. The customer required a reliable replacement urgently, to avoid disruption to their shipping schedules.

Vortex’s Solution: Vortex addressed this challenge by measuring one of the customer’s remaining filters on our state-of-the-art Perkin Elmer 1050 spectrometer. This analysis provided key data on the filter’s performance and enabled our engineering team to design a match to the original’s performance characteristics. We shared this information with the customer and developed a new specification, we could then move forward to production. The filter coating was deposited onto larger rectangular substrate, they were checked for optical performance and surface quality and diced onsite to the final size. The edge chip specification was < 0.1 mm but using in-house proprietary methods it passed comfortably.

Outcome: Vortex successfully designed and manufactured the new notch filter. The water band was successfully attenuated, and the new batch of filters worked just as well in the system as the previous filter.

The timely delivery of the replacement filter enabled the customer to continue their delivery schedule without interruption. This project not only highlighted Vortex’s expertise in developing custom optical filters but also reinforced our commitment to supporting clients facing critical challenges in their operations. We pride ourselves on being there when our customers need us most.