Case Study: 550 nm Short Pass Filter

Case Study: How Layer Pairs Influence Slope (%) on Short Pass Filters

Customer Challenge: Because of an instrument upgrade, the customer needed a replacement steep, short pass blocking filter with high transmission for 530 – 540 nm. This was to maximise the laser output in their system which the manufacturer specified at 535+/-3nm. Additionally high-density blocking was needed from 575 – 700 nm. Our study and the comparison with the existing filter, dictated that it needed an edge slope of less than 1.5%.

Vortex’s Solution: Using optical design software we were able to check all 3 criteria could be met with one design (i.e. high blocking, steep slope and high ‘no ripple’ passband transmission over 530-540 nm. A theoretical design is one thing, but it needs to be manufacturable, economically viable and repeatable. We were then able to take the theoretical design and using our in-house process control software turn it into a ‘real filter’ that the customer could initially test and then install within their instruments on a permanent basis. This is shown by the red line below.

The Outcome: The customer’s input was very important in terms of making this work. Our years of experience and deep understanding of instruments coupled with accurate input from the customer, meant the solution was produced very quickly. This approach makes Vortex an excellent partner for any project be it initial system development, low volume applications or high production volumes.