Case Study: 1500 - 1750 nm Wide Band Pass Filter

Case Study: Enhancing Wide Bandpass Filter Blocking Through Substrate Choice

Customer Challenge: Vortex undertook a project to develop a wide bandpass filter that transmits light in the 1500 – 1750 nm range with out of band blocking from 300 – 3000 nm. The challenge was to achieve this broad blocking range while maintaining cost efficiency. In optical filter manufacturing, the substrate often represents a smaller portion of the total cost, and the coating process is typically more expensive. With careful substrate choices the blocking requirements can often be assisted by the substrate, reducing coating time and total cost.

Vortex’s Solution: Particularly to meet the cost targets, we used a Silicon substrate because of its visible and near infra-red blocking.  This approach significantly reduced coating time and minimised costs for the customer.

The Result: The filter performed as expected and met all of the necessary requirements such as transmission above 80% through the passband and blocking less than 0.1% average from the UV to 3000 nm whilst also keeping the overall cost of the filter down.  At Vortex we have a wide knowledge of substrate properties and hold appropriate stock for immediate coating. This is an essential requirement for making problem solving fast prototypes.