A wide variety of interference filters in the IR range is available: Bandpass filters, long-pass filters, short-pass filters, blocking filters, and dichroic splitters are included in this range of products.
Dielectric coatings. Customer-specific solutions are also available for IR long-pass filters.
Long-pass infrared filters, unlike semiconductor filters, are constructed from stacks of thin layers. OD 3 rejection in the suppression range is not as high as it is with semiconductor filters, but it has the advantage of free choice of slope position.