IR Cut Filters
Knight Optical offers IR-cut filters with excellent visible range transmission whilst effectively blocking any unwanted UV and NIR light. Our IR-cut filters demonstrate sharp transitions between the transmission and reflections bands for superior performance.
Currently Knight Optical stock precision IR cut filters which have an AR coating on the rear surface to reduce unwanted reflections and improve transmission. We offer these in 5mm to 50mm diameters, or 5x5mm to 50x50mm squares, all as 1.1mm thick standard option. Typically borosilicate (or equivalent) glass is used due to its chemical resistance and low thermal expansion.
Knight Optical can also provide custom IR cut filters, either as differing dimensions on our standard 1.1mm thick sheet material, or fully customised including dimensions, application of an AR coating, and surface quality.
The typical transmission for our IR cut filters is > 94% between 420-620nm, with band blocking of < 2% transmission between 700-1000nm.
For further information or help with your enquiry contact our technical sales team who will be happy to assist you.
Why use an IR-cut filter?
IR-cut filters are predominately used in cameras utilising CMOS/CCD sensors which are more sensitive than the human eye to NIR light.
By using an IR-cut filter, especially in the day time, these NIR wavelengths are blocked from entering the system and therefore improve the colour accuracy of the image.
These filters are used in camera systems such as:
- ANPR cameras
- CCTV smart surveillance.
Knight Optical also supplies hot mirrors with an extended transmission band to 710nm rather than 620nm. These filters will reflect unwanted heat away from the system.