Custom Interference Bandpass Filters

Interference bandpass filters are excellent for applications requiring specific spectral tolerances. The manufacturing process allows a high level of control on the transmission parameters.
 
Though we have an extensive stock range of interference bandpass filters, Knight Optical can also provide custom filters manufactured to your specification. We can tailor the spectral properties to meet your application demands including:

• Peak transmission – either as a minimum value, or regulated to perform within a certain range.
• Centre wavelength (CWL) within the UV, visible or infrared waveband.
• Bandwidth or FWHM – we can supply narrowband (< 10nm), standard (10-50nm) and broadband filters (> 50nm).
• Out-of-band blocking – Typically OD4 (T < 0.01%) but

Knight Optical can also provide differing dimensions to fit into your application, including mounted and unmounted options. We typically supply 12.5mm, 12.7mm, 25mm, 25.4mm, 50mm, and 50.8mm diameter mounts, which can be etched with your unique batch number if required, however custom mount sizes can also be supplied.
Our filters are:

• CNC scribed which involves removing the outer diameter of coating and so enabling a glass-to-glass epoxy seal, rather than a glass-to-coating seal, which provides an excellent barrier against moisture.
• If mounted, they are hermetically sealed to further protect against moisture and there increase the long-term stability.

You can find our typical manufacturing capabilities below, however, please enquire for further information. Please note, the spectral properties are dependent on factors such as the design wavelength and bandwidth size.
 

  
Knight Optical can offer individual and sets of interference filters, and stock storage boxes to hold 12.5mm, 25mm and 50mm filters.

Contact our technical sales team for further information on our interference bandpass filters and how we can help you with your enquiry.