In terms of the spectral characteristics there are three basic types of filters:

• Band pass filters (BP) that transmit light only around a certain center wavelength.
   

  Standard band pass filters
  BP 565 140	BP 590 50	BP 640 110
  BP 655  50	BP 680 100	BP 855 70

• Long pass filters (LP) that transmit light with wavelengths longer than a certain cut-on wavelength.
   

• Short pass filters (SP) that transmit light with wavelengths shorter than a certain cut-off wavelength.

Concerning the physical principle there are two basic types of filters:
 

• Absorption filters which suppress the undesired part of the spectral energy by transforming it into heat in the bulk of the filter material.
   

• Reflection filters which reflect the undesired part of the spectral energy back from the filter surface by interference (interference filters).

 The latter is realized by deposition of multiple thin layers of material with certain thicknesses and refractive indices in several steps onto a glass substrate. The effective thickness of the thin layers and therefore the spectral characteristic of the filter depends on the angle of incidence of light.

By designing a specific thin film layer system, nearly any desired transmission characteristic can be achieved. By combining both principles, i.e. using an absorptive glass as substrate for the multiple thin layers, special spectral characteristics can be achieved.

For OEM volumes, we offer the design and manufacture of an appropriate filter per special requested transmission characteristic. Please use the parameters listed below to specify your requirements.

Key Features

Custom special transmission characteristic

Available in mounts with all common thread sizes

Absence of vignetting due to large clear aperture

Applications

Machine Vision and other imaging applications

Bio analytics

Scientific & research measurement

Print version
(pdf: 170 kB)