Optical filters
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Optical Filters

Coated filter optics and color glass filters

Filter types

Optical filters are used to block, transmit, reflect or filter out certain wavelength ranges in optical systems. There are two main types of optical filters, coated- and absorbing filters. Coated filters are typically based on dielectric thin film coatings, rarely also on metal layers. Such filter optics typically separate two or more spectral ranges by reflecting (blocking) or transmitting them. Absorbent filters, on the other hand, are usually based on color filter materials that absorb specific wavelength ranges.


Typical applications

In lighting systems often absorbing-, heat-reflecting-, or color filters are used. Laser systems often have dichroic color splitters based on purely dielectric filter coatings. But also in image processing special filter optics which have the task to increase the contrast of a camera system by blocking the infrared range are used. And there are numerous other optical filter applications, e.g. in fluorescence spectroscopy or optical analysis systems.


Filter Characteristics

Optical filters can have different characteristics. For example, a bandpass filter is used to transmit a particular wavelength range, while the spectral range below and above is blocked. A short pass filter, on the other hand, allows lower wavelengths to pass while blocking higher wavelengths. In contrast, a long pass filter transmits the higher light spectrum and blocks the lower wavelengths. In addition to these filter characteristics, there are filters that provide neutral attenuation and notch filters that block a defined wavelength range and have transmission above and below this blocking range and there are edge filters that ususally have a steep filter curve.


We provide a filter solution for your application

Whether you need colored glass filters, coated filters or custom optical filters, we can provide a solution for your optical task, because our company manufactures and supplies all optical filter types for industry, science, and research. Below you find the most popular and continuously available standard filters for various optical applications from our extensive manufacturing program. Please follow the links for more details and specifications:


Cemented optical filters that create a bandpass filter combinationnullspacerCoated optical filters


Optical filters made from SCHOTT colored filter glasses

More than 100 different high-quality optical color glass filters from SCHOTT for various applications and wavelengths from stock. Our extensive SCHOTT-filter program includes shortpass, longpass, bandpass, neutral density, color filters, as well as conversion filters. This type of filter optics is based on absorption. More...


Neutral Density Filters, Grey Filters, Optical Density Filters

NG 1, NG 3, NG 4, NG 9, NG 10, NG 11 & NG 12 SCHOTT-filters attenuate incident light with a defined density level. The filter materials are neutral in color and have a broadband transmission. SCHOTT NG-Filters represent a standard in neutral density filters. More...


Heat Reflection Filters (Heat Reflecting Hot Mirrors) SIR Series

Our SIR-dielectric heat reflection edge filters have a dichroic filter coating which is highly transparent to visible light and effectively blocks the infrared band up to a wavelength of approx. 1100nm. This filter is often used used to reflect the laser beam in eye-tracking systems while being transparent to the eye. More...


Heat Reflecting Filters with extended blocking range, SIR-IR Series

The SIR-IR filters feature a high transmission in the visible and a broadband blocking of infrared wavelengths. This dichroic filter system represents the best possible compromise regarding maximum blocking bandwidth and high visible transmission. View more...


Cold Light Filters, SHD-Series

Our dichroic SHD cold light filter reflects the visible light of a light beam by 45° while it simultaneously transmits the infrared band up to 2500 nm at i = 0°. The function principle is that of a dichroic beamsplitter. It can also be used to split visible from infrared lasers. View more...


Heat-Absorbing Filters KG1-KG5

Heat-absorbing filters made of SCHOTT KG filter materials allow the transmission of the visible wavelength range and absorb the heat radiation of a light source. Such heat protection filters operate largely independently of the angle of incidence. KG-filters are visible bandpass filters. View more...


You are looking for optical filters that are not listed here or you need technical support?

Please take into account that it is impossible to list the many different types of optical filters and filter coatings we make for the most diverse light and laser applications in detail on this website. To request a quotation for custom filters, cemented filter combinations, fluorescence filters, or special interference filters for individual applications please use our coating request form. If you are in search of engineering support, please do not hesitate to send us the requirements of your optical filter.


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