Optical Filters – Filter Coatings and Optical Glass Filters
Filter optics for virtually any application
Optical filters are of critical importance for a wide variety of applications in industry, science, research, spectroscopy, telecommunications, and medical technology. Depending on their properties, they can transmit, reflect, absorb, or filter specific wavelengths of light. Absorbing filters attenuate the light intensity within a specific spectrum. Reflective filters, which are frequently used in laser applications or imaging systems, selectively reflect or transmit specific wavelengths, thereby enabling precise control of the light spectrum or light output. Another important category of optical filters is interference filters, which utilize the principle of interference optics to separate specific wavelengths from one another and either transmit or block them.
Optical filters are useful in various fields, such as astronomy, to isolate specific spectral lines for precise analysis. They are also widely used in microscopy and medical imaging. In fluorescence microscopy, filters are used to excite fluorescent dyes at specific optical wavelengths and selectively capture the emitted light, enabling a detailed examination of cellular structures. In medical imaging applications, optical filters can improve image quality, remove haze or glare, and delineate specific tissue or organ features for accurate diagnosis. In addition to their applications in science and research, optical filters have also become indispensable in modern telecommunications systems.
Below you will find an overview of the most common optical filters from our extensive product range. Follow the links at the end of each section to access the data sheet and obtain further information about the properties of the respective filters.
Optical Filter Glasses from SCHOTT
We stock the raw materials of over a hundred high-quality color filter glasses from SCHOTT to ensure rapid manufacturing and delivery of polished filter optics. The SCHOTT filter program includes short pass-, long pass, band pass, neutral density, notch, narrowband, and conversion filters for various wavelengths. Each glass filter material is precisely specified in terms of its transmission properties. These filters are based on absorption.
Further details about the SCHOTT filter materials…
Neutral Density Filters | Grey Filters | Optical Density Filters
SCHOTT's NG neutral density filters are perfect for precisely defined light attenuation. The NG Filter family consists of NG 1, NG 3, NG 4, NG 9, NG 10, NG 11, and NG 12. They are color-neutral and offer a broadband transmission at a defined level and represent an industry standard for neutral-density filters. ND filter sets are available on request.
More details about neutral density filters …
Heat Reflection Filters | Heat Reflecting Hot Mirrors | SIR Series
Our SIR dielectric heat-reflection filters are based on a dichroic coating, which is highly transparent to visible light and effectively blocks the infrared up to around 1100 nm. This type of coated optical short-pass filter is also often called a hot mirror. The SIR also often works as a mirror for eye-tracking applications, as it can reflect an infrared laser beam while remaining transparent to the eye.
More details about the SIR hot mirror …
Heat-Reflecting Filters with Extended Blocking Range | SIR-IR Series
SIR-IR filters offer high optical transmission in the visible range and a significantly broader blocking range for infrared wavelengths than most other filters of this type. This dichroic filter represents the best possible compromise between maximum IR-rejection bandwidth and excellent visible transmittance.
Further information about the SIR-IR …
Cold Light Filters | SHD-Series
Our high-performance dichroic SHD cold light filters (also called cold mirrors) efficiently block the visible spectrum by reflecting it at a 45° incidence angle while transmitting infrared light up to 2500 nm at 0° incidence. Its dielectric coating is also capable of separating visible from infrared laser beams. The SHD is frequently used to efficiently remove heat from an optical beam path.
Further details on the SHD …
Heat-Absorbing Filters | SCHOTT KG1-KG5
SCHOTT KG heat-absorbing filters are band pass filters that transmit the visible light while simultaneously absorbing the heat radiation of a light source. Such heat protection filters operate almost independently of the incidence angle and are ideal for many lighting applications. Specifications and mor information about the KG-filters…
Are you looking for optical filters not listed here?
It is not possible to list the many possible filter variants we fabricate for any existing imaging, light- and laser-based application on this website. Please consider using our inquiry page to request a quotation for custom optical filters, cemented filter combinations, fluorescence filters, narrowband filters, and special dichroic or high-performance interference filters for individual wavelength ranges. If you require engineering support or additional information, please do not hesitate to send us your inquiry with your optical filter's requirements.
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Last update: November 11, 2025