- Long Pass- & Short Pass Filters
- Dichroic Long Pass- & Dichroic Short Pass Filters
- Band Pass-, Notch- & Neutral Density Filters
- Dielectric and Absorption Filters
Optical Filters are elements with specific spectral transmission characteristics.
They are used to modify the properties of a light source or to block unwanted wavelengths of light.
There are two different types of optical filters, depending on the physical principle exploited during the manufacturing process:
absorption filters (colour filters) and dielectric filters.
| wdt_ID | wdt_created_by | wdt_created_at | wdt_last_edited_by | wdt_last_edited_at | Specifications | Absorption Filters | Dielectric Filters |
|---|---|---|---|---|---|---|---|
| 1 | benjamin | 04/05/2026 12:55 PM | benjamin | 04/05/2026 12:55 PM | Range of dimensions | 1mm – 300mm | 1mm – 300mm |
| 2 | benjamin | 04/05/2026 12:55 PM | benjamin | 04/05/2026 12:55 PM | Highest available surface figure | λ/4 (DIN: 3/0,5) | λ/4 (DIN: 3/0,5) |
| 3 | benjamin | 04/05/2026 12:55 PM | benjamin | 04/05/2026 12:55 PM | Highest available surface quality | 40-20 S/D (DIN: 5/2×0,16) | 40-20 S/D (DIN: 5/2×0,16) |
| 4 | benjamin | 04/05/2026 12:55 PM | benjamin | 04/05/2026 12:55 PM | Highest available tolerance of beam deviation | 3” (arcsec) | 3” (arcsec) |
| 5 | benjamin | 04/05/2026 12:55 PM | benjamin | 04/05/2026 12:55 PM | Blocking | — | OD3 (standard), OD5 (high blocking) |
Optical Band Pass Filters
Optical band pass filters are precision components designed to transmit a specific range of wavelengths while blocking unwanted light. By allowing only a defined spectral band to pass through, these optical filters improve signal clarity, reduce noise and enhance overall system performance.
They are widely used in applications such as machine vision, spectroscopy, medical imaging, laser systems, and optical sensing. Available in various wavelength ranges, bandwidths and optical densities, band pass filters can be tailored to meet exact technical requirements.
Our optical band pass filters are engineered for high transmission efficiency, excellent blocking performance, and long-term stability, ensuring reliable results in demanding industrial and scientific environments.
Optical Notch Filters
Notch Filters are precision optical components designed to selectively block a narrow band of wavelengths while allowing the rest of the spectrum to pass with minimal loss. They are widely used to suppress unwanted laser lines, reduce background noise, and improve signal-to-noise ratios in demanding optical systems.
Common applications include spectroscopy and fluorescence imaging, where precise wavelength control is critical. Modern notch optical filters offer high optical density at the blocked wavelength, steep cut-off slopes, and excellent transmission outside the notch, ensuring reliable performance without compromising system efficiency.
Available in a range of center wavelengths, bandwidths, and substrate options, optical notch filters can be tailored to specific lasers or light sources. Their durability and stability make them suitable for both laboratory and industrial environments, providing consistent, long-term optical performance.
Optical Long Pass Filters
Optical Long Pass Filters are precision components designed to transmit wavelengths longer than a specified cutoff while effectively blocking shorter wavelengths. They are widely used to isolate desired spectral regions, reduce unwanted background light, and improve signal clarity in optical systems.
Manufactured with high-quality optical coatings, long pass filters offer excellent transmission efficiency, sharp cutoff performance, and long-term stability. They are ideal for applications such as fluorescence microscopy, spectroscopy, machine vision, laser systems, and scientific instrumentation. Available in a range of cutoff wavelengths and formats, long pass optical filters can be tailored to meet the exact requirements of your application, ensuring reliable performance and consistent results.
Optical Short Pass Filters
Optical short pass filters are precision components designed to transmit wavelengths shorter than a specified cutoff while blocking longer wavelengths. They are widely used in applications such as fluorescence microscopy, spectroscopy, machine vision, and laser systems, where accurate spectral separation is essential.
Manufactured using advanced thin-film coating technologies such as IAD, IBS and PARMS, short pass optical filters offer high transmission in the passband, sharp transition edges, and excellent blocking performance in the stopband. They can be customized for specific cutoff wavelengths, angles of incidence, and environmental requirements, ensuring reliable performance in demanding optical systems.
By improving signal quality and reducing unwanted background light, optical short pass filters help enhance measurement accuracy, image contrast, and overall system efficiency.
Optical Dichroic Long Pass Filters
Optical dichroic long pass filters are precision components designed to transmit longer wavelengths of light while efficiently reflecting shorter wavelengths. Using advanced multilayer thin-film coatings such as IAD, IBS und PARMS, these optical filters provide sharp cut-on transitions.
Long pass dichroic filters are widely used in applications such as fluorescence microscopy, machine vision, spectroscopy, laser systems, and optical sensing. Their angle-dependent performance and durability make them ideal for demanding optical environments where stability, repeatability, and low optical loss are critical.
Available in a range of cut-on wavelengths, sizes, and substrates, dichroic long pass filters can be customized to meet specific system requirements, delivering reliable wavelength separation and enhanced system performance.
Optical Dichroic Short Pass Filters
Optical dichroic short pass filters are precision-coated optical components designed to transmit wavelengths below a defined cutoff while efficiently reflecting longer wavelengths. Using advanced thin-film interference coatings methods such as IAD, IBS und PARMS, these optical filters deliver sharp spectral transitions.
Short pass dichroic filters are widely used in applications such as fluorescence microscopy, laser systems, machine vision, spectroscopy, and optical instrumentation. Their angle-dependent design allows them to function as both spectral filters and beam splitters, making them ideal for compact and high-performance optical assemblies.
Manufactured on high-quality optical substrates, dichroic short pass filters offer long-term stability, low absorption, and high damage thresholds, ensuring reliable performance in demanding scientific and industrial environments.
Optical Neutral Density (ND) Filters
Optical neutral density (ND) filters are precision components designed to uniformly reduce light intensity without altering color balance or image quality. By controlling exposure, ND filters enable longer shutter speeds, wider apertures, and accurate light management across imaging systems—from photography and cinematography to scientific and industrial applications.
Manufactured from high-quality optical glass or coatings, ND optical filters provide consistent attenuation, minimal distortion, and excellent spectral neutrality. They are available in fixed and variable densities to suit a wide range of lighting conditions, making them essential for achieving optimal performance, repeatable results, and creative control in professional optical setups.
Absorption Filters (Colour Filters)
Absorption filters (colour glass filters) function on the basis of choosing a optical glass filter recipe with chromophoric constituents which absorb a specific range of wavelengths.
Typically these are long band pass edge filters, but some band pass types with limited functionality are available.
Note that this filter type may fluoresce when used for blocking UV light.
Dielectric Filters (Interference Filters)
Dielectric filters (Interference Filters) absorb very little light. The functionality is based on reflection of the unwanted spectral regions based on optical interference within the layer structure of the filter coating. These filters can be manufactured as UV, visible and IR optical filters.
In order to reduce the number of coating layers – and thus the cost – a combination may be made by dielectric coating a colour (absorption type) glass substrate. This is common for some optical bandpass filters.
Interference filters have a complex coating structure consisting of several layers. They allow high transmission for a sharply limited wavelength range and also a high blocking of the remaining spectrum.
The blocking of the light spectrum is described by the wavelength-dependent optical density OD. A transmission of 0.1% corresponds to an optical density of 4 and a transmission of 10% to an optical density of 1.
Different types of filters can be produced by the interference layers. The highest possible attenuation over a broadband wavelength range can be achieved by using neutral density filters.
Bandpass filters characterize a highly transmissive region for single wavelengths or narrow wavelength ranges.
Optical shortpass filters transmit light up to a certain wavelength and optical longpass filters transmit light only above a certain wavelength. Such filters are found, for example, as heat blocking filters, also known as hot mirrors, or correspondingly as cold blocking filters, also known as cold mirrors.
