Interference band-pass filters
These Interference Band pass Filters are used to isolate and transmit a narrow wavelength that is required and block all other wavelengths through reflections using our optical components. This range of optical Interference Band pass Filters (see optical filters PDF)consist of an all-dielectric coating along with other optical coatings for additional blocking and cemented together to form a stack. The individual filters are mounted in nested component rings, providing a labyrinth epoxy edge seal for greatly extended life. Although these are mounted, unmounted component types can be supplied at special request. These Interference Band pass Filters are all typically 3-7 cavity.
Uses of these optical scientific parts include line selection, laser signal selection, colorimetry and fluorimetry. They can also be used for imaging. When using high powers the reflective side must be towards the incoming light
Glass Neutral density filters
These Glass Neutral Density Filters are an inexpensive form of absorption density filter. They are made using the Schott range of NG glass types. Neutral density filters attenuate light by absorption whilst achieving minimum reflection. The optical density of neutrality of the filters is achieved through selection of the filter type and calculation of the thickness. The optical density is reasonably consistent in the visible (400-600nm) but may be higher or lower in the NIR depending on glass type component
Dichroic beamsplitters (45°)
These dichroic beamsplitters are a special type of interference filter, they split the light into two or three spectral bands, some are transmitted and the others reflected. Generally the bands are based on the three primary colours of red, green and blue. Dichroic Beamsplitters are widely used in LCD projectors and in some sensor systems.
As the name suggests these are used at 45° incidence and the reflected light is deviated through 90°. Typical applications for Dichroic Beamsplitters are in separation of laser wavelengths in fluorescence microscopy. Dichroic beamsplitters separate beams of light into spectral bands by reflecting a band of wavelengths and transmitting another.
These filters are used at 45° to the incident light beam and are often used in laser systems as output couplers, LCD projection systems and in conjunction with other optical filters in fluorescence spectroscopy technology where the separation of excitation and emission beams is integral to the instrumentation.
View our PDF on Short Pass Filter Range
View our PDF on Long Pass Filter Range
View our PDF on Short Wave Filter Range
Polyester-Colour filters
Polyester Colour Filters are manufactured by using organic dyes in a gelatine material to achieve the desired colour effects, which is not possible in optical colour glass, especially band-pass types. Thinner substrates can also be achieved, and at 0.1mm thick may be useful where space is limited. The well-known `Wratten’ gelatine filters are the wider range and are more accurately controlled and documented. The Polyester Filters are much more robust and less expensive components.
Gelatine neutral density filters
Gelatine Neutral Density Filters offer accurate achromatic attenuation and are sufficiently thin (0.1mm) not to alter appreciably the state of focus of a system. These Gelatine Neutral Density Filters are manufactured by dissolving colloidal carbon with certain dyes in a gelatine material to achieve the desired density performance. Although these Gelatine Neutral Density Filters are lacquered for protection they are of course easily damaged by moisture or heat and care is needed in hanging
UV transmitting filters-Glass type
These solid UV Transmitting Colour Glass Filters transmit unwanted UV and Visible wavelengths at relatively low cost. The following thickness has been chosen for average transmitting in relation to filter type, however if you require any other wavelength we can make simple calculations in relation to the thickness to achieve your required wavelength
Wratten gelatine-Colour filters
Wratten Colour Filters are manufactured by using organic dyes in a gelatine material to achieve the desired colour effects, which is not possible in colour glass, especially band-pass types. Thinner substrates can also be achieved and at 0.1mm thick may be useful where space is limited. The well-known `Wratten’ gelatine filters are the wider range and are more accurately controlled and documented. The Polyester Filters are much more robust and less expensive optical scientific components.
Optical Schott Colour-glass filters
Solid Colour Glass Filters are useful for wavelength selection absorbsion, and achieve much higher blocking densities than dichroics. The spectral transmission properties are uniform over the entire aperture of the Colour Glass Filter. A wider range of Schott Colour Glass filters are available, and the following thickness has been chosen for average blocking percentages in relation to filter type. If you require a different wavelength block, we can make a simple calculation in relation to the thickness to achieve your required wavelength. Our photonic filters (540FCS5050) are used with silicon detectors or cameras to adapt the spectral response to be approximately that of the ee
Metallic neutral density filter components
These Metallic Neutral Density Filters attenuate light through reflection rather than absorption as in the glass type of neutral density filter. Metallic Neutral Density Filters consist of a thin layer of nickel-chromium alloy vacuum-deposited on a glass substrate. This gives excellent neutrality and very accurate attenuation across the surface. About half the rejected light is absorbed and the remainder reflected, so these filters can also be used as beamsplitters.
The visible/IR range of Metallic Neutral Density Filters are on low-expansion borosilicate glass substrates and covers the range 350-2500nm. Our UV range of Metallic Neutral Density Filters is on synthetic fused silica and extend the useful UV range down to about 170nm. Please note that the density of all filters is specified at 550nm, but in the UV it can be up to 40% higher-see curves.
All filters are supplied with a copy transmittance scan taken on a filter from the same production run.
Optical Heat-control optics-Hot mirrors (0°)
Hot Mirrors transmit the visible and reflect the near-infrared (heat) spectrum and therefore are another alternative for displacing heat. Hot Mirrors are more expensive than colour glass KG1 filters, however they divide much more sharply between the IR and visible. These Hot Mirrors remove the heat by reflection rather that absorption as in Schott Colour Glass KG type of heat-control optics. They are coated with a multilayer dielectric coating and there for can handle much more power. These Hot Mirrors are ideally suited to laser applications as optical components.