• Dichroic colour filters
Elliot Scientific offers a range of low-cost high-quality stock filters in standard sizes. ND and coloured Schott glass filters are usually offered with diameters of 12.5 or 25 mm, or as 50 mm square filters. RGB and CMY dichroic filters are normally supplied as 50 mm squares or with 25 mm diameters. However, custom sizes and colours can be manufactured on request.
Light is attenuated in the visible spectrum by absorption within the glass. Different filters can be stacked to achieve intermediate densities not available in the standard range.
Attenuation is achieved by a partially reflective vacuum deposited coating. This metallic film offers a broader and more consistant neutral density which is ideal for use in laser projects due to its non-absorption. Filters can be stacked, but care needs to be taken to ensure there are no multiple reflection effects. These can be eliminated by slightly tilting the stack. A useful feature of this type of filter is that it can be used as a beamsplitter.
Schott Short Pass Filters block undesired longer wavelengths. The BG series are blue or blue/green in colour, while the KG series are virtually colourless and ideal for blocking heat, especially from lamps.
Schott Band Pass filters are designed to pass a specific wavelength range. The BG series offer transmission in the central part of the visible spectrum, while the UG range are practically black in colour and are designed for work in the UV. Applications include UV illumination & excitation, fluorescence microscopy, sterilization equipment, sensitivity correction, CCD colour correction, airport lighting, and laser safety.
Schott Long Pass Filters are designed to block shorter wavelengths such as blue and green. Deep red to almost black filters are ideal for IR transmission. Applications include airport lighting, laser safety, sensor applications, ifrared surveillance systems, and bar code readers.
Elliot Scientific offer RGB and CMY dichroic filters in 50 mm squares and 25 mm diameters. Custom sizes and colours on request