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There are a number of systems known for the colour splitting of light used in television systems. One of the frequently beam splitting system used is the Philips prism system which has been implemented with many modifications. The Philips prism system consists of two prisms and an optical wedge with nonstandard angles. The Philips system also contains two thin film stacks which are not easy to manufacture in mass production. Further, great attention must be paid to the positioning of the components during their assembly. The new beam splitting system being developed in our laboratory is to be used in cameras for robotic systems, TV or video cameras containing tubes or COD chips. The major advantages of the new system over the Philips prism are a) almost complete insensitivity to the polarization of the incident light, b) better colour balance over the whole aperture and, c) a lower weight. The new prism system offer the following advantages: a) it is assembled from standard optical parts, namely right angle prisms, b) it is easy to compensate the optical paths of three independent colour channels by the adding of two planoparallel plates to the two channels, c) there is possibility to maintain the fourth white or infrared channel very easy to fulfil colorimetry criterion of television systems. There is still one optical thin film stack which is difficult to implement, but that is one less than in the Philips prism. The main difference between the new prism and the Philips prism is that the new beam-combiner contains anisotropic optical component. This paper describes the principal scheme, the results of mathematical models generating the chromatic characteristics and, the design of partially polarizing stack with the thin film technology used.
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