||Compact metal halide lamps came onto the lighting market at around about the same time that fibre optic systems were being trialled as a future general lighting method.Prior to this time, fibre optics had only been employed in highly specialised applications, for example medical endoscopy and microscope illumination. Short arc reflector lamps were the preference in these most demanding of applications, but the price of such lamps was far too high and their lifetimes too short to be of any interest in the general lighting sector.
The first general lighting fibre optic systems were thus developed around the considerably cheaper tungsten halogen lamps. This limited how much light could be injected into the fibres, since many are fabricated in plastic materials, which would overheat with high power halogen lamps.
This lamp was therefore developed as the first relatively low cost discharge lamp for fibre optic applications, and it was hoped that its high power and cool beam would push forward the possibilities for fibre optics in general lighting. The light source here is in fact a standard HQI-T single ended arc tube with quartz outer jacket, the whole being cemented into a dichroic coated hard glass reflector.
The light is efficiently collected and focussed down to a small spot a few centimetres in front of the lamp while infrared passes through the reflector coating. Lamps are mounted in the optical system by the rim, which ensures good reproducibility in position after replacement. Electrical connections are made at the end of the flexible cables.