The Cairn classic light source comprises of two components; namely a lamphouse and an appropriate power supply for the lamphouse. In addition, components for connecting the light source output to a fluorescence microscope via an epifluorescence port will usually be supplied. This connection will take one of three forms: A direct coupling, an indirect coupling, or a beam collimator. The direct coupling relays the light from the light guide directly into the rear of the objective; the indirect coupling relays the light via aperture and field stops to the objective; and the beam collimator relays the light into the entry port of the microscope manufacturers epifluorescence coupling. The classic lamphouse has been on sale for the best part of a decade now, and it's been very successful. We originally designed a 75W lamphouse and power supply because our customers were fed up with having their measurement equipment fried by other manufacturers' light sources (more about this below). This is a thoroughly tried and tested design, which is suitable for many applications and uses our well-established 75W power supply with constant-power regulation for stable output and long lamp life. It uses switch mode technology for compact size, minimum heat generation and universal power input requirements (90-250V, 50-60Hz). Following the introduction of our Optoscan monochromator, we began selling more systems to customers with interests in high-speed imaging, where the highest possible light intensities are required. The Classic source actually works well with the Optoscan, but the Optosource has been custom-designed for this application, and gives typically 2-3 times more light (the exact improvement depends on the input slit width, which is variable in our design). For other applications, including flash photolysis, the Optosource allows more efficient coupling of the light output into a smaller diameter light guide, which is likely to be translated into a higher light intensity at the experimental sample. From theoretical considerations we expect an approximately two-fold improvement. For many users the most important feature of our light sources is that they can be used safely in close proximity to any other equipment! While xenon lamps typically run at only about 10-20V, they require a high-voltage trigger pulse of around 30KV to initiate the arc. Some other manufacturers seem to ensure that this trigger voltage reaches the lamp by spraying it around everywhere else as well, which makes short work of any semiconductors in the vicinity, such as those in your computer, for example. Our approach is to generate the high voltage pulse INSIDE the lamphouse, which is electrically screened, and to do so in a way that is balanced with respect to ground. This is another tried-and-tested feature, so we can confidently say that it will NOT damage your other equipment. It is important to mention here that the two types of lamp that the classic lamphouse supports (75W xenon or mercury/xenon continuous, and xenon flash) require different mountings. This prevents the wrong lamp being used with your system. However, it is quite easy to change the mountings if required. It is also possible to upgrade from the Classic to Optosource, as a number of components are identical. Please contact our sales department for further details if you are considering this option. | 
