Although primarily designed for therapeutic purposes where the sun does not shine, [Nava Whiteford] The Wolf 5151 Xenon endoscopic light source also works well for microscopy and general optical testing, especially since you can get it fairly cheaply in the second hand market. It costs just US 50 USD, which is a steal when you consider replacing its 300-watt Olympus-made bulb.
Said, [Nava] Recently moved to a more compact light source, and realized that this was a good enough excuse to crack the Wolf 5151 and see what it ticks. In this particular post he looks only at the optical side of things, which is arguably the most interesting aspect of the device. Helpfully, the whole assembly is mounted on its own sled which can be pulled from the light source for a closer test.
Beyond the expensive bulb we mentioned earlier, there is a thicker piece that looks like standard plate glass that is being used as an IR and UV filter. [Nava] It is suspected that this material is responsible for protecting the rest of the optics from overheating, which is backed up by the fact that the metal plate mounted on it appears to have a K-type thermocol feature to monitor its operating temperature. It has a unique aspheric lens on the front which probably features a rough spot to scatter light in the center of the beam.
For the most interesting material we have to go to the vote neutral density (ND) filter, which is used to control the intensity of light. In more pedestrian light sources you can simply dim the bulb, but in this case, the Wolf 5151 uses a metal disc to drill holes in it. By rotating the disc with a DC motor, the lens can be rotated to reduce the amount of light reaching the aperture connecting the fiber cable.
While it’s probably no surprise that the build quality of this medical gear is more than enough of the commercial gadgets we’ve got to play with, it still doesn’t hold a candle (no pun intended) in a laser module drawn from a tornado jet fighter.