A system for transmitting the light required for a medical device is disclosed generally comprising an endoscope body, a light guide for transmitting light from a light source to the instrument body, where the light guide includes a bundle of optical fibers having a tapered portion, and a ceramic housing disposed around at least part of the tapered portion of the bundle. In certain embodiments, the ceramic has a pigment for improving insulation. In some embodiments, the taper and ceramic housing are located in an endoscope handle, which may be coupled to the endoscope body via an input post, and in certain embodiments, the inner diameter of the ceramic housing has an increase substantially equal to the decrease of diameter of the taper.