In an endoscopic system there is a source of radiation and a waveguide, which is symmetric about an axis and receptive of the radiation for guiding the radiation therealong. A coupling mechanism engages or disengages the waveguide to or from an endoscope. An attenuator is deployable in a first position when the waveguide is engaged to the endoscope and deployable in a second position when the waveguide is disengaged from the endoscope. When the attenuator is deployed in the first position, the radiation passes from the waveguide to the endoscope and when the attenuator is in the second position, the radiation is at least partially blocked from passing from the waveguide to the endoscope or from exiting the fiber optic cable.