The original (non-animated) light saberlightsaber was apparently a wooden slat that could rotate covered with a reflective tape:
What kind of reflective tape are we talking about here? The light is so intense and pure, it seems too bright for any reflective tape I have seen. If the illuminator was mounted on the camera shining at the saber so that it would reflect light back towards the camera why do we not see a spotlight effect on the actors?
Also, one of the animation techniques used for the sabers was rotoscoping. How did this work?