i remember when I first started out with this, the unit was mounted in large airconditioned trucks, and all up cost around $3M for the truck with the gear inside. The fibre splice was created with an small electric arc, and the machine would melt the ends of the glass, and push them together and then pull them apart whilst still molten to get the profile you see at the end. X and Y views were flipped back of forth with a prism mirror for inspection.