These are the "outside vapor deposition" (OVD) process developed by Coming Glass Works and the "vertical axial deposition" (VAD) version developed by a consortium of Japanese cable makers and Nippon Telephone and Telegraph Corporation. It relates more specifically to an optical assembly referred to as an "optical cable header", which is intended to enable the individual fibers of an optical cable to be optically connected to optical fibers in other cables and/or equipment independently of the other fibers in the cable, and. The raw materials used in the initial stages of optical fibre manufacture include high quality synthetic quartz substrate tubes, ultra-pure halides such as silicon tetrachloride (SiCl 4 ) and germanium tetrachloride (GeCl 4 ), as well as the gaseous forms of pure oxygen (O 2 ), Helium (He). The Modified Chemical Vapor Deposition (MCVD) process was developed in 1974 at Bell Labs to improve traditional Chemical Vapor Deposition (CVD) methods for fabricating optical fibers. In MCVD, a quartz tube is used as the initial substrate or source material. In specialty fiber factories, draw tower heights typically range from 7 to 14 meters. Draw tower. Key optical fiber manufacturing equipment includes drawing towers for creating the fiber, coloring and buffering lines for protection and identification, stranding machines (like SZ stranding lines) to assemble the cable core, and jacketing lines to apply the final protective sheath. The OVD process is one of the most common techniques used.