Milestone-Proposal:Invention and development of vapor-phase axial deposition (VAD) method for mass production of high-quality optical fiber for telecommunication

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Docket #:2013-18

This Proposal has been approved, and is now a Milestone

To the proposer’s knowledge, is this achievement subject to litigation?

Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

Vapor-phase Axial Deposition Method for Mass Production of High-quality Optical Fiber, 1977-1983

Plaque citation summarizing the achievement and its significance:

In 1977, Dr. Tatsuo Izawa of Nippon Telegraph and Telephone Corp. (NTT) invented the vapor-phase axial deposition (VAD) method suitable for the mass production of optical fiber. NTT, Furukawa Electric, Sumitomo Electric, and Fujikura collaboratively investigated the fabrication process. The technology successfully shifted from research and development to commercialization. The VAD method contributed greatly to the construction of optical-fiber networks.

200-250 word abstract describing the significance of the technical achievement being proposed, the person(s) involved, historical context, humanitarian and social impact, as well as any possible controversies the advocate might need to review.

IEEE technical societies and technical councils within whose fields of interest the Milestone proposal resides.

In what IEEE section(s) does it reside?

IEEE Tokyo Section, Japan

IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: IEEE Tokyo Section
Senior Officer Name: Toshitaka Tsuda

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: IEEE Tokyo Section
Senior Officer Name: Toshitaka Tsuda

IEEE section(s) monitoring the plaque(s):

IEEE Section: IEEE Tokyo Section
IEEE Section Chair name: Toshitaka Tsuda

Milestone proposer(s):

Proposer name: Akira Okada
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates in decimal form of the intended milestone plaque site(s):

NTT Atsugi R&D Center, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198 Japan.

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need.

Are the original buildings extant?

No, the original building was located at Shirakata Tokaimura Nakagun, Ibaraki Prefecture, 319-1106 Japan. NTT Ibaraki Electrical Communication Laboratory was at this location until 2002, and now the function is succeeded at NTT Atsugi R&D Center.

Details of the plaque mounting:

The plaque will be placed near the reception area at the floor entrance hall. It will be displayed in a transparent hard case.

How is the site protected/secured, and in what ways is it accessible to the public?

NTT’s receptionists are always near the plaque. The plaque will be placed near the reception area at the floor entrance hall. All visitors have free access to this hall.

Who is the present owner of the site(s)?

NTT (Nippon Telegraph and Telephone) corporation

What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include justification here. (see section 6 of Milestone Guidelines)

From 1975 to 1983, NTT and three Japanese electric wire and cable manufacturers (Furukawa Electric, Sumitomo Electric, and Fujikura) worked collaboratively on the research and development of optical fiber for telecommunication. Then in 1977, NTT researcher Dr. Tatsuo Izawa invented the vapor-phase axial deposition (VAD) method for fabricating optical fiber preforms that were highly suitable for the mass production of optical fiber. The invention of the VAD method and the collaborative work to improve the process undertaken by NTT and the three electric wire and cable manufacturers established the basis for the low-cost mass production of high-quality low-loss optical fiber. The VAD method is currently the most used optical fiber fabrication method and accounts for more than 50% of the optical fiber used for telecommunications. The VAD method has contributed to the building of optical telecommunication networks that support our advanced information and communication society.

What obstacles (technical, political, geographic) needed to be overcome?

In 1966, Dr. Charles K. Kao expanded the possibility of long-distance communication using glass optical fiber. Then in 1970, Corning demonstrated silica-glass optical fiber with a propagation loss of 20 dB/km at a wavelength of 632.8 nm. This sparked an interest in optical fiber throughout the world, and in 1974 Bell Labs realized fiber with a 1.1 dB/km propagation loss at a wavelength of 1060 nm by using the modified chemical vapor deposition (MCVD) method. In Japan, NTT and the Japanese electric wire and cable manufacturers Furukawa Electric, Sumitomo Electric, and Fujikura started R&D collaboration in 1975 with the aim of developing practical optical fiber. Optical fiber is fabricated by drawing a string of fiber from a cylindrical glass preform that is being heated in an electric furnace. To build optical communication systems that provide long distance and broadband communications, optical fiber must exhibit a low optical propagation loss and its fabrication method should allow mass production, which is important for providing optical fiber at low cost. The development of a method for manufacturing large optical fiber glass preforms at a relatively high speed was an important problem in terms of the mass production of optical fiber. In 1977, while working on a solution to the above problem, Dr. Tatsuo Izawa, an NTT researcher, invented the vapor-phase axial deposition (VAD) method. In the VAD method process, a porous preform is grown by the deposition of fine glass particles synthesized by the flame hydrolysis of halide raw materials such as SiCl4 and GeCl4 while being pulled upward in the axial direction. This process allows the growth of long and large-diameter porous preforms. The porous glass is consolidated by using an electric furnace to obtain a transparent glass perform from which to draw optical fiber. The VAD method achieved a fast glass deposition speed and made it possible to fabricate a large glass perform, and this paved the way to the mass production of optical fiber.

What features set this work apart from similar achievements?

With the VAD method, the porous glass preform is fabricated by the deposition of fine glass material via flame hydrolysis onto the end surface of a starting silica glass rod used as a seed. The starting rod is pulled upward, and the porous preform is grown in the axial direction. The porous glass is successively consolidated into a transparent glass preform for the fiber drawing process by arranging the melting zone region at the upper position in the axial direction. By contrast, other glass preform fabrication methods such as modified chemical vapor deposition (MCVD) and outside vapor deposition (OVD) require a collapsing process before they can prepare a transparent glass preform for fiber drawing. The fact that the VAD method does not need a collapsing process enables the continuous fabrication of a glass preform, which is preferable for the low cost mass production of optical fiber.

Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.

<Journal articles and conference papers> [1] T. Izawa, S. Kobayashi, S. Sudo, and F. Hanawa, “Continuous fabrication of high silica fiber preform”, Int. Conf. Integrated Optics and Optical Fiber Commun., 375, 1977. [2] T. Izawa, N. Shibata, and A. Takeda, “Optical attenuation in pure and doped fused silica in the IR wavelength region,” Applied Phys. Lett. Vol.31, No.1, pp.33-35, 1977. [3] T. Izawa, S. Sudo, and F. Hanawa, “Continuous Fabrication Process for High-Silica Fiber Preforms,” IECE of Japan, Vol.E-62, No.11, 1980. [4] F. Hanawa, S. Sudo, M. Kawachi, and M.Nakahara, “Fabrication of Completely OH-FREE V.A.D Fibre,” Electon. Lett., Vol. 16, No. 18, pp.699-700, 1980. [5] T. Izawa and N. Inagaki, “Materials and Processes for Fiber Preform Fabrication—Vapor-Phase Axial Deposition,” Proc. IEEE, Vol.68, No.10, pp.1184-1187, 1980. [6] T.Edahiro, S.Takahashi, K.Yoshida, M.Yoshida, and T.Shioda, “Long single-mode fiber made by vapor-phase axial deposition,” Proc. IOOC’1981, TUC2, pp.50-51, 1981. [7] M.Nakahara, N.Ingaki, K.Yoshida, M.Yoshida, O.Fukuda, “Fabrication of 100-km graded-index fiber from a continuously consolidated VAD perform,” Proc. IOOC’1981, WD4, pp.100-101, 1981. [8] M. Kawachi, M. Yasu, S. Tomaru, T. Edahiro, and S. Sakaguchi, “Wholly synthesized VAD single-mode fibre,” Electron. Lett., Vol. 18, No. 18, pp. 328-330, 1982.

<Patent> [1] T. Izawa, T. Miyashita and F. Hanawa, “ Continuous optical fiber preform fabrication method”, US Patent 4062665(Filed date: April. 5, Issued date: December 13, 1977)

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to Please see the Milestone Program Guidelines for more information.

Supporting Materials VAD(IEEE Milestone).pdf

Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to with the subject line "Attention: Milestone Administrator." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s).

Please recommend reviewers by emailing their names and email addresses to Please include the docket number and brief title of your proposal in the subject line of all emails.

Supporting Materials VAD(IEEE Milestone).pdf