Milestone-Proposal talk:Fiber optic connectors

Advocate for this Milestone Proposal -- John Vardalas (talk) 20:14, 7 August 2019 (UTC)

I've been asked to be the advocate for this proposal. I'm currently developing a list of external expert reviewers. My goal is to get three reviewers. For the moment I have two who have agreed to review the proposal. When their reviews are ready they will be posted on this Discussion Page. When I have a third reviewer, his, or her, review will also be posted.

Once all the reviews are posted we can proceed with the evaluation of this proposal. In the meantime I am bringing myself up to speed on this proposal. I'm looking forward to moving this Milestone forward to the next step in the process.

John Vardalas, Ph.D. Member, IEEE History Committee

First external review of proposal -- John Vardalas (talk) 01:13, 31 October 2019 (UTC)

Posting of a review by Dr. Mitsuru Kihara, Professor, Osaka Electro-Communication University, Japan. This is an exact copy of his review.

"The proposal shows that the proposers invented the physical contact (PC) connection technology that have proved fundamental in supporting the performance and reliability of fiber optic connectors. The proposers used the PC connection technology to develop an SC connector and an MPO connector as representative simplex and multiplex fiber optic connectors. Both connectors are widely used throughout the world.

I agree that the work is historically significant for optical fiber communication systems. Many fiber optic connectors that are currently in practical use are based on the invented PC connection technology. I think that proposers established clear historical significance. Their arguments are technically strong. The answers adequately support the Milestone claim.

Many kinds of fiber optic connectors have been developed and currently used in optical fiber network systems. Fiber connections, except fusion splices, are classified into two types of connection states. One is a connection with physical contact (PC), and the other uses refractive-index matching material. PC-type connectors are mostly used for intra-office fiber connections and premises where frequent reconnections are required. In contrast, connectors and mechanical splices with refractive-index matching material are mostly used in outside facilities, where frequent reconnections are unnecessary. Therefore, PC-type connectors have superior operability.

The work contributes to realize physical contact (PC) connection technology and most major PC-type connectors that are currently in practical use throughout the world. The PC connection technology have important factors such as push-pull coupling mechanism and high-precisely polishing ferrule end-face. Using the PC connection technology, the proposers have developed SC and MPO connectors. Both SC and MPO connectors could realize excellent operability and high density connection. In addition, both SC and MPO connectors employed plastic-molded components and they could lead to cost-effective connection. Consequently, the invented PC connection technology and these developed SC and MPO connectors are historically important for optical fiber communication systems.

Finally, I think that the wording of the citation is accurate.

My advice:

With the answers to “What obstacles (technical, political, geographic) needed to be overcome?”, In second sentence of second paragraph: The sentence “and they use an expensive ceramic ferrule” should be deleted. This is why SC connectors also use a ceramic ferrule and could not lead to low cost.

With the “Supporting texts and citations to establish the dates, location, and importance of the achievement”, Reference [2]: This journal article is in Japanese. If possible, the appropriate journal article in English should be used."

Second external review of proposal -- John Vardalas (talk) 01:34, 31 October 2019 (UTC)

Below are Dr.Shin'ichi Iwano's responses to the questions I put to him regarding the merits of this proposal. Dr. Iwano is the Executive Manager. Global Business Headquarters. NTT Advanced Technology Corporation. My questions are bolded

What is the historical significance of the work (its technological, scientific, or social importance)?

I believe it is very clear that the proposed PC connection with a push-pull coupling mechanism has a historical-technological significance. A fiber optic connector has a technological difficulty compared to electrical connectors, and was a big challenge. Most of all communication laboratories including NTT's Labs, AT&T's Bell Labs, BT Labs, Telecom Italia CSELT, etc., had researched and developed a various optical connectors and connection technologies until 1980s. These had been replaced and unified to the PC connection with a push-pull coupling mechanism when after it had proposed in the end of 1980s. The PC connection with a push-pull coupling mechanism over comes the challenges realizing precise alignment of the connecting two fibers in ease of operation and with high reliability in low cost.

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

Fiber optic connectors are needed to realize low insertion losses, low reflection between connecting fibers, high long-term-durability, ease of operation and maintenance, and low in cost of the connectors. However, it was a big challenges because the fiber optic connector should precisely align fiber cores of two mating fibers in 1 micrometer or less,0.1 degree or less in tilt, and no separation. Also these precise alignment should be realized by easy human operation. This also should be kept in long terms in various severe circumstance. In order to overcome this challenge a lot of experiment results and thick theoretical discussion had done in the end of 1980's - early 1990 which were summarized technical papers and technical and scientific conference presentations. Based on these theoretical and experimental results, the PC connection with a push-pull coupling mechanism had proposed, which overcome and satisfy all of such all requirements. Therefore most of current optic connectors utilize the technology of the PC connection with a push-pull coupling mechanism.

What features set this work apart from similar achievements?

Until the provision of the PC connection with a push-pull coupling mechanism, a variety of connectors had been developed utilizing various coupling mechanisms and had been used for the realization of fiber optic network systems. They were AT&T' biconic ferrule connectors and ST connectors, NTT's FC connectors, and EU's EC connectors, etc. Some put matching gel between two connectors to reduce reflection which is not good for repeated connection and is not good to realize long time durability. Some others used flat polished ferrules which had a large reflection and a relatively large insertion loss. Some other connectors utilized angular polished ferrule to reduce the reflection: however this having some large insertion losses. In addition, most old connectors used screw nut coupling mechanism which is not ease to operate compared to the push-pull coupling mechanism. Please assess the strengths and weaknesses of the answers given by the proposers.

Have they established clear historical significance?

As stated as above, most of all fiber optic connectors uses the PC connection with a push-pull coupling mechanism. We can find connectors uses the PC connection with a push-pull coupling mechanism anywhere and any systems fiber connectors are using.

Are their arguments technically strong?

Yes I think so.

Do the answers adequately support the Milestone claim: "In 1986, Nippon Telegraph and Telephone Corp. (NTT) invented the physical contact (PC) connection technology that has proved fundamental in supporting the performance and reliability of fiber optic connectors. NTT invented SC and MPO connectors that provide PC connection with a push-pull coupling mechanism for high-density connection and superior operability. SC and MPO connectors are widely used by carrier networks and data center networks throughout the world."

I believe that the description provided by the proposer is very correct.

In your view is the wording of the citation accurate? Finally have they provided adequate "Supporting texts and citations to establish the dates, location, and importance of the achievement"?

Yes, I think it is accurate.

Please feel free to express any additional views on this proposed Milestone and make any suggestions for improvement.

The physical contact (PC) connection technology and the SC and MPO connectors have been standardized not only in the proposer's country but also in most countries worldwide where fiber optic network systems installed. Most of all fiber optic connector manufactures provide these connectors worldwide. These were have greatly help to construct today's fiber optic network systems worldwide.

Need for a third review -- John Vardalas (talk) 01:44, 31 October 2019 (UTC)

The History Committee's Milestone Subcommittee feels that it would be wiser to add a third expert review, from someone who does not have an affiliation with NTT. I am working with the Committee to find such a person.

Re: Need for a third review -- Takashi Noshiro (talk) 06:43, 9 December 2019 (UTC)

I have read and reviewed the Milestone Proposal for Fiber Optic Connectors and concluded with the following 5 point of views.

1) Have they established clear historical significance?

Yes.

The proposed technology for the physical contact (PC) connection had a large and direct impact on the fiber optic connector design rule by eliminating the necessity of using the index matching gel material. It also provided excellent operability, durability, long-term reliability and economic reasoning allowing the fiber optic industry to expand and grow as we know the industry today with the ever-increasing traffic by broadband networks, high speed mobile networks and cloud computing.

It was an historical pivot point in the industry.

As proposed, the conventional fiber optic connector had limitations for high-density applications due to the rotating coupling nut mechanism as well as quality issues. At times, an optical fiber end face has circular damage when rotating a coupling nut due to the tolerances of the metal parts. However, the push-pull coupling mechanism solved and eliminated this issue.

One of the historical achievements for the push-pull mechanism was the encouraging development of smaller optical transceivers. Conventional optical connectors such as FC and ST could not provide duplex style connectors and therefore, conventional fiber optic communication needed individual optical transmitter and receiver units. However, the push-pull mechanism could allow the use of high-density duplex style connectors allowing the development of the integrated optical transceiver.

In conclusion, I support this Milestone proposal.

2) Are their arguments technically strong?

Yes.

There are many kinds of standardized fiber optic connector designs in the IEC standards; However, the optical fiber connection performance standards utilize only the physical contact (PC) and angled physical contact (APC) connection technologies.

Almost all standardized connector designs and recent new proposals all refer to the standardized PC connections.

The fiber optic communication industry has not created new technology with economic reasoning, therefore physical contact (PC) connection technology is a very strong solution.

In addition, SC connectors and MPO connectors which utilize the push-pull coupling mechanism and feature are still widely used in today’s market, specifically the MPO style connectors, which are more active in recent datacenter interconnect activities.

In conclusion, the push-pull coupling mechanism is actively used as a major connector technology making it a strong and needed technology in the world of fiber optic networks and equivalent.

3) Do the answers adequately support the Milestone claim:

"In 1986, Nippon Telegraph and Telephone Corp. (NTT) invented the physical contact (PC) connection technology that has proved fundamental in supporting the performance and reliability of fiber optic connectors. NTT invented SC and MPO connectors that provide PC connection with a push-pull coupling mechanism for high-density connection and superior operability. SC and MPO connectors are widely used by carrier networks and data center networks throughout the world."

Yes.

4) In your view is the wording of the citation accurate?

Yes.

5) Finally, have they provided adequate "Supporting texts and citations to establish the dates, location, and importance of the achievement:"

Yes.

Proposal Review by Takashi Noshiro -- John Vardalas (talk) 07:26, 19 December 2019 (UTC)

Mr. Takashi Noshiro is the Executive Officer of R&D Div. at the Adamant Namiki Precision Jewel Co., Ltd. (https://www.ad-na.com/en/). He has spent over 25 years working on fiber optic interconnect devices and components.

Since 2007 Mr. Noshiro has served on the IEC TC86 for the Telecommunications Industry Association. The activity of this technical committee covers fibre optic interconnecting devices and passive components.

The citation -- John Vardalas (talk) 21:35, 8 January 2020 (UTC)

Except for the citation, I think that this proposal is ready to go the full History Committee for a vote.

I believe that there is room for improvement in the citation. The first time an acronym is used in a citation is should be written out in full, e.g. Multifiber Push On (MPO). Can the words "proved fundamental in supporting" be made more specific. For example, did PC technology significantly, or greatly, improve performance and reliability? Was there a dramatic breakthrough in performance and reliability?

Can one be more specific about the duration in the worldwide importance of PC technology. For example, can one start the last sentence with something like, "For the next decade", or "During the 1990s"?

Re: The citation -- Yoshiteru Abe (talk) 02:05, 13 February 2020 (UTC)

The proposers would like to post the revised citation.

[Revised citation] In 1986, Nippon Telegraph and Telephone Corp. (NTT) invented the physical contact (PC) connection technology that significantly improved the performance and reliability of fiber optic connectors. NTT invented Single-fiber Coupling (SC) and Multi-fiber Push On (MPO) connectors that provide PC connection with a push-pull coupling mechanism for high-density connection and superior operability. SC and MPO connectors have been used worldwide in carrier networks and data center networks since 1990s.

Re: Re: The citation -- John Vardalas (talk) 23:34, 13 February 2020 (UTC)

I like the changes. Does the last sentence mean that SC and MPO connectors have become a worldwide standard since the 1990s? Or does it mean that, since the 1990s, most of the world's carrier networks and data centers have adopted SC and MPO connectors? Does "since the 1990s" mean that it is still the case today?

Re: Re: Re: The citation -- Yoshiteru Abe (talk) 04:54, 14 February 2020 (UTC)

The last sentence contains both meanings. SC and MPO connectors were standardized as the international standard connector by the IEC in the 1990s. Since the 1990s, SC and MPO connectors have been adopted in most of the world`s carrier networks and date centers. “since the 1990s” means that it is still the case today.

Re: Re: Re: Re: The citation -- John Vardalas (talk) 05:49, 14 February 2020 (UTC)

What do you think of changing the last sentence to

Since the 1990s, these connectors have been adopted by most of the world’s carrier, and data center networks. ?

I incorporated your phrase "adopted in most..." and replaced "SC and MPO connectors" with "these connectors". I also only used "networks" once at the end of the sentence.

This gives us exactly 70 words.

=Re: Re: Re: Re: Re: The citation -- Amy Bix (talk) 21:50, 14 February 2020 (UTC)=

I'm wondering whether the citation still contains a bit too many acronyms and jargon to be meaningful to a wider audience, as IEEE intends. Could I suggest some rewriting to eliminate some of this and emphasize the broader significance to electrical history (and eliminate passive voice) perhaps as follows:

In 1986, Nippon Telegraph and Telephone Corp. (NTT) invented the physical contact connection technology that advanced performance and reliability of fiber optic connectors. NTT developed two types of connectors, simplex (SC) and multiplex (MPO), that used push-pull coupling mechanisms. These provided better optical results at lower cost. Since the 1990s, most global carriers and data center networks have adopted these connectors, facilitating construction of systems for speedy worldwide communication. [69 words]

Of course, this requires checking to be sure that none of these edits would accidentally change the meaning or introduce historical or technical errors.

==Re: Re: Re: Re: Re: Re: The citation -- John Vardalas (talk) 23:21, 14 February 2020 (UTC)==

Greatly improves the citation. Thank you Amy.

=Re: Re: Re: Re: Re: The citation -- Yoshiteru Abe (talk) 07:59, 14 February 2020 (UTC)=

Thank you very much for your valuable proposal. We agree with your revised citation.

==Re: Re: Re: Re: Re: Re: The citation -- Ebruton (talk) 21:46, 16 February 2020 (UTC)==

I was just logging in to say pretty much what Amy said and to suggest a revision much like the one she suggested so I agree with the changes too.

Ebruton (talk) 21:46, 16 February 2020 (UTC)

Re: The citation -- Jason.k.hui (talk) 13:48, 23 February 2020 (UTC)

The current citation in the proposal uses the acronym "SC," without having it been defined. Please update the citation on the main proposal page.

Re: Re: The citation -- John Vardalas (talk) 03:01, 24 February 2020 (UTC)

Both the proposers and I agree that Amy Bix's version (see above) of the citation is the best version to date. All comments should be aimed at improving Amy's version. When all the dust settles, the proposers will incorporate all the suggestions into the final version of the citation which will be submitted to the Committee before out meeting.

Amy's version has the SC acronym covered.

Re: Re: Re: The citation -- Jason.k.hui (talk) 14:18, 27 February 2020 (UTC)

Looks like Amy's version doesn't really make use of the SC and MPO acronyms as it's only used once when they're initially introduced. As such, I propose revising the citation without them:

In 1986, Nippon Telegraph and Telephone Corp. (NTT) invented the physical contact connection technology that advanced performance and reliability of fiber optic connectors. NTT developed two types of connectors, simplex and multiplex, that used push-pull coupling mechanisms. These provided better optical results at lower cost. Since the 1990s, most global carriers and data center networks have adopted these connectors, facilitating construction of systems for speedy worldwide communication.

Re: Re: Re: Re: The citation -- John Vardalas (talk) 21:42, 27 February 2020 (UTC)

As it stands now, we are only left discussing the value of acronyms in Amy's version. I understand your effort to simplify. But in changing the citation by removing any references to acronyms, do we not run the risk of losing important specificity? Is "the physical contact connection technology" too vague? For example, if this were a Milestone on Pulse-Code Modulation (PCM) and the citation only read "invented the modulation technology". Would we would consider that citation adequate?

What do the proposers think?

=Re: Re: Re: Re: Re: The citation -- Yoshiteru Abe (talk) 07:14, 3 March 2020 (UTC)=

Proposers think that the citation loses important specificity by removing references to acronyms. We think that the acronym and define of the SC and MPO should be left because the use of acronyms is important information that clearly distinguishes our developed connectors from other connectors.

Re: The citation -- Yoshiteru Abe (talk) 07:18, 3 March 2020 (UTC)

Thank you very much for valuable proposal and discussion. Proposers would like to revise our citation based on the proposals of Amy Bix and Juan Carlos.

[Revised citation] In 1986, Nippon Telegraph and Telephone Corp. (NTT) invented the physical contact connection technology that advanced performance and reliability of fiber optic connectors. NTT developed Single-fiber Coupling (SC) and Multi-fiber Push On (MPO) connectors; their compactness and easy to use push-pull operation were major advantages. Since 1990 they have been adopted by most Carriers and Data Centers. This technology facilitated the construction of systems for world-wide communications.

Re: Re: The citation -- Administrator7 (talk) 21:37, 3 March 2020 (UTC)

May I suggest some small changes in your revised citation?

In 1986, Nippon Telegraph and Telephone Corp. (NTT) invented the physical contact connection technology that advanced performance and reliability of fiber optic connectors. NTT developed Single-fiber Coupling (SC) and Multifiber Push-On (MPO) connectors; their compactness and simple push-pull operation were major advantages. Since 1990 most carriers and data centers have adopted them. This technology facilitated the construction of systems for near light-speed, digital, global communications. (65 words)

The changes accurately represent one acronym (SC: see below); reduce the word count from 67 to 65 through simpler terms ("simple" for "easy-to-use", "global" for "world-wide", active voice construction for sentence beginning "Since 1990..."); and specify the global consequences of the achievement. That is, high-speed global networks existed before fiber-optic cables; the difference is in their photonic and digital nature.

"Single-fiber coupling" does not represent the acronym SC in any obvious reference work. There are four other common explanations for SC: Snap-in Connector [FOA “Connector Identifier”]; Square Connector [PPC blog: “Fiber Connectors-What’s the Difference?”]; Standard Connector [PC Mag Encyclopedia]; Subscriber Connector [PC Mag Encyclopedia] [These last 3 are also referred to in U.S. Patent 2014/0126875 as terms of the art].

I suggest that you use whichever of these terms that NTT used internally to describe the SC connector. Otherwise, "Standard Connector" is the most appealing choice because "standard" suggests its widespread adoption.

Alex Magoun, IEEE History Center

Re: Re: Re: The citation -- Yoshiteru Abe (talk) 06:11, 6 March 2020 (UTC)

Thank you very much for your proposal and investigation of the acronym SC. We agree with your revised citation. NTT, the inventor of SC connector, now states that SC is an acronym for Single-fiber coupling.

-- Juan Carlos (talk) 14:30, 1 March 2020 (UTC)

In the 1990’s I was deeply involved and lead the design and implementation of a FO backbone in my company, at the dam, offices and switchyards in Salto Grande. I had to work with different Fiber optics types (about 20 trunks, 30Km)., terminal equipments and connectors. We had some bayonet-type ST but abandoned them quickly. In my opinion this proposal deserves a Milestone. However, I think the NAME is a little bit too long, I suggest a shorter, more direct one like this:

Physical Contact Push-Pull Technology for Fiber Optic Connectors, 1986

About the citation, from the study of the proposal and the comments, analysis shows four points to mention: 1 - The Physical Contact Technology - and people don’t need to be explained the “PC” acronym 2 - The SC and multiplex connector - “SC” is vey much common (used at a lot of homes in Uruguay) and needs to be explained; in case of MPO, MULTIPLEX as Amy says would be much simple for the public. 3 - The advantages of the method: push-pull ease of use and compactness, allowing high-density. 4 - worldwide adoption - as Jason says, they facilitated the CONSTRUCTION of communications systems

I suggest a 59-word citation (additions are possible?) like this:

In 1986, Nippon Telegraph and Telephone Corp. (NTT) invented the physical contact connection technology for fiber optic connectors. NTT developed Single-fiber Coupling (SC) and multiplex connectors; their compactness and easy to use push-pull operation were major advantages. Since 1990 they have been adopted by most Carriers and Data Centers. This technology facilitated the construction of systems for world-wide communications.

Re: -- Yoshiteru Abe (talk) 07:12, 3 March 2020 (UTC)

Thank you very much for acknowledging the value of our proposal. Proposers agree with your revised NAME. We’d like to keep the description of the MPO connector on the citation. Since only the MPO connector is now in widespread use as a standard multiplex PC connector, there can be a citation that MPO connector is described as a multiplex connector as you suggest. However, in the future, other multiplex connectors may be widely used. Therefore, we think the MPO connector should be distinguished with the future multiplex connectors on the citation. We think that the advantages of both the physical contact connection and push-pull mechanism should be left on the citation because they are important specificity for our proposal.

Dave Kemp comments -- Djkemp (talk) 23:05, 1 March 2020 (UTC)

I support this milestone proposal. I suggest that the citation be modified to make it more friendly to the public. This would include for example spelling in full the text for "SC" and "MPO"

Michael Polis - Comments -- Polismpp (talk) 19:13, 7 March 2020 (UTC)

I have no problems with this proposal.