Talk:Optical fiber connector/Archive 1

Force Inc. link
I removed one of the links, Introduction to fiber connectors. It had some good material but it also appeared to be a front for Force Inc. --A. B. 22:47, 12 June 2006 (UTC)


 * Is there something bad about Force Inc. specifically, or linking to commercial sites (pls excuse my ignorance)? This page doesn't seem biased or particularly commercial, just a few ads, and I've found the info on it pretty useful. I'd like to revert this change.... --gurnec 19 July 2006


 * See these Wikipedia pages:
 * External links, especially the section "Links normally to be avoided"
 * Spam, espcially the section "External link spamming"
 * Spamdexing -- much of Wikipedia's external spam-linking is not even done to lure Wikipedia readers -- it's just there to build search engnine rankings. Google "loves" links leaving Wikipedia and seems to weight them pretty highly when computing search rankings.


 * I may have been a bit hasty in deleting this one -- I'm constantly deleting spammy links from the fiber articles (case in point: see Talk:Timbercon and Articles for deletion/Timbercon).


 * One telling mark of a spammer is to go to Search web links and search for instances of the same domain name. Use a * for a wildcard (example: *.fiber-optics.info ) and see how many links you get back. In the case of the fiber-optics.info domain, just the one above. So, yes, I was probably quick on the trigger -- feel free to add it back in.


 * And please -- if you see spammy links getting added, revert them and put a warning notice on the spammer's talk page.--A. B. 23:57, 19 July 2006 (UTC)

MIC is less-common? No way!
Where I work (University hospital of Leipzig, Germany) we have got MIC wall outlets/plugs all over the place. Most of the cables used are either MIC-ST or MIC-SC depending on the NIC and connection speed in use in the area, MT-RJ is used only for patching, but even there we got lots of MIC, SC and ST plugs/outlets. I propose MIC to be moved into the "common" section.

EDIT: After some research it dawned on me that MIC is in fact FDDI. In case there's no other type called MIC I suggest merging those two.91.66.216.247 (talk) 19:44, 4 August 2008 (UTC)


 * FDDI defines way more than just the connector; it includes the optical media specifications, the data link protocols, ring management, etc. I'd say MIC should link to FDDI, and indeed, have done just that.  I've also merged the two tables, because while I don't know what's common and what isn't, the claims to that effect in this article were completely unsourced.  I suspect they arbitrary anyway, since the article never defined what "Common" was.  Plus, I just don't see that distinction being useful to the reader in the first place. — DragonHawk (talk|hist) 22:40, 4 August 2008 (UTC)

TX/RX specification?
Is there a standard or practice for a consistent use or marking of transmit (TX) and receive (RX) ports on plugs or patch panels? I don't believe that the only solution is to try connecting it, and if doesn't work, switch it around. It isn't so easy, especially with the duplex connectors (LC, SC, MIC) and 4 port LC adapters. —Preceding unsigned comment added by 195.38.110.188 (talk) 12:41, 24 December 2008 (UTC)

Usually TX is on the left side and RX on the right side, if you are standing in front of the plug and you look into the plugs. Hint: Check one of the SFP datasheets. I could poste a link to one of the SFP datasheets, but independent which company's SFP I would choose, wikipedia guys would complain that I chose one company. 80.254.148.43 (talk) 13:19, 10 November 2009 (UTC)

APC clarification
The article reads, "Angle-polished connections are distinguished visibly by the use of a green strain relief boot, or a green connector body. The parts are typically identified by adding "/APC" (angled physical contact) to the name." So does APC actually mean Angle-Polished Connections or Angled Physical Contact and what is the significance of whatever part it refers to being angled? —MegaPedant 12:46, 28 February 2010 (UTC)
 * APC is "angled physical contact", as the article says. Note 2 below the table explains what is angled, and why.--Srleffler (talk) 19:54, 28 February 2010 (UTC)

Both the core and surrounding ferrule face are slightly angled. Illustrated on Slide 21 Connector End Finishes at http://www.thefoa.org/tech/ref/termination/Term/Term.htm : "The final solution for singlemode systems extremely sensitive to reflections, like CATV or high bitrate telco links, was to angle the end of the ferrule 8 degrees to create what we call an APC or angled PC connector. Then any reflected light is at an angle that is absorbed in the cladding of the fiber."-96.237.78.13 (talk) 22:38, 22 August 2010 (UTC)

Connector details: dimensions, terms, adapters
Please add dimension information for the connectors, with mechanical drawings.

Are the terms "male" and "female" used? How are the mating parts designated/referred to?

Please mention couplers/adapters, with photos. Are adapters always cable-to-cable couplers, for different types of connectors? Or do they sometimes "adapt" a cable to plug into a receptacle? Do couplers introduce one or two optical junction losses?-96.237.78.13 (talk) 22:42, 22 August 2010 (UTC)


 * Mechanical drawings are going to be hard to get because we can't use copyrighted material on Wikipedia without a proper license. This means drawing have to be either made specially for Wikipedia, or someone with copyrights to existing drawings has to release them under a suitable license.


 * I don't think I have heard "male" and "female" used to refer to single-fiber connectors. Some of the multi-fiber connectors such as MTP/MPO do have male and female variants, distinguished by alignment pins vs. holes to receive them.


 * For common connectors such as FC, SC, LC, etc. the usual couplers are just a simple mating sleeve that allows a connector to be mated to each end. There is only one optical junction: the end of one fiber is butted directly against the end of the other. Receptacles on equipment are more variable. A receptacle can be a bulkhead-style mating sleeve to mate a fiber inside the equipment with one outside, or can hold the external fiber in close proximity to a detector, or can have optics to image the external fiber's end into an optical system inside the device.


 * A general-purpose adaptor to allow a fiber with one type of connector to be plugged directly into a receptacle for another seems unlikely. It's easier to just use a short length of fiber with the appropriate connector types on each end. I have seen some equipment that could be adapted to different connectors by exchanging a fitting.--Srleffler (talk) 04:34, 23 August 2010 (UTC)

Thank you Srleffler for all that useful info!

It seems like "receptacle" is the common term? A coupler might be said to have two receptacles? Would the complementary term be "plug" for what is at the end of a cable, that mates with the receptacle?

For dimension information, it would be very helpful to have side-view pics with a grid in the background, or even just a ruler. Or even just some scale markings added to side-view pics after the fact? Anything would help a novice identify an unknown connector. It is unfortunate that almost all WP pics lack dimension clues. Also, single group photos of the most common connector types together, a side view and an end view, would be very helpful in understanding relative sizes.

What are the best resources for learning about Fiber Optic test equipment? It seems quite specialized and expensive. Any do-it-yourself hacking resources for learning/experimenting with minimal expense?-96.237.78.13 (talk) 13:26, 25 August 2010 (UTC)


 * I think I usually call it a "connector" rather than a "plug", but maybe that's just me. Yes, for many connector types a coupler is essentially two receptacles back to back, spaced such that the fibers butt together when they are mated to the two sides.--Srleffler (talk) 02:44, 26 August 2010 (UTC)

Dust, contamination, air gap, attenuators
Under normal conditions, how often does dust of what sizes contaminate the mating surfaces, with what effects? Basics of cleaning here: http://www.thefoa.org/tech/cleaning.htm Pictures of contamination and damage here: http://thor.inemi.org/webdownload/newsroom/Presentations/Optical_performance.pdf Where can one find a typical plot of air gap size vs. loss for standard 62.5/125 multimode cable ends?

Please add info about attenuators to the Optical attenuator Fiber optic attenuator WP article, which is just a stub. Can the quality (signal strength margin) of a FO connection be roughly judged in the field by just loosening a cable and sliding it in and out to vary the air gap, see how big the gap can be and still have a working link? -96.233.19.223 (talk) 22:13, 29 August 2010 (UTC)

Sharp bends stress optic fibers and can cause losses. If a received signal is too strong a temporary fix is to wrap the cable tightly around a pencil until the desired level of attenuation is achieved.Using Attenuators With Fiber Optic Data Links

The three basic types of gap loss are angular misalignment loss, lateral offset loss, and longitudinal displacement loss. The losses tend to be proportional to the ratio of the core radius to the size of the gap or displacement. Formulas, examples and graphs can be found at Fiber Optic Communication - Couplers and Connectors According to those equation plots, end separation gap of one core radius adds a loss of about 0.4 dB in multimode SI fiber. The theoretical gap loss for single mode fibers is much less, about 0.4 dB for a gap of ten core radii, about 1.0 dB for an end gap of about 17 radii. (This assumes perfect axial alignment, so may be quite different from ordinary experience.)-96.233.19.223 (talk) 00:53, 30 August 2010 (UTC)

usually no gap loss at detector
"Gap loss is not usually significant at the optical detector, because the sensitive area of the detector is normally somewhat larger than the cross section of the fiber core. Unless the separation is substantial, all light emerging from the fiber, even though it diverges, will still strike the detector."

Is this usually true? When is it less true?-96.237.15.180 (talk) 14:59, 30 August 2010 (UTC)


 * It's just a geometric effect. Light comes out of the fiber in a cone, with cone angle determined by the fiber's mode field diameter (for singlemode fiber) or NA (for multimode fiber). Whether the detector receives all of the light depends on how big it is and how close it is to the fiber, as you would expect.


 * You really should ask questions like this at the Science reference desk. Article talk pages are for discussion related to improving the article, not general questions about the subject matter.--Srleffler (talk) 04:30, 31 August 2010 (UTC)

ELIO connector
83.206.126.140 wrote in an edit comment: "I added in the chart the ELIO optical contact which is a worldwide used Std in aircraft industry (like luxcis)especially at Airbus and other harsh environment application. I would like to share also a picture of it, how to proceed?"


 * If you have a picture that you took yourself, there are instructions on how to upload it at Files for upload. (If you have a Wikipedia account, go to Upload instead.) After you upload it, you can post the name of the file here, and I will help with adding it to the article.
 * Do not upload a picture unless you own the copyrights to it or it is licensed for free re-use. Generally images you find on the web or in company publications are not acceptable, due to copyright restrictions.--Srleffler (talk) 02:32, 3 September 2011 (UTC)

Move discussion in progress
There is a move discussion in progress on Talk:Fiber optic sensor which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 17:02, 14 August 2019 (UTC)