| Full title | Fibre optic interconnecting devices and passive components. Fibre optic connector interfaces (parts numbered 1 to 37, not all numbers used) |
| Publisher | IEC, TC 86/SC 86B Fibre optic interconnecting devices and passive components |
| Current edition | Each part has its own edition. Part 1 (general and guidance) is edition 2.0, 2013 |
| Status | Published and maintained part by part. Parts 2, 4 and 6 were revised or amended in 2026 |
| Related standards | IEC 61755-3 series and IEC 63267-3 series (optical interfaces); IEC 61300 series (tests); IEC 61076-3-106 |
What it covers
Each part of IEC 61754 defines the standard interface dimensions of one connector family. These are the minimum features that matter when a plug mates with and leaves its adaptor or receptacle. Plugs and adaptors from different makers that meet them are intended to fit together.
Interface dimensions are not optical performance. The ferrule end-face and optical interface are specified in the IEC 61755-3 series and IEC 63267-3 series, which the newer parts reference. Test methods are in the IEC 61300 series. Part 1 gives the general rules and the conventions for reading the interface drawings.
Main parts used in premises cabling
| Part | Connector family | Current version | Published |
|---|---|---|---|
| IEC 61754-1 | General and guidance | Ed. 2.0 | 2013-08 |
| IEC 61754-2 | BFOC/2,5 | Ed. 2.0 | 2026-04 |
| IEC 61754-4 | SC | Ed. 3.0 + Amd 1:2026 (consolidated 3.1) | 2022-02; Amd 2026-06 |
| IEC 61754-4-100 | SC simplified receptacle, SC-PC | Ed. 1.0 | 2015-11 |
| IEC 61754-6 | MU | Ed. 3.0 + Amd 1:2026 (consolidated 3.1) | 2022-02; Amd 2026-10 |
| IEC 61754-7-1 | MPO, one fibre row | Ed. 1.0 | 2014-09 |
| IEC 61754-7-2 | MPO, two fibre rows | Ed. 1.0 | 2017-12 |
| IEC 61754-7-3 | MPO, two rows 16 fibres wide | Ed. 1.0 | 2019-04 |
| IEC 61754-13 | FC-PC | Ed. 3.0 + Cor. 1:2025 | 2024-05 |
| IEC 61754-20 | LC | Ed. 2.0 + Amd 1:2022 (consolidated 2.1) | 2012-04; Amd 2022-06 |
| IEC 61754-20-100 | LC with protective housings, to IEC 61076-3-106 | Ed. 1.0 | 2012-05 |
IEC 61754-7:2008, the single MPO part, was replaced by Parts 7-1 and 7-2.
LC: IEC 61754-20
The parent LC connector is a simplex plug, used in a plug, adaptor, plug arrangement. It has:
- A 1.25 mm nominal ferrule. For 1 mm plastic optical fibre, the fibre itself acts as the ferrule.
- A single coupling latch and a ferrule spring loaded along the optical axis.
- A single male key to set orientation.
- Alignment by a rigid bore sleeve or a resilient sleeve.
The part defines PC and APC plug interfaces, duplex and quad plugs, simplex, duplex and quad adaptors, and active device receptacles. An informative annex gives dimensions for simplex, duplex square flange, duplex rectangular flange and quad adaptors. The 2012 edition added interfaces IEC 61754-20-9 to -20-16 for plastic optical fibre.
SC: IEC 61754-4
The SC is a single position plug with a 2.5 mm nominal ferrule and a push-pull coupling. The coupling is spring loaded relative to the ferrule. The plug has a single male key, and alignment is by a sleeve. The part also defines active device receptacles. The 2022 edition added the ferrule compression force test, IEC 61300-3-22, and an informative annex on panel cut-outs for testing mounted adaptor strength.
MPO: IEC 61754-7 series
MPO is a multi-fibre push-pull connector with a rectangular ferrule, normally 6.4 mm × 2.5 mm. Two guide pins align the ferrules. A male plug has the pins fitted. A female plug has none.
| Part | Fibre layout | Guide pins |
|---|---|---|
| IEC 61754-7-1 | One row, 2 to 12 fibres | 0.7 mm diameter |
| IEC 61754-7-2 | Two rows, 16 to 24 fibres | 0.7 mm diameter |
| IEC 61754-7-3 | Two rows of 16, 32 fibres | 0.55 mm diameter |
Plugs may have a flat end-face or an angled one. Angled plugs are either down-angled or up-angled, seen with the key on top. An opposed keyway adaptor joins two down-angled or two up-angled plugs. An aligned keyway adaptor joins one of each.
What it means in practice
- “Compliant with IEC 61754-20” means the connector is intended to fit standard LC parts. It says nothing about insertion loss or return loss.
- Check the optical interface grade and end-face geometry separately, against the IEC 61755-3 or IEC 63267-3 series.
- For MPO, check male or female, fibre count, end-face angle and adaptor keyway type before ordering. These affect whether parts mate correctly.
- Mounted adaptors can use different flange styles, so panel cut-outs must match the adaptor.
Related reading: Fibre optic connectors explained: LC vs SC and UPC vs APC · Fibre insertion loss and return loss explained.