Guides
What to specify, what to ask and what the numbers mean. Written for engineers and buyers who order fibre assemblies.
The Radix Fibrotech guides explain what to specify when buying fibre optic cable and assemblies: cable types (single-mode, multimode, OFC, armoured, tactical, active optical), connectors (LC, SC, ST, FC, MPO, UPC vs APC, adapters), MPO polarity, splicing and pigtails, patch panels, loss budgets, prices and how to write an RFQ. They are written for engineers and buyers by the people who build the cable.
MTP/MPO and the data centre
What is an MPO cable?
An MPO cable carries 8 to 24 or more fibres in one connector. Fibre counts, pin gender, keying, polish and the details to state when ordering MPO assemblies.
ReadGuideMPO connector: ferrule, types, gender and polish
How the MPO connector works: MT ferrule rows, MPO-8 to MPO-32 types, male and female pins, key-up and key-down adapters, APC polish and what to order.
ReadGuideMTP vs MPO: what is the difference?
MTP is a branded MPO connector. How the two differ in housing, guide pins, ferrule float and loss grades, whether they intermate, and how to write the order.
ReadGuideMPO polarity: Type A, B and C explained
MPO polarity Type A, B and C explained: fibre maps, key-up and key-down adapters, the patch cords each TIA-568 method needs, and polarity for parallel optics.
ReadGuideOM3 vs OM4 vs OM5: which multimode fibre?
OM3, OM4 and OM5 compared: modal bandwidth, IEEE 802.3 reach for 10G, 40G, 100G and 400G, jacket colours, and when OM5 is worth specifying for a new link.
ReadGuideCabling for 400G and 800G parallel optics
Cabling for 400G and 800G parallel optics: SR8, DR4 and DR8 fibre counts, MPO-12 vs MPO-16, base-8 and base-16 trunks, breakouts and planning for upgrades.
ReadGuideHow to clean MPO connectors
How to clean MPO and MTP connectors: inspect with an MPO probe, clean with dry or wet-to-dry methods, and re-inspect against IEC 61300-3-35 zone criteria.
ReadGuideHow to calculate a fibre loss budget
How to calculate a fibre loss budget: add fibre attenuation, connector and splice losses using TIA-568 allowances, with worked single-mode and MPO examples.
ReadCable types
Types of fibre optic cable
Fibre optic cable types by fibre grade, buffer, armour, jacket fire rating and fibre count, from OS2 and OM4 to loose tube, LSZH, plenum and MPO trunks.
ReadGuideSingle-mode fibre optic cable
Single-mode fibre has a 9 µm core and runs at 1310 and 1550 nm. OS1a vs OS2, G.652.D and G.657 fibre, UPC or APC connectors, and what to specify when ordering.
ReadGuideMultimode fibre optic cable
Multimode fibre has a 50 or 62.5 µm core and runs short links at 850 nm. OM1 to OM5 grades, VCSEL optics, LC and MPO connectors, and what to specify.
ReadGuideSingle mode vs multimode fibre
Single-mode fibre has a 9 µm core for long links; multimode uses 50 or 62.5 µm cores for short runs. Compare OS2 and OM grades, reach and optics cost.
ReadGuideOFC cable: full form, core counts and types
OFC means optical fibre cable. What 4, 6, 12 and 24 core OFC mean, unitube vs multitube, armoured, ADSS and duct types, termination and what to specify.
ReadGuideArmoured vs unarmoured fibre cable
Armoured fibre cable adds steel tape, interlocking or wire armour against rodents and crushing. Compare armour types, bend radius, earthing and when to skip it.
ReadGuideTactical fibre optic cable guide
Tactical fibre optic cable uses tight-buffered fibre, aramid and a polyurethane jacket for links that are laid and recovered. Construction, reels and specs.
ReadGuideSMPTE hybrid cable explained
SMPTE 311M hybrid camera cable carries two single-mode fibres plus power and control copper to 304M connectors. How it works and how to specify length and drum.
ReadGuideActive optical cable (AOC): what it is and when to use one
An active optical cable has a transceiver built into each end. How AOC compares with DAC and separate optics, QSFP and HDMI types, and what to specify.
ReadGuideFibre colour codes
The TIA-598 fibre colour code: the 12-colour sequence, striped fibres 13 to 24, buffer tube colours, jacket colours by fibre type and MPO position mapping.
ReadConnectors
Fibre optic connector types
LC, SC, FC, ST, MPO, E2000, expanded beam and MIL circular fibre connectors compared: ferrule, coupling, typical use, and when to choose UPC or APC polish.
ReadGuideLC connector: types, duplex, polarity and uses
The LC connector uses a 1.25 mm ferrule and push-pull latch. Simplex vs duplex, uniboot, UPC vs APC colours, A-B polarity, LC vs SC, and what to specify.
ReadGuideSC connector: SC/UPC, SC/APC and where each is used
The SC connector has a 2.5 mm ferrule and square push-pull body. SC/UPC vs green SC/APC, why FTTH and PON use APC, SC vs LC, hybrid cords and what to order.
ReadGuideST connector: the bayonet fibre plug and where it is still used
The ST connector is a keyed 2.5 mm bayonet fibre plug, mostly multimode. Where ST is still installed, how it compares with SC and LC, and what to order.
ReadGuideUPC vs APC connectors
UPC vs APC fibre connectors: 8 degree angled and domed end faces, return loss, blue and green colour codes, why they never mate, and where each one is used.
ReadGuideFibre optic adapters and attenuators: types and uses
How fibre adapters and couplers work: ceramic vs bronze sleeves, LC, SC, hybrid and MPO types, UPC vs APC colours, and when a link needs an attenuator.
ReadGuideExpanded beam connectors explained
Expanded beam fibre connectors use lenses instead of ferrule contact, so dirt and wear matter less. How they work, where they are used and the loss trade-off.
ReadInstallation and hardware
Fibre optic splicing: fusion and mechanical
Fibre optic splicing joins two fibres permanently. Fusion vs mechanical splices, steps of a fusion splice, TIA-568 loss limits, OTDR testing and alternatives.
ReadGuideFibre pigtails: types, connectors and splicing
A fibre pigtail has a factory connector on one end and bare fibre on the other for splicing. Buffer types, SC and LC options, colour sets, splicing and loss.
ReadGuideFibre optic patch panels: types, cassettes and ODFs
How fibre patch panels work: rack and wall enclosures, LC, SC and MPO ports, MPO cassettes vs breakouts, ODFs, splice panels, labelling and cords to order.
ReadBuying
How to write an RFQ for fibre optic assemblies
What to put in a quote request for fibre assemblies: fibre, connectors, polarity, length tolerance, jacket rating, labels and test report, plus a checklist.
ReadGuideFibre optic cable price: what sets it and how to compare quotes
Why fibre optic cable and patch cord prices vary: fibre type, armour, connectors, testing, quantity and Incoterms, and how to compare quotes like for like.
ReadToolFibre loss budget calculator
Add up fibre, connector and splice loss for a link and compare it with what your optic allows.
Open the calculatorQuestions buyers ask
Where should I start if I am new to MPO?
Start with What is an MPO cable, then MTP vs MPO, then MPO polarity Type A, B and C. Those three cover most ordering mistakes.
Is there a tool to check a link?
Yes. The free fibre loss budget calculator adds fibre, connector and splice loss and compares the total with what your optic allows.
Send us your drawing.
Tell us the fibre type, count, connectors and lengths. An engineer reads every request and replies with questions or a quote.