Fibre Optic Terminology Explained

This page defines various terms related to the optical domain. It covers SDH, PDH, SONET, DWDM, FTTH, WDM, PDMA, wavelength converters, optical ADMs, EDFAs, and SOAs.

Fibre Optic TermsBasic Description
SDHStands for Synchronous Digital Hierarchy
PDHStands for Plesiochronous Digital Hierarchy
SONETStands for Synchronous Optical Networking
DWDMStands for Dense Wavelength Division Multiplexing
FTTHStands for Fibre to the Home
WDMStands for Wavelength Division Multiplexing
PDMAStands for Polarisation Division Multiple Access
Wavelength ConverterConverts optical light from one wavelength to another.
Optical ADMOptical Add Drop Multiplexer
EDFAStands for Erbium-Doped Fiber Amplifier
SOAStands for Semiconductor Optical Amplifier
SMFSingle Mode Fiber
MMFMultimode Fiber
CWDMCoarse Wavelength Division Multiplexing
OLTOptical Line Terminal
ONUOptical Network Unit
ONTOptical Network Terminal
ODNOptical Distribution Network
PONPassive Optical Network
GPONGigabit Passive Optical Network
EPONEthernet Passive Optical Network
FTTxFiber To The x (Home, Building, Curb, etc.)
FTTHFiber To The Home
FTTBFiber To The Building
FTTCFiber To The Curb
FTTNFiber To The Node
OSAOptical Spectrum Analyzer
OTDROptical Time Domain Reflectometer
OPMOptical Power Meter
ROADMReconfigurable Optical Add-Drop Multiplexer
OADMOptical Add-Drop Multiplexer
SFPSmall Form-factor Pluggable
SFP+Enhanced Small Form-factor Pluggable
QSFPQuad Small Form-factor Pluggable
VCSELVertical Cavity Surface Emitting Laser
PMDPolarization Mode Dispersion
CDChromatic Dispersion
OXCOptical Cross-Connect
WSSWavelength Selective Switch
BIDIBi-Directional (optical module)
APCAngled Physical Contact (connector type)
UPCUltra Physical Contact (connector type)
PCPhysical Contact (connector type)
MPOMulti fiber Push On (connector)
MTPMulti fiber Termination Push on (enhanced MPO connector)
PLCSplitter Planar Lightwave Circuit Splitter
FBGFiber Bragg Grating
OSNROptical Signal to Noise Ratio
RRHRemote Radio Head (fiber connected to BBU)
WSSWavelength Selective Switch