OA：Optical Amplifier，光放大器。關聯詞：EDFA、OFA、OSΑ

OADM：Optical Add-Drop Multiplexer，光分插復用設備

OBS：Optical Burst Switching，光突發交換。關聯詞：OPS、OWS  

OCC：Cross Connecting Cabinet for Communication Optical Cable，通信光纜交接箱 

ODB：Optical Fiber Cable Distribution Box，光纜分纖箱

ODF：Optical fibres Distribution Frame，光纖配線架。關聯詞：MDF、DDF

OF：Optical fibres，光導纖維

OFA：Optical Fiber Amplifier，光纖放大器

OI：Optical Internet，光互聯網

OMAN：Optical Metropolitan Area Network，光城域網 

OMDF：Optical Main Distribution Frame，光纖總配線架。關聯詞：MDF、ODF、DDF

OPGW：Optical Ground Wire，光纖復合地線。關聯詞：OPPC

OPPC：Optical Phase Conductor，光纖復合相線。關聯詞：OPGW

OPS：Optical Packet Switching，光分組交換。關聯詞：OBS、OWS

OSΑ：Optical Semiconductor Amplifier，半導體光放大器

OTDM：Optical Time Division Multiplex，光時分復用 

OTDR：Optical Time Domain Reflectometer，光時域反射儀

OTN：Optical Transport Network，光傳送網絡

OTU：Optical Transponder Unit，光轉換器單元

OVPN：Optical Virtual Private Network，光虛擬專用網

OWS：Optical Wavelength Switching，光波長交換。關聯詞：OBS、OPS

OXC：Optical Cross-Connect，光交叉連接