Uses LED or laser to transmit data in the form of light through a thin glass fiber
Mainly used for Wide Area Network (WAN)
High Bandwidth and Long Distances, Immune to EMI, Doesn’t Emanate Signals
Cable Types
Single-Mode Fiber (SMF)
Has a small core size (8.3-10µ)
Can only transmit single signal at a time
Can be used for very longer distances (40 kms)
More expense compared to MMF
SMFs generally have yellow colored sheath
Multi Mode Fiber (MMF)
Has larger core size (50-100µ)
Can carry multiple signals at a time
Used for short distances (Up to 2 kms)
MMFs generally have a aquamarine blue/ orange sheath
Cable Connectors
SC (Subscriber Connector)
ST (Straight Tip) Connector
LC (Lucent Connector)
MTRJ (Mechanical Transfer Registered Jack) Connector
For SC, ST and LC separate lines are required for sending and receiving connection
ST connector is connected like BNC (Stick and Twist)
LC is generally found as a pair (Sender and Receiver joined together)
APC Connector
APC: Angle Physical Contact
The cable is connected with the connector at a 8 degree incline
This provides better signal with less noise
Used for by SC Connectors
Green connector denotes APC
UPC Connector
UPC: Ultra Physical Contact
The light will be reflected straight back to the source
Causes a bit of signal loss
MTRJ mostly uses UPC
Blue connector denotes UPC
Wavelength Division Multiplexing (WDM)
Allows to transmit multiple optical signals over a single cable by multiplexing the signals to wavelengths of the source laser
Using WDM we can send and receive data over the same fiber cable
Coarse WDM (CWDM)
Supports up to 18 channels
Each wavelength is separated by 20 nm
Supports up to 10 Gbps (Ethernet) and up to 16 Gbps (Fiber)
Used for short distances (up to 70 kms)
For distances over 40 kms only 8 of the 18 channels can be used
Dense WDM (DWDM)
Supports up to 80 channels
Each wavelength is separated by 0.8nm
Supports up to 8 Tbps (100 Gbps/channel)
Used by infrastructure that forms the internet backbone
It is also used by ISP running Synchronous Optical Network (SONET) systems