FIBRE OPTICS
INTRODUCTION
TO
FIBRE OPTIC CABLES
HOW DOES FIBRE OPTIC
WORK ?

Carries Signals as Light Pulses
 signals
converted from electrical to light
(and visa-versa) by special equipment
e.g. fibre-optic “transceiver” (transmitter /
receiver)
FIBRE CONSTRUCTION
125 Cladding Glass
8, 50, 62.5
Core Glass
PRIMARY BUFFER
Primary Buffer 250
Cladding 125
Core (62.5)
SECONDARY BUFFER
Secondary Buffer 900
Primary Buffer 250
Cladding 125
Core (62.5)
FIBRE MATERIAL



Silica Glass
 used for high-speed data applications
Plastics
 used for low-speed data / voice applications
Composite Constructions
 used for low-speed and specialized applications
FIBRE TRANSMISSION


Multi-Mode
 graded-index
used for short / medium distance applications
 step-index
early fibre type - no longer used
Single-Mode
 a.k.a Mono-Mode
used for long-distance / very high-speed applications
e.g. cross-country and transatlantic communications
LIGHT TRANSMISSION
MultiMode
Step Index
MultiMode
Graded Index
SingleMode
COMMON FIBRE SIZES
50 µm
62.5 µm
125 µm
125 µm
MultiMode Graded Index
100 µm
140 µm
8 µm
125 µm
SingleMode
TIGHT JACKET
Outer Jacket
Kevlar Fibres
Optical Fibre
(with Primary & Secondary Buffers)
LOOSE TUBE
CONSTRUCTION
Tube
Gel filled loose tube
Optical Fibre
(with Primary Buffer)
FIBRE CABLE
CONSTRUCTION

Tight-Buffer
 fibre has primary and secondary coatings
 outer jacket is drawn tight over fibre
used mainly for “indoor” applications

Loose-Tube
 fibre has primary buffer only
 fibres are loosely-packed in support tube
used mainly for “outdoor” applications
INDUSTRIAL FIBRE
CABLES
NON-METALLIC FIBRE OPTIC DUCT CABLE 2-12 FIBRE
DATA SHEET SST1
OUTER SHEATH
ARAMID YARNS
GEL FILLED TUBE
MULTI MODE
FIBRES
NON-METALLIC FIBRE OPTIC DUCT CABLE 12-24 FIBRE
DATA SHEET SST2
OUTER SHEATH
MULTIMODE
FIBRES
POLYMERIC TUBES
INTERSTICES
FILLERS
INDUSTRIAL FIBRE CABLES
NON-METALLIC FIBRE OPTIC EXTERNAL CABLE 2 - 24 FIBRES
DATA SHEET SST5
OUTER SHEATH
GEL FILLED TUBES
INTERSTICES
MULTIMODE
FIBRES
INNER SHEATH
INDOOR/OUTDOOR INDUSTRIAL CABLE 2-12 FIBRE
DATA SHEET SST6
SHEATH
ARMOUR
MULTI MODE
FIBRES
BEDDING
ARAMID YARNS
INDUSTRIAL FIBRE CABLES
FIRE SURVIVAL FIBRE OPTIC CABLE
DATA SHEET SST7
OUTER SHEATH
BRAID
MICA TAPED LOOSE TUBES
STRENGTH MEMBER
INNER SHEATH
INDUSTRIAL FIBRE
CABLES
ARMOURED FIBRE OPTIC CABLE 2-24 FIBRE
DATA SHEET SST3
GEL FILLED TUBES
OUTER SHEATH
INNER SHEATH
MULTIMODE
FIBRES
ARMOUR
LEAD SHEATHED AND ARMOURED FIBRE OPTIC CABLE
2-24 FIBRE
DATA SHEET SST4
OUTER SHEATH
LEAD SHEATH
MULTIMODE
FIBRES
GEL FILLED TUBES
ARMOUR