INTRODUCTION TO FIBRE OPTIC CABLES 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 8, 50, 62.5 125 Cladding Glass Core Glass The slide above shows the construction at the very heart of optical fibre, namely the “core” and the “cladding”. These two elements are both made of glass, in a manufacturing process which creates them as an inseparable unit. The core and cladding layers have slightly different optical properties, which combine to enable to the core to transmit the light pulses produced by the transmitter. The property used in this case is the “refractive index” of the glass, which is a measure of how much it can “bend” light - the same property which makes a straw appear to be bent where it enters a glass of water. As we said earlier, the fibre itself is very small, typically only a few thousandths of an inch in diameter. The most commonly-used fibre actually has a core of 62.5 microns diameter, and a cladding of 125 microns (about 0.005”) diameter. How big is a micron? One micron - or micrometre - is 1,000 of a millimetre, or approximately 0.00004”. By comparison, an average human hair is a huge 0.004” diameter - 100 times as large !

PRIMARY BUFFER Primary Buffer 250 Cladding 125 Core (62.5) As the optical fibre is so small, it needs some measure of protection so that it can be easily handled and installed. To this end, the manufacturer puts a coating called the “Primary Buffer” onto the fibre during the process of drawing the glass from a rod down into a fibre. ALL optical fibre has a Primary Buffer coating, regardless of what type of construction is ultimately used to make the cable. The Primary Buffer is usually a polymer material, and gives some degree of physical protection to the fibre, while making it easier to handle (and easier to see !). The Primary Buffer is always 250 microns (0.25 mm, or approx. 0.010”) in diameter. If the fibre is to be used in a cable construction known as “loose-tube”, this is the only coating applied directly to the fibre, and is normally coloured so that individual fibres in a multi-fibre bundle can be easily identified.

SECONDARY BUFFER Secondary Buffer 900 Primary Buffer 250 Cladding 125 Core (62.5) For fibre which is to be used in a cable type known as “tight-jacketed”, the fibre is given a further protective coating, known as the “Secondary Buffer”. This coating is normally applied by the cable manufacturer, rather than the fibre manufacturer, and is always 900 microns (0.9 mm, or approx. 0.036”) in diameter. The Secondary Buffer is usually a nylon type of material, which gives considerable extra strength and resilience to the fibre. As with Primary Buffer, the Secondary Buffer coating is normally colour-coded when the fibre is to be used in a multi-fibre cable.

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 Although we have so far only mentioned glass as the material for the fibre itself, other materials are sometimes used, such as various types of plastics. Such materials are only used for low-speed applications, as their performance in terms of speed and distance is nowhere near that of glass. They do however have the advantage of being very cheap to produce compared with glass, and are most robust in the “bare” state. Typical applications for plastic fibres include process-control sensors in factories, especially in industries such as petro-chemicals, where the absence of electrical connections means that the risks of hazards such as sparks are reduced to nil. Another increasing use of plastic fibre is for the interconnections between hi-fi units, especially from CD players, which are all-digital in operation.

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 Although a detailed discussion of the transmission through optical fibre is beyond the scope of this course, we do need to mention that there are several different methods used. The most common method uses what is known as “Multi-Mode” transmission, in which rays of light are propagated along the length of the fibre by being “bounced” between the sides of the core. This method is further sub-divided into two variations on the theme, namely “Step-Index”, and “Graded-Index”. The Step-Index method was the first to be employed, but has been superseded by a more sophisticated technique called Graded-Index, in which light takes a more curved path through the core, rather than being bounced between the walls of the core in straight lines. This results in a much-improved quality of signal at the receiving end of the fibre, which in turn has allowed higher-speed signals to be transmitted over greater distances. Step-Index fibre is no longer used in the commercial environment. Applications using the highest data rates, over the longest distances, require even higher signal quality to be maintained over the length of the fibre, and use the technique known as “Single-Mode” (or “MonoMode”) propagation. In this method, Lasers are used as the transmitters instead of LEDs, with the light beam travelling straight down the middle of the core, rather than being bounced between the core walls. As might be expected, the fibre and transceivers needed for Single-Mode operation are considerably more expensive than their Multi-Mode counterparts.

LIGHT TRANSMISSION MultiMode Step Index MultiMode Graded Index The slide above illustrates the three different types of propagation within optical fibres. SingleMode

COMMON FIBRE SIZES 125 µm 50 µm 62.5 µm 140 µm 100 µm 8 µm MultiMode Graded Index SingleMode Unlike copper cables, which need to be produced in a very wide range of conductor sizes, fibre only needs to be made in a relatively small range of size options, and in fact just two of the four variants shown above are commonly used. Fibre sizes are expressed by the diameters of the core and cladding, e.g. 50/125, 100/140, and so on. The most common by far is the type designated “62.5/125”, in which the core is 62.5 microns, and cladding is 125 microns in diameter. Earlier installations used the “50/125” standard, whereas the 100/140 size was used by IBM in the early optical systems. Because of the propagation method used in Single-Mode fibre, the core is a very much smaller diameter than for Multi-Mode. Typically, Single-Mode fibre is designated “8/125”, i.e. with core size of just 8 microns. The cladding is left as 125 microns to provide some degree of stability, and make it possible to use normal termination techniques.

(with Primary & Secondary Buffers) TIGHT JACKET Kevlar Fibres Outer Jacket Optical Fibre (with Primary & Secondary Buffers) The slide above shows the typical construction of a tight-jacketed cable. The secondary-buffered fibre is covered by a layer of “Kevlar” fibres (the same material used to make bullet-proof vests) for added strength, over which an outer jacket of a material such as PVC, PE, or LSF is laid. For more cables needing further mechanical protection against crushing or abrasion, etc. the cable may employ further layers of armouring, similar to those used in copper cables.

LOOSE TUBE CONSTRUCTION Gel filled loose tube Optical Fibre (with Primary Buffer) The general construction of loose-tube fibre is shown above. As can be seen , the fibre is primary-buffered only, with the fibres being loosely contained in a rigid or semi-rigid tube. This tube may have additional embedded wire or yarn elements, which are mainly used for pulling the cable into ductwork, etc. The illustration shows only the inner construction of the central tube element of the cable - the tube itself is further protected by optional moisture-proof tape, and / or metallic armouring, especially where the cable is intended to be buried, or used in exposed situations. For complete moisture-proofing, of underground cables, the tube itself is sometimes filled with a moisture-resistant barrier gel. When used between buildings, loose-tube cable is normally spliced onto tight-jacketed cable in a termination box located within a few metres of the point of entry of the cable into the building.

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 As mentioned earlier, there are two types of fibre cable constructions - “Tight-Jacket”, and “Loose-Tube”. Broadly speaking, tight-jacketed fibres are used for “indoor” applications such as riser and distribution cables within a building, and for patch cords and equipment cables. They are more flexible and easier to handle than loose-tube cables, but are more expensive to produce. Tight-jacketed cable is the only type to which connectors are fitted. Loose-tube cables are generally used for “outdoor” applications, such as links between buildings, or for cable TV distribution. Loose-tube cables are cheaper to produce, but cannot be directly-terminated in connectors, as the fibre only has a primary buffer coating, and is therefore too delicate to withstand the repeated handling stresses of being connected and disconnected. Loose-tube cables are therefore “spliced” - i.e. directly jointed - onto other cables within protected enclosures. The fibres are generally spliced onto “pigtail” cables of tight-jacketed construction, which are then terminated with connectors to allow easy interconnection of equipment.

INDUSTRIAL FIBRE CABLES NON-METALLIC FIBRE OPTIC DUCT CABLE 2-12 FIBRE DATA SHEET SST1 OUTER SHEATH MULTI MODE FIBRES ARAMID YARNS GEL FILLED TUBE NON-METALLIC FIBRE OPTIC DUCT CABLE 12-24 FIBRE DATA SHEET SST2 OUTER SHEATH POLYMERIC TUBES FILLERS MULTIMODE FIBRES SST1 370-482-6PE2-02 2 FIBRE 370-482-6PE2-04 4 FIBRE 370-482-6PE2-08 8 FIBRE 370-482-6PE2-12 12 FIBRE SST5 370-487-6NY2-02 2 FIBRE 370-487-6NY2-04 4 FIBRE 370-487-6NY2-08 8 FIBRE 370-487-6NY2-12 12 FIBRE 370-487-6NY2-16 16 FIBRE 370-487-6NY2-24 24 FIBRE INTERSTICES

INDUSTRIAL FIBRE CABLES NON-METALLIC FIBRE OPTIC EXTERNAL CABLE 2 - 24 FIBRES DATA SHEET SST5 OUTER SHEATH INNER SHEATH GEL FILLED TUBES MULTIMODE FIBRES INTERSTICES INDOOR/OUTDOOR INDUSTRIAL CABLE 2-12 FIBRE DATA SHEET SST6 SST2 370-482-6PE2-16 16 FIBRE 370-482-6PE2-24 24 FIBRE SST6 370-403-6LS2-04 4 FIBRE 370-483-6LS2-08 8 FIBRE 370-483-6LS2-12 12 FIBRE SHEATH ARMOUR MULTI MODE FIBRES BEDDING ARAMID YARNS

INDUSTRIAL FIBRE CABLES FIRE SURVIVAL FIBRE OPTIC CABLE DATA SHEET SST7 OUTER SHEATH BRAID INNER SHEATH MICA TAPED LOOSE TUBES STRENGTH MEMBER SST7 370-203-6LS2-04 4 FIBRE 370-203-6LS2-08 8 FIBRE 370-203-6LS2-12 12 FIBRE

INDUSTRIAL FIBRE CABLES ARMOURED FIBRE OPTIC CABLE 2-24 FIBRE OUTER SHEATH INNER SHEATH ARMOUR GEL FILLED TUBES MULTIMODE FIBRES DATA SHEET SST3 LEAD SHEATHED AND ARMOURED FIBRE OPTIC CABLE 2-24 FIBRE DATA SHEET SST4 OUTER SHEATH LEAD SHEATH ARMOUR MULTIMODE FIBRES GEL FILLED TUBES SST3 370-483-6PE2-04 4 FIBRE 370-483-6PE2-08 8 FIBRE 370-483-6PE2-12 12 FIBRE 370-483-6PE2-16 16 FIBRE 370-483-6PE2-24 24 FIBRE SST4 CURRENTLY NON STOCK ITEM

CCTV SYSTEMS OVER OPTICAL FIBRE INTRODUCTION & TRAINING

What is Closed Circuit Television? CCTV Installations are: Directly Linked Non Broadcast Video Systems VIDEO MONITOR CABLE

VIDEO + DATA + AUDIO TRANSMISSION EQUIPMENT FOR SECURITY AND SURVEILLANCE END USER APPLICATION AREA’S City Center Surveillance Utilities - Water/Gas/Electricity Traffic Surveillance Railways - Station Complexes London Underground Ltd Shopping Complexes Ministry of Defense Airports Public & Business Parks Power Stations

What are the Basic System Components? Camera : Black & White or Colour Lens ( Fixed or variable Focus) Iris ( Manual or Automatic) Power ( DC,AC, Mains.) Transmission Coaxial Cable Twisted Pair Optical Fibre Microwave Point to Point Infra Red Point to Point Monitor : Black & White or Colour Screen Size 9” to 19” Resolution Vertical 625 Lines (PAL) Horizontal 750 type B/W 330 type Colour

OPTICAL FIBRE TRANSMISSION SYSTEM Operating Wavelength 850nm Multimode Fibre 50/125 or 62.5/125 Video Signal (Composite) 1Volt peak to peak Video Only Operation Signal Fibre Video+Data+Audio Operation Dual Fibre

OPTICAL FIBRE TRANSMISSION SYSTEM Bi - Directional Data RS 232 RS 422 RS 485 20mA Current Loop TTL Bi Directional Audio Bandwidth 50Hz-20KHz I/P Z 47Kohm O/P Z <20ohm Signal/Noise 45dB

PRODUCT SELECTION GUIDE Does the system require video only signal transfer ? Does the system require VIDEO+DATA+AUDIO signal transfer ? Does system require VIDEO+DATA VIDEO+AUDIO What are the extra system requirements ? YES Are there more than 3 cameras in the system ? NO SELECT Video Tx-2321 Video Rx-2213 15VDCP. S.-2275 NO YES SELECT Video Tx-2231 Video Rx-2113 &2111 Chassis-2000 15VDCP. S.-2275 SELECT 224X Video Tx+Data Tx/Rx+Audio Tx/Rx 213X Video Rx+Data Tx/Rx+Audio Tx/Rx 2000 19” 10 Module Chassis inc Power supply 2275 15 VDC Power supply Select Data Interface required: insert identifier No at X YES NO SELECT 226X Video Tx+Data Tx/Rx 215X Video Rx+Data Tx/Rx 2000 19” 10 Module Chassis inc Power supply 2275 15 VDC Power supply Select Data Interface required: insert identifier No at X YES NO SELECT 228X Video Tx+Audio Tx/Rx 217X Video Rx+Audio Tx/Rx 2000 19” 10 Module Chassis inc Power supply 2275 15 VDC Power supply Select Data Interface required: insert identifier No at X YES NO

PRODUCT RANGE 2100 Series Rackmount Plugin Modules 2200 Series Standalone Units 2300 Series Mini Modules Video Only Facilities 2321 Video Tx Minimodule 2111 Single Channel Video Rx Rack 2113 3 Channel Video Rx Rack 2211 Single Channel Rx Standalone 2213 3 Channel Rx Standalone Video + Data + Audio Facilities 2130 Video Rx + Data Tx/Rx + Audio Tx/Rx Rack 2240 Video Tx + Data Tx/ Rx + Audio Tx/Rx Standalone Video + Data Facilities 2150 Video Rx + Data Tx/Rx Rack 2260 Video Tx + Data Tx/Rx Standalone Video + Audio Facilities 2170 Video Rx + Audio Tx/Rx Rack 2280 Video Tx + Audio Tx/Rx Standalone

Market by Customer Type nd User’s rely on :- Consultants : Specify The System Requirements. System Integrators : Respond to the Specification with a “Best Solution” based on Price & Performance. e.g.. Thorn Security Chubb Alarms Securicor Security Systems Installers : Serve System Integrators by providing installation services which may include the supply of cable & transmission equipment. e.g.. Drake & Scull Eurotech Services Larkins Security Cerberus Ltd

SYSTEM LAYOUT VIDEO ONLY - Standalone Configuration o o o > AMG coax cable 12v DC Supply VIDEO TX 1V p-p Composite Video optical cable 22XX Standalone Receiver Rx

SYSTEM LAYOUT VIDEO ONLY - Rackmount System o o o 21XX > AMG System 2000 coax cable 12v DC Supply VIDEO TX 1V p-p Composite Video inc power supply Optical Cable Chassis

SYSTEM LAYOUT Video - Audio - Data Camera Site Composite Video 1v p-p PTZ Data Audio Link Video+Data +Audio < > AMG coax cable 12v DC Supply opto OUT opto IN MIC 22XX TX Data + Audio

SYSTEM LAYOUT Video - Audio - Data Composite Video 1v p-p Audio Link o o o O PTZ Data 21XX Video+Data +Audio < > AMG System 2000 Chassis coax cable 12v DC Supply opto OUT opto IN Duplex Patchcord +ve -ve MIC 22XX TX RX Data + Audio inc Power Supply