Health and Safety
Fibre optic glass is very sharp and can easily pierce the skin or eye. Once embedded, it is very difficult to remove and can cause permanent damage.
NEVER – pick up cut glass with your fingers always use tweezers to remove glass from clothing or tape to pick up the glass from a surface.
NEVER – bend the exposed fibre
NEVER – look into a tester or fibre being tested – the light beam is infrared, we cannot see it but it will cause damage to the eyes
ALWAYS – treat the glass with care
Why Fibre?
Transmission Benefits
•Higher bandwidth giving faster data transmission
•Smaller attenuation over longer distance
•No electrical interference
Mechanical Benefits
•Smaller and lighter than a copper cable
•More flexible, faster to install
•Resistant to corrosion
Economic Benefits
•Unlimited resources (quartz sand)
•Better price/ performance values over long distances
How Fibre Works
Fibre is basically a waveguide for infrared (IR) light.
Digital signals are encoded into analogue pulses of light giving either an Off (0) state or an On (1) state.
These pulses are then transmitted along the fibre and turned back into a digital signal at the receiver
Types of Fibre
fibre classification
Losses in Fibre
All fibre will attenuate (lose) light along it’s length. Typically a single mode fibre will lose 0.35dB/ Km @ 1310nm.
Each connection, bend, repair and coupler will introduce further losses of between 0.05 and 0.5dB each.
A 3dB loss along a cable will result in the received light being halved in power from the source.
Dispersion – The spreading out of a light pulse as it travels down the fibre
•Modal Dispersion – Multimode only. Each mode enters the fibre at a different angle and reaches the end of the fibre at different times.
•Material Dispersion – Multimode only. Light loss through the refraction on the beam through bends or deflection.
•Wavelength Dispersion – Single Mode only. Caused by some of the light beam entering the cladding and not traveling down the core.
Bending losses – Attenuation caused by modes radiating from excessive macro or micro bends.
Connector loss – light leaking out at a connector caused by
•Dirt on the end of a connector dispersing light
•Damaged joiner/ coupler creating a lateral offset
•Air gap
•Core diameter mismatch – MM and SM cannot be connected together.
Bit rate errors – high dispersion & weak signal cause some bits not to reach the receiving threshold at the receiver.
Splice loss – Resulting light escaping through a poor splice
Absorption and scattering loss – caused by light hitting impurities within the core and turning to heat or being backscattered to the light source.
Types of Connector
Fibre Cleaning
The number 1 failure of a fibre optic system is contamination of the connectors
Dust particles are attracted to the connector via static. Grease from the air or touching other surfaces can also cause contamination. If not removed, this is easily transferred between connectors.
Contamination can stop or scatter the light beam, cause scratch damage to both connected surfaces or produce an air gap between surfaces.
Clean each connector each time before plugging it in.
Dry Clean
Use a ‘One Click’ pen with the tip on to clean the connector, remove the tip to clean the socket.
Alternatively use a lint free cloth to clean the connector and a lint free swab to clean the socket.
Wet Clean
Put a small amount of Isopropyl Alcohol (IPA) onto a lint free cloth or swab to clean the connector or socket.
Always re-clean with a dry cloth/ swab after using the IPA.
Only use an area of lint free cloth once – a used cloth can leave fibres on the connector.
Fibre Testing
OTDR – Optical Time Domain Reflectometer
•Single end test instrument
•Measure length, attenuation, connectors and splice loss of cable
An IR pulse of light is sent down the fibre, when it hits an incident such as a micro bend, coupler, splice or the end of the cable a part of the pulse is reflected back to the OTDR. The incident is shown on the OTDR screen as a sharp drop or spike.
Light Source/ Power meter
•Requires a meter at both ends of the cable
•Measure the power lost in the cable and connections
•Null patch cables before connecting fibre to be tested.
The light source sends a beam with a known power down the cable. The power meter reads the power received at the other end. The loss of the cable is given in dB’s.
Guide to Splicing
Fujikura 90S+ Splice Kit
Fujikura 90S+ Main screen
The touch screen on the font of the splicer should have the above details displayed on power up.
If the splice mode requires changing, press in the Splice Mode box and select Auto.
If the Heater Mode reads 40mm, press the Heater Mode box and select 60mm
Single mode fibre strippers have been pre set to strip the coating, cladding and cladding adhesive and should not be adjusted.
Ensure blades are clear of debris before continuing to strip fibre. Any debris stuck in the blades may cause the fibre to break
•Place Splice Bar Protection Sleeve onto fibre. The splice bar is only required on one side of the splice pair
•Use middle 250um cladding blade of the fibre stripper to remove 25mm of the coloured buffer. Only remove in small increments of about 5mm to stop the fibre snapping.
•Use inner 125um core blade to remove glue residue from cladding. Only make a maximum of 2 passes to clean fibre
•Clean stripped fibre with Isopropyl Alcohol
•Ensure the stripped fibre is free from cladding glue residue and dirt, an unclean fibre will not cleave or will give a poor cleave.
•Open the cleaver by pressing down the lid and pulling the clip forwards
•Open the lid fully to lock the cutting blade in place
•Lift the fibre retaining clip and place stripped fibre into the V grove
•Line up the cladding to be on the 10mm marker and close the retaining clip
•Close cleaver lid and press down to cleave fibre
•Power on the splicer, the fusion block lid will open automatically
•Open the Left hand fibre retention clamp,
•Place the cleaved fibre into the fusion block V groove ensuring the fibre does not pass the arcing probes and close the fibre retention clamp
•Strip and prepare the right hand fibre in the same way as the left hand side. The splice Bar Protection Sleeve can be slid onto either fibre but only one is required per splice.
•Open the right hand retention clamp, this also has a secondary clamp which will need opening.
•Load the fibre into the V grove ensuring it does not cross the arcing probes.
•Once the right hand retention clamp is closed the fusion block door will automatically close
•If the splicer has timed out and shut down, power back on, or if the door does not close press reset on the screen
•Once the Fusion Block is shut the splicer will automatically align and fuse the fibres.
•The fibre block door will then re-open.
•Open the left hand retention clamp
•Keeping the fibre straight but not pulling it, slide the splice bar protection sleeve up to the join
•Supporting the fibre and keeping it straight, open the right hand retention clamp
•Slide the splice bar fully over the join
•Hold the fibre on either side of the join
•Lift out the fibre into the heater and line up the splice bar with the guide above the heater.
•Lower the fibre into the heater, the clamp will automatically engage and the door close
•The heater will time out and once complete the door open. Move to the cooling tray behind the splicer
common error messages
| Error Message | Cause | Solution |
| Too Long Fibre | Fibre placed beyond arc probe centre line | Press Reset and re-position fibre |
| Too Dusty Fibre | Dust or dirt on the fibre surfaceDust or dirt is on the objective lens | Remove and clean fibre with IPAClean Lens with lint free swab |
| ZL/ ZR Motor Overrun | Fibre is set too far back from arcing probes | Press Reset and re-position fibre |
| Large Cleave Angle/ Cleave shape NG | Bad fibre end face | Remove fibre, re-strip, clean and cleave. If problem persists rotate cleaver blade one step |
| High Estimated Loss/ Bubble in fibre | Dust contamination during arcing | Remove fibre, cut join and re-prepare fibre |
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