Optical Connectors

Question 1

State the two functions that optical fibre connectors perform?

Answer 1

Provide a method of attaching fibres to the communications equipment at each end of the link.

And

Provide in-line joints between fibres at patch panels and cross connect facilities allowing flexibility in use and reconfiguration capabilities.

Question 2

What desirable feature should optical fibre connectors include?

Answer 2

• Low loss
• Easy installation
• Repeatability
• Consistency
• Economical

Question 3

From the front to the back, name the parts of a connector?

Answer 3

Ferrule
Body
Back End

Question 4

Optical fibre connectors have two different size ferrules, what are the sizes used?

Answer 4

2. 5mm Diameter.

1. 25mm Diameter

Question 5

What material is most commonly used as ferrules due to the material’s durability

Answer 5

• Ceramic - Zirconia ceramic.

Question 6

Ferrules are manufactured using different profiles known as PC, UPC and APC. What do these abbreviations stand for?

Answer 6

PC (Physical Contact)

UPC (Ultra Physical Contact)

APC (Angled Physical Contact)

Question 7

What are the common methods for attaching optical fibre connectors to cable?

Answer 7

Crimp and Adhesive

Question 8

Which connector types are predominantly used within the military environment?

Answer 8

ST (Straight Tip) Connector

FC/PC (Fibre Connector/Physical Contact) Connector

Question 9

Explain the general termination process of an optical fibre connector?

Answer 9

• Prepare the fibre.
• Attach the connector.
• Cleave the fibre.
• Polish the fibre;
i. Fibre optic lapping film is used to provide a smooth, consistent finish to the tips (ferrules) of the optical fibre connectors which improve the transmission of light and signal particles.
ii. The grades and colours of the polishing paper may vary. Always follow the manufacturers recommendations for the perfect finish.

• Conduct visual inspection of connector.

Question 10

State four typical defects with optical fibre connectors?

Answer 10

Resin Still Present
Chips
Cracks
Scratches
Pitting
Dark Fibre
Concentricity Defects

Question 11

What considerations to optical fibre connectors can mitigate against cross-patching Red and Black networks?

Answer 11

Bundles of 12 fibres are carried in individually colour coded sheaths within an outer reinforced cable sheath.

Where there are 24 cores, then cores 13-24 are identified utilising the same colour code incorporating a black indicator mark on each core.

Termination of the multi-core cable is to be to an internal splice enclosure with subsequent routing of fibre to appropriate patch panels in accordance with the requirements of TIA/EIA Fibre Colour Code.

Question 12

What piece of equipment is used to inspect end-face criteria of an optical fibre connector?

Answer 12

Compact handheld field Fibre microscopes.

Question 13

Prior to inspecting optical fibre connectors, state three precautions that should be considered?

Answer 13

• Always turn off any laser sources
• Always make sure that the cable is disconnected at both ends
• Always wear the appropriate safety glasses when required in your area.
• Always inspect the connectors or adapters before you clean.
• Always inspect and clean the connectors before you make a connection.
• Always use the connector housing to plug or unplug a fibre.
• Always keep a protective cap on unplugged fibre connectors.
• Always store unused protective caps in a resealable container in order to prevent the possibility of the transfer of dust to the fibre.
• Always discard used tissues and swabs properly.