Jodies Random Potluck

Question 1

4 main safety aspects in FO?

Answer 1

Chemicals
Light sources
Glass/sharps
High voltages

Question 2

4 Chemicals uses and risks?

Answer 2

Isopropyl alcohol - cleaning bare fibres
Methylated spirits - surplus grease remover
Paint stripper - pro coating becomes brittle
Resins super glues - termination of fibres with connectors

Question 3

4 main Chemical risk areas?

Answer 3

Absorption
Ingestion f
Fire/explosion
Drowsiness

Question 4

5 precautions when working with chemicals?

Answer 4

COSSH REGS 2002 APPLY
read safety data sheet
Safe area for food and drink 
Wash hands at end
PPE

Question 5

3 types of light sources?

Answer 5

LED
VCSEL
LASER

Question 6

FO Wavelength?

Answer 6

850nm - 1550nm

Question 7

7 laser clarification and power?

Answer 7

1  0 - 0.0004mW
1M 0 - 0.0004mw
2 0 - 1mW
2M 0 -1mW
3R 1-5mW
3B 5-500mW
4 500mW+

Question 8

6 advantages of fibre?

Answer 8

Wide bandwith
Low attenuation 
Security- immunity  to EMI / NO radiation of signal
Nom sparking
cost
Lightweight and size

Question 9

What are the disadvantages of FO?

Answer 9

Cannot carry electrical power

Loss of very large number channels/circuits

Question 10

Windows of operation and modes?

Answer 10

1st window 800 - 900nm : 850nm
2nd window 1260 - 1360nm : 1300/1310nm
3rd window 1530 - 1565nm : 1550nm

Question 11

What is optical communication?

Answer 11

Use of light to pass information

Question 12

What is propagation?

Answer 12

Manner of which an electromagnetic wave t’s it’s energy from one point to another

Question 13

Reflective index of silicone glass?

Answer 13

1.50

Question 14

Snells law?

Answer 14

Links the bending of light with the refractive index change of the materials at that point: known as refraction

Question 15

What 2 things must take place for TIR to take place?

Answer 15

Core must be dencer than cladding

Angle of incidence must be greater than critical angle

Question 16

Define Numerical Aperture? NA

Answer 16

The light collecting ability of the fibre

Question 17

What is the make up of an all glass fibre?

Answer 17

Secondary coating 900um
Primary coating 250um
Glass cladding 125um
Variable glass core MM 62.5 & 50um
SM 9um

Question 18

Variable core diameters?

Answer 18

62.5/125 & 50/125 um MM

9/125 um SM

Question 19

How can we reduce module distortion?

Answer 19

Use a graded index fibre

Question 20

5 joint sealings?

Answer 20

Gaskets
O rings
Clamps and latches
Heat shrink/resin
Sealing tape

Question 21

Basic principle of fusion splicing?

Answer 21

Where 2 prepared fibres are brought together and their ends melted to form a homogeneous joint

Question 22

3 types of bad cleaved?

Answer 22

Angular cleave
Hackle/burr
Chip

Question 23

How do we prevent leaky modes?

Answer 23

To prevent leaky modes Propogation along the fibre we can employ “mode stripping” by inserting a mandrel fitted to the cable

Question 24

What is zero dispersion point?

Answer 24

1310nm

Question 25

What is a connector?

Answer 25

Makes a tempory connection between 2 fibre ends or between optical equipment

Question 26

4 parts of a connector?

Answer 26

Fertile
Body
Boot
Alignment key

Question 27

3 uses for connectors?

Answer 27

Fibre to fibre
Equipment to fibre
Temp connectors

Question 28

5 termination methods?

Answer 28

Crimp and cleave
Pot and polish
Hot melt
cold cure
Mechanical

Question 29

4 come for requirements?

Answer 29

Low insertion loss
Repeatability
Consistency
Economical

Question 30

Name 7 connectors?

Answer 30

St/pc - straight tip physical contact
Fc/pc - face contact physical contact
Sc - subscriber connect
Lc - Lucent connector