Fiber Optics 1

Question 1

What is attenuation?

Answer 1

Single loss

Question 2

How long is the grounding electrode for bonding?

Answer 2

At least 20 feet , 250.50D

Question 3

What do you need for fusion splicing?

Answer 3

Cleaver, fiber stripper, fusion splicer

Question 4

What is fiber immune to?

Answer 4

EMI/RFI

Question 5

A single path for fiber ranges from ___ to ___.

Answer 5

8mm to 62.5mm

Question 6

What is fiber constructed of? (cable)

Answer 6

Jacket - covering,
Buffer - color-coded plastic
Cladding - glass
Core - glass path for the signal

Question 7

Name the connector types.

Answer 7

ST, SC, LC, Duplex multimode CC. They are a non-permanent device for interconnection.

Question 8

What is a ferel?

Answer 8

The white tip at the end of the connector.

Question 9

What are the ranges of SM and MM types?

Answer 9

SM: 1310mm - 1550mm
MM: 850mm - 1300mm

Question 10

What is macroband?

Answer 10

Overbending the fiber

Question 11

OSP cables not rated for fire resistance can run how far into the building?

Answer 11

50’

Question 12

Indicate the signal loss for each:
Connector mating
Splice
Cable (both MM and SM)
       - MM @ 850mm
       - MM @ 1300mm
       - SM @ ISP
       - SM @ OSP

Answer 12

Connector mating - 0.75dB
Splice - 0.3dB
Cable (both MM and SM)
       - MM @ 850mm - 3.5dB/km
       - MM @ 1300mm - 1.5dB/km
       - SM @ ISP - 1.0dB/km
       - SM @ OSP - 0.5dB/km

Question 13

Modal dispersion happens in what type of fiber and what is it?

Answer 13

Multimode - modes don’t arrive at other end at the same time.

Question 14

What’s chromatic dispersion?

Answer 14

A result of widening of the signal. The result of the different colors, or wavelengths, in a light beam arriving at their destination at slightly different times.

Question 15

Name three fiber cable constructions.

Answer 15

Tight buffered, loose tube, ribbon

Question 16

What is the differences between OFN and OFC types?

Answer 16

OFN is non-conductive and OFC is conductive.

Question 17

What is the bend radius of under pulling tension / not under tension

Answer 17

20x diamter of the cable / 10x

Question 18

What is the difference between analog vs digital?

Answer 18

Analog: uses the natural waveform. Signal degrades quickly.
Digital: Essentially uses on and off states to represent 1s and 0s.

Question 19

Name two types of splicing.

Answer 19

Fusion - welding

Mechanical - locked manually together

Question 20

Signal Sources:

Answer 20

850, 1300, 1310, 1550mm

Question 21

What can be used to terminate an anaerobic connector?

Answer 21

Polishing film, polishing puck, scribe

Question 22

What are the two classes of signal generators?

Answer 22

LED = cheap, low power. Used in LAN’s with mm fiber

Laser

Question 23

What’s a repeater?

Answer 23

They boost the signal. Used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction.

Question 24

How does fiber work?

Answer 24

The signal bounces of the core/cladding boundary.

Question 25

Name two types of mm fiber index.

Answer 25

graded and step index

Question 26

Single mode almost always uses ___ index.

Answer 26

step

Question 27

Attenuation is attributable to what two things?

Answer 27

Absorption - loss converted to heat

Scattering - signal hitting molecules wrong and redirected

Question 28

Define the following performance problems:
Attenuation
Dispersion
Bandwidth
Scattering

Answer 28

Attenuation: Signal loss along the path
Dispersion: Different modes travel at different speeds
Bandwidth: Operating frequency range
Scattering: Loss due to signal hitting impurities in fiber