Chapter 2 - Introduction

Question 1

Define: Decibels (dB)

Answer 1

A ratio of the percentage of signal attenuation.

Question 2

What is a relative measurement?

Answer 2

Decibels (dB)

Question 4

___________, ___, and __________ are expressed as “dB”.

Answer 4

Attenuation, gain, and reflection

Question 5

What is used to define fiber and cable attenuation at specific wavelengths?

Answer 5

“dB/km”

Question 6

0 dBm = ___ mW

Answer 6

1.0

Question 7

___ dBm = 2 mW

Answer 7

+3

Question 8

___ dBm = 0.5 mW

Answer 8

-3

Question 9

What is an absolute, objective measurement?

Answer 9

dBm

Question 10

Power is expressed as?

Answer 10

dBm

Question 11

dBm (input) - dBm (output) = _____

Answer 11

dB or Decibels

Question 12

Kilometers (km) X ______ = Miles

Answer 12

0.62

Question 13

Miles X _____ = Kilometers (km)

Answer 13

1.61

Question 14

1,000,000,000 Quantity = _____ Power

Answer 14

10^(9)

Question 15

What is the prefix for 1,000,000,000?

Answer 15

GIGA

Question 16

What is the symbol for GIGA?

Answer 16

G

Question 17

0.1 = ______ Power

Answer 17

10^(-1)

Question 18

What is the prefix for 0.1?

Answer 18

DECI

Question 19

What is the symbol for DECI?

Answer 19

d

Question 20

0.000001 = _____ Power

Answer 20

10^(-6)

Question 21

What is the prefix for 0.000001?

Answer 21

MICRO

Question 22

What is the symbol for MICRO?

Answer 22

u

Question 23

0.000000001 = _____ Power

Answer 23

10^(-9)

Question 24

What is the prefix for 0.000000001?

Answer 24

NANO

Question 25

What is the symbol for NANO?

Answer 25

n

Question 26

What is a mode?

Answer 26

A discrete light path within the core of the Fiber between the transmitter and the receiver.

Question 27

The number of _______ in a fiber will increase as the wavelength decreases.

Answer 27

modes

Question 28

__________ fibers have a single light path at a single wavelength

Answer 28

Single-mode

Question 29

__________ fibers have multiple light paths.

Answer 29

Multimode

Question 30

What is attenuation?

Answer 30

The loss of light or signal power. It is expressed as dB. dB/km is loss referenced to a kilometer length of optical fiber.

Question 31

What is the abbreviation for dBmW, a decibel (dB) relative to one milliwatt (mW) of power?

Answer 31

dBm

Question 32

What is displayed on the vertical scale?

Answer 32

Attenuation

Question 33

Dispersion

Answer 33

The general name for any of a group of phenomena that cause the pulse of an optical signal to be spread out in time, so that it becomes increasingly difficult to tell one pulse from another.

Question 34

What is it when the horizontal scale distorts the pulse or signal, limiting system bandwidth?

Answer 34

Dispersion

Question 35

What types of dispersion is single-mode systems limited by?

Answer 35

chromatic and polarization mode dispersion

Question 36

What type of dispersion limits bandwidth in multimode systems?

Answer 36

Modal dispersion

Question 37

What is reflection?

Answer 37

Affects the operation of lasers used in transmitters, thereby affecting signal quality.

Question 38

Causes of __________ are connectors, mechanical splices, open fiber ends, and lensed components.

Answer 38

Reflection

Question 39

When a light beam changes direction at an interface between two dissimilar media and returns into the medium from which it originated.

Answer 39

Reflection

Question 40

What is coating?

Answer 40

Protects against abrasion and assures high strength.

Question 41

What is cladding?

Answer 41

Glass or plastic, with a lower index of refraction. Keeps the optical signal with the core.

Question 42

What is core?

Answer 42

The glass or plastic in which light propagates through the fiber. Has a higher index of refraction than the cladding.

Question 43

What is MFD?

Answer 43

Mode Field Diameter

Question 44

The diameter of the spot of light transmitted through a single-mode fiber.

Answer 44

Mode Field Diameter

Question 45

OM2/3/4/5 is what type of multimode?

Answer 45

50/125 Multimode (50 core/125 cladding)

Question 46

OM1 is what type of multimode?

Answer 46

62.5/125 - 62.5 core/125 cladding

Question 47

G.652 & G655 is what type of fiber?

Answer 47

Single mode (8-10 core/125 cladding)

Question 48

When was the first North American commercial fiber optic system installed?

Answer 48

1975

Question 49

What is a mode in an optical fiber?

Answer 49

Discrete light path within the core of the fiber between the transmitter and the receiver.

Question 50

What are the 3 C's of an optical fiber?

Answer 50

Coating, Cladding, & Core

Question 51

What are the three critical factors to be considered when working with a fiber optic network?

Answer 51

Attenuation, Dispersion, & Reflection

Question 52

What does the acronym ITU represent?

Answer 52

International Telecommunication Union

Question 53

What are the three components of an optical transmission system?

Answer 53

Transmitter, Receiver, & Physical plant

Question 54

What are the two most commonly used sizes of multimode cores?

Answer 54

50 & 62.5

Question 55

What unit of measurement is used to measure and express wavelengths?

Answer 55

Nanometer (nm)

Question 56

What unit of measurement is used to denote the size of a fiber's core, cladding, and coatings?

Answer 56

Micron (um)

Question 57

What is the outside diameters of single-mode and multimode claddings?

Answer 57

125