Optics

Question 1

Optical wave guide or “light pipe”

Answer 1

Optical fiber

Question 2

An optical source is usually a/an

Answer 2

LED or laser

Question 3

Typical optical detector

Answer 3

Photodiode.

Question 4

Greek letter used to represent wavelength

Answer 4

Lambda

Question 5

Speed of light in a vacuum

Answer 5

C, ~300million meters per second
299,792 kilometers per second.
186,282 miles per second

Question 6

Visible spectrum

Answer 6

400Thz-790Thz

750nm-380nm

Question 7

1Ghz in wavelength

Answer 7

300cm

Question 8

54 MHz in wave length

Answer 8

5.6 m

Question 9

1550 nm in frequency

Answer 9

193.5 Thz

Question 10

1310 nm to frequency

Answer 10

229 Thz

Question 11

1000nm in frequency

Answer 11

300 Thz

Question 12

750 nm in frequency

Answer 12

400 Thz.

Also red light

Question 13

3 Phz in wavelength

Answer 13

10 um

Question 14

455 nm to frequency

Answer 14

659 Thz

Also violet light

Question 15

480 nm to frequency

Answer 15

625 Thz

Also blue light

Question 16

550 nm to frequency

Answer 16

545 Thz

Also green light

Question 17

750 nm to frequency

Answer 17

400 Thz

Question 18

Optical fiber index of refraction

Answer 18

1.47

Question 19

In telecom fiber both the core and cladding is made of

Answer 19

Plastic, glass or silica

Question 20

Protective cover is made of

Answer 20

One or more layers of polymer or other protective substances

Question 21

At the output of the fiber the varying path delays result in a

Answer 21

Smearing of the output signal as a function of time.

Question 22

Smearing of the output signal as a function of time. AKA

Answer 22

Modal dispersion

Question 23

As the diameter of the core of the fiber decreases the number of paths for light

Answer 23

Also decreases.

Question 24

Typical multi mode fiber core size

Answer 24

50-62.5 um

Question 25

Typical single mode fiber core diameter

Answer 25

9 um

Question 26

Typical cladding size for both single and multi mode fibers

Answer 26

125 um

Question 27

Fiber bent to sharply results in

Answer 27

Macrobend

Question 28

Tool to use finding macro bends

Answer 28

Visual fault locator

Question 29

Bend radius for fiber

Answer 29

5-10 times the outer diameter unloaded 15 times the outer diameter loaded 1 inch or 3cm for single mode fiber

Question 30

Causes high loss by allowing light to escape into the cladding

Answer 30

Macrobend

Question 31

Tiny kinks or nicks in fiber during manufacturing or by mishandling

Answer 31

Microbends

Question 32

Components of an optical fiber cable.

Answer 32

``` Optical fiber Buffer tube Strength member Water blocking elements Armor Jacket ```

Question 33

Contains multiple bundles of fibers.that are loosely grouped in a hollow buffer tube that surrounds a central member

Answer 33

Central loose tube

Question 34

Has groups of fibers contained in buffer tubes to facilitate fiber identification and fiber splicing

Answer 34

Stranded loose tube.

Question 35

Typical fiber bundle contains how many fibers.

Answer 35

12 fibers

Question 36

Has multiple fibers arranged in a flat row

Answer 36

Ribbon fiber or stacked ribbon fiber

Question 37

Directly codes digital 1s and 0s as pulses of light

Answer 37

Baseband digital modulation

Question 38

Varies the intensity of light in direct proportion to the analog signal that is applied

Answer 38

Analog intensity modulation

Question 39

Is robust and can be sent long distances over optical fibers

Answer 39

Baseband digital modulation

Question 40

Does not require linear optical sources or optical detectors

Answer 40

Baseband digital modulation

Question 41

BDM requires optical sources to be turned up and down how offten

Answer 41

Millions or billions of times per second

Question 42

A seniconductor device that converts light into an electrical current

Answer 42

Photodiode

Question 43

Highly linear optical sources and detectors are required for high quality

Answer 43

Analog intensity modulation

Question 44

A 1 dB change in optical loss will result in what for the electrical output

Answer 44

2 dB change

Question 45

Analog intensity modulation can use this as an input and will produce this as an output

Answer 45

RF signal

Question 46

Constructed using special fibers that have been doped(infused with) special impurities

Answer 46

Fiber amplifier

Question 47

Used where high optical power is required at the input of the optical fiber

Answer 47

EDFA

Question 48

Used where links of 75 mi are possible using a wavelength of 1550 nm

Answer 48

EDFA

Question 49

EDFA’s produce an optical power in the range of

Answer 49

+26 dBm Almost half a watt Can cause severe eye damage and burn connectors if not handled properly

Question 50

Popular because of spetral purity, linearity and excellent power output levels

Answer 50

DFB Distributed feed back Can produce +11 dBm

Question 51

Has low output and high dispersion

Answer 51

Fabre-Perot

Question 52

An optical technology allowing multiple optical signals onto a single fiber by using different wavelengths

Answer 52

Wave division multiplexing

Question 53

Architecture that directly connects the headend to a customer premise location

Answer 53

FTTP

Question 54

Conventional HFC networks can also be called

Answer 54

Fiber to the node

Question 55

Removes all amplifiers between the optical node and customer premise

Answer 55

Fiber deep.

Question 56

ODN

Answer 56

Optical distribution network

Question 57

Describes networks in which the fiber extends to within several hundred miles of the customers home or not all the way to customers home

Answer 57

FTTP

Question 58

This is a passive optical splitter

Answer 58

Multiplexing point

Question 59

By reducing the amount of hardline cable we limit exposure to

Answer 59

Ingress and egress

Question 60

Mid split frequency range up and down

Answer 60

5-88 up 108- 1002 down All MHz

Question 61

Take in fiber from headend or hub and distribute it to within 1000’ of the customer home

Answer 61

Multiplexing point

Question 62

R-ONU acts a an interface between these two things

Answer 62

ODN and the subscriber coaxial wiring.

Question 63

Ethernet standard for EPON

Answer 63

802.3ah

Question 64

A router with Ethernet interfaces on one side and coax RF interfaces on the other side

Answer 64

CMTS

Question 65

GPON ODN interfaces with

Answer 65

ONT | Optical network terminal

Question 66

EPON ODN interfaces with

Answer 66

ONU | Optical network unit

Question 67

Use this to examine optical fibers

Answer 67

Video fiber scope

Question 68

When cutting or splicing you should work above a

Answer 68

Tacky mat

Question 69

Fiber working table should be

Answer 69

A flat smooth surface Chemical resistant Dark preferably black

Question 70

Floor of the work area for fiber should be

Answer 70

Smooth material such as a coated or polished concrete | Made of a non patterned flooring material

Question 71

What should you use to pick up fiber remnants

Answer 71

Teflon tipped tweezers

Question 72

Damage to eye from amplified light

Answer 72

Retinal burns or | Cataracts

Question 73

Affected tissue shows burn characteristics and damage due to

Answer 73

Denaturation of protein

Question 74

Used to detect the output of a fiber optic line

Answer 74

Infrared detection card