Fiber Optics: Exam One, Chapters 1-12 Cards Revised, improved format Flashcards
The phenomenon of total internal reflection is caused by?
The phenomenon of total internal reflection is caused by confining a material by surrounding it with another material with lower refractive index.
Ch 1
Abraham van Heel, in order to increase the total internal reflection, covered bare fiber with transparent cladding of ___
In order to increase the total internal reflection, Abraham van Heel covered bare fiber with transparent cladding of lower refractive index.
Ch 1
The high loss of early optical fiber was mainly due to what?
The high loss of early optical fiber was mainly due to impurities.
Ch 1
Robert Maurer, Donald Keck and Peter Schultz of Corning Glass Works, used fused ___ to make the first low loss singlemode optical fiber.
Robert Maurer, Donald Keck and Peter Schultz of Corning Glass Works used fused silica to make the first low loss singlemode optical fiber.
Ch 1
Erbium-doped optical fiber can serve as what?
Erbium-doped optical fiber can serve as an amplifier.
Ch 1
The main advantages of optical fiber are its ability to do these three things:
The main advantages of optical fiber are its ability to do these three things:
transport more information, transport it faster as well as farther. It is also more secure and not subject to EMI (electromagnetic interference).
Ch 2
A fiber optic data link is made up of three elements:
A fiber optic data link is made up of three elements:
- A light source
- The fiber
- The light detector
Ch 2
Plastic optical fibers are what two types of index?
Plastic optical fibers are both large core step-index and large core graded index fibers.
Ch 2
Optical fiber is comprised of three layers:
Optical fiber is comprised of three layers:
- Core
- Cladding
- Buffer coating
Ch 2
What does 62.5 refer to when written 62.5/125?
62.5 refers to fiber diameter when written 62.5/125.
Ch 2
In graded-index optical fiber, the index profile approximates a parabola. The benefit of this is what?
In graded-index optical fiber, the index profile approximates a parabola. The benefit of this is reduced modal dispersion. (increased bandwidth).
Match the following fibers to the application they are best suited for:
Graded-index multimode-
Step-indexed multimode-
Singlemode-
(a) long distance telecommunications
(b) data communications
(c) efficient source power coupling
Match the following fibers to the application they are best suited for:
Graded-index multimode- (b) data communications
Step-indexed multimode- (c) efficient source power coupling
Singlemode- (a) long distance telecommunications
Ch 2
Match the following fibers to the application they are best suited for:
Graded-index multimode-
Step-indexed multimode-
Singlemode-
(a) long distance telecommunications
(b) data communications
(c) efficient source power coupling
Match the following fibers to the application they are best suited for:
Graded-index multimode- (b) data communications
Step-indexed multimode- (c) efficient source power coupling
Singlemode- (a) long distance telecommunications
Ch 2
Optical fiber’s bandwidth, or information transmission capacity, is limited by what two factors?
Optical fiber’s bandwidth, or information transmission capacity, is limited by modal dispersion and chromatic dispersion.
Ch 2
Three areas in which fiber is used:
Three areas in which fiber is used:
- telephony
- CATV
- local area networking
Ch 3
FTTC stands for what?
FTTC stands for fiber to the curb.
Ch 3
FTTH stands for what?
FTTH stands for fiber to the home.
Ch 3
Fiber was made cost-effective for CATV applications by the development of what?
Fiber was made cost-effective for CATV applications by the development of AM analog systems.
Ch 3
Unshielded twisted pair cable was adopted for computer networks for at least three reasons:
Unshielded twisted pair cable was adopted for computer networks because it was already used for telephones, cheaper than coax, easier to install than coax.
Ch 3
In replacing Cat e5 link with fiber, most of the additional cost is from what?
In replacing Cat e5 link with fiber, most of the additional cost is from the electronics.
Ch 3
In an industrial environment, fiber is most often used to do what?
In an industrial environment, fiber is most often used to prevent electromagnetic interference.
Ch 3
Which of the following are necessary in a centralized fiber optic cabling architecture? Repeaters or hubs wall outlets telecom closets NIC cards
Repeaters or hubs, wall outlets and NIC cards are necessary in a centralized fiber optic cabling architecture.
Ch 3
Copper networks can be converted to fiber optics easily using what?
Copper networks can be converted to fiber optics easily using media converters.
Ch 3
Buffered fiber comes in three styles:
Buffered fiber comes in three styles:
loose-tube, tight tube and ribbon.
Ch 4
Loose tube cable is used when?
Loose tube cable is used where high pulling strength is required.
Ch 4
A composite cable contains what?
A composite cable contains copper conductors and optical fibers.
Ch 4
Match the type of cable with the description in the right column:
zipcord cable tightpack cable breakout cable loose-tube cable composite cable hybrid cable
(a) contains single and multimode fibers
(b) two fibers, tight-buffered, mostly used for patch cords
(c) contains copper conductors and optical fibers
(d) distribution cables
(e) a small diameter high-fiber count cable
(f) several simplex units cabled together
Match the type of cable with the description in the right column:
zipcord cable (b) two fibers, tight-buffered, mostly used for patch cords tightpack cable (d) distribution cables breakout cable (f) several simplex units cabled together loose-tube cable (e) a small diameter high-fiber count cable composite cable (c) contains copper conductors and optical fibers hybrid cable (a) contains single and multimode fibers
Ch 4
When pulling fiber, it is best to pull on what part of the cable?
When pulling fiber, it is best to pull on the strength member of the cable.
Ch 5
When being pulled into place, the minimum bending radius of an optical fiber cable should be no less than ___ times the cable diameter.
When being pulled into place, the minimum bending radius of an optical fiber cable should be no less than 20 times the cable diameter.
Ch 5
Cables that contain both multimode and single mode are called what?
Cables that contain both multimode and single mode are called hybrid cables.
Ch 4
No cable should be installed indoors unless it is listed for flame resistance for NEC compliance.
True or False?
True.
No cable should be installed indoors unless it is listed for flame resistance for NEC compliance.
Ch 5
All outdoor cable are specifically designed to prevent what?
All outdoor cable are specifically designed to prevent moisture damage to the fiber.
Ch 5
The design type of cables with very large fiber counts is usually what?
The design type of cables with very large fiber counts is usually ribbon cable.
Ch 4
The advantage of a breakout cable over a distribution cable is what?
The advantage of a breakout cable over a distribution cable is the breakout cable can be installed without additional hardware for protection of the terminations.
Ch 4
Two specifications must be considered when specifying optical cable. They are:
Two specifications must be considered when specifying optical cable. They are installation specifications and environmental specifications.
Ch 5
A nonconductive optical fiber for use in an air-handling plenum would be labeled with which four letters?
A nonconductive optical fiber for use in an air-handling plenum would be labeled OFNP.
Ch 5
Match the following: Minimum recommended installation bend radius- Minimum long-term bend radius- Plenum rated- "Self supported" cable- Armored cable- "Filled and blocked" cable-
(a) resistance to water
(b) OFCP
(c) rodent resistance
(d) no less than 20 times the diameter of the cable
(e) cable designed for long-term use loads
(f) no less than 10 times the diameter of the cable
Minimum recommended installation bend radius- (d) no less than 20 times the diameter of the cable
Minimum long-term bend radius- (f) no less than 10 times the diameter of the cable
Plenum rated- (b) OFCP
“Self supported” cable- (e) cable designed for long-term use loads
Armored cable- (c) rodent resistance
“Filled and blocked” cable- (a) resistance to water
Ch 5