Introduction To Fiber Optics

Question 1

What is fiber optics?

Answer 1

The technology of transmitting light through strands of glass or plastic fibers using modulated light for signal transmission.

Question 2

What are common applications of fiber-optic technology?

Answer 2

Communications, lighting, medicine, optical inspection, and sensor manufacture.

Question 3

Who is the FOA and what do they focus on?

Answer 3

The Fiber Optic Association (FOA) focuses on communications fiber optics.

Question 4

When and where did fiber-optic communications begin?

Answer 4

In the 1970s, in R&D labs like Corning and Bell Labs; first installed commercially in Dorset, England.

Question 5

When was fiber first installed in the U.S.?

Answer 5

1976, in Chicago by AT&T.

Question 6

What major change happened with fiber optics by the mid-1980s?

Answer 6

Introduction of single-mode optical fibers, which increased bandwidth and distance capabilities, replacing copper and satellite links.

Question 7

What did CATV companies use fiber for in the mid-1990s?

Answer 7

To improve network reliability and later offer phone and internet services.

Question 8

Why did the Internet surpass voice in traffic volume by the late 1980s?

Answer 8

Due to the growth of the web and email; fiber handled digital data more efficiently than voice-optimized phone systems.

Question 9

Why did cities adopt fiber optics early?

Answer 9

For smart infrastructure—schools, city agencies, traffic systems, and surveillance.

Question 10

What are LANs and how do they relate to fiber?

Answer 10

Local Area Networks; they started using fiber in the late 1970s for industrial and graphics-intensive applications.

Question 11

What role do utilities play in fiber use?

Answer 11

Utilities run fibers along pipelines and electrical lines for smart grid efficiency.

Question 12

What is the significance of dielectric material in fiber optics?

Answer 12

It enables total internal reflection of light for signal propagation.

Question 13

What are the two main categories of fiber optic design?

Answer 13

Outside Plant (OSP) and Premises fiber optics.

Question 14

What is OSP fiber optics?

Answer 14

Fiber used outside buildings—e.g., telephone networks, CATV, utilities.

Question 15

What are the four OSP cable installation methods?

Answer 15

Underground (in conduit), direct buried, aerial, and submarine.

Question 16

What are submarine cables used for?

Answer 16

International communications; extremely rugged and laid by cable ships.

Question 17

How many fibers can OSP cables contain?

Answer 17

Up to 288 fibers or more.

Question 18

Why are OSP cable designs optimized?

Answer 18

To resist tension, moisture, rodent damage, and extreme weather based on installation type (conduit, buried, aerial, submarine).

Question 19

Why is splicing necessary in long fiber runs?

Answer 19

Because fiber cables are not manufactured longer than 4 to 5 km (2.5–3 miles).

Question 20

What splicing method is commonly used in OSP installations?

Answer 20

Fusion splicing.

Question 21

What are the most common connector types used?

Answer 21

SC (Subscriber Connector) and LC (Lucent Connector) styles.

Question 22

What tests are performed after fiber installation?

Answer 22

Optical Time-Domain Reflectometer (OTDR) and Optical Loss Test Set (OLTS).

Question 23

Who typically performs OSP installations?

Answer 23

Telecommunications companies, but some specialized contractors do CATV, utility, and municipal work.

Question 24

What is premises cabling?

Answer 24

Fiber installed inside buildings or campuses, involving short lengths and fewer fibers.

Question 25

What type of fiber is typically used in premises cabling?

Answer 25

Mostly multimode, though hybrid cables (multimode and single-mode) are becoming common.

Question 26

Is splicing common in premises cabling?

Answer 26

No, splicing is practically unknown in premises applications.

Question 27

What types of jackets are used in premises cabling between buildings?

Answer 27

PE (Polyethylene) for OSP, PVC (Polyvinyl Chloride) for fire resistance inside buildings.

Question 28

What are the typical connector types used in premises cabling?

Answer 28

SC (Subscriber Connector), ST (Straight Tip), and LC (Lucent Connector).

Question 29

What is the purpose of cable route markers?

Answer 29

To mark buried cable locations for safety during digging and maintenance.

Question 30

How far apart should cable markers be placed?

Answer 30

No more than 1,000 feet apart, with marker tape 6–12 inches above the buried cable.

Question 31

What is a common method for terminating fiber in premises cabling?

Answer 31

Installing connectors directly on the fiber ends using adhesive or prepolished splice techniques.

Question 32

How is fiber testing performed during termination?

Answer 32

With a light source and power meter; installers should also use a flashlight-type tracer for continuity checks.

Question 33

How does the role of a premises cable installer differ from an OSP technician?

Answer 33

They typically handle indoor cabling, often installing power and data cables (Category 5 or 6) along with fiber.

Question 34

What investment is needed for premises fiber installation?

Answer 34

A relatively small investment in training, tools, and test equipment.

Question 35

What common tools might premises installers use for testing?

Answer 35

Light source, power meter, and flashlight-type tracer.

Question 36

What components are common in premises fiber-optic connections?

Answer 36

Fiber-optic connectors and closet connector housings.

Question 37

What does a VFL (Visual Fault Locator) do?

Answer 37

It emits a red light to detect fiber breaks or improper terminations.

Question 38

Why is fiber preferred over copper for data transmission?

Answer 38

It supports longer distances, has higher bandwidth, less noise and error, and requires fewer repeaters and less power.

Question 39

What are the advantages of fiber over copper?

Answer 39

Higher bandwidth, lower power needs, less maintenance, electromagnetic immunity, lighter weight.

Question 40

Why was wireless dropped as a long-distance solution?

Answer 40

Because of limited transmission frequencies; fiber offered better reliability and performance.

Question 41

What role does fiber play in local wireless networks?

Answer 41

Fiber acts as the backbone and connects to the international phone system.

Question 42

How has fiber adoption changed over time?

Answer 42

It used to be expensive and expert-only; now it’s widely used with modern training and tools.

Question 43

What are some current limitations of DSL over copper?

Answer 43

Limited bandwidth and unsupported DSL speeds on older copper lines.

Question 44

What are projected future speeds over optical fiber?

Answer 44

10 to 100 Gbps.

Question 45

Why are standards important in fiber optics?

Answer 45

They ensure product compatibility and proper system operation.

Question 46

Are fiber standards legally required?

Answer 46

No, they are voluntary guidelines, not laws.

Question 47

Which groups create fiber-optic standards in the U.S.?

Answer 47

EIA, TIA, and IEEE.

Question 48

Which international organizations govern fiber standards?

Answer 48

ISO and IEC.

Question 49

Where can fiber standards be found online?

Answer 49

On the FOA website (www.thefoa.org) and supplier websites.

Question 50

Is eye damage a major risk in typical fiber installations?

Answer 50

No, typical fiber installations don’t use high-power lasers that pose such risks.

Question 51

Are fiber optics light sources typically high-powered?

Answer 51

No, most are low-power except in DWDM systems used in high-power telecom and CATV.

Question 52

Why is eye safety important when using a fiber-optic microscope?

Answer 52

It can concentrate all the light into the eye, potentially causing damage.

Question 53

What should be used before looking into a fiber?

Answer 53

A power meter to confirm no infrared light is present.

Question 54

What standard safety risks are present during fiber installation?

Answer 54

Heavy equipment, climbing poles, and proximity to power cables.

Question 55

What U.S. safety standards must installers follow?

Answer 55

OSHA (Occupational Safety and Health Administration) standards.

Question 56

What is the real safety concern during splicing and termination?

Answer 56

Sharp glass scraps that can injure skin or eyes.

Question 57

What are four key safety rules when working with fiber?

Answer 57

1. Wear safety glasses. 2. Dispose of scraps properly on a black pad. 3. Do not drop scraps on the floor. 4. Do not eat or drink near the work area.

Question 58

What common cleaning agent used in fiber work is flammable?

Answer 58

Isopropyl alcohol.

Question 59

Why must installers follow MSDS instructions?

Answer 59

Because adhesives and cleaners used in splicing and termination can be hazardous.

Question 60

How tolerant is fiber optics to dirt?

Answer 60

Near zero—dirt causes scratches and signal loss.

Question 61

What is the size of dirt particles relative to fiber cores?

Answer 61

Similar in size to the core of single-mode fiber.

Question 62

What are four best practices to keep fiber connections clean?

Answer 62

1. Work in a clean area away from heating vents. 2. Always use dust caps on connectors and panels. 3. Use fiber-optic cleaners or lint-free pads with isopropyl alcohol. 4. Use metal or ceramic alignment sleeves only for testing to avoid contamination.

Question 63

What happens if alignment sleeves get dirty?

Answer 63

They can scrape material onto ferrules, causing signal attenuation and visible blackening.

Question 64

What is this?

Answer 64

Visual Fault Locator