Deck 7: Optical Fiber Communication and Fabrication

Question 1

Modified Chemical Vapor Deposition (MCVD) process is also called as an inside vapor phase oxidation (IVPD) technique.

Answer 1

True

Question 2

Multimode step index fiber has

A)large core diameter & large numerical aperture
B)large core diameter and small numerical aperture
C)small core diameter and large numerical aperture
D)small core diameter & small numerical aperture

Answer 2

large core diameter & large numerical aperture

Question 3

. A typically structured glass multimode step index fiber shows as variation of attenuation in range of

A)1.2 to 90 db km^?1at wavelength 0.69?m
B)3.2 to 30 db km^?1at wavelength 0.59?m
C)2.6 to 50 db km^?1at wavelength 0.85?m
D)1.6 to 60 db km^?1at wavelength 0.90?m

Answer 3

2.6 to 50 db km^?1at wavelength 0.85?m

Question 4

A multimode step index fiber has a large core diameter of range

A)100 to 300 ?m
B)100 to 300 nm
C)200 to 500 ?m
D)200 to 500 nm

Question 5

Multimode step index fibers have a bandwidth of

A)2 to 30 mhz km
B)6 to 50 mhz km
C)10 to 40 mhz km
D)8 to 40 mhz km

Question 6

Multimode graded index fibers are manufactured from materials with

A)lower purity
B)higher purity than multimode step index fibers.
C)no impurity
D)impurity as same as multimode step index fibers.

Question 7

The performance characteristics of multimode graded index fibers are

A)better than multimode step index fibers.
B)same as multimode step index fibers.
C)lesser than multimode step index fibers
D)negligible

Question 8

Multimode graded index fibers have overall buffer jackets same as multimode step index fibers but have core diameters

A)larger than multimode step index fibers.
B)smaller than multimode step index fibers.
C)same as that of multimode step index fibers.
D)smaller than single mode step index fibers.

Question 9

Multimode graded index fibers with wavelength of 0.85?m have numerical aperture of 0.29 have core/cladding diameter of

A)62.5 ?m/125 ?m
B)100?m/140 ?m
C)85 ?m/ 125 ?m
D)50 ?m/ 125?m

Question 10

Multimode graded index fibers use incoherent source only.

Question 11

In single mode fibers, the most beneficial index profile is

A)step index
B)graded index
C)step and graded index
D)coaxial cable

Question 12

The fibers mostly not used nowadays for optical fiber communication system are

A)single mode fibers
B)multimode step fibers
C)coaxial cables
D)multimode graded index fibers

Question 13

Single mode fibers allow single mode propagation; the cladding diameter must be at least

A)twice the core diameter
B)thrice the core diameter
C)five times the core diameter
D)ten times the core diameter

Question 14

A fiber which is referred as non-dispersive shifted fiber is

A)coaxial cables
B)standard single mode fibers
C)standard multimode fibers
D)non zero dispersion shifted fibers

Question 15

Standard single mode fibers (SSMF) are utilized mainly for operation in

A)c-band
B)l-band
C)o-band
D)c-band and l-band

Question 16

Fiber mostly suited in single-wavelength transmission in O-band is

A)low-water-peak non dispersion-shifted fibers
B)standard single mode fibers
C)low minimized fibers
D)non-zero-dispersion-shifted fibers

Question 17

When optical fibers are to be installed in a working environment, the most important parameter to be considered is

A)transmission property of the fiber
B)mechanical property of the fiber
C)core cladding ratio of the fiber
D)numerical aperture of the fiber

Question 18

It is not important to cover these optical fibers required for transmission.

Question 19

Optical fibers for communication use are mostly fabricated from

A)plastic
B)silica or multicomponent glass
C)ceramics
D)copper

Question 20

An Si-O bond with a Young's modulus of 9*10¹⁰Nm^?1 have an elliptical crack of depth 7nm. The surface energy is 2.29 J. Estimate fracture stress for silica fiber.

A)4.32*10⁹nm^?1
B)6.32*10⁹nm^?1
C)5.2*10⁹nm^?1
D)3*10⁹nm^?1

Question 21

Calculate percentage strain at break for a Si-O bond with a fracture strength of 3.52*10¹⁰Nm^?1 and Young's modulus of 9 *10⁹nm^?1.

A)3.1 %
B)2.8 %
C)4.5 %
D)3.9 %

Question 22

Stress corrosion must be considered while designing and testing optical fiber cables.

Question 23

Which statistics are used for calculations of strengths of optical fibers?

A)edwin statistics
B)newton statistics
C)wei-bull statistics
D)gamma statistics

Question 24

What does n denotes in the equation given below, if vc is the crack velocity; A is the constant for the fiber material and KI is the strength intensity factor?

A)refractive index
B)stress corrosion susceptibility
C)strain
D)young's modulus

Question 25

Optical fibers for communication use are mostly fabricated from

A)plastic
B)silica or multicomponent glass
C)ceramics
D)copper