Question 1

An incandescent lamp is operating at a temperature of 1000K at an operating frequency of 5.2×1014 Hz. Calculate the ratio of stimulated emission rate to spontaneous emission rate.

Accepted Answer

A)  3×10-13
B)  1.47×10-11
C)  2×10-12
D)  1.5×10-13E) B) and C)
F) A) and B)

Question 2

A device which is made of isolators and follows a closed loop path is called as a ____________

Accepted Answer

A)  circulator
B)  gyrator
C)  attenuator
D)  connectorE) B) and C)
F) B) and D)

Question 3

How many implementation methods are available for optical isolators?

Accepted Answer

A)  one
B)  four
C)  two
D)  threeE) A) and B)
F) A) and C) D

Question 4

The lower energy level contains more atoms than upper level under the conditions of ________________

Accepted Answer

A)  isothermal packaging
B)  population inversion
C)  thermal equilibrium
D)  pumpingE) B) and C)
F) None of the above

Question 5

An FBG is developed within a fiber core having a refractive index of 1.30. Find the grating period for it to reflect an optical signal with a wavelength of 1.33?m.

Accepted Answer

A)  0.51 ?m
B)  0.58 ?m
C)  0.61 ?m
D)  0.49 ?mE) C) and D)
F) A) and C)

Question 6

A combination of a FBG and optical isolators can be used to produce non-blocking optical wavelength division add/draw multiplexers.

Accepted Answer

A) True 
 B)False

Question 7

An injection laser has active cavity losses of 25 cm?1and the reflectivity of each laser facet is 30%. Determine the laser gain coefficient for the cavity it has a length of 500?m.

Accepted Answer

A)  46 cm?1
B)  51 cm?1
C)  50 cm?1
D)  49.07 cm?1E) All of the above
F) C) and D)

Question 8

Longitudinal modes contribute only a single spot of light to the laser output.

Accepted Answer

A) True 
 B)False

Question 9

Which process gives the laser its special properties as an optical source?

Accepted Answer

A)  dispersion
B)  stimulated absorption
C)  spontaneous emission
D)  stimulated emissionE) A) and B)
F) C) and D)

Question 10

It is a passive device which allows the flow of optical signal power in only one direction and preventing reflections in the backward direction.

Accepted Answer

A)  fiber slice
B)  optical fiber connector
C)  optical isolator
D)  optical couplerE) A) and B)
F) All of the above

Question 11

How many types of sources of optical light are available?

Accepted Answer

A)  one
B)  two
C)  three
D)  fourE) All of the above
F) B) and D)

Question 12

Calculate the splitting loss if a 30×30 port multimode fiber star coupler has 1 mW of optical power launched into an input port.

Accepted Answer

A)  13 db
B)  15 db
C)  14.77 db
D)  16.02 dbE) A) and D)
F) C) and D)

Question 13

The radiation emission process (emission of a proton at frequency)  can occur in __________ ways.

Accepted Answer

A)  two
B)  three
C)  four
D)  oneE) All of the above
F) A) and C)

Question 14

The frequency of the absorbed or emitted radiation is related to difference in energy E between the higher energy state E2 and the lower energy state E1. State what h stands for in the given equation?

Accepted Answer

A)  gravitation constant
B)  planck's constant
C)  permittivity
D)  attenuation constantE) None of the above
F) A) and C)

Question 15

Considering the values given below, calculate the mode separation in terms of free space wavelength for a laser.

Accepted Answer

A)  1.4×10-11
B)  1.6×10-12
C)  1×10-12
D)  6×10-11E) None of the above
F) C) and D)

Question 16

A ruby laser has a crystal of length 3 cm with a refractive index of 1.60, wavelength 0.43 ?m. Determine the number of longitudinal modes.

Accepted Answer

A)  1×102
B)  3×106
C)  2.9×105
D)  2.2×105E) A) and B)
F) All of the above

Question 17

The commercially available circulators exhibit insertion losses around ________________

Accepted Answer

A)  2 db
B)  0.7 db
C)  0.2 db
D)  1 dbE) A) and D)
F) A) and C)

Question 18

A _____________ coupler comprises a number of cascaded stages, each incorporating three or four-port FBT couplers to obtain a multiport output.

Accepted Answer

A)  star
B)  ladder
C)  wdm
D)  three-portE) A) and B)
F) B) and D)

Question 19

A semiconductor laser crystal of length 5 cm, refractive index 1.8 is used as an optical source. Determine the frequency separation of the modes.

Accepted Answer

A)  2.8 ghz
B)  1.2 ghz
C)  1.6 ghz
D)  2 ghzE) A) and B)
F) None of the above C

Question 20

A device which converts electrical energy in the form of a current into optical energy is called as

Accepted Answer

A)  optical source
B)  optical coupler
C)  optical isolator
D)  circulatorE) A) and B)
F) A) and C) A

Exam 11: Optical Fiber Devices and Components

An incandescent lamp is operating at a temperature of 1000K at an operating frequency of 5.2×1014 Hz. Calculate the ratio of stimulated emission rate to spontaneous emission rate.

Correct AnswerverifiedShow Answer

A device which is made of isolators and follows a closed loop path is called as a ____________

Correct AnswerverifiedShow Answer

How many implementation methods are available for optical isolators?

Correct AnswerverifiedD

The lower energy level contains more atoms than upper level under the conditions of ________________

Correct AnswerverifiedShow Answer

An FBG is developed within a fiber core having a refractive index of 1.30. Find the grating period for it to reflect an optical signal with a wavelength of 1.33?m.

Correct AnswerverifiedShow Answer

A combination of a FBG and optical isolators can be used to produce non-blocking optical wavelength division add/draw multiplexers.

Correct AnswerverifiedShow Answer

An injection laser has active cavity losses of 25 cm?1and the reflectivity of each laser facet is 30%. Determine the laser gain coefficient for the cavity it has a length of 500?m.

Correct AnswerverifiedShow Answer

Longitudinal modes contribute only a single spot of light to the laser output.

Correct AnswerverifiedShow Answer

Which process gives the laser its special properties as an optical source?

Correct AnswerverifiedShow Answer

It is a passive device which allows the flow of optical signal power in only one direction and preventing reflections in the backward direction.

Correct AnswerverifiedShow Answer

How many types of sources of optical light are available?

Correct AnswerverifiedShow Answer

Calculate the splitting loss if a 30×30 port multimode fiber star coupler has 1 mW of optical power launched into an input port.

Correct AnswerverifiedShow Answer

The radiation emission process (emission of a proton at frequency) can occur in __________ ways.

Correct AnswerverifiedShow Answer

The frequency of the absorbed or emitted radiation is related to difference in energy E between the higher energy state E2 and the lower energy state E1. State what h stands for in the given equation?

Correct AnswerverifiedShow Answer

Considering the values given below, calculate the mode separation in terms of free space wavelength for a laser.

Correct AnswerverifiedShow Answer

A ruby laser has a crystal of length 3 cm with a refractive index of 1.60, wavelength 0.43 ?m. Determine the number of longitudinal modes.

Correct AnswerverifiedShow Answer

The commercially available circulators exhibit insertion losses around ________________

Correct AnswerverifiedShow Answer

A _____________ coupler comprises a number of cascaded stages, each incorporating three or four-port FBT couplers to obtain a multiport output.

Correct AnswerverifiedShow Answer

A semiconductor laser crystal of length 5 cm, refractive index 1.8 is used as an optical source. Determine the frequency separation of the modes.

Correct AnswerverifiedC

A device which converts electrical energy in the form of a current into optical energy is called as

Correct AnswerverifiedA

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An injection laser has active cavity losses of 25 cm^?1and the reflectivity of each laser facet is 30%. Determine the laser gain coefficient for the cavity it has a length of 500?m.

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