Question 1

Injection laser have a high threshold current density of

Accepted Answer

A) 104acm?2and more 
B) 102acm?2 
C) 10-2acm?2 
D) 10-3acm?2 
A) 104acm?2and more 
B) 102acm?2 
C) 10-2acm?2 
D) 10-3acm?2 A

Question 2

Some refractive index variation is introduced into lateral structure of laser.

Accepted Answer

A) True 
 B)False  True

Question 3

Single longitudinal mode operation is obtained by

Accepted Answer

A) eliminating all transverse mode 
B) eliminating all longitudinal modes 
C) increasing the length of cavity 
D) reducing the length of cavity 
A) eliminating all transverse mode 
B) eliminating all longitudinal modes 
C) increasing the length of cavity 
D) reducing the length of cavity D

Question 4

A double-channel planar buried hetero-structure (DCP BH) has a planar active region, the confinement material is

Accepted Answer

A) alga as 
B) ingaasp 
C) gaas 
D) sio2 
A) alga as 
B) ingaasp 
C) gaas 
D) sio2

Question 5

In a DH laser, the sides of cavity are formed by _______________

Accepted Answer

A) cutting the edges of device 
B) roughening the edges of device 
C) softening the edges of device 
D) covering the sides with ceramics 
A) cutting the edges of device 
B) roughening the edges of device 
C) softening the edges of device 
D) covering the sides with ceramics

Question 6

In Buried hetero-junction (BH) lasers, the optical field is confined within

Accepted Answer

A) transverse direction. 
B) lateral direction. 
C) outside the strip. 
D) both transverse and lateral direction. 
A) transverse direction. 
B) lateral direction. 
C) outside the strip. 
D) both transverse and lateral direction.

Question 7

The total efficiency of an injection laser with GaAs active region is 12%. The applied voltage is 3.6 V and band gap energy for GaAs is 2.34 eV. Determine external power efficiency.

Accepted Answer

A) 7.8 % 
B) 10 % 
C) 12 % 
D) 6 % 
A) 7.8 % 
B) 10 % 
C) 12 % 
D) 6 %

Question 8

The spectral width of emission from the single mode device is

Accepted Answer

A) smaller than broadened transition line-width 
B) larger than broadened transition line-width 
C) equal the broadened transition line-width 
D) cannot be determined 
A) smaller than broadened transition line-width 
B) larger than broadened transition line-width 
C) equal the broadened transition line-width 
D) cannot be determined

Question 9

Laser modes are generally separated by few

Accepted Answer

A) tenths of micrometer 
B) tenths of nanometer 
C) tenths of pico-meter 
D) tenths of millimeter 
A) tenths of micrometer 
B) tenths of nanometer 
C) tenths of pico-meter 
D) tenths of millimeter

Question 10

Stimulated emission by recombination of injected carriers is encouraged in

Accepted Answer

A) semiconductor injection laser 
B) gas laser 
C) chemist laser 
D) dye laser 
A) semiconductor injection laser 
B) gas laser 
C) chemist laser 
D) dye laser

Question 11

The external power efficiency of an injection laser with a GaAs is 13% having band gap energy of 1.64 eV. Determine external power efficiency

Accepted Answer

A) 0.198 
B) 0.283 
C) 0.366 
D) 0.467 
A) 0.198 
B) 0.283 
C) 0.366 
D) 0.467

Question 12

A particular laser structure is designed so that the active region extends the edges of devices.

Accepted Answer

A) True 
 B)False

Question 13

A homo-junction is an interface between two adjoining single-crystal semiconductors with different band-gap energies.

Accepted Answer

A) True 
 B)False

Question 14

?T Is known as slope quantum efficiency. State true or false

Accepted Answer

A) True 
 B)False

Question 15

Buried hetero-junction (BH) device is a type of _____________ laser where the active volume is buried in a material of wider band-gap and lower refractive index.

Accepted Answer

A) gas lasers. 
B) gain guided lasers. 
C) weak index guiding lasers. 
D) strong index guiding lasers. 
A) gas lasers. 
B) gain guided lasers. 
C) weak index guiding lasers. 
D) strong index guiding lasers.

Question 16

A GaAs injection laser with an optical cavity has refractive index of 3.6. Calculate the reflectivity for normal incidence of the plane wave on the GaAs-air interface.

Accepted Answer

A) 0.61 
B) 0.12 
C) 0.32 
D) 0.48 
A) 0.61 
B) 0.12 
C) 0.32 
D) 0.48

Question 17

Quantum well lasers are also known as

Accepted Answer

A) bh lasers. 
B) dh lasers. 
C) chemical lasers. 
D) gain-guided lasers. 
A) bh lasers. 
B) dh lasers. 
C) chemical lasers. 
D) gain-guided lasers.

Question 18

In semiconductor injection laser, narrow line bandwidth is of the order

Accepted Answer

A) 1 nm or less 
B) 4 nm 
C) 5 nm 
D) 3 nm 
A) 1 nm or less 
B) 4 nm 
C) 5 nm 
D) 3 nm

Question 19

A correct DH structure will restrict the vertical width of waveguide region

Accepted Answer

A) 0.5?m. 
B) 0.69 ?m 
C) 0.65 ?m 
D) less than 0.4 ?m 
A) 0.5?m. 
B) 0.69 ?m 
C) 0.65 ?m 
D) less than 0.4 ?m

Question 20

Quantum well lasers are providing high inherent advantage over

Accepted Answer

A) chemical lasers. 
B) gas lasers. 
C) conventional dh devices. 
D) bh device. 
A) chemical lasers. 
B) gas lasers. 
C) conventional dh devices. 
D) bh device.

Injection laser have a high threshold current density of

Some refractive index variation is introduced into lateral structure of laser.

Single longitudinal mode operation is obtained by

A double-channel planar buried hetero-structure (DCP BH) has a planar active region, the confinement material is

In a DH laser, the sides of cavity are formed by _______________

In Buried hetero-junction (BH) lasers, the optical field is confined within

The total efficiency of an injection laser with GaAs active region is 12%. The applied voltage is 3.6 V and band gap energy for GaAs is 2.34 eV. Determine external power efficiency.

The spectral width of emission from the single mode device is

Laser modes are generally separated by few

Stimulated emission by recombination of injected carriers is encouraged in

The external power efficiency of an injection laser with a GaAs is 13% having band gap energy of 1.64 eV. Determine external power efficiency

A particular laser structure is designed so that the active region extends the edges of devices.

A homo-junction is an interface between two adjoining single-crystal semiconductors with different band-gap energies.

?T Is known as slope quantum efficiency. State true or false

Buried hetero-junction (BH) device is a type of _____________ laser where the active volume is buried in a material of wider band-gap and lower refractive index.

A GaAs injection laser with an optical cavity has refractive index of 3.6. Calculate the reflectivity for normal incidence of the plane wave on the GaAs-air interface.

Quantum well lasers are also known as

In semiconductor injection laser, narrow line bandwidth is of the order

A correct DH structure will restrict the vertical width of waveguide region

Quantum well lasers are providing high inherent advantage over

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Fiber Optics: Dispersion, Absorption, and Losses

Optical Fiber Communication: Scattering, Polarization, and Dispersion

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Various Aspects of Optical Fiber Design and Performance

Fiber Optic Coupling and Losses

Fiber Splicing Techniques and Requirements

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Key Concepts in Laser and Optical Fiber Communication Technology

Laser Technology and Devices

Led Efficiency and Power Generation in Optical Communication

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Exam 13: Semiconductor Laser Technologies: Refractive Index, Junctions, Efficiency, and Structures

Injection laser have a high threshold current density of

Some refractive index variation is introduced into lateral structure of laser.

Single longitudinal mode operation is obtained by

A double-channel planar buried hetero-structure (DCP BH) has a planar active region, the confinement material is

In a DH laser, the sides of cavity are formed by _______________

In Buried hetero-junction (BH) lasers, the optical field is confined within

The total efficiency of an injection laser with GaAs active region is 12%. The applied voltage is 3.6 V and band gap energy for GaAs is 2.34 eV. Determine external power efficiency.

The spectral width of emission from the single mode device is

Laser modes are generally separated by few

Stimulated emission by recombination of injected carriers is encouraged in

The external power efficiency of an injection laser with a GaAs is 13% having band gap energy of 1.64 eV. Determine external power efficiency

A particular laser structure is designed so that the active region extends the edges of devices.

A homo-junction is an interface between two adjoining single-crystal semiconductors with different band-gap energies.

?T Is known as slope quantum efficiency. State true or false

Buried hetero-junction (BH) device is a type of _____________ laser where the active volume is buried in a material of wider band-gap and lower refractive index.

A GaAs injection laser with an optical cavity has refractive index of 3.6. Calculate the reflectivity for normal incidence of the plane wave on the GaAs-air interface.

Quantum well lasers are also known as

In semiconductor injection laser, narrow line bandwidth is of the order

A correct DH structure will restrict the vertical width of waveguide region

Quantum well lasers are providing high inherent advantage over

Fiber Optics Communication

Optical Fibers: Refraction, Transmission Losses, and Dispersion

Fiber Optics: Dispersion, Absorption, and Losses

Optical Fiber Communication: Scattering, Polarization, and Dispersion

Fiber Optics and Dispersion

Fiber Optics Fabrication Techniques and Phenomena

Optical Fiber Communication and Fabrication

Various Aspects of Optical Fiber Design and Performance

Fiber Optic Coupling and Losses

Fiber Splicing Techniques and Requirements

Optical Fiber Devices and Components

Yag Laser and Optical Fiber Communications

Semiconductor Laser Devices and Mechanisms

Key Concepts in Laser and Optical Fiber Communication Technology

Laser Technology and Devices

Led Efficiency and Power Generation in Optical Communication

Optical Communication and Led Performance Analysis

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