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WorksheetsOPTICAL COMMUNICATION QUIZ - 3
Total questions: 30
Worksheet time: 15mins
A silica optical fiber with a large core diameter has a core refractive index of 1.5 and a Cladding refractive index of 1.47. Determine the acceptance angle in air for the fiber.
(a)
A silica optical fiber with core diameter large enough to be considered by Ray theory has a core refractive index of 1.5 and cladding refractive index of 1.47.Determine numerical aperture.
(a)
calculate the cut off wavelength of a single mode fibre with core radius of 4 m and index difference= 0.003
(a)
The V number of a fiber is 4. then the fiber is
Single mode
Multimode
Range of optical communication
700 nm to 1700 nm
800 nm to 1600 nm
800 nm to 1200 nm
800mm to 1600 mm
Fiber optics system transmit using infrared light, invisible to the human eye.
Say true or false.
True
False
Which is the fundamental mode of propagation in fibers?
LP01
LP11
LP21
LP22
Numerical aperture of a fiber is given by :
(n1^2 - n2^2)^1/2
(n2^2 - n1^2)1/2
(n1^2 - n2^2)
(n1^2 - n2^2)^3/2
What is the energy of blue photon (lambda = 400 nm)?
79.5 × 10 ^ -19 J
4.97 × 10 ^-19 J
1.8 × 10 ^ -19 J
8 × 10 ^ -19 J
For efficient propagation of light through a fiber angle of incident of light rays at the fiber input should be :
Less than critical angle
Less than acceptance angle
Less than Brewster's angle
The ratio of the refractive index difference of the
core and cladding to the refractive index of core of an optical fiber
Fractional Index Change
V-Number
Numerical Aperture
Acceptance Angle
Which of these types of optical fibers is almost impossible to manufacture?
Single mode, step index OFC
MUlti mode, Step index OFC
Single mode, graded index OFC
Multi mode, graded index OFC
Optical fibers are also called
(a)
The condition for propagation of light in optical fibers is
Sinθi<NA
Sinθi>NA
Sinθi=NA
Sinθi=0.5
The schematic represents
Graded index optical fibre
Step index optical fibre
Single mode optical fibre
Dual optical fibre
Which of the following statements best explain the concept of material absorption?
A loss mechanism related to the material composition and fabrication of fiber.
A transmission loss for optical fibers.
Results in attenuation of transmitted light.
Causes of transfer of optical power.
How many mechanisms are there which causes absorption?
1
3
2
4
Absorption losses due to atomic defects mainly include-
Radiation
Missing molecules, oxygen defects in glass
Impurities in fiber material
Interaction with other components of core
The effects of intrinsic absorption can be minimized by-
Ionization
Radiation
Suitable choice of core and cladding components
Melting
Which of the following is not a metallic impurity found in glass in extrinsic absorption?
Fe2+
Fe3+
Cu
Si
Dominant intrinsic loss mechanism in low absorption window between ultraviolet and infrared absorption tails is
Mie scattering
Rayleigh scattering
Stimulated Raman scattering
Stimulated Brillouin scattering
What is dispersion in optical fiber communication?
Compression of light pulses
Broadening of transmitted light pulses along the channel
Overlapping of light pulses on compression
Absorption of light pulses
3dB optical bandwidth is always ___________ the 3dB electrical bandwidth.
Smaller than
Larger than
Negligible than
Equal to
The core of the optical fibre is
opaque and conducting material.
opaque and dielectric material.
transparent and conducting material.
transparent and dielectric material.
The unit of Numerical aperature is
meter
degree
Coulomb per meter
no unit.
If the numerical aperature of an optical fibre is 0.515, then the maximum angle of incidence is __________ degree.
0.008
17.5
31
67
Fiber optics provide data security.
True
False
Which of the following statements best explain the concept of material absorption?
A loss mechanism related to the material composition and fabrication of fiber.
A transmission loss for optical fibers.
Results in attenuation of transmitted light
Causes of transfer of optical power.
