Download experiment 1: optical fiber characteristics

EKT 442 Optoelectronics Communication
Name: _________________________________________
Laboratory Module
Date: ___________________
Matrix No.: _________________________________
Exercise 1:
Answer all questions:
1.
Light, in fiber optics vocabulary, means electromagnetic radiation or energy in the wavelength
range including infrared, visible and ultraviolet.
a) True b) False
2.
Dispersion is the technical term for the spreading of light pulses as they travel down an optical
fiber.
a) True b) False
3. Choose the basic types of optical fiber:
a)
b)
c)
d)
e)
f)
g)
h)
Single-mode
X-mode
Microwave-mode
Graded-index mode
Multi-mode
A and C
Band D
A and E
4. Attenuation is a linear relationship between optical output power and input power.
a) True b) False
5. Single-mode fiber has the advantage of greater bandwidth capability. It has the disadvantage of:
a)
b)
c)
d)
e)
Being harder to bend
Smaller mechanical tolerances in connectors and splices
Being difficult to couple light into
Band C
None of the above
6. Numerical aperture of a fiber determines its light-gathering capability.
a) True b) False
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EKT 442 Optoelectronics Communication
Laboratory Module
7. The first operating window for fiber optics was:
1550 nm
660 nm
1300 nm
850 mm
None of the above
a)
b)
c)
d)
e)
8.
Most modern optical fiber is manufactured with which materials?
a)
b)
c)
d)
9.
Ultra-pure materials
Vaporized gases
Preformed silica tubes
All of the above
Silicon is the base material for most of the optical fiber used in communications today.
a)
True b) False
10. High dispersion is a very undesirable characteristic of multimode fiber.
a)
True b) False
11. Operation of optical fiber is based on:
a)
b)
c)
d)
e)
Total internal reflection
Total internal refraction
Snell's law
Einstein's theory of reality
None of the above
12. Chemical composition of a detector suitable for the third fiber optic operating window would
be:
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13. Do you find it hard to identify a person's voice at the other location? If so why?
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EKT 442 Optoelectronics Communication
Laboratory Module
14. Do some sounds or voices transmit better than others? If so, identify them.
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15. Do you notice any difference with audio quality or amplitude (volume) using the green LED
source instead of the red LED source?
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16. What happens to the size of the light pattern on the IR sensor card as it moves further away
from the receptacle?
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