1. How has fiber optics revolutionized the telecommunications industry?
 Hint: Think bandwidth, durability, interference, etc
2. Explain the science behind fiber optics.
 Hint: Think TIR, bending around corners, refractive indices, etc
3. Explain how increasing the refractive index of an optical fiber’s core will affect its numerical aperture and
confinement of light.
4. Describe to causes for attenuation in optical fiber.
 Hint: Absorption and Scattering
5. Define the four types of dispersion and indicate which type of fiber it affects (SMF, MMF)
 Modal, Waveguide, Material, Polarization
6. Explain dispersion and how it affects signals transmitted in fiber.
7. Compare and contrast single mode and multimode fiber.
8. Draw the structure of a multimode fiber and indicating each part. Explain the purpose of each part in your
answer.
 Core, Claddding, Buffer, Jacket
9. What are two factors to consider when coupling light into fiber, explain how they effect this process.
 Hint: Diffraction Limit and Numerical Aperture
10. During the process of coupling light into a fiber, you notice that the fiber is glowing red over a large portion of
fiber and not much light is coming out of the end. What could be the problem and how would you fix it?
11. During the process of coupling light into a fiber, you notice a very bright spot in the middle of your fiber and not
much light is coming out at the end. What could be the problem and how would you fix it?
12. Explain how dispersion shifted fiber is designed.
13. What are two types of light sources used with fiber and what type of applications are most appropriate for
each?
14. Explain how pulse spreading occurs in a fiber.
15. One mobile application for optical fiber is Media Optical System Transport (M.O.S.T.) Explain how optical fiber is
used and what type of fiber is preferred for this application.
16. One mobile application for optical fiber is Fiber Optic Guided Missiles (FOG-M). Explain how optical fiber is used
and what type of fiber is preferred for this application.
17. One mobile application for optical fiber is Byteflight. Explain how optical fiber is used and what type of fiber is
preferred for this application.
Calculation Problems
18. A has a core index, 𝑛0 = 1.495 and a cladding index, 𝑛1 = 1.491. Calculate the numerical aperture of a fiber.
19. Calculate the max diameter for single mode fiber for Problem 18 at a wavelength, 𝜆 = 633 𝑛𝑚.
20. Calculate the cut off wavelength for single mode fiber for Problem 18 with a core diameter, 𝐷 = 100 𝑛𝑚.
21. A fiber has a core index, 𝑛0 = 1.500 and a cladding index, 𝑛1 = 1.494, and a core diameter, 𝐷 = 50 𝜇𝑚.
Calculate the number of modes at 𝜆 = 1.55 𝜇𝑚.
22. A fiber has a core index, 𝑛0 = 1.500 and a cladding index, 𝑛1 = 1.494, and an operating wavelength of 𝜆 =
1.55 𝜇𝑚. Calculate the diameter that would support only 10 modes.
23. Calculate the Acceptance angle for the fiber in Problem 22.
24. Calculate the length of a pulse after travel through 2 km of multimode fiber when the original pulse is 10 ns.
𝑛𝑠
 Material Dispersion, Δt 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙 = 0.2 𝑘𝑚
𝑛𝑠

Waveguide Dispersion, Δt 𝑤𝑎𝑣𝑒𝑔𝑢𝑖𝑑𝑒 = −0.4 𝑘𝑚

Modal Dispersion, Δt 𝑚𝑜𝑑𝑎𝑙 = 6.0 𝑘𝑚
𝑛𝑠
25. A fiber has a power attenuation rate of 0.5 dB per km.
 Calculate the total attenuation after 7 km.

If the input power is 250 mW. What is the output power?