- For a step-index multimode fiber,
n1 = 1.5
and D = 0.015, calculate n2, NA, and the maximum acceptance angle. (Answer: 1.477,
0.26, 15o)
- Based on the previous problem,
consider the same step-index fiber immersed in water of refractive index 1.33.
Calculate the maximum acceptance angle.
- The power of a 2-mW laser beam
decreases to 15 mW after the beam traverses through 25 km of a
single-mode optical fiber. Calculate the attenuation of the fiber. (Answer:
0.85 dB/km)
- A 5-mW laser beam passes through
a 26-km fiber of loss 0.2 dB/km. Calculate the power at the output end.
(Answer: 1.5 mW)
- Consider an SIF with n1 = 1.5, a = 40 mm, and D = 0.015, operating at 850 nm with a
spectral width of 50 nm. a) Is this a single-mode fiber or a multimode
fiber? b) Calculate the material dispersion, intermodal dispersion, and total
pulse dispersion. [Answer: (b) 4.2 ns/km, 75 ns/km, 75.1 ns/km]
- Based on the previous problem,
consider a parabolic-index fiber with n1 = 1.5, a = 40 mm, and D = 0.015, operating at 850 nm with a
spectral width of 50 nm. a) Is this a single-mode fiber or a multimode
fiber? b) Calculate the material dispersion, intermodal dispersion, and total
pulse dispersion. [Answer: (b) 4.2 ns/km, 0.6 ns/km, 4.2 ns/km]
- Consider a single-mode fiber with
a = 3 mm operating with a V-number of 2.3. Calculate the spot size of the
fundamental mode. [Answer: 3.4 mm]
- Consider the SIF given in
Problem 5. Calculate the splice loss at a joint between two such identical
fibers with transverse misalignments of 5, 10, and 15 mm. [Answer:
0.36 dB, 0.75 dB, 1.2 dB]
