1) Describe the elements of an optical fiber transmission link with the neat diagram.

2) A multimode step index fiber with the core diameter of 80 µm and a relative index difference of 1.5% is operating at the wavelength of 0.85µm if n1=1.48 find out the normalized frequency for fiber and number of guided modes.

3) describe the evolution of fiber optic communication system.

4) Develop the structures of the step index and the graded index fibers with their typical dimensions.

5) Draw and describe the electric field distribution of lower order guided modes within the symmetrical slab waveguide.

6) Consider the fiber with the 25 μm core radius, a core index n1 = 1.48 and Δ = 0.01.

a) If λ = 1320 nm, find the value of V and how many modes propagate in the fiber?

b) What percent of optical power flows in the cladding?

c) If the core-cladding difference is decreased to Δ = 0.003, how many modes does fiber support and what fraction of optical power flows in cladding?

7) A beat length of 10 cm is observed in the typical single-mode fiber when the light of wavelength 1.0 μm is launched into it. Determine:

a) The difference between the propagation constants for two orthogonally polarized modes, and

b) The modal birefringence.