Question 1) Describe the following terms:
(a) Fiber birefringence
(b) Spot Size
(c) Continement factor.
Question 2) Write down significance, applications of double hetero junction and direct band semiconductors.
Question 3) Write a brief note on LASER structures and their characteristics.
Question 4) Given that the following measurements were taken for an APD, calculate the multiplication factor for the device. Received optical power = 1.35 μW, Corresponding output photocurrent (After Avalanche gain) = 4.9 μA, Quantum efficiency at 1.35 μm = 4O%.
Question 5) Explain shot, thermal noise mechanisms in optical receivers.
Question 6) Write down the causes of optical power loss and nonlinear phase modulation through optical fibers? Provide thorough picture of them.
Question 7) A 1.3 μm long haul light wave system is designed to operate at 1.5 Gb/s. It is capable of coupling 1 mW of average power into the fiber. The 0.5 dB/ km fiber cable loss includes splice losses. The connectors at each end have 1 dB losses. The InGaAs p-i-n receiver has a sensitivity of 250 nW. Make the power budget and compute the repeater spacing.
Question 8) What are system performances issues in the design of WDM lightwave systems? Describe in detail each of them.