problem 1) Define the noise figure of an optical amplifier. Describe the difference between optical and electrical signal-to-noise ratio (SNR)?

problem 2)a) Find out the bandwidth of the LED source with a rise time equal to 10 ns.

b) Describe the noise figure of an optical amplifier. Describe the difference between optical and electrical signal-to-noise ratio (SNR).

problem 3) Compute the optical power coupled into the fiber generated by an optic device with a bias current of 20mA and forward voltage of 1.5 V. The device's internal efficiency is 2% and the fiber θ= 20º.

problem 4) Describe the difference between optical TDM and WDM, using diagrams wherever essential.

problem 5)a) prepare down the limitations of FP laser? With help of appropriate diagram describe how a DFB laser overcome the limit ations imposed by FP. prepare down its important advantages.

b) prepare down different fiber non-linearties. Describe how they degrade the performance of an optical communication system or Network. What is the permissible BER in case of ordinary optical communications and WDM networks?

problem 6)a) Describe any one in detail. describe design, operation and features of the EDFA.

b) prepare brief note on optical modulators and their applications. describe the impact of chirping on modulator  performance?

problem 7)a) describe the terms material dispersion and waveguide dispersion. Describe the mechanism of change of pulse shape introduced by group velocity dispersion in fiber communication system? How does the pulse broadening affect the performance of the system?

b) With schematic diagram describe how the unknown core diameter of fiber is measured.