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BCS


Unit - 2


Light Wave Systems

Q1) Explain the system architecture of broad band system.

 

Q2) Write a note on point to point links.

 

Q3) Write a note on the system requirements.

 

Q4) A transmitter has an out power of 0.1 mW. It is used with a fiber having NA = 0.25 attenuation of 6db/km and length 0.5 km .The link contains two connectors of 2db average loss. The receiver has a minimum acceptable power (sensitivity) of 35dBm. The designer has allowed a 4db margin. Calculate the link power budget.

 

Q5) For a multi mode fiber link following parameters are recorded:

  • LED with drive circuit has rise time of 15ns
  • LED spectral width = 40nm
  • Material dispersion related to rise time degradation = 21ns
  • Receiver bandwidth = 25MHz
  • Modal dispersion rise time = 3.9nsec

Calculate system rise time.

 

Q6) Explain optical power budget.

 

Q7) Explain rise time budget.

 

Q8) Explain receiver rise time.

 

Q9) Write a short note on Long Haul systems.

 

Q10) A fiber link has the following data :

Component

Bandwidth

Rise time(tr)

Transmitter

200 Mhz

1.75 nsec

LED(850nm)

100 Mhz

3.50 nsec

Fiber cable

90 MHz

3.89 nsec

PIN detector

350 MHz

1.00 nsec

Receiver

180 MHz

1.94 nsec

 

Compute system rise time and Bandwidth