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