Hi Jyoti,
Now i would like to share advantage and disadvantage of EDFA:
Characteristics of EDFAs (advantages):
High power transfer efficiency from pump to signal power (> 50%).
Wide spectral band amplification with relative flat gain (>20 dB) – useful for
WDM applications.
Saturation output > 1 mW (10 to 25 dBm).
Gain-time constant long (>100 msec) to overcome patterning effects and intermodulation
distortions ( low noise).
Large dynamic range.
Low noise figure.
Polarization independent.
Suitable for long-haul applications.
Disadvantages of EDFAs:
Relatively large devices (km lengths of fiber) – not easily integrated with other
devices.
ASE – amplified spontaneous emission. There is always some output even with
no signal input due to some excitation of ions in the fiber – spontaneous noise.
Cross-talk effects.
Gain saturation effects.