Lab Demonstration: EDFA Characterization

Hi all. I am Fredy Francis. Welcome to this laboratory session of our course. So as you would have seen in the video, this week is dedicated for optical amplifiers. And which is the most popular optical amplifier it is the E D F A, erbium-doped fiber amplifier. So erbium-doped fiber amplifier came into forefront in the early 1990s and it caused

a real revolution in the capacity of optical fiber or the capacity used in the optical fiber. So as you know, a single wave can be amplified using a S O A, but E D F A has a very big optical bandwidth so that multiple channels can be simultaneously amplified which create, which make W D M, wavelength distributed multiplexing possible.

So here we will see how an optical amplifier that is the E D F A in this case is characterized and we will see, we will do particular analysis on input and signal, signal and pump characteristic. So, as you can see here, this is a setup we are using. But before diving deep, I will give a brief introduction of, just a introduction of how

the E D F A works. As you know, E D F A is a 3 level system. It has got 3 levels and the pump which is at 980 pushes the erbium ions from the ground state to the upper, from which, from where ground relatively decays to the metastable state where it has a higher lifetime of around 10 millisecond and it stays there for 10 millisecond

But then when the signal comes it stimulates the emission causing asymmetric emission at 1550 which is in same phase as the signal system as a signal for the, so this causes the amplification. So this is how the E D F A works, you might have studied in the lectures previous too, in the laboratory.