Strange behavior of Electro Absorption Modulator (EAM)

[Ibn Aziz]

Hi every one !

I am using on Electro Absorption (EAM) to produce Optical pulses and i also got required optical pulse (pulse width and time period) after modulation.

But problem is that when i made a transfer function (2-D) of input amplitude Vs output power then i get a straight line in graph. It should not be like that because we are getting pulses at the output of modulator so the curve should show some behavior or ramdomness rather than showing straight line.

Can any one know why opti sys is behaving like that ?? and how can i rectify this problem.

I am attaching the file and also amplitude vs optical output graph.

I wil be very thakful to u for ur this act of kindness.

Plz help

Best Regards
Best Wishes

Attachments:

1. 

   Capture1.jpg
   

[Ibn Aziz]

I am attacting here above scenario file.

And for “Getting transfer” ftn i made a new scenario in which all parametrs and elements are copied from attached scenario but i changed Dc bias amplitd value to 3 as did in sine genrator so that i get required transfer ftn.

Further i sweep it between 3 to -3 for getting graph between input amplitude vs output optical power, rest is same for both cases.

Kindly go through it and tell me hw can i recover from it.

i wil be very thakful to u for ur this act of kindness

Plz help

Best Reagrds
Best wishes.

Attachments:

1. EAM_-Scenario.osd

[Damian Marek]

I don’t understand how your simulation is setup, because the project file you attached is different than what you are describing. You want to plot the output optical power as a function of the input optical power?

[Ibn Aziz]

Thanks Damian Marek for ur kind response !

Sorry for confusion, i make it clear now,

1. The file i have attached above (and again attaching below) is showing modulation of Input sine signal with Optical Carrier through EAM, in result we are getting modulated optical pulses with time period of 7.8125 nsec and pulse width of 1.22 nsec.

At the output, optical pulse power changes from min value to max value when reaches peak. similarly at the input sine signal, amplitude changes from min to max value.

So when i make a 2D graph between “input sine signal amplitud” at x-axis and “output optical power” at y-axis then i got a “straight line” which should not be like that.
Because at the modulator output, optical pulse power changes and at the input sine signal amplitude changes therefor it is not possible to have a straight line in a graph.

SO i want to know y i am getting straight line ?

2. hw can i modify it ?

3. and how can i get a tranfer function of EAM in which i get a random behavior of input sine signal amplitude and output optical power ?

Hope u understand it now….

(Leave my 2nd comment above, in which i asked to use DC bias for another scenario. i wil explained it later)

I wil be very thakful to u for ur ths act of kindness.

best regards
best wishes.

Attachments:

1. EAM_-Scenario1.osd

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