Can the normal EDFA amplify the weak signal?

Recently I encounter the problem during my experiment of B-OTDR fiber sensor. Once the length of sensing fiber is too long, the backscattered signal is very weak (about -80dBm by theoretical prediction). It's not reasonable to directly detect weak signal. Then I want to amplify the weak signal with EDFA. Then the problem comes out: if the signal is directly inputted into homemaded or commercial EDFA, the output signal is buried into EDFA ASE and could not be coherently detected even with fiber grating filter.

Now I want to know whether EDFA can amplify the very weak signal? Who can give me some help to solve this problem, or give me new method to amplify the weak signal?

Thank in advance for your help.

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What if you used the EDFA to boost the input signal?

P. Danek

Wooddoor wrote:

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Thanks. But because EDFA has the strong ASE noise pedestal, the amplified weak signal is still buried into the ASE noise. I still have no idea how to solve this problem.

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First off I would calculate what the signal to noise ratio of your

-80dBm signal actually is, just considering shot noise. This will of course depend on your signal bandwidth, but I could imagine that it is not going to be very good.

You need to improve your signal level before this point, as once it is buried in noise you are in trouble.

How about using a high power EDFA to boost you launch signal.

To use in an OTDR configuration you might want to consider a circulator at the launch / receive side to further improve the received signal level.



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good morning sir,

Iam A.Rajendrababu doing Mtech in IITM,INDIA. please send me some information and links about "Transient Gain Control EDFA ".

I am planing to do project on this so it is very urgent for me.

Thanking you, sir.

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sir , Iam Rajendra babu.A doing Mtech in IITM,INDIA. i want some documentation information and links about "Transient Gain Control EDFA ". I am planing to do project on this. so it is very urgent for me. please send it.

THanking you sir.

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