EDFA gain question

[mschnabe]

The dwdm design I'm working with calls for several EDFA's but I dont need the default 23 db gain I only want 10 according to my optical budget. What is the best way to accomplish this?

Thanks in advance

Mark

[bunker]

See if the edfa's have the ability to change the gain otherwise you may need optical attenuators to reduce the gain. It can get messsy at that point.

Why do you need the amps? The distance that long?

[mschnabe]

These are EDFA1's and they have 3 modes: constant-pump current mode, constant-pump power mode and constant-output power mode. What I'm looking for is what mode to be running and how to config them to only get 10db gain out instead of the default 23db gain

thanks

mark

[rtappend_2]

Are these existing EDFA-1's? The EDFA-1 only offers constant gain of 23dB, and this will require attenuators to adjust the input/output levels accordingly to get 10dB gain.

The different modes you mention offer varying levels of control, but typically constant gain mode is used within a DWDM network as it allows you to ensure stability across all your wavelengths to keep them within tolerance under most conditions (eg add/drop of wavelengths).

For example, in constant output power mode, if you suddenly lost half your wavelengths, the remaining wavelengths would be given extra gain to try to maintain the higher output power. The resulting power levels could overdrive the receivers and the service would fail - and vice versa.

What does the rest of the network consist of? ONS15216/ONS15454?

If possible, you might want to consider the ONS15216 EDFA-2 which includes a built-in VOA on the EDFA ingress to control input (and hence output) power. You may need to consider the impact on OSNR depending on where the attenuation is used within your network.

[markschnabel]

Yes they are..Thanks for the reply. Maybe the TAC will read this and then they will know.