Question about gravitational waves, E modes

[Frank Einstein]

Hi everybody, I have been reading about gravitational waves, but I don't get how the E modes work; in one place I read that they were created during the inflation time, but in other I read that they come from the recombination.
Does it mean that they were produced almost when the Big Bang happened but I cam only see the ones from the recombination era?

Thanks for reading.

 

[mfb]

Do you mean E modes in the cosmic microwave background? Those are not gravitational waves.