I am looking for the transfer function of the electroabsorption modulators (EMLs); however, unfortunately the community of fier-optic communications seems not to be mathematically oriented and a mathematical model seems to have no place for them. 

Can anyone give me a reference that I may find a closed-form formula for the **output electric field** (not power) in terms of the input small-signal electrical waveform (not input power) of an EML?