Efficient Time Domain Modeling of Rib Waveguide RF Modulators

This paper presents an efficient and physically consistent method for modeling lumped electroabsorption (EA) RF modulators. The method extends the original spectral index (SI) waveguide simulation method to the time domain in order to model the time-varying phenomena occurring in the multiple-quantum wells of these modulators. The accuracy of the methodology is first verified on the simpler cases of time-varying homogeneous media and time-varying slab waveguides. The time domain SI method is then used to model pulse generation and chirp phenomena in lumped EA modulators operating at both 10 and 40 GHz producing predictions in good agreement with previously published experimental values