Polarization-independent and ultra-high bandwidth electroabsorption modulator in multiquantum-well deep-ridge waveguide technology

Electroabsorption modulators with polarization-independence of transmission (TE/TM sensitivity <0.4 dB at 1550 nm) over a wide wavelength range from 1540-1560 nm have been realized using tensile-strained InGaAs and InGaAsP quantum wells. Both designs show 42-GHz modulation bandwidth with a high bandwidth-to-drive-voltage ratio of >23 GHz/V. Polarization insensitivity of modulator transmission and chirp is demonstrated. Technical realization has been done in ridge waveguide technology with low-pressure MOVPE, reactive ion etching (RIE) for semiconductor etching and polyimide for planarization.