Editing Electro-optic modulator (section)

== EOM technologies ==
EOMs can be based on many operating principles and platforms. One can divide the EOMs in two categories – phase and amplitude modulation. In the following some prominent approaches in SiPh are presented.<ref>{{Cite journal |last1=Rahim |first1=Abdul |last2=Hermans |first2=Artur |last3=Wohlfeil |first3=Benjamin |last4=Petousi |first4=Despoina |last5=Kuyken |first5=Bart |last6=Thourhout |first6=Dries Van |last7=Baets |first7=Roel G. |date=April 2021 |title=Taking silicon photonics modulators to a higher performance level: state-of-the-art and a review of new technologies |journal=Advanced Photonics |volume=3 |issue=2 |pages=024003 |doi=10.1117/1.AP.3.2.024003 |bibcode=2021AdPho...3b4003R |issn=2577-5421|doi-access=free |hdl=1854/LU-8728539 |hdl-access=free }}</ref> Operating principles for phase modulation are the plasma dispersion effect, pockels effect, interband transitions, and carrier accumulation/depletion+Franz-Keldysh effect. For the amplitude modulation some operating principles are the Franz-Keldysh effect, quantum confined Stark effect, and electrical gating.

The plasma dispersion effect can be based on carrier injection, depletion, or accumulation. The most established Pockels type modulators are based on the lithium niobate on silicon platform. In recent years, other platforms were introduced, such as BTO on silicon, silicon polymer hybrid, silicon organic hybrids, plasmonics and thin-film lithium niobate. Interband transition rely on 2D materials and the carrier accumulation/depletion+Franz-Keldysh is based on a III-V platform.

The Franz-Keldysh effect is used in electro-absorption modulators which are semiconductor devices. It describes a change in the absorption spectrum due to a shift in the band gap edge when an electric field is present. They are often built on a silicon-germanium platform. Modulators running on the quantum confined stark effect can rely on a III-V platform or on Ge-Si-Ge quantum wells. Electrical gating is built on a 2D material platform.