Voltage-controllable optical-mode transformer integrated with electroabsorption modulator by undercut-wet etching

In this work, a novel and reliable structure of OMT-integrated EAM is proposed and demonstrated to release the burden in the tapered structure. By applying electrical field on thin quantum well (Q.W.) structure, the efficient phase modulation can be achieved through refractive index change in (QW). Thereby, using ion-implantation to electrically isolate OMT and EAM, the voltage-controllable OMT (VCOMT) can be integrated with high-speed EAM, where not only the parasitic capacitance can be reduced to attain high-speed properties, but also the tunable function in the OMT transform efficiency can be expected.