Simulation of an electro-optic modulator based on the quantum-confined Stark effect in a two-layer InAlGaAs rib waveguide on an InP substrate

An electro-optic Mach - Zehnder modulator based on the quantum-confinement Stark effect in layered multiple-quantum-well InAlGaAs structures on InP substrate is numerically simulated. The novelty of the modulator design is the use of a two-layer rib optical waveguides, which provide technologically efficient (loss of 1.5 dB per element) coupling of the modulator with optical fibre. It is shown that, changing the electrode width and the distance between two waveguides in two Mach - Zehnder interferometer arms, one can match the impedance of the modulator with an external 50-Ω load and the velocities of microwave and optical waves in the modulator. The results of the study can be used in integrated optics, optical communication, and radiophotonics devices.