Optical properties of interdiffused quantum well modulators

In this paper, the waveguide type and vertical type electro-absorptive diffused-quantum-well modulators will be reviewed. The contributions of interdiffusion of the quantum wells, which act as the active region of the modulator, to the performance of the modulator in terms of the operating wavelength, optical properties and the modulation strength. For waveguide type optical devices, the polarization independent optical properties including absorption coefficient and optical gain using interdiffusion will be discussed. As a consequence, with appropriate interdiffusion, the operating wavelength can be adjusted while the quality and optical properties of the quantum well can be improved for use of modulation devices.