Semiconductor optical waveguide devices modulated by surface acoustic waves

Abstract

This paper reviews the application of coherent acoustic phonons in the form of surface acoustic waves to control the response of semiconductor optical waveguide devices. We lay special emphasis on devices built upon three-dimensional rectangular waveguides, which offer excellent possibilities for integration due to the stronger confinement of the optical fields. We address the spatial distribution of the acoustic fields, as well as the excitation of surface acoustic waves in piezoelectric materials using interdigital transducers. The mechanisms responsible for the interaction between light and the acoustic modes in the optical waveguides, as well as the influence of waveguide parameters in the performance of the devices, are also discussed. Finally, we review the most important advances on the modulation of semiconductor optical waveguide devices built upon three-dimensional waveguides, and explore several exciting future technological possibilities. These include, among others, the generation of slow light in photonic crystal waveguides to enhance the sound-light interaction in the reviewed devices.