Travelling-wave optoelectronic devices for microwave applications

In this paper, we will discuss the fundamental concepts of ultrafast microwave photonic devices based upon the interaction between propagating microwaves and optical signal beams. Such travelling-wave optoelectronic devices utilizing, for example, microstrip or coplanar transmission lines as electrical waveguides exhibit cut-off frequencies not limited by the usual RC time constant. As a result, a high bandwidth together with improved efficiency and power capabilities are expected. In particular, travelling-wave photodetectors, waveguide and vertical electrooptical modulators, microstrip optical switches and coplanar laser diodes are presented. Preliminary experimental results are also discussed.<>