This paper reports the lecture delivered by Prof. Michal Lipson, from the School of Electrical and Computer Engineering, Cornell University, Ithaca, USA, and is an introduction to the field of silicon photonics, an area of research that has become increasingly important over the past 15 years due to its particularly great potential for replacing electrical by optical data communication in a CMOS-compatible fashion. The basic concepts of waveguide fabrication will be discussed as well as a selection of devices relevant to optical signal transmission such as resonators, electro-optics modulators and isolators. Moreover, other applications of silicon photonic devices e.g. for optofluidics and optomechanics will be presented.