Rapid progress has been made in achieving control in group velocity of optical signals. We review advances of ultraslow and fast light in semiconductors and their applications. We examine key figures of merit.
The ubiquitous role occupied by optical fibres in modern photonic systems has steadily stimulated research to realize slow and fast light devices directly in this close-to-perfect transmission line. This potentially offers the key advantage of a direct and flexible integration in most existing optical systems. The recent progress in the realization of optically-controlled delays in optical fibres, under normal environmental conditions and in the high-transparency spectral region, has paved the way towards real applications based on slow and fast light. This presentation shows the state-of-the-art research in this fascinating field and the possible outcomes in the near future.