The optical switch for fast cell-switching networks comprises an optical interconnection network (CM) and an electrical control network (CT). In order to fully exploit optical component capabilities and to overcome the constraints imposed by operating speed limits of electronic components, each input (IN1...INk) of the interconnection network (CM) is associated with means (PAC1...PACk) forming aggregates of cells which are to follow a same path through the interconnection network and time-compressing the aggregates, and each output (OU1...OUk) is associated with means (PAD1...PADk) for the time expansion of the aggregates and separation of the aggregate cells.