Abstract: A device for the frequency transposition of optical signals receiving data elements liable to be at different wavelengths (.lambda.0, .lambda.1 . . . .lambda.n) and capable of delivering, at output, these data elements at one of the reception wavelengths. The device comprises a circulator (30); at least one optical arm comprising a rejection filter (31) followed by a wavelength converter (32); the circulator comprising a port for the reception of the data packets at the different wavelengths (.lambda.0, .lambda.1 . . . .lambda.n), a port for the transmission of data packets without changing their wavelength and at least one other port for each optical arm, so that each of these ports is connected to a rejection filter (31) to receive the data packets at the different wavelengths and reintroduce the data packets reflected by this filter into the circulator; the converter (32) at output of each rejection filter enabling the conversion into a desired wavelength of the data packets not reflected by the filter.

Abstract: An optical crossconnect includes optical elements (D1 . . . DM) for wavelength demultiplexing of optical signals and elements (MT) for optically processing the demultiplexed signals which give each optical signal a specific wavelength and bring to one of the outputs (S1 . . . SM) the signal with the specific wavelength under the control of a management unit (G). Such an optical crossconnect may find particular application in telecommunication networks.