Abstract: An extract-and-insert optical wavelength division multiplexer includes a broadcaster (D1) for applying an incoming multiplex signal to N outputs, a combiner-diffuser (D2) for broadcasting the multiplex to be inserted (MI) on N outputs, a first set of N tunable filters (FIT, . . . , FNT) for selecting the carriers of the signals which are to be used for modulating the carriers of the outgoing multiplex (MS), a second set of N tunable filters (F1E, . . . , FNE) for selecting the carriers which are to constitute the extracted multiplex (MT), N wavelength converter devices (CL1, . . . , CLN) suitable for supplying N carriers of the outgoing multiplex (MS), and N two-input, two-output optical switches (SW1, . . .

Abstract: A tunable optical filter tuning device suitable for use in the receive part of an optical transmission system rejects some of the optical noise superimposed on a wanted optical signal. The device commands displacement of the characteristic of the optical filter along the wavelength axis and includes a tuning detector to detect the time at which this displacement can be stopped. The tuning detector includes an optical power detector receiving a signal from the optical filter and detects any modulation of a signal from the optical power detector. The displacement is stopped when the detector detects modulation of the signal from the optical power detector.