Abstract: A reconfigurable directional optical system comprises N ports that can be configured individually as inputs or outputs. A system of this kind comprises at least one optical device having unidirectional inputs and outputs the total number of which is equal to or less than N, and an N×N optical switch such that each of the ports can be coupled interchangeably either to one of the inputs or to one of the outputs of the optical device.

Abstract: A method is disclosed of reconfiguring a ring optical network made using a single optical fiber (100). A traffic concentrator (120) and stations (140) are optically connected to the fiber. The concentrator sends a light signal to and receives a light signal from both ends of the fiber using two groups of wavelengths (110, 150) in order to be able to communicate with all the stations. When the network is established, a virtual break (170) is created between two stations. If a real break is detected in the optical fiber, then the virtual break is shifted until it coincides with the real break, thereby enabling traffic to be re-established between the concentrator and the stations. Each station is equipped with a three-state optical switch (400) for changing the direction of the light signals.

Abstract: A device for erasing overhead modulation of an optical signal, wherein said optical signal is injected into an optical device able to modulate the optical signal (for example a semi-conductor optical amplifier driver by a bias control) and for which one an automatic gain control does not need to detect the residual overhead modulation, is characterised in that said bias control means applies to said amplifier a compensation voltage presenting a modulation out of phase with respect to said overhead modulation, and in that modulation index of said compensation voltage is (substantially) proportional to the modulation index of said optical signal.

Abstract: The invention relates to a method in a wavelength-division multiplexed (WDM) network to organize (wavelength) channels between (optical) nodes (M1) of said WDM network, wherein the nodes (M1) each have optical filters (FAD, FDH1, F1, . . . , Fl) for selecting a first set of wavelengths with respect to a set of other wavelengths and wherein, in each case, the wavelengths of one of these sets are forwarded and the other set of wavelengths is dropped, wherein at least one node (M1) has both at least one statically preset optical filter (FAD, FDH1) and at least one optical filter (F1, . . . , Fl) that can be dynamically tuned during operation and in that only respective dynamic optical filters (F1, . . . , Fl) in the affected nodes (M1) have to be tuned in the event of a dynamic reconfiguration of channels, and also to an optical wavelength multiplexed (WDM) network, an optical hub and an optical add/drop multiplexer for the purpose.

Abstract: A device for erasing overhead modulation of an optical signal, wherein said optical signal is injected into an optical device able to modulate the optical signal (for example a semi-conductor optical amplifier driver by a bias control) and for which one an automatic gain control does not need to detect the residual overhead modulation, is characterised in that said bias control means applies to said amplifier a compensation voltage presenting a modulation out of phase with respect to said overhead modulation, and in that modulation index of said compensation voltage is (substantially) proportional to the modulation index of said optical signal.

Abstract: In particular for selectively dropping and/or inserting channels of a wavelength division multiplex, while minimizing losses, the apparatus includes n stop filters and optical switching means provided with n+1 inlet ports of ranks 0 to n, and n+1 outlet ports of ranks 1 to n+1, as well as a set of waveguides making it possible to couple each outlet port selectively to one of said inlet ports of lower rank. Each filter is provided with first and second opposite ports coupled respectively to an associated outlet port and to an associated inlet port of the same rank. Application to optical transmission, in particular for performing routing operations.