Abstract: The invention relates to a method of providing protected transmission between two nodes (1, 2) of a wavelength-division multiplexed network. The invention proposes to have loss of signal over the main line (3) detected by a node, and then to interrupt transmission of data over the main line by said node. By interrupting transmission, it is thus possible to force loss of signal on the other node: the other node then switches its transmission of protected data over to the backup line (4). Interrupting the transmission of data can be achieved by switching off the laser of said node. The invention also describes a method of testing with a view to re-using the main line (3). The invention provides means for switching the protected data over to the backup path that are particularly simple in terms of protocol.

Abstract: Wavelength division multiplex ring communication network equipment comprises a first multiplexer connected to a first optical fiber portion dedicated to transporting multiplexed signals and a second multiplexer connected to a second optical fiber portion. The equipment comprises signal protection circuitry connected to the first and second multiplexers and to a terminal which, in the event of local detection of interruption of signal transmission at a first wavelength on the first optical fiber portion, send the signals coming from the terminal to the second multiplexer at a second wavelength so that it communicates them to the second optical fiber portion, and sends to the terminal the signals that are addressed to it and that come from the second optical fiber portion at the second wavelength.

Abstract: The laser type semiconductor optical component comprises:

Abstract: The present invention provides a vertical structure semiconductor laser comprising bottom and top cladding layers (1, 2), a light guide (G) superposed on the bottom cladding layer, and a semiconductor active layer (CA).

Abstract: The present invention concerns an optical component having at least one guide with a ridge structure obtained by chemical etching on a substrate made of semiconductor material, the ridge having a base and a top face, the guide having an outline with at least one curved section, the tangent at any point on the outline defining the local orientation (&bgr;) of the guide. According to the invention, the width of the base (weff) of the ridge is substantially constant all along the guide and the width of the top face (w) of the ridge varies according to the local orientation (&bgr;) of the guide with respect to the reference crystallographic direction (R) of the substrate.