Abstract: The present document relates to passive optical networks (PON). More particularly but not exclusively, it relates to the use of a reflective semiconductor optical amplifier (RSOA) for amplifying signals in a Gigabit PON (GPON) or WDM-PON. An apparatus configured to amplify light at different wavelengths in an optical network is described. The apparatus comprises a first active material configured to amplify light at a first wavelength and a second active material configured to amplify light at a second wavelength. Furthermore, the apparatus comprises a first reflector which separates the first and second active materials and which is configured to reflect light at the first wavelength and which is configured to be substantially transparent to light at the second wavelength. In addition, the apparatus comprises a second reflector adjacent the second active material opposite to the first reflector which is configured to reflect light at the second wavelength.

Abstract: The present document relates to passive optical networks (PON). More particularly but not exclusively, it relates to the use of a reflective semiconductor optical amplifier (RSOA) for amplifying signals in a Gigabit PON (GPON) or WDM-PON. An apparatus configured to amplify light at different wavelengths in an optical network is described. The apparatus comprises a first active material configured to amplify light at a first wavelength and a second active material configured to amplify light at a second wavelength. Furthermore, the apparatus comprises a first reflector which separates the first and second active materials and which is configured to reflect light at the first wavelength and which is configured to be substantially transparent to light at the second wavelength. In addition, the apparatus comprises a second reflector adjacent the second active material opposite to the first reflector which is configured to reflect light at the second wavelength.

Abstract: Method of manufacturing an optical device, and an optical device, the optical device having one or more layers (13) of quantum-dots located in-between barrier layers (12). A spacer layer (15) is grown on a barrier layer (12), such that the spacer layer (15) is adapted for substantially blocking strain fields induced by quantum-dot layers, thereby producing a smooth growth front for a subsequent barrier layer (12).

Abstract: Method of manufacturing an optical device, and an optical device, the optical device having one or more layers (13) of quantum-dots located in-between barrier layers (12). A spacer layer (15) is grown on a barrier layer (12), such that the spacer layer (15) is adapted for substantially blocking strain fields induced by quantum-dot layers, thereby producing a smooth growth front for a subsequent barrier layer (12).

Abstract: A method of fabricating a component having a crystalline silicon substrate includes the steps of depositing a layer of silica onto a crystalline silicon substrate, this silica layer being doped with dopants, and then treating the substrate. Before the doped silica layer is deposited, a barrier layer is formed on the substrate, consisting of a barrier material opposing diffusion of the dopants. The doped silica layer is deposited onto this barrier layer. The invention finds one particular application in connecting flat bundles of fibers in communication networks.

Abstract: In a method of fabricating a surface-emitting laser, to assure good electrical confinement and good flatness of the mirrors defining the resonant cavity of the laser an electrical confinement layer is formed by carrying out the following steps:forming an undercut layer,at least one growth step on the undercut layer,forming a mesa defining the shape and the location of the top mirror and exposing the undercut layer on its vertical walls, andcontrolled lateral etching of the undercut layer. Applications include the fabrication of a semiconductor laser on a III-V (e.g. InP or GaAs) substrate.

Abstract: For end-to-end alignment of two optical waveguides one of which is in the form of a strip buried in a semiconductor wafer, a longitudinal lateral mark is used constituted by the flank of a valley etched in the wafer and self-aligned to the strip formed beforehand. To achieve this self-alignment a protection layer is deposited in the area in which the mark is to be formed, a register layer is deposited on top of the protection layer and a photosensitive resin is deposited on top of these layers and the substrate. First selective etching eliminates the register layer at the location of the valley of the mark. Second and third selective etching respectively etch the lateral channels of the strip and then the valley of the mark.

Abstract: A metal contact is formed by etching a metal film that is locally protected by a spot of photosensitive resin. Thereafter the resin is caused to flow in the presence of vapor of a solvent for the resin, so as to form a protective spot of increased size. This larger spot makes it possible to etch the semiconductor substrate while ensuring that the projection formed in this way is automatically aligned relative to the metal contact. The resin remains photosensitive, thereby enabling subsequent etching. The invention is particularly applicable to the manufacture of avalanche diodes.

Abstract: In the method, a protective resist (108) used for lithographic etching is caused to flow plastically under the constraint of its surface tension, thereby increasing its thickness around a projection (106) on which a window (104) is to be formed. The invention is particularly applicable to manufacturing semiconductor lasers.

Abstract: In a method of manufacturing a planar buried heterojunction laser, after etching to delimit a laser stripe in relief on a substrate, lateral layers to surround the stripe are formed by a non-selective growth method not only at the sides of the stripe but also above it to create a parasitic projection. This projection is then removed after separation from the substrate by selective attack of a lift-off stripe which was deposited for this purpose above the stripe prior to this etching. Passages are formed for the attack medium used for this purpose. The invention can be applied in particular to the manufacture of fiber optic transmission systems.