Abstract: The invention relates to a semiconductor optical amplifier including a buried guide active structure (12), characterized in that the guide active structure (12) is subjected to an external stress to render the gain of said amplifier insensitive to the polarization of the light to be amplified, said external stress coming from a force induced by a deposit of a material (50) against a ridge (15) surrounding said guide active structure (12).

Abstract: A semiconductor optical component is disclosed which includes a semiconductor material confinement layer containing acceptor dopants such that the doping is p-type doping. The confinement layer is deposited on another semiconductor layer and defines a plane parallel to the other semiconductor layer. Furthermore, the p-type doping concentration of the confinement layer has at least one gradient significantly different from zero in one direction in the plane. A method of fabricating the component is also disclosed.

Abstract: The invention concerns a semiconductor optical amplifier including at least two amplifier sections (30, 40) respectively favoring a higher gain of the TE mode and the TM mode of polarization of the light to be amplified, said sections each having an active guide structure (12) of the same thickness (e), the amplifier being characterized in that the active guide structure (12) of the two sections (30, 40) is subjected to respective different tension stresses and/or has a different geometry so as to render the overall gain of the amplifier insensitive to the polarization of said light to be amplified, and in that there is no discontinuity of the effective refractive index at the transition between the sections (30, 40).

Abstract: A semiconductor optical component is disclosed which includes a semiconductor material confinement layer containing acceptor dopants such that the doping is p-type doping. The confinement layer is deposited on another semiconductor layer and defines a plane parallel to the other semiconductor layer. Furthermore, the p-type doping concentration of the confinement layer has at least one gradient significantly different from zero in one direction in the plane. A method of fabricating the component is also disclosed.

Abstract: The invention concerns a semiconductor optical amplifier including at least two amplifier sections (30, 40) respectively favoring a higher gain of the TE mode and the TM mode of polarization of the light to be amplified, said sections each having an active guide structure (12) of the same thickness (e), the amplifier being characterized in that the active guide structure (12) of the two sections (30, 40) is subjected to respective different tension stresses and/or has a different geometry so as to render the overall gain of the amplifier insensitive to the polarization of said light to be amplified, and in that there is no discontinuity of the effective refractive index at the transition between the sections (30, 40).

Abstract: The invention relates to a semiconductor optical amplifier including a buried guide active structure (12), characterized in that the guide active structure (12) is subjected to an external stress to render the gain of said amplifier insensitive to the polarization of the light to be amplified, said external stress coming from a force induced by a deposit of a material (50) against a ridge (15) surrounding said guide active structure (12).

Abstract: A common corrective eyeglass lens blank and a common mirror, Plano or magnifying, are brought together in a “compact” (small sized) construction and assembly to provide the very thing long desired in mirrors and not elsewhere found—corrected vision and ample working room between the eyes and any lenses, at the same time, at reasonable cost, in an elegance of implementation.

Abstract: The invention relates to a semi-conductor optical amplifier insensitive to the polarization of light. The active layer (20) of this amplifier is made up of an alternating series of solid sub-layers alternately under tensile stress (21) and compressive stress (22) and having the same forbidden band-width. The sub-layers under tensile stress (21) favour the propagation of the TM mode of polarization of light and the sub-layers under compression (22) favour the propagation of the TE mode of polarization of light. In addition, the thicknesses of the sub-layers have values which ensure equal gains G(TE) and G(TM) for the active layer.

Abstract: Two semiconductor layers of the laser form a tunnel junction enabling an electrical current for pumping the laser to pass from an N doped semiconductor Bragg mirror to a P doped injection layer belonging to the light-amplifying structure. The Bragg mirror co-operates with another mirror of the same type having the same doping to include said structure in an optical cavity of the laser. In a variant, the tunnel junction may be buried and located so as to constitute confinement means for said pumping current. The laser can be used in an optical fiber communications network.

Abstract: An epitaxial deposition process is used to deposit materials that can be crystallized lattice matched to gallium arsenide onto an indium phosphide crystalline wafer. A material of this kind forms a metamorphic layer. Metamorphic layers of this kind constitute two semiconductor Bragg mirrors to form resonant cavities of surface emitting lasers of a matrix. This matrix is consolidated by a silicon support. Applications include optical telecommunications.

Abstract: To form an integrated optical component comprising a thick waveguide coupled to a thin waveguide, the method consists in:depositing a first guiding layer of said thick waveguide on a substrate;locally etching said first guiding layer over a portion allocated both to a coupling interface and to the thin waveguide;depositing a second guiding layer on the first guiding layer and on the locally etched portion so as to form said thick waveguide in a manner such that it has a maximum thickness in a first zone, a graded-thickness section in a second zone, and a reduced-thickness section in a third zone;locally etching the second guiding layer over a portion of the third zone, said portion being allocated to the thin waveguide; anddepositing a third guiding layer in said portion of said third zone so as to form said thin waveguide.

Abstract: A semiconductor Bragg reflector and to a method of fabricating it. The reflector comprises a plurality of stacked layers on a substrate of a III-V type material, one of the stacked layers forming a holographic grating. The layer forming the grating comprises an alternating succession of air pockets and of III-V type material. Such a reflector is particularly suitable for use in laser devices.

Abstract: The invention relates to wavelength converters for optical signals, as used in telecommunications, in particular for routing signals. The invention relates in particular to a wavelength converter including an interferometer structure for delivering an output optical signal, in which converter first and second branches, including at least one first semiconductor optical amplifier, are coupled to input peripheral semiconductor optical amplifiers and/or to an output peripheral semiconductor optical amplifier, wherein the structure of the active waveguide of at least one peripheral amplifier is so designed that it has a ratio of active area to confinement factor greater than that of the active waveguide of said first amplifier.

Abstract: The invention concerns a semiconductor optical amplifier. The optical guide structure of this amplifier comprises a rectangular cross-section active stripe (12). Its material is homogeneous and it is subjected to a tensile strain sufficient to render the amplifier insensitive to the polarisation of the light to be amplified.The invention finds an application in optical telecommunications.

Abstract: In order to facilitate resuming molecular beam epitaxy after etching a substrate or an epitaxial layer, the etching method is implemented in an ultra-high vacuum, and it consists in producing at least two simultaneous chemical beams converging towards the substrate or the layer, the beams being formed of substances, each of which is capable of reacting with elements of different types in the substrate or the layer so as to form volatile compounds. Application in particular to manufacturing photonic and optoelectronic components.

Abstract: In a method of fabricating a surface emitting semiconductor layer, to achieve good electrical confinement and good flatness of the mirrors delimiting the resonant cavity of the laser, an electrical confinement layer is made by growing a localized aluminum alloy layer on the active layer, except for an opening area on top of which the mirror is to be formed. After epitaxial regrowth, the alloy layer is oxidized laterally. Applications include the fabrication of semiconductor lasers on III-V substrates such as InP and GaAs.

Abstract: A semiconductor photonic diplex transceiver includes a laser to generate a first optical signal having a certain wavelength and a photodetector to detect a second optical signal having another wavelength. The diplex transceiver also includes an absorber of the first signal disposed between the laser and the detector which form integral parts of an optical waveguide. The laser generates the first signal in the form of a continuous wave and is disposed between the absorber and a selective modulator of the first signal. This reduces the problems of optical and electrical crosstalk between the transmit and receive functions. Applications include user premises optical fiber transmit/receive equipments.

Abstract: From a top face of a semiconductor structure of the III-V type, inter-diffusion of elements between the wells and the barriers of an internal quantum structure is hot induced. The inter-diffusion is performed in one segment of the structure only, namely a segment in which the characteristic wavelength is to be shifted so as to constitute an amplitude modulator, another segment of the structure including a Bragg grating so as to constitute a laser emitter. In accordance with the invention, the inter-diffusion is induced by a layer of indium maintained in contact with the top face by means of a dielectric encapsulation layer. The invention is applicable in particular to optical telecommunications.

Abstract: An optical waveguide includes, in monolithic manner, a rear segment, a transition segment, and a front segment extending and succeeding one another along the length of the waveguide. A lateral confinement factor and a width the waveguide are respectively larger and smaller in the rear segment than in the front segment. According to the invention, the width increases in the transition segment until it reaches a value that is larger than that of the front segment. The invention is particularly applicable to integrating together a laser and an optical modulator for a telecommunications system.

Abstract: In the method, a doped semiconductor coating is to be deposited on a disturbed surface (S) of a semiconductor base (9) doped with a dopant having the same conductivity type as the coating. According to the invention, prior to depositing a main layer (28) of the coating (10), a superdoped layer (24) is deposited, which superdoped layer has a dopant concentration that is greater than twice the mean concentration of the coating. The invention applies in particular to manufacturing a semiconductor laser for an optical fiber telecommunications system.