Abstract: A method for the making of an optoelectronic device comprising at least one quantum well, the barriers of which are made of GaInP and the well of which is made of GaAs, is carried out by the interdiffusion of elements between barriers and quantum wells in such a way that there is a migration of at least indium elements from a barrier to the quantum well. The method can be applied to the making of quantum well lasers, photodetectors and optical guides.

Abstract: The present invention relates to processes for the construction of semiconductor lasers.The process according to the invention is essentially characterized in that it consists in forming a layer 1 of a laser semiconductor active medium, in forming an optical cavity 2 associated with this layer, in disposing, on at least a part of the surface of the layer, first 6 and second 7 layers of materials of impurities of opposite polarities, in causing diffusion into the active medium of at least a part of the two materials of impurities to form, in the first layer, a cylinder 8 axis substantially parallel to the axis of the optical cavity and formed of two semi-cylindrical half-shells 9, 10 of diffused impurities of opposite polarities, and in connecting two conductors 12 of the electrical energy respectively to the two half-shells.Application to the construction of a plurality of laser diodes on one and the same support substrate, to create a homogeneous and dense single laser beam.

Abstract: A system for the optical pumping of a cell of atomic or molecular gases comprises at least one optical cavity comprising at least one cell of atomic or molecular gases, one optical pumping wave being coupled to the optical cavity.

Abstract: The method consists of the following successive steps: the deposition on a substrate, by epitaxy, of an optical confinement layer, formed by a first semiconducting material; the deposition, by epitaxy of an active layer, formed by a second semiconducting material; the deposition, by epitaxy, of a stop layer, formed by a third semiconducting material, with a thickness of between 0.005 and 0.02 microns; the deposition, by epitaxy, of a guide layer, formed by a fourth semiconducting material, with a thickness of between 0.01 and 0.

Abstract: A laser diode having an active layer which has a composition:Ga.sub.x In.sub.1-x Pwith: 0.51.ltoreq.x.ltoreq.0.53 corresponding to a point of the straight line of the quaternary diagram GaInAsP which satisfies the condition of compatability of the crystal lattice parameter with that of a GaAs substrate. The confinement layers of the laser diode have a composition corresponding to a point of the straight line of the adjacent quaternary diagram GaAlInP which satisfies the condition of compatability of the crystal lattice parameter with that of the GaAs substrate, namely in respect of that point of said straight line which is located at the most favorable end of the line:In.sub.z Al.sub.1-z Pwith: 0.45.ltoreq.z.ltoreq.0.49.

Abstract: A phototransistor which is capable of operating alternately in the emission mode and in the reception mode can be coupled under favorable conditions to an optical fiber in a telecommunications system. An active layer constitutes the base of the transistor and forms a heterojunction with two layers of opposite conductivity type which constitute the emitter and collector of the transistor. The base contact is formed by a heavily doped region of the same conductivity type as the active layer and defines the useful zone of photon coupling between the optoelectronic component and the entrance face or exit face of the optical fiber.

Abstract: A phototransistor in planar technology for optical fiber communications permitting an easy formation of the contact connection of the transistor base located within the intermediate layer of an npn stack as well as accurate localization of the pn junction. To this end, the upper semiconductor layer initially receives a first diffusion of doping impurity in a first region which penetrates into the lower layer to a slight extent and forms the base region. An impurity of opposite type is then implanted in a second region which is located within the first and forms the emitter region whilst the substrate constitutes the collector. The base and emitter connections are formed on the free face whilst the collector is connected on the substrate side.

Abstract: A semiconductor laser wherein a wide range of laser emission wavelengths can be obtained by varying the composition of monocrystalline alloys employed as semiconductor material. The semiconductor structure comprises on a monocrystalline indium phosphide substrate of a predetermined conductivity type successive epitaxial layers consisting of a first confinement layer of the same conductivity type, an active layer having the formula (Ga.sub.x Al.sub.1-x).sub.0.47 In.sub.0.53 As where x is within the range of 0 to 0.27, and a second confinement layer of opposite conductivity type. The confinement layers are composed of either InP or a ternary alloy Al.sub.0.47 In.sub.0.53 As or a quaternary alloy Ga.sub.x' Al.sub.1-x' As.sub.y' Sb.sub.1-y' where x' and y' are chosen so that the material should have a predetermined crystal lattice and an energy gap of greater width than the substrate material.

Abstract: The invention relates to a low cost photovoltaic cell, using a minimum thickness layer of semiconductor compounds able to provide the photovoltaic effect and specifically in polycrystalline form. On a molybdenum sheet an auxiliary polycrystalline germanium layer is deposited in order to facilitate subsequent depositions. This is followed by an intermediate polycrystalline layer of gallium aluminum arsenide and an active layer of polycrystalline gallium arsenide. The presence of the intermediate layer with a wider forbidden band than that of the active layer compensates the effect on the efficiency of the limited thickness of the active layer.

Abstract: The invention relates to a semiconductor laser with a distributed reflector comprising a semiconductor junction, one of whose semi-transparent mirrors is a split face of the semiconductor in which is integrated a light emitting junction with epitaxial layers. The active layer of this junction is coupled to a waveguide integrated in a dielectric medium, on one face of which is engraved a grating forming a distributed reflector playing the part of the second mirror. The reflector, when functioning according the second order of counter coupling emits a diffracted wave normal to the waveguide which can easily be coupled to an optical fiber.

Abstract: A light-emitting and light receiving diode comprises an active zone which, in the emitting mode, is the seat of a strong current. The emission surface has a central semiconducting region which channels the current lines and an insulating region transparent to light. In the receiving mode, the photons pass through the entire receiving surface which is none other than the emission surface and the active zone has a sufficient thickness and a sufficiently low doping concentration to be in the space charge state.

Abstract: A field effect transistor deposited upon a substrate having a wide forbidden band comprises an active layer of n-type conductivity which forms a heterojunction with the substrate. Since the subjacent material has a forbidden band higher than the forbidden band of the active layer, the formation of electronic currents between the source and the drain and in the substrate is avoided.

Abstract: An avalanche photodiode has an avalanche voltage relatively low. In one of the two elements of the junction there is a zone doped more heavily than said element and having the same conductivity type.

Abstract: An avalanche photodiode whose avalanche voltage is relatively low, comprises a detector region, which is p-type doped to sufficiently small depth at its central region in order for the reverse voltage applied across its terminals to develop a field strength in the order of the avalanche field strength there.