摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Primary molecules are formed by sublimation in a sublimation chamber (2), they are then transferred at a transfer flow-rate to a decomposition head (10) at a higher temperature, and they are transformed therein into secondary molecules that are lighter in weight to form molecular beams (16). In accordance with the invention, the transfer flow-rate is adjusted by adjusting an effective vector flow-rate which is the vector flow-rate of a vector gas inserted into the sublimation chamber via a feed tube (26) and sucked out via a suction tube (30). The invention applies, in particular, to making III-V type semiconductor components by molecular beam epitaxy.
摘要:
A vacuum evaporation device incorporates a main treatment enclosure connected to an auxiliary chamber containing a material evaporation cell. The cell is fixed to a tight bellows displacement member able to displace the cell between a first advanced position towards a main enclosure and a second retracted position. A sealing valve provided with a slide is provided for the main enclosure from the auxiliary chamber, whereby the material of the evaporation cell can thus be changed without placing the main enclosure under atmosphere again. A fixed heating tube, connecting the main enclosure to the auxiliary chamber, has a first end engaged in the main enclosure and a second end issuing into the auxiliary chamber. The second end is provided with an end piece made from a thermally insulating material ensuring mechanical continuity and thermal insulation with the support part and able to bearingly receive the evaporation cell when the latter is in the advanced position. The slide of the sealing valve is inserted between the end piece and the evaporation cell when the latter is in the retracted position, the travel of the cell between these end positions and consequently travel of the bellows being limited to the space necessary for closing the valve.
摘要:
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.
摘要:
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.