Abstract: An optical device comprising a Photonic Forbidden Band (PFB) component composed of a thick material including a distribution of regularly spaced holes, the said photonic forbidden band component being delimited by first and second ends and comprising a wave guide of the total internal reflection (TIR) type, characterised in that the photonic forbidden band component comprises a mode adapter integrated on the first and/or second end of the said photonic component, the mode adapter also consists of a distribution of holes in the photonic forbidden band (PFB) component causing an adiabatic widening of the total internal reflection (TIR) waveguide on the said first and/or second end of the component.

Abstract: To fabricate a buried ribbon laser, a thin n-doped layer is formed on a p-doped layer immediately adjacent an active layer. After etching the active layer to form the ribbon, the ribbon is buried in an n-doped layer so that the four lateral faces of the ribbon are all in contact with an n-doped layer. One face is in contact with the thin layer and the other three faces are in contact with the burying layer. This improves the electrical confinement of the ribbon.

Abstract: To fabricate a buried ribbon laser, a thin n-doped layer is formed on a p-doped layer immediately adjacent an active layer. After etching the active layer to form the ribbon, the ribbon is buried in an n-doped layer so that the four lateral faces of the ribbon are all in contact with an n-doped layer. One face is in contact with the thin layer and the other three faces are in contact with the burying layer. This improves the electrical confinement of the ribbon.

Abstract: Optical semiconductor light guide device having a low divergence emergent beam, application to Fabry-Perot and distributed feedback lasers. According to the invention, the core of the guide of the device comprises at least one semiconductor layer (8), whose refractive index is higher than that of each of the confinement or cladding layers (4, 6) of the guide and at least one second semiconductor layer (10), whose refractive index is lower than that of each of the confinement or cladding layers or close thereto. Application to optical telecommunications.

Abstract: A semiconductor (10) is subject to ionic etching (14) through a mask, whereof one side determines the location of the mirror. This mask is constituted by a crystalline layer (12), whereof the side (16) is a crystallographic plane.

Abstract: Process for producing an integrated laser-photodetector structure.A buffer layer and a double heterostructure are deposited on a substrate. Part of the double heterostructure is etched to form a cleaved face and to free the buffer layer. On the latter is formed a photodetector, e.g. with the aid of a Schottky contact.Application to the production of light sources for optical telecommunications.

Abstract: Process for producing a laser having several wavelengths, wherein:a first double heterostructure is produced by epitaxy with an active layer having a first composition,the first double heterostructure obtained is etched into the substrate, through a mask having openings in the form of strips, which leads to a substrate on which there are strips of the first double heterostructure separated by etched portions,a second double heterostructure with an active layer having a second composition is grown in the etched portions,a groove is formed between the first and second heterostructures down to the contact layer, andthe groove undergoes proton bombardment.The invention also relates to the laser obtained by this process.Application to optical telecommunications.