Abstract: The present invention relates to a semiconductor emission device with fast wavelength modulation and constituted by three sections, namely two lateral sections, each having an active layer and a DFB network and which produce an optical gain, connected across a central electroabsorbant section, to which is applied a reverse voltage making it possible to quasi-instantaneously modify the absorption rate in said section.

Abstract: A distributed feedback semiconductor laser structure of the type having a guidance zone providing lateral guidance by refractive index variation, including a phase-shifting diffraction grating extending between two end regions along a light propagation direction, for obtaining coupling within the structure between light propagating in one direction and light propagating in the opposite direction. The diffraction grating is adapted to implement coupling of varying amplitude along the structure between said end regions, and the width of said guidance zone varies such that the phase shift induced by said variation in width compensates for the phase shift induced by the variation in the coupling amplitude.

Abstract: For burying the active strip, two narrow bands are etched on either side of the strip and localized epitaxy repeat takes place on said two bands, which makes it possible to work at lower temperatures. Moreover, the substrate and confinement layer are of type p and the epitaxy repeat layer of highly doped type n.sup.+. The guide layer can be etched to constitute a defractive network.

Abstract: A light source with a semiconductor junction having a substrate on which are successively deposited a first and second semiconductor layer having opposite doping and means for injecting charge carriers from a power supply, wheein the means includes a highly doped contact layer partly covered by an alloyed metal layer forming an ohmic contact and a metal layer covering the alloyed layer, together with the remainder of the second semiconductor layer, with the metal layer being connected to the power supply and wherein the semiconductor constituting the second layer is chosen from among those which form a Schottky diode in contact with a metal like that of the metal layer. The diode is reverse polarized under the normal operating conditions of the source with the zone in which charge injection takes place consequently being limited to a single ohmic contact zone, excluding the zones in which there is a Schottky diode.