Abstract: The invention relates to lasers, and more particularly to solid state lasers such as neodymium on lithium niobate crystal lasers. The invention provides a structure with several juxtaposed optical waveguides (12) sufficiently close to each other laterally to be coupled laterally. In order to take into account the risks of inhomogeneity in the refractive indices or inaccuracies in the dimensions which would alter the distribution of the electromagnetic field of the propagation supermode in the coupled structure, it is proposed to act on the value of the index of propagation in each guide using an individual control (generally electrical). Because of the variation in index, individually controlled, phase differences in the laser wave between the different guides are produced and these phase differences react on the composition of the electromagnetic field defining the supermode. It is possible to go as far as modifying the directivity of the laser beam by this electrical control.

Abstract: Disclosed is a frequency doubler having a quantum well semiconductor structure and a second-order non-linear susceptibility grating that can be used to amplify notably the frequency doubling. The grating can be recorded optically or electrically within the semiconductor structure and has a pitch in the plane of the structure. Such a frequency doubler finds particular application to optical recording or reading systems.

Abstract: A quantum well wave modulator comprises a central well sandwiched by two lateral wells. The central well is populated with electrons and the two lateral wells, having different constitutions, are coupled to the central well so as to modulate two light waves under the effect of the application of an electrical field perpendicularly to the structure in one direction or in the opposite direction.

Abstract: A structure providing a monolithic integration of an optical detector with an optical transmitter working in the region of the visible or the near IR spectrum. This source type makes it possible to transpose a perceived image belonging to a wavelength region to another wavelength region with a good output (photons/electrons coupling). Such a device may find particular application in imagery and signal processing systems.

Abstract: The invention relates to a high energy solid-state laser using a new optical pumping device, comprising optical fibers coupled to optical pumping sources of great power and to a laseing medium. The coupling surface through which optical pump energy is transmitted onto the laseing medium is displaced by motor for improved heat dissipation and selective coupling of the pump energy to various resonant cavities.

Abstract: A laser having a glass enclosure placed in an optical cavity receives a pump beam and generates at least one first-order and one second-order Stokes wave. The construction is such that an optical waveguide placed in the gas enclosure is used to select the first and the second-order Stokes wave.

Abstract: A system for the display of images comprising:a spatial modulator of light receiving a first light beam and retransmitting a modulated beam;an energy transfer device receiving the modulated beam and a second light beam and transferring the energy from the second light beam towards the modulated beam.

Abstract: The detector can be used to detect a wave in the medium infrared range by controlling the detector through optical pumping by means of a near infrared wave. In this case, the detector has a quantum well structure consisting of alternating first layers and second layers, these materials being such that there is a potential well in the conduction band and the valence band of each first layer. The thickness of each first layer is such that the electrons of the conduction band have at least one permitted discrete level of energy, such that the difference in energy between this level and the bottom of the conduction band in the second layers is smaller than or equal to the energy corresponding to the frequency of the wave to be detected; and such that the difference in energy between the fundamental level permitted for the holes in the valence band and the fundamental level permitted for the electrons in the conduction band corresponds to a frequency close to the frequency of the control wave.

Abstract: The disclosure relates to the making of lasers. It is sought to obtain a laser that emits at only one frequency without using frequency selection means (such as filters, etc.) needed in certain types of spectral wideband lasers (vibronic type lasers for example). It is also sought to make the laser tunable by simple means. To achieve these goals, it is proposed to define a laser cavity in which one of the mirrors is not a standard mirror but a mirror with an active function in the sense that it does not merely reflect light but itself produces light at only one wavelength. The active mirror is preferably a Bragg reflector made with an alternation of layers, at least one of which is a semiconductor layer. This layer collects electron-hole pairs in response to the excitation by the fluorescence photons. It re-emits photons at a wavelength determined by the forbidden band width of the semiconductor.

Abstract: An optic waveguide includes a buffer layer with an index n1, a strip with a high index n2 and a guiding layer with an index n3. The refraction indices correspond to the relationship: n2>n3>n1. The thickness of the strip is chosen to be very small so as to induce no optic losses. The device can be applied to the making of optic and electrooptical components.

Abstract: Disclosed is a solid state rod laser, monolithically integrated with a generator of optic frequencoes different from the emission frequency of the laser. The laser diode pumped solid state laser device has a rod, the seat of the laser effect, made of a nonlinear optic material, by doping with a rare earth, and includes an optic waveguide made in the mass of said rod of doped nonlinear optic material, parallel to the axis of the rod, said optic waveguide cooperating with means for changing the optic frequency of the laser beam. A preferred application is the obtaining of a laser frequency that is double the fundamental frequency making it possible, in the case of a neodymium laser, to obtain a green radiation, for example in digital optic disk readers.

Abstract: A miniature optical source which includes at least one thin film of active laser materials having, in addition, non-linear properties. A pump laser for emitting a beam of a wavelength allowing for the pumping of the thin film of active laser material perpendicularly to the plane of the thin film. Also, an optical cavity constituted by two mirrors whose coefficients of reflection are maximum at the laser wavelength of the active laser material is further provided. The miniature optical source may find particular application in a physically compact laser emitting in the visible spectrum.

Abstract: Disclosed is a laser source with beam scanning, of the type comprising: a pump laser source emitting a pump beam with a determined wavelength; a pressurized gas cell receiving the pump beam and emitting, by Raman effect, an output beam with a wavelength called a Stokes wavelength; a control light source transmitting a control beam to the gas cell, this control beam having a wavelength that is substantially equal to the Stokes wavelength; wherein said light source includes means for the spatial and/or temperal modification of the injection of the control photons of the control beam into said cell constituted by a multiple-laser strip structure, forming a power slave laser and cooperating with means for modifying the radiation pattern of said multiple-laser strip structure, so as to prompt the emission of the output beam in a variable direction.

Abstract: A tunable laser source comprising a laser source emitting a pump beam towards a Raman cell. It transmits a beam at a Stokes wavelength to a non-linear crystal. Depending on the angle of this beam with the optical axis of the crystal, the non-linear crystal transmits two output waves at wavelengths that are different from the Stokes wavelength.

Abstract: The field of the invention is that of power lasers pumped by coherent optical sources, such as laser diodes. The aim of the invention is to provide a structure of illumination of a laser rod enabling both efficient removal of the calories released by the coherent optical pumping sources and high homogeneity of the rod pumping operations. The structure is characterized in that the optical sources of at least one set of optical sources are arranged on one and the same delocalized support and in that said structure comprises reflecting means for the transmission, towards the rod, of the illumination beam from said set of delocalized optical sources.

Abstract: A quantum well electromagnetic wave detector disclosed having a semiconductor structure including a stacking of layers of material wherein the widths of the forbidden gaps of the materials are used to obtain a profile of potential energy corresponding to the bottom of the conduction band for the electrons in such a way that a first layer has a relatively low energy level with second and third layers having an intermediate energy higher than the energy of the first layer and fourth and fifth layers having high energy greater than either the intermediate or the low energy levels.

Abstract: Disclosed is a power laser in which several laser diodes emit pump beams towards amplifier media. The beams coming from these amplifier media are combined by an optical system to give a common beam transmitted to an output mirror. The mirror and a reflecting face of each amplifier forms an optical cavity.

Abstract: A ring-shaped interferometer device containing optical means for phase shifting which act on the rays passing through the rings, these means containing an oscillator which delivers a periodic voltage of frequency 1/2.tau., in which .tau. is the time taken by a ray to pass through the ring and a saw-tooth generator whose resonant frequency is slaved to the non reciprocal phase shift.

Abstract: Disclosed is an optical device for the processing of an optical wave by non-linear effects, comprising, on the surface, a guide and doping zones arranged transversally to the direction of the guide. The distribution pitch of these zones is equal to an even multiple of the length of coherence for the interaction envisaged. The length of each zone along the direction of the guide is equal to an odd multiple of the length of coherence.

Abstract: A modulator/commutator comprises two optical guide waves coupled to each other on a length and connected to an input guide by a Y junction. Electrodes are associated with each wave guide and enable the application of an interaction field on an interaction length. The optical and electrical waves have different propagation speeds. The interaction length and the coupling length are fixed so that their ratio has a value enabling an optical wave to successively experience the positive and negative alternations of an alternating field applied to the device by the electrodes, thus simulating a multiple-section operation. This device gives 100% efficiency of switching over to either of the two optical guides.