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: 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 modulator enables the modulation of a wave in the medium infrared range by means of a signal modulating the amplitude of another electromagnetic wave in the near infrared range. The modulator comprises: a central layer such that the electrons of the conduction band have at least two permitted discrete levels of energy, the energy difference of which corresponds to a frequency close to the frequency of the wave to be modulated, and such that the holes of the valence band have permitted levels of energy such that the difference in energy between the permitted fundamental level for the holes in the valence band and the permitted fundamental level for the electrons in the conduction band has a value close to that corresponding to the frequency of the control wave.

Abstract: A frequency shifter to shift the frequency of a guided wave in the medium infrared range comprises:an optical guide, formed by semiconducting materials, on the surface of which a diffraction grating is created by carriers photo-induced by a periodic illumination.standard optic means projecting, on the surface of the guide, two wave beams having different frequencies in the near infrared or visible range, to produce, by interference, a periodic illumination of the surface of the guide. This illumination induces photocarriers constituting a diffraction grating which is in translational motion at constant speed. This motion shifts the frequency of the diffracted wave by Doppler effect.

Abstract: Mode coupling using grating of ridges and furrows to curve the fibre along a zig-zag path are associated with an index matcher which surrounds the fibre. The average axis of the zig-zag fibre coincides that of the matcher. Light travels along lines all at the same angle to the axis of the matcher and pass through via a conical optical end surface thereof. The optical surface converts the said rays into a parallel beam for coupling with large aperture optical means such as a photo-cell or a LED.