摘要:
A “paper look-alike” display comprises pixels formed of dielectric particles suspended in a non-conducting liquid. By applying a voltage to electrodes the particles may be switched between positions in which they are stored in vertical columns normal to the surface of the pixel and have no effect on the color of the pixel, and a position in which they occupy a major part of the surface area of the pixel and influence the color of the pixel accordingly.
摘要:
A device for directional and wavelength-selective optical coupling formed in a photonic crystal (12) and comprising two parallel waveguides (14, 16) separated by a coupling zone (18) enabling a particular frequency to be extracted from a signal (30) injected in fundamental mode into one of the waveguide (14) and to recover said frequency at the outlet (34) of the other waveguide (16), extraction and injection being performed by coupling between fundamental and high order modes in each waveguide.
摘要:
The present invention relates to processes for the construction of semiconductor lasers.The process according to the invention is essentially characterized in that it consists in forming a layer 1 of a laser semiconductor active medium, in forming an optical cavity 2 associated with this layer, in disposing, on at least a part of the surface of the layer, first 6 and second 7 layers of materials of impurities of opposite polarities, in causing diffusion into the active medium of at least a part of the two materials of impurities to form, in the first layer, a cylinder 8 axis substantially parallel to the axis of the optical cavity and formed of two semi-cylindrical half-shells 9, 10 of diffused impurities of opposite polarities, and in connecting two conductors 12 of the electrical energy respectively to the two half-shells.Application to the construction of a plurality of laser diodes on one and the same support substrate, to create a homogeneous and dense single laser beam.
摘要:
A system for the optical pumping of a cell of atomic or molecular gases comprises at least one optical cavity comprising at least one cell of atomic or molecular gases, one optical pumping wave being coupled to the optical cavity.
摘要:
The electron source disclosed comprises a solid having a first semiconductor layer capable of releasing electrons under the effect of an electrical field, means to make at least one of its faces partially transparent to at least one part of the released electrons, and to enable this part of the electrons to be ejected from the solid, and a second unstable composite semiconductor layer having a structure having a negative differential resistance located between the first layer and its face which is at least partially transparent, in contact with the first layer. The electron source further includes means to form, with said first layer and the composite layer, an electrical resonant cavity.
摘要:
A photocathode having internal amplification includes a first electrode adapted for receiving a first voltage, and for transmitting received photons. An absorption layer is disposed adjacent the first electrode and comprises a P-type semiconductor material having a forbidden band of sufficiently small width to cause photons received through said first electrode to be converted into electron-hole pairs. At least one ionization-induced electron multiplication layer is disposed adjacent the absorption layer. Each such multiplication layer comprises two layers of N-type semiconductor material having respectively two different compositions at an interface therebetween. The two different compositions at the interface cause the multiplication layer, when biased, to accelerate the electrons received from the absorption layer to a degree greater than the acceleration provided to the holes received from the absorption layer. A second electrode is disposed adjacent the multiplication layer and receives a second voltage to cause the photocathode to be biased. In addition, the second electrode transmits the accelerated electrons received from the multiplication layer. An emission layer is disposed adjacent the second electrode and comprises a material which produces negative electron affinity to cause the accelerated electrons received from the second electrode to be emitted into a vacuum.
摘要:
A device for supporting chromophore elements comprises a plane mirror covered in a layer of material that is transparent at the wavelengths to be detected, said layer having a set of spots on which the chromophore elements are fixed, the spots being subdivided into a plurality of zones of different thicknesses so as to cause the intensity of the fluorescence emitted by the chromophore elements to vary by destructive interference or by constructive interference, respectively.
摘要:
Disclosed is a semiconductor laser that is constituted by at least one active layer sandwiched between two confinement layers with P and N type doping to constitute a PN junction. In at least one of the confinement layers and/or the active layer, holes are designed on each side of the cavity so as to form structures of photonic bandgap material along the lateral walls of the cavity and the ends of the cavity.
摘要:
The object of the invention is to reduce the influence of dislocations on the functioning of structures for optoelectronic component, such as laser, made from semiconductor materials. Accordingly, one of the lasers of such a structure comprises three-dimensional inclusions in a semiconductor material with a thinner forbidden band than the forbidden band of the layer material. The inclusions are e.g. distributed over several planes of the active layer of a laser, and may be in InAs introduced into a layer in GaAs.
摘要:
A method of fabricating an integrated detection biosensor, the biosensor comprising an assembly (10) of photodetectors (12) of CCD or CMOS type on which there is deposited or formed a filter for rejecting excitation light λe, the filter comprising at least one absorbent layer (14) together with a Bragg mirror or an interference filter, forming a support for chromophore elements that are to be illuminated by the excitation light λe.