Abstract: The method embodying the invention authorizes communication bit rate reservations in a packet switching network. According to the method, a new communication is only accepted by the network if the communication does not exceed a maximum bit rate flowable by the switches of the network. A packet switch in the network comprises a bit rate reservation device for memorizing bit rate informations that are representative of total bit rates flowed by the switch and for processing said information as a function of data carried by service packets. The bit rate reservation device mainly comprises registers respectively associated with multiplex ways of the switch for memorizing the bit rate informations, an adder for incrementing and decrementing the bit rate informations as a function of service packet data, and a comparator for detecting overstepping of the maximum flowable bit rate.

Abstract: 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.

Abstract: An Electro-Optic modulation method and device using a low-energy oblique transition of a tightly coupled super-grid. According to the present invention, a luminous beam is injected into a tightly coupled super-grid and an electric field (E) is applied to the super-grid whose amplitude is made to gradually vary so as to cause the intensity of the beam to vary. This beam is injected parallel to the plane of the films of the super-grid which guides the injected beam. The electric field is weak and applied along the growth direction of the super-grid, which provokes the appearance of a low energy oblique transition (TB) in a domain of wavelengths where the super-grid is transparent in the absence of any electric field. The super-grid is one whereby the wavelength of the luminous beam is contained in this domain. Such a device may find application in optical telecommunications systems.

Abstract: A device for the electric characterization of samples, comprises a UHF resonator intended to be coupled locally to the sample. The resonator is formed by a microstrip or triplate line loop (20) carried by a conducting plane (16) and having a gap of small length with respect to the length of the loop and an assembly (32) for receiving the sample in a position in which the sample is coupled selectively to the edges of the gap without being interposed therebetween. The edges of the gap of the loop are fixed to two electrodes of small area passing through a thin plate of dielectric material having a flat face for application against the sample.

Abstract: A loop-back device is particularly designed to fit line terminals in half-duplex optical transmission systems thereby facilitating fault location in these transmission systems. An optical fiber coupler having a high crosstalk generates an echo in a reception channel of the terminal, from a test signal transmitted in a transmission channel of the terminal, to an optical transmission medium. Means are provided for cancelling transmission of the echo in the reception channel when the loop-back is de-activated, i.e. when a data signal is carried in the transmission medium, and for amplifying and regenerating said echo when the loop-back is activated, i.e. when said test signal is transmitted. A memory is used for delaying the echo and for transmitting it to a receiving circuit in the terminal during a signal reception period of the half-duplex transmission.

Abstract: A method for manufacturing a MOS transistor formed in a silicon block on insulator with convex rounded up edges, initially consisting in etching the block in a thin layer of silicon on insulator (SOI). In this method etching of the block comprises the following steps: forming at the position where it is desired to obtain the block a mask layer portion (3) having a thickness slightly higher than that of the SOI; depositing a second silicon layer (11) having a predetermined thickness; and anisotropically etching silicon until said insulator is apparent outside the mask layer portion.

Abstract: An apparatus for controlling the size of a wafer supporting boat such that the wafers maintained by the boat have to be positioned at predetermined distances from at least two specific utmost faces of said boat. This apparatus comprises a slanted plane (31), two reference surfaces (32), guiding means (34) arranged in order that, when the boat is laid on the slanted plane, it may slide on it in such a way that the utmost faces abut against the reference surfaces, at least one plate (50) provided with a portion of reference groove (51) arranged so as to prolong according to their plane the supporting grooves of a wafer at a determined position. Thus, when the utmost faces are abuting against the reference surfaces, a wafer can be inserted into its supporting grooves and into the reference groove only if the size of the boat corresponds to a determined standard.