摘要:
The antenna includes at least one group of antenna elements (EA1, EA2, . . . , EAp). Microwaves emitted by a central emitter (EH) reach a particular element (EA1 for example) by passing through a controllable phase shifter (VE1), a laser (LE1) which modulates a carrier light signal at a frequency specific to said antenna element with the microwaves, via an optical deflector (FIE) which injects said light signal into an optical waveguide (GE) which is common to all of the antenna elements in the group, via an optical deflector (FPE) which directs said light signal to a detector which is specific to said antenna element (EA1), and which reconstitutes the microwaves, and via a microwave amplifier (AE1) which applies the microwaves to said antenna element. The system is applicable to telecommunications and to radar.
摘要:
An optical fiber telecommunication device comprises an interconnecting volume and N stations connected to this volume by pairs of transmit and receive optical fibers. Each station comprises a tunable optical frequency laser coupled to the transmit fiber and a heterodyne receiver system coupled to the receive fiber. It is provided with a tunable frequency laser local oscillator. The volume is disposed in a central office comprising a clock to determine different timing periods assigned to the N stations. The carrier frequency of the laser for each station is initially adjusted to a first frequency reserved for modulating ringing signals in the respective channels. The central office comprises a processor connected to the interconnecting volume to receive the ringing signals and designate a carrier frequency for each call request. This frequency is transmitted through the interconnecting volume to the calling station and the called station on a second reserved frequency. This is in order to adjust the frequency of the laser and the frequency of the local oscillator to the designated frequency. The designated frequencies are different for all calls in progress at the same time.
摘要:
Optical system having application to robotics for determining an object's position. The present system consisting of a laser generator 1 with, devices 11 modulating the wavelength of laser generator frequency along an ascending ramp. An optical system 8 for concentrating radiation near the object, receiver 16 picks up a luminous signal transmitted by the object 10 and reflected on to an optical lamp 6. A processing circuit 17 measures the time in which elapses between the beginning of the shift in wavelength and the moment when the luminous signal is picked up by the receiver.
摘要:
The invention relates to a method and to apparatus for remotely measuring the distribution of a physico-chemical parameter in a medium. The method consists in exciting measurement points (20) situated in a medium (17) in succession via an optical fiber (18), with each point (20) being excited by two light pulses of different wavelengths offset from each other in time occurring simultaneously at said point, each measurement point returning radiation at a third wavelength representative of the temperature of the measurement point. The apparatus includes two lasers (3, 4) emitting different wavelengths, a delay circuit (5) for delaying the light pulse from one (4) of the two lasers, and the measurement points include a material sensitive to biphotonic excitation.
摘要:
This system includes optical fibers (21,26,49,51) which connect subscriber sets (p,n) to an optical interconnection center (59). An optical frequency F.sub.p and a modulation frequency f.sub.p are ascribed to each subscriber p, these frequencies being specific to the subscriber. The set of each subscriber p includes a laser (19) which delivers a wave (22) of frequency F.sub.p and means (9, 12 to 18) to modulate the amplitude of this wave at the frequency f.sub.n ascribed to the subscriber n with whom he wishes to communicate.