초록 ▼

The system comprises a laser transmitter/receiver set which transmits laser radiation and processes the radiation received by retro-reflection and a remotely-placed retro-reflecting and modulating set which modulates the laser radiation and sends it back to the receiver. These two sets are mechanica

The system comprises a laser transmitter/receiver set which transmits laser radiation and processes the radiation received by retro-reflection and a remotely-placed retro-reflecting and modulating set which modulates the laser radiation and sends it back to the receiver. These two sets are mechanically separated, and one can be placed on board an aircraft and the other on the ground, for example. The modulation is done by a frequency-controlled acousto-optical deflector to obtained the operating conditions of diffraction according to Bragg\s law. The laser radiation, after crossing the deflector, is sent back by a catadioptric device along its original path. The double passage through the deflector, on the way out and back, produces a shift in the frequency of the laser radiation, the value of the said shift being equal to twice the control frequency of the deflector. A double axis or single axis optical scanning device is added on, for functioning in a wide field.

대표청구항 ▼

A system of identification using a laser beam retro-reflecting and modulating device, said system comprising: a retro-reflecting and modulating set having an acousto-optical defector which periodically receives an electrical signal from a control circuit, of a frequency to obtain a diffraction of a

A system of identification using a laser beam retro-reflecting and modulating device, said system comprising: a retro-reflecting and modulating set having an acousto-optical defector which periodically receives an electrical signal from a control circuit, of a frequency to obtain a diffraction of a radiation beam in accordance with operating conditions of Bragg\s law, said deflector being mechanically coupled with a catadioptric device placed downstream to receive radiation beam and to send back a diffracted radiation beam in the same direction and, after this radiation has passed through the deflector in the reverse direction, to produce a retro-reflection of the radiation beam, the retro-reflection having a frequency shift with a value equal to twice a frequency of said control signal; a mechanically separate laser transmitter/receiver set which is placed remotely from said retro-reflecting and modulating set and receives said retro-reflection therefrom, the transmitter producing a radiation in the direction of said retro-reflecting and modulating set and the receiver comprising circuits for detection and processing of said retro-reflection sent back from said retro-reflection and modulation set; and an optical scanning device for scanning a determined range in one plane, comprising a rotating, reflecting mirror, rotating on an axis orthogonal to said one plane, wherein the retro-reflecting and modulating set is servo-linked to the rotation of the mirror according to a determined ratio of a type which (a) makes it possible to preserve the diffraction conditions of Bragg\s law, and (b) makes it possible to determine a deviation from a reference plane.