SU945843A1 - Method of transmitting optical signal through non-homogenious turbulent layer - Google Patents

Description

The invention relates to optical information processing and optical communication and can be used to create devices for transmitting one- and two-dimensional optical messages through turbulent and other phase-inhomogeneous media. A known method of transmitting an optical signal through an inhomogeneous turbulent layer consists in recording a hologram. In this case, the reference wave, necessary for recording the hologram, is formed with the help of a light source whose image is to be transmitted through the turbulent layer 1 next to the object. The disadvantage of this method is low image quality in the case where the non-uniform layer has a large layer. depth or is located far from the hologram. The closest to the proposed technical essence is a method of transmitting an optical signal through a non-uniform turbulent layer, which consists in forming an inverted wave carrying information about the transmitted optical signal by affecting a non-linear medium with a wave transmitted through a non-uniform turbulent layer and two complex-coupled pumping waves. In accordance with this method, an object whose image is to be transmitted through a non-uniform turbulet layer is irradiated with a light wave, for example, from a laser. The signal wave thus obtained, distorted by an inhomogeneous layer, is directed to a layer of nonlinear matter whose optical properties (refractive index, absorption coefficient J depend on the density of light energy incident on this layer. At the same time

the same layer is directed by two opposing complex-conjugate pump waves. As a result of the nonlinear interaction of the signal wave and the pump waves, a reverse wave occurs in the layer of the indicated substance. It has the same amplitude-phase distribution in space as the signal wave, but propagates strictly in the opposite direction. After passing through a turbulent layer in the opposite direction, the radiated wave compensates for the phase distortions introduced into the signal wave, and at the output of this layer builds an undistorted image of the object located in the plane of the object itself and coinciding with it in all parameters. This image can be output using a translucent mirror to any other plane and project into the recording plane f2 J.

The disadvantage of this method is the impossibility of transmitting optical communication through a non-uniform turbulent layer in one direction. To eliminate the distortions introduced into the signal by an inhomogeneous layer, it is necessary to pass the light wave carrying the information twice through the same optical inhomogeneities: first in the forward direction and then in the opposite direction. As a result, the optical message is returned back to its sending location. Thus, the undistorted optical information cannot be transmitted to the other side.

turbulent layer.

The purpose of the invention is the transmission of an undistorted optical signal during its unidirectional passage through a non-uniform turbulent layer.

The goal is achieved by the fact that according to the method of transmitting an optical signal through a non-uniform turbulent layer, consisting in the formation of an inverted wave carrying information about the transmitted optical signal, by acting on a nonlinear medium with a wave transmitted through a non-uniform turbulent layer, and two complex O O matched pumping waves, reversal wave shaping is performed by passing waves with a known shape through this layer

wavefront with simultaneous space-time amplitude-phase modulation of one of the pump waves

transmitted optical signal. The drawing shows the implementation of the proposed method. A method of transmitting an optical signal through an inhomogeneous turbulent layer from object 1, with which it can control a transponder, for example, a two-dimensional matrix of discrete signals, a light-valve device implementing an optical communication line, or an electro-optical shutter, for example, as follows.

From the receiving part 2.

(highlighted by a dotted line, the transmission lines form a wave 3 with a known wavefront shape, for example, flat or spherical and pass it through a non-uniform turbulent layer

. This layer 4 distorts wave 3, in

as a result, it does not acquire a complex configuration and turns into wave 5. The latter affects the nonlinear medium 6 located

in the transmitting part 7 (highlighted by the dotted line of the transmission line. As the medium 6, for example, an antireflective solution, sodium vapor or Kerr CS fluid can be used. The nonlinear medium is also affected by two complex-conjugate pump waves 8 and 9, which can be, for example, flat. One of these waves, for example, 8 is passed through the object 1, thus accomplishing the spatial and / or

temporal amplitude-phase modulation of this wave with information on the transmitted optical signal.

 In this case, the propagation directions of the pump waves 8 and the waves 5 relative to each other can be from L-. by angle to a greater or lesser extent. Otherwise this one.

the angle is 0.

As a result of the impact on the nonlinear medium 6 of three light waves 5.8 and 9, the reverse wave 10 is formed in it, carrying information about

object 1 and passing through an inhomogeneous turbulent layer k in the opposite direction of the original wave 3 directions. Wherein

Claims (1)

The claims' j A method for transmitting an optical signal through an inhomogeneous turbulent layer, which consists in generating a backward wave carrying information about the transmitted optical signal by exposing the nonlinear medium to a wave transmitted through an inhomogeneous turbulent layer and two complex conjugate pump waves, characterized in that, with the purpose of transmitting an undistorted optical signal during its unidirectional passage through an inhomogeneous turbulent layer, the formation of a reverse wave is carried out by passing through e This wave layer with a known wavefront shape with simultaneous spatio-temporal amplitude-phase modulation of one of the pump waves with information about the transmitted optical signal.