RU62316U1 - OPTICAL COMMUNICATION SYSTEM - Google Patents

Abstract

The utility model relates to optical communication systems and can be used in open communication lines. Achievable technical result is the ability to transmit information in both digital and analog form, increasing the noise immunity of the communication line, ensuring the secrecy of information transmission and reducing the effect of noise of photodetectors on the reception of an information signal. This is due to the introduction of a nonlinear optical element and a pump laser, while the system simultaneously transmits two information optical signals, compares them and eliminates noise and interference. 1 ill.

Description

The utility model relates to optical communication systems and can be used in digital and analog communication systems in open communication lines.

Known wireless duplex optical communication system, RF patent No. 2178954, class. Н 04 В 10/00 of January 27, 2002, containing two transceivers, which include two spatially separated optical transmitters, which are emitters with modulators, and two spatially separated optical receivers of modulated radiation. The outputs of the first and second optical receivers of each of these transceivers are associated with the output of the corresponding demodulator through the adder.

The spatial separation of the optical transmitters and receivers at each point (end) of the communication line reduces the likelihood of a communication failure when it is crossed by opaque objects.

However, the specified spatially spaced arrangement of optical receivers and transmitters does not fully eliminate the effect of artificial or natural optical interference, in particular atmospheric interference, since the radiation in the duplicate communication channels passes through separate paths and experiences various effects of fluctuations in the medium, for example, the atmosphere.

Also known is an optical communication system (prototype), RF patent No. 2121229, Cl. N 04 B 10/00 of 10/27/1998, the System provides a wireless exchange of information and contains transmitting and receiving parts, made in the form of an optical transmitter and an optical receiver.

The disadvantages of this system are the influence of environmental anomalies and random or deliberate introduced optical interference on the stability and quality of communication, if necessary, to ensure high transmission speeds of information, as well as on the communication range and low service life at a fairly high cost of production and operation.

Anomalies in the communication medium that lead to poor communication include atmospheric phenomena such as fog, rain, snow, fluctuations in the refractive index and loss factor of the optical signal in air or water, affecting the attenuation or distortion of signals in the communication line.

The purpose of the utility model is to provide the ability to transmit information in both digital and analog form, increase the noise immunity of the communication line, ensure the secrecy of information transmission and reduce the influence of noise of photodetectors on the reception of an information signal.

This goal is achieved by the fact that in the optical communication system, consisting of a transmitting and receiving part, made in the form of an optical transmitter and optical receiver, as well as wireless

an optical non-linear optical element (crystal) and a pump laser are additionally introduced, wherein the optical transmitter is connected to a non-linear optical element that is connected to a pump laser, the non-linear optical element being connected via a wireless optical communication line to a separator, which, in its in turn, the first output is connected to the first photodetector, and the second output is connected to the second photodetector, while the photodetectors are connected to a differential amplifier (corrector), which is connected by its output optical receiver.

In FIG. shows a block diagram of an optical communication system. It contains:

1 - optical transmitter, used for signal radiation. Signal radiation is an information signal;

2 - a nonlinear optical element (crystal), is a nonlinear optical waveguide or nonlinear optical crystal;

3 - pump laser, used to pump radiation. The pump radiation is introduced into the nonlinear optical element in order to provide an optical switching mode at which the differential power gain of the optical radiation is achieved, significantly exceeding unity, but the shape of the amplified optical signal is not distorted, i.e. each of the unidirectional distributed coupled waves (ORSV) at the output of the nonlinear optical element (NOE) corresponds to an information signal at the input;

4 - optical communication line (OLS). OLS passes through the air;

5 - separator, serves to separate ORSV;

6, 7 - the first and second photodetectors;

8 - differential amplifier, subtracts the signals received at its input in antiphase;

9 - optical receiver, is used to receive an information signal.

The system simultaneously transmits two optical information signals, receives these signals, compares them and eliminates noise and interference. Information optical signals are generated at the output of the nonlinear optical element 2 by supplying one optical radiation to the input of this nonlinear optical element 2 and changing the input power, or phase, or frequency of one optical radiation supplied to the input of the nonlinear optical element 2. Parameters of the nonlinear the optical element 2 and the optical radiation supplied to the input of the nonlinear optical element 2 are selected in such a way as to provide optical distributed communication between the two propagating a nonlinear optical element 2 of the unidirectional distributed-coupled waves and optical waves switching between said output nonlinear optical element 2. Each of these waves on the output member 2 corresponds to the information channel. Noise and interference are eliminated by supplying each of the distributed waves to its own photodetector 6 or 7. Electrical signals from the photodetectors are fed to a differential amplifier 8,

which highlights the coinciding part of the dependence of the amplitude of the electrical signals on time.

The inventive system can operate when one radiation is introduced into the nonlinear optical element 2, which is an information optical signal, the average intensity of which is higher than the threshold, determined from the condition that the differential gain exceeds 1.1.

The system can also be operated by introducing a constant in intensity radiation into element 2, while the information channel is either an electric signal that creates an electric field applied to the element, or an acoustic signal that creates an acoustic field, or a mechanical effect applied to element 2.

For example, an informational electric signal can modulate the parameters of element 2 (the coefficient of distributed wave coupling and the difference between the effective refractive indices of the OCRS) due to the electro-optical effect, which allows modulating (in accordance with the transmitted information) radiation of constant power supplied to the input of element 2.

Similarly, an acoustic signal can modulate the parameters of element 2 (the coefficient of distributed wave coupling and the difference between the effective refractive indices of the ODSW) due to the acousto-optical effect; mechanical stress can also change the parameters of element 2.

This allows you to modulate (in accordance with the transmitted information) radiation of constant power supplied to the input of element 2.

After the radiation leaves the element 2 and passes through the air in front of the photodetectors, separation of the ODSV is required. This separation is achieved using a separator (separator 5) of these waves. The separator 5 is a separator of waves of various polarizations (birefringent prisms, polaroids, directional couplers, etc.) or frequencies (dispersion element: directional coupler, prism, diffraction grating).

System operation.

At the input of the nonlinear optical element 2 from the optical transmitter 1, optical radiation is supplied, variable in intensity, phase or frequency, carrying useful information, or variable in intensity, phase or frequency, carrying useful information of optical radiation (signal) and pump radiation from laser 3 .

In element 2, there is a switch between OCRS. After passing through the open communication line 4, these ODSVs are separated by a separator 5. The separated ODSVs are each fed to their photodetector 6, 7, from the outputs of which electrical signals (corresponding to the initial information signal) are fed to a differential amplifier or corrector 8. The differential amplifier subtracts the signals received at his entrance is in antiphase. Correlator representing

An electrical unit, by analyzing the signals arriving at its input, selects their common part. And when subtracting the signals and when highlighting their common part, the useful signal is cleared of noise and interference. Thus, the output of the differential amplifier 8 or the correlator generates a signal corresponding to the original information signal, cleared of noise and interference.

The claimed system provides the ability to transmit information in both digital and analog form in open optical communication lines, increasing the noise immunity of the communication line and signal / noise ratio, secrecy of information transmission, as well as eliminating or reducing the effect of noise of photodetectors on the reception of an information signal.

Claims (1)

An optical communication system comprising transmitting and receiving parts made in the form of an optical transmitter and an optical receiver, as well as a wireless optical communication line, characterized in that a non-linear optical element (crystal) and a pump laser are introduced into the system, while the optical transmitter is connected to non-linearly an optical element that is connected to a pump laser, the nonlinear optical element being connected via a wireless optical communication line to a separator, which, in turn, is connected to the first output by the first the second photodetector, and the second output is connected to the second photodetector, while the photodetectors are connected to a differential amplifier (corrector), which is connected to the optical receiver by its output.