An apparatus for joint optical frequency comparison and optical physics layer key distribution

Abstract

The application discloses a device for combining optical frequency comparison and optical physical layer key distribution, which comprises a master station and a slave station. The master station comprises a master light source, an optical frequency comparison and compensation unit, a polarizer, an optical connector, a polarization information detection unit and a signal acquisition and key quantization unit. The slave station comprises a slave light source, an optical frequency comparison and compensation unit, a polarizer, an optical connector, a polarization information detection unit and a signal acquisition and key quantization unit. The device can realize optical physical layer key distribution on the basis of optical frequency comparison, and saves channel resources and lasers.

Description

Technical Field

[0001] This invention relates to optical frequency matching and optical physical layer key distribution, and in particular to an apparatus for combining optical frequency matching and optical physical layer key distribution. Background Technology

[0002] With the continuous development of optical time-frequency transfer technology, optical frequency transfer has now reached a level better than 2×10⁻⁶. -15 With a stability of @1s, it has been widely applied in scientific fields such as gravitational wave detection and verification of relativistic effects.

[0003] Optical physical layer key distribution technology does not require a third-party key management center; the keys are "endogenous" in the optical physical layer, reducing the risk of key leakage and system complexity when distributing keys at the upper layer of the network.

[0004] The channel resources in existing optical networks are very precious, and the spectrum of the signals transmitted by both is relatively narrow. Therefore, by utilizing the correlation between the two to simultaneously realize optical frequency matching and optical physical layer key distribution, the utilization rate of channel resources can be effectively improved, and the number of lasers used can be reduced, thus saving costs. Summary of the Invention

[0005] The present invention aims to achieve joint optical frequency comparison and optical physical layer key distribution to reduce the number of lasers used and improve the utilization of channel resources. The present invention proposes an apparatus for joint optical frequency comparison and optical physical layer key distribution, comprising a master station and a slave station connected by a transmission link.

[0006] The main site includes: a main light source, a first optical frequency comparison unit, a first polarizer, a first optical connector, a first polarization information detection unit, and a first signal acquisition and key quantization unit; the first interface of the main light source is connected to the first port of the first optical frequency comparison unit; the second port of the first optical frequency comparison unit is connected to the first port of the first polarizer; the second port of the first polarizer is connected to the second port of the first optical connector; the first port of the first optical connector is connected to one end of the transmission link, and the third port is connected to the first port of the first polarization information detection unit; the second port of the first polarization information detection unit is connected to the first port of the first signal acquisition and key quantization unit.

[0007] The site includes: a light source, a second optical frequency comparison unit, a second polarizer, a second optical connector, a second polarization information detection unit, and a second signal acquisition and key quantization unit; the first interface of the light source is connected to the first port of the second optical frequency comparison unit; the second port of the second optical frequency comparison unit is connected to the first port of the second polarizer; the second port of the second polarizer is connected to the second port of the second optical connector; the first port of the second optical connector is connected to one end of the transmission link, and the third port is connected to the first port of the second polarization information detection unit; the second port of the second polarization information detection unit is connected to the first port of the second signal acquisition and key quantization unit.

[0008] The output light from both the main light source and the slave light source is single-wavelength continuous light.

[0009] The optical transmission between the first optical connector and the second optical connector is as follows:

[0010] Light input from the first port can be output from the second and third ports;

[0011] Light input from the second port can be output from the first port.

[0012] Light input from the third port can be output from the first port.

[0013] The first polarization information detection unit and the second polarization information detection unit can output the intensity information of light in a certain polarization state or the normalized Stokes matrix.

[0014] The polarization states output by the first polarizer and the second polarizer should be the same.

[0015] The first signal acquisition and key quantization unit can acquire the information from the first polarization information detection unit, and the second signal acquisition and key quantization unit can acquire the information output by the second polarization information detection unit. After normalization, a key sequence is generated according to the same quantization method.

[0016] The positions and functions of the primary and secondary sites are relative, their functions are equivalent, and they can be interchanged.

[0017] The reciprocity of the link can be determined by sending part of the information detected by the first polarization information detection unit to the slave station and part of the information detected by the second polarization information detection unit, and by using the correlation of the polarization information of the link sensed by the master and slave stations.

[0018] The transmission link between the master and slave sites can be a fiber optic link, a free space link, an underwater link, or any other link capable of optical transmission.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] Combining optical frequency matching with key distribution saves the transmission channels required in optical fibers, and the two functions share a single light source, saving one light source compared to separate solutions. Attached Figure Description

[0021] Figure 1 This is a structural diagram of a device for joint optical frequency comparison and optical physical layer key distribution according to the present invention.

[0022] Figure 2 This is a schematic diagram of the structure of a device system embodiment of the present invention, which combines optical frequency comparison and optical physical layer key distribution. Detailed Implementation

[0023] The present invention will be further described below with reference to embodiments and accompanying drawings, but this should not be construed as limiting the scope of protection of the present invention.

[0024] In the description of this invention, it should be understood that the terms 'master station' and 'slave station' are used to describe different stations only and do not refer to any specific station.

[0025] The following description, in conjunction with the accompanying drawings, details an apparatus for joint optical frequency comparison and optical physical layer key distribution according to an embodiment of the present invention.

[0026] Please refer to Figure 1 , Figure 1 This is a structural diagram of an apparatus for joint optical frequency comparison and optical physical layer key distribution according to the present invention. As can be seen from the figure, the apparatus for joint optical frequency comparison and optical physical layer key distribution according to the present invention includes a master station and a slave station connected by a transmission link.

[0027] The main station includes: a main light source a1, a first optical frequency comparison unit a2, a first polarizer a3, a first optical connector a4, a first polarization information detection unit a5, and a first signal acquisition and key quantization unit a6; the first interface a1-1 of the main light source a1 is connected to the first port a2-1 of the first optical frequency comparison unit a2; the second port a2-2 of the first optical frequency comparison unit a2 is connected to the first port a3-1 of the first polarizer a3; the second port a3-2 of the first polarizer a3 is connected to the second port a4-2 of the first optical connector a4; the first port a4-1 of the first optical connector a4 is connected to one end of the transmission link, and the third port a4-3 is connected to the first port a5-1 of the first polarization information detection unit a5; the second port a5-2 of the first polarization information detection unit a5 is connected to the first port a6-1 of the first signal acquisition and key quantization unit a6.

[0028] The site includes: a light source b1, a second optical frequency comparison unit b2, a second polarizer b3, a second optical connector b4, a second polarization information detection unit b5, and a second signal acquisition and key quantization unit b6; the first interface b1-1 of the light source b1 is connected to the first port b2-1 of the second optical frequency comparison unit b2; the second port b2-2 of the second optical frequency comparison unit b2 is connected to the first port b3-1 of the second polarizer b3; the second port b3-2 of the second polarizer b3 is connected to the second port b4-2 of the second optical connector b4; the first port b4-1 of the second optical connector b4 is connected to one end of the transmission link, and the third port b4-3 is connected to the first port b5-1 of the second polarization information detection unit b5; the second port b5-2 of the second polarization information detection unit b5 is connected to the first port b6-1 of the second signal acquisition and key quantization unit b6.

[0029] The output light from both the main light source a1 and the secondary light source b1 is continuous light.

[0030] The optical transmission between the first optical connector a4 and the second optical connector b4 is as follows:

[0031] The light input from the first port a4-1, b4-1 can be output from the second port a4-2, b4-2 and the third port a4-3, b4-3;

[0032] Light input from the second ports a4-2 and b4-2 can be output from the first ports a4-1 and b4-1.

[0033] Light input from the third port a4-3, b4-3 can be output from the first port a4-1, b4-1.

[0034] The first polarization information detection unit a5 and the second polarization information detection unit b5 can output the intensity information of light in a certain polarization state or the normalized Stokes matrix.

[0035] The polarization states output by the first polarizer a3 and the second polarizer b3 should be the same.

[0036] The first signal acquisition and key quantization unit a6 can acquire the information from the first polarization information detection unit a5, and the second signal acquisition and key quantization unit b6 can acquire the information output by the second polarization information detection unit b5. After normalization, they generate a key sequence according to the same quantization method.

[0037] Furthermore, the reciprocity of the link can be determined by sending part of the information detected by the first polarization information detection unit a5 to the second polarization information detection unit b5 detected by the slave station, and by utilizing the correlation between the polarization information of the link perceived by the master and slave stations.

[0038] Cross-correlation analysis is performed on the link polarization state information obtained from the master station and slave station. The cross-correlation results are compared with a set threshold. If the cross-correlation result is greater than the threshold, the link is considered to be symmetrical; otherwise, the link is considered to be asymmetrical.

[0039] The positions and functions of the primary and secondary sites are relative, their functions are equivalent, and they can be interchanged.

[0040] The transmission link between the master and slave sites can be a fiber optic link, a free space link, an underwater link, or any other link capable of optical transmission.

[0041] A schematic diagram of an embodiment of the device system for joint optical frequency comparison and optical physical layer key distribution of the present invention is shown below. Figure 2 As shown in the diagram, both the main and secondary light sources utilize narrow-linewidth single-wavelength lasers. The first and second polarization information detection units are polarization analyzers capable of outputting the Stokes matrix of the polarization state. Optical frequency comparison is achieved using devices such as an AOM (Analog-to-Organic Array), a 2×2 coupler, a frequency counter, and a bandpass filter. The signal acquisition and key quantization unit converts the link polarization state fluctuation information acquired by the polarization analyzer into a normalized Stokes matrix, and quantizes the S2 parameter of the normalized Stokes matrix according to a value greater than 0.5 (1) and less than 0.5 (0) to serve as the communication key.

Claims

1. An apparatus for joint optical frequency comparison and optical physical layer key distribution, comprising: The master station and slave station connected via a transmission link are characterized in that, The main station includes: a main light source (a1), a first optical frequency comparison unit (a2), a first polarizer (a3), a first optical connector (a4), a first polarization information detection unit (a5), and a first signal acquisition and key quantization unit (a6); the first interface (a1-1) of the main light source (a1) is connected to the first port (a2-1) of the first optical frequency comparison unit (a2); the second port (a2-2) of the first optical frequency comparison unit (a2) is connected to the first port (a3-1) of the first polarizer (a3); The second port (a3-2) of the first polarizer (a3) ​​is connected to the second port (a4-2) of the first optical connector (a4); the first port (a4-1) of the first optical connector (a4) is connected to one end of the transmission link, and the third port (a4-3) is connected to the first port (a5-1) of the first polarization information detection unit (a5); the second port (a5-2) of the first polarization information detection unit (a5) is connected to the first port (a6-1) of the first signal acquisition and key quantization unit (a6). The slave station includes: a slave light source (b1), a second optical frequency comparison unit (b2), a second polarizer (b3), a second optical connector (b4), a second polarization information detection unit (b5), and a second signal acquisition and key quantization unit (b6); the first interface (b1-1) of the slave light source (b1) is connected to the first port (b2-1) of the second optical frequency comparison unit (b2); the second port (b2-2) of the second optical frequency comparison unit (b2) is connected to the first port (b3-1) of the second polarizer (b3); The second port (b3-2) of the second polarizer (b3) is connected to the second port (b4-2) of the second optical connector (b4); the first port (b4-1) of the second optical connector (b4) is connected to one end of the transmission link, and the third port (b4-3) is connected to the first port (b5-1) of the second polarization information detection unit (b5); the second port (b5-2) of the second polarization information detection unit (b5) is connected to the first port (b6-1) of the second signal acquisition and key quantization unit (b6). The polarization states output by the first polarizer (a3) ​​and the second polarizer (b3) should be the same.

2. The apparatus for joint optical frequency comparison and optical physical layer key distribution according to claim 1, characterized in that, The output light from both the main light source (a1) and the secondary light source (b1) is single-wavelength continuous light.

3. The apparatus for joint optical frequency comparison and optical physical layer key distribution according to claim 1, characterized in that, The optical transmission between the first optical connector (a4) and the second optical connector (b4) is as follows: Light input from the first port (a4-1, b4-1) can be output from the second port (a4-2, b4-2) and the third port (a4-3, b4-3); Light input from the second port (a4-2, b4-2) can be output from the first port (a4-1, b4-1); Light input from the third port (a4-3, b4-3) can be output from the first port (a4-1, b4-1).

4. The apparatus for joint optical frequency comparison and optical physical layer key distribution according to claim 1, characterized in that, The first polarization information detection unit (a5) and the second polarization information detection unit (b5) can output the intensity information of light in a certain polarization state or the normalized Stokes matrix.

5. The apparatus for joint optical frequency comparison and optical physical layer key distribution according to claim 1, characterized in that, The first signal acquisition and key quantization unit (a6) acquires the information output by the first polarization information detection unit (a5), and the second signal acquisition and key quantization unit (b6) acquires the information output by the second polarization information detection unit (b5). After normalization, a key sequence is generated according to the same quantization method. The reciprocity of a link is determined by the correlation of the polarization information of the link sensed by the master and slave stations.

6. The apparatus for joint optical frequency comparison and optical physical layer key distribution according to claim 1, characterized in that, The positions and functions of the primary and secondary sites are relative, their functions are equivalent, and they can be interchanged.

7. The apparatus for joint optical frequency comparison and optical physical layer key distribution according to claim 1, characterized in that, The transmission link between the master and slave sites can be a fiber optic link, a free space link, or an underwater link.

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