CN118011409A - A time phase coded quantum safe ranging radar device and ranging method - Google Patents

Abstract

The invention provides a time phase coding quantum safety ranging radar device and a ranging method, and belongs to the field of laser radars. The apparatus includes a primary laser; an unequal arm interferometer module for splitting the optical pulse into two sub-pulses with a time difference; the slave laser is used for randomly outputting a first time state of the optical pulse at the previous time position or a second time state of the optical pulse at the later time position under the drive of the drive signal through injection locking of the two sub-pulses, and the front and back time positions under the X base comprise one coding state of phase states of the optical pulse; an attenuator; a telescope; polarization processing and beam splitting modules; a first circulator; a second circulator; a first single photon detector and a second single photon detector. The device has low error rate, does not have the problem of phase drift, and reduces the complexity of the system; when the device is used for ranging, the ranging resolution can be improved to r=7.5cm.

Description

A time phase coded quantum safe ranging radar device and ranging method

Technical Field

The present invention belongs to the field of laser radar, and in particular relates to a time phase coded quantum safe ranging radar device and a ranging method.

Background technique

Quantum information technology has strong anti-interference and high resolution characteristics. Applying quantum information technology to the field of radar detection can greatly improve the stealth and resolution of radar detection, and has extremely high application value. Since quantum states have characteristics such as non-cloning and measurement collapse, real-time monitoring can be carried out by encoding and decoding photons and detecting the bit error rate, so as to effectively detect the interception and retransmission attack of the jammer and greatly improve the security and reliability of detection. In 2012, M. Malik et al. (Malik M, et al, Quantum-secured imaging. Applied Physics Letters, 2012, 101(24): 241103.) proposed the concept of quantum secure imaging, which encodes and decodes the polarization of the photons of the detection target, and can determine whether the target is interfered or deceived by monitoring the bit error rate. However, this scheme has many problems. For example, the polarization state of photons will be affected by atmospheric disturbances when transmitting in free space, and will change significantly when scattered on the surface of the target object, so that a high bit error rate will still be obtained when there is no interference, which will make the false alarm rate too high and the practicality is low. In addition, since the polarization encoding of this scheme uses an electromechanical device, the encoding rate is low, and the reliability and long-term stability are low. In 2015, Wang Qiang et al. proposed a quantum secure radar scheme using pseudo-random modulation based on this scheme (Wang Qiang, et al, Pseudorandom modulation quantum secured lidar. Optik, 2015, 126, 33444-3348). By randomly encoding the pulse position and randomly modulating and demodulating the photon polarization state, safe ranging can be achieved. This scheme can increase the modulation frequency of the signal, but there is also the problem of unstable polarization state, and it is necessary to load 4 random voltages on the electro-optical modulator to achieve 4 polarization state encoding, and use 4 single-photon detectors for decoding, which greatly increases the complexity of the system. In addition, since the ranging resolution is inversely proportional to the modulation frequency of the electro-optical modulator, the resolution is only 1.5 meters when the modulation frequency is 100MHz.

Summary of the invention

In order to solve the technical problems of unstable polarization state, complex polarization encoding and decoding devices, and low ranging resolution, the present invention proposes a time phase coded quantum secure ranging radar device and a ranging method.

To achieve the above object, the technical solution adopted by the present invention is as follows:

On the one hand, the present invention provides a time phase coded quantum secure ranging radar device, the device comprising:

A master laser for generating light pulses with a period of T;

An unequal-arm interferometer module, used for splitting the optical pulse into two sub-pulses with a time difference, and for interfering the second echo component to generate an interference optical signal and send it to the second single-photon detector;

a first circulator, for transmitting the two sub-pulses to the slave laser, and for transmitting the coded state randomly output by the slave laser to the attenuator;

A slave laser is used to output a coded state through injection locking of the two sub-pulses under the driving of a driving signal, wherein the coded state includes a first time state in which the sub-pulse is at a previous time position under a Z basis and a second time state in which the sub-pulse is at a subsequent time position, and a phase state in which both the previous and subsequent time positions under an X basis contain sub-pulses;

an attenuator, for attenuating the coded state to a predetermined intensity to generate a corresponding emission quantum state;

A second circulator, used for transmitting the emission quantum state to the telescope, and for transmitting the echo quantum state returned by the telescope to the polarization processing and beam splitting module;

A telescope, used to expand the emitted quantum state and illuminate the target, and to receive the echo quantum state reflected by the target;

A polarization processing and beam splitting module, used for adjusting the polarization state of the echo quantum state, splitting it into a first echo component and a second echo component, and sending the first echo component and the second echo component to a first single-photon detector and an unequal-arm interferometer module respectively;

The first single-photon detector and the second single-photon detector are used to detect the first echo component and the interference light signal respectively.

On the other hand, the present invention provides a ranging method, wherein the above-mentioned time phase coded quantum secure ranging radar device performs the following steps:

Step S1: The light pulse generated by the master laser is split into two sub-pulses by the unequal-arm interferometer module and then injected into the slave laser, randomly generating three time-phase coded emission quantum state sequences as detection signals of the quantum security radar;

Step S2: The detection signal irradiates the target object and forms an echo quantum state after being reflected. The echo quantum state generates a first echo component and a second echo component after being polarized and processed by a beam splitting module;

Step S3: the first echo component enters the first single-photon detector for detection, and the first detection sequence D1 is recorded; the second echo component returns to the unequal-arm interferometer module for interference, and the generated interference light signal enters the second single-photon detector for detection, and the second detection sequence D2 is recorded;

Step S4: performing a shift cross-correlation operation on the emission quantum state sequence and the first detection sequence D1, and obtaining the target distance when the shift cross-correlation operation reaches a peak value;

Step S5: According to the target distance obtained in step S4, the transmitted quantum state sequence is matched with the detection results of the first echo component and the second echo component respectively, the Z-basis bit error rate is calculated according to the first detection sequence D1, and the X-basis bit error rate is calculated according to the second detection sequence D2, and the average bit error rate of the Z-basis and the X-basis is obtained. When the average bit error rate is greater than the bit error rate threshold, it is determined that there is deception interference on the target.

The beneficial effects of the present invention are:

(1) The time phase encoding quantum state is used, in which the time state is encoded in the relative time position, so it is very stable and has a low bit error rate; the phase state encoding and decoding reuses the same unequal arm interferometer, which can offset the change in the optical path difference between the long and short arms, and is therefore not affected by environmental changes, and there is no phase drift problem, which also has a low bit error rate. In addition, polarization processing can eliminate the influence of the polarization change of the echo quantum state on decoding. Therefore, compared with the polarization encoding scheme, it has higher stability and lower false alarm rate.

(2) The temporal phase state encoding is performed by combining unequal-arm interferometer with laser injection locking. The encoding and decoding reuse the same interferometer, and only three quantum states and two single-photon detectors need to be modulated. There is no need to use intensity modulators and phase modulators, which greatly reduces the system complexity.

(3) Without the need for an electro-optic modulator, the system repetition frequency can be increased to more than 1 GHz, and by using time phase encoding, the detection counting cycle is T/2, and the ranging resolution can be increased to r = c T/4=7.5cm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a time phase coded quantum secure ranging radar device according to the present invention;

FIG2 is a schematic diagram of the laser output result of an embodiment of the present invention;

FIG3 is a schematic diagram of a first embodiment of a time phase coded quantum secure ranging radar device according to the present invention;

FIG4 is a schematic diagram of a second embodiment of a time phase coded quantum secure ranging radar device according to the present invention;

FIG5 is a schematic diagram of a third embodiment of a time phase coded quantum secure ranging radar device according to the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in FIG1 , a schematic diagram of a time phase coded quantum secure ranging radar device of the present invention is shown, and the device comprises:

A master laser for generating light pulses with a period of T;

An unequal-arm interferometer module, used for splitting the optical pulse into two sub-pulses with a time difference, and for interfering the second echo component to generate an interference optical signal and send it to the second single-photon detector;

a first circulator, for transmitting the two sub-pulses to the slave laser, and for transmitting the coded state randomly output by the slave laser to the attenuator;

A slave laser is used to output a coded state through injection locking of the two sub-pulses under the driving of a driving signal, wherein the coded state includes a first time state in which the sub-pulse is at a previous time position under a Z basis and a second time state in which the sub-pulse is at a subsequent time position, and a phase state in which both the previous and subsequent time positions under an X basis contain sub-pulses;

an attenuator, for attenuating the coded state to a predetermined intensity to generate a corresponding emission quantum state;

A second circulator, used for transmitting the emission quantum state to the telescope, and for transmitting the echo quantum state returned by the telescope to the polarization processing and beam splitting module;

A telescope, used to expand the emitted quantum state and illuminate the target, and to receive the echo quantum state reflected by the target;

A polarization processing and beam splitting module, used for adjusting the polarization state of the echo quantum state, splitting it into a first echo component and a second echo component, and sending the first echo component and the second echo component to a first single-photon detector and an unequal-arm interferometer module respectively;

The first single-photon detector and the second single-photon detector are used to detect the first echo component and the interference light signal respectively.

The specific working process and principle are as follows:

The master laser generates a light pulse with a period of T, which is split into two sub-pulses with a time difference by the unequal-arm interferometer module. The two sub-pulses are transmitted to the slave laser through the first circulator and injection-locked. The period of the slave laser is used as the period of the system. Preferably, the operating frequency of the drive signal of the slave laser is twice that of the master laser. In one period, the two drive signals of the slave laser may include the following three situations:

(1) The previous drive signal exceeds the operating threshold of the slave laser, and the next drive signal is 0 or lower than the operating threshold of the slave laser;

(2) The previous drive signal is 0 or lower than the working threshold of the slave laser, and the next drive signal exceeds the working threshold of the slave laser;

(3) Both driving signals exceed the operating threshold of the slave laser.

The intensity of the optical pulse generated by the master laser in case (3) is half of the intensity of the optical pulse generated by the master laser in cases (1) and (2).

When the slave laser driving signal exceeds the working threshold, it will output a light pulse under the injection locking of the master laser. Therefore, within one cycle, the output results of the slave laser include: in case (1), the light pulse output from the slave laser is at the previous time position, which is the first time state; in case (2), the light pulse output from the slave laser is at the next time position, which is the second time state; in case (3), the output result of the slave laser contains light pulses at both the previous and next time positions, which is the phase state. The first time state and the second time state belong to the Z basis, and the phase state belongs to the X basis. The schematic diagram of the output result of the slave laser is shown in Figure 2.

Each cycle controls the driving signal of the slave laser to randomly select one of the above three situations to drive it, and can randomly generate a coding state among the first time state, the second time state, and the phase state.

The coded state generated from the laser then passes through the first circulator to the attenuator, where it decays to a predetermined intensity, generating a corresponding emission quantum state, i.e., the first time state , second time state/> , Phase State .

The emission quantum state is expanded by a telescope and then irradiates the target, and is collected by the telescope after being reflected by the target to form an echo quantum state; the echo quantum state enters the polarization processing and beam splitting module, which adjusts the polarization and splits it into a first echo component and a second echo component.

Preferably, the first echo component and the second echo component have the same amplitude and polarization state.

The first echo component directly enters the first single-photon detector for detection, and obtains the first detection sequence D1; the second echo component enters the unequal-arm interferometer module for interference, and the destructive interference optical signal enters the second single-photon detector for detection, and obtains the second detection sequence D2. Since the optical signal in the system passes through the unequal-arm interferometer module back and forth, the phase drift caused by the change in the optical path difference between the long and short arms can be automatically compensated, so a very stable interference result can be obtained without being affected by environmental changes.

Since the echo quantum state contains two time positions in one cycle, two detection time windows are required accordingly, so the detection count cycle in the first detection sequence D1 is T/2. The target distance L=c can be obtained by performing shift cross-correlation operation on the emission quantum state sequence and the first detection sequence D1. N/> T/4, where N is the displacement corresponding to the peak value of the cross-correlation result, and c is the speed of light in vacuum. The distance resolution is r = c/> T/4, when the operating frequency of the main laser is 100MHz, that is, the period is 10ns, the distance resolution is 0.75 meters. The operating frequency of the laser can easily reach 2GHz, so when the operating frequency of the main laser is 1GHz, the distance resolution can reach 7.5cm. It can be seen that compared with the distance resolution of 1.5 meters of the scheme (Optik, 2015, 126,33444-3348) of Wang Qiang et al. using pseudo-random modulation quantum secured lidar, the distance resolution of the present invention can be increased to more than 2 times, and increasing the operating frequency of the laser can even increase the distance resolution to 10 times.

After obtaining the target distance, the emission quantum state sequence can be matched with the detection results of the first echo component and the second echo component respectively. First, each element of the first detection sequence D1 is matched one by one with each element of the emission quantum state sequence, so that two adjacent elements in the first detection sequence D1 are taken as a group, corresponding to the previous time window and the next time window of the first single-photon detector respectively. By counting the detection counts C1E and C1L of the two time windows before and after the first detection sequence D1 corresponding to the first time state in the emission quantum state sequence, and the detection counts C2E and C2L of the two time windows before and after the first detection sequence D1 corresponding to the second time state in the emission quantum state sequence, the Z-based bit error rate can be calculated as Ez=(C1L+C2E)/(C1E+C1L+C2E+C2L).

Then the second detection sequence D2 is corresponded to the emission quantum state sequence one by one, so that two adjacent elements in the second detection sequence D2 are taken as a group, corresponding to the previous time window and the next time window of the second single-photon detector respectively. By counting the detection count Cx of the next time window in the second detection sequence D2 corresponding to the phase state in the emission quantum state sequence, and counting the detection count Cs1 of the previous time window in the second detection sequence D2 corresponding to the phase state when the previous quantum state in the emission quantum state sequence is the first time state and the next quantum state is the phase state, and counting the detection count Cs2 of the previous time window in the second detection sequence D2 corresponding to the second time state when the previous quantum state in the emission quantum state sequence is the phase state and the next quantum state is the second time state, the X-based bit error rate Ex=Cx/[8(Cs1+Cs2)] can be calculated.

Since the probability of selecting the Z basis and the X basis is 1/2, the average bit error rate Ea=(Ez+Ex)/2 can be calculated. When the target intercepts and retransmits the transmitted quantum state, since the transmitted signal is a random quantum state, the target may obtain an erroneous measurement result by selecting an intermediate basis to measure the transmitted quantum state. When it is re-prepared and sent to the radar device for measurement, at least 25% bit error rate will be introduced. The bit error rate threshold can be set to 25%. When the average bit error rate is greater than the bit error rate threshold, it is judged that the target has deception interference.

Embodiment 1

As shown in FIG3 , it is a schematic diagram of an improved embodiment 1 of a time phase coded quantum secure ranging radar device of the present invention:

The unequal-arm interferometer module includes a first beam splitter, a second beam splitter and a third circulator;

The two output ports of the first beam splitter and the two input ports of the second beam splitter are respectively connected through optical fibers of unequal lengths to form an unequal-arm interferometer;

The first port, the second port, and the third port of the third circulator (corresponding to ports 1, 2, and 3 of the third circulator in FIG. 3 , respectively) are connected to the main laser, the input port of the first beam splitter, and the second single-photon detector, respectively;

The two output ports of the second beam splitter are respectively connected to the first port of the first circulator (i.e., port 1 of the first circulator in FIG3 ) and an output port of the polarization processing and beam splitting module;

The polarization processing and beam splitting module includes a polarization controller and a third beam splitter;

The polarization controller is used to adjust the polarization of the echo quantum state to horizontal polarization, and its input port serves as the input port of the polarization processing and beam splitting module, and its output port is connected to the input port of the third beam splitter;

The two output ports of the third beam splitter are respectively used as two output ports of the polarization processing and beam splitting module;

The master laser is an electro-absorption laser, and the master laser light intensity corresponding to the phase state generated by the slave laser is half of the master laser light intensity corresponding to the first time state or the second time state generated by the slave laser.

The specific working process and principle of embodiment 1 are as follows:

The master laser generates a light pulse with a period of T, which enters the input port of the first beam splitter of the unequal-arm interferometer through the third circulator and is split into two sub-pulses. The two sub-pulses are transmitted along the two arms of the unequal-arm interferometer and arrive at the second beam splitter one after another. Since the lengths of the optical fibers in the two arms are unequal, there is a certain time difference when the two sub-pulses are output from the second beam splitter. Preferably, the time difference is T/2. Then the two sub-pulses are transmitted through the first circulator one after another to reach the slave laser, and are injection-locked to randomly generate the first time state. , second time state/> , phase state/> , ultimately emitting a sequence of quantum states at random output from the telescope.

The transmitted quantum state sequence is reflected by the target and returns to the telescope to become an echo quantum state. The polarization state is first adjusted to horizontal polarization by the polarization controller, and then enters the third beam splitter for beam splitting to generate the first echo component and the second echo component, both of which have the same amplitude and polarization state.

The first echo component directly enters the first single-photon detector for detection, and obtains the first detection sequence D1; the second echo component enters the unequal-arm interferometer from the second beam splitter for interference, and the generated destructive interference light signal enters the second single-photon detector for detection through the third circulator, and obtains the second detection sequence D2. When it passes through the unequal-arm interferometer in the forward direction, the phase drift occurs due to the difference in optical path length between the long and short arms affected by environmental changes./> , the actual phase state is/> When it passes through the unequal-arm interferometer in the reverse direction, the quantum state has a short flight time and the phase drift remains unchanged. The two components that interfere are and , the same phase factor between the two/> It can be regarded as a global phase and has no effect on the interference result. Therefore, environmental changes will not affect the interference, making the system extremely stable.

Finally, ranging and deception interference detection can be performed according to the above method.

Embodiment 2

As shown in FIG4 , it is a schematic diagram of a second improved embodiment of a time phase coded quantum secure ranging radar device of the present invention:

The unequal-arm interferometer module includes a first beam splitter, a second beam splitter and a third circulator;

The two output ports of the first beam splitter and the two input ports of the second beam splitter are respectively connected through optical fibers of unequal lengths to form an unequal-arm interferometer;

The two input ports of the first beam splitter are connected to the main laser and the second single photon detector respectively;

The first port, the second port, and the third port of the third circulator (corresponding to ports 1, 2, and 3 of the third circulator in FIG. 4 , respectively) respectively correspond to an output port connected to a polarization processing and beam splitting module, an output port of the second beam splitter, and a first port of the first circulator (i.e., port 1 of the first circulator in FIG. 4 ).

The polarization processing and beam splitting module includes a polarization scrambler and a polarization beam splitter;

The polarization scrambler is used to reduce the polarization degree of the echo quantum state to 0, and its input port serves as the input port of the polarization processing and beam splitting module (i.e., the second circulator, used to transmit the emission quantum state to the telescope, and to transmit the echo quantum state returned by the telescope to the polarization scrambler), and its output port is connected to the input port of the polarization beam splitter;

The two output ports of the polarization beam splitter are respectively used as two output ports of the polarization processing and beam splitting module.

The specific working process and principle of the second embodiment are similar to those of the first embodiment, with the following differences:

The optical pulse generated by the master laser directly enters an input port of the first beam splitter. The two sub-pulses emitted from the output port of the second beam splitter enter the second port of the third circulator. After being emitted from the third port of the third circulator, they enter the slave laser through the first circulator for injection locking, and randomly generate three coding states.

The echo quantum state first passes through a polarization scrambler to reduce the polarization degree to 0, that is, it becomes a random polarization state. Therefore, when entering the polarization beam splitter for beam splitting, the probability of being reflected and transmitted is 50%, that is, the first echo component and the second echo component are generated, and the two have the same amplitude and polarization state. The second echo component enters the first port of the third circulator, and then enters the output port of the second beam splitter after being emitted from the second port of the third circulator. Since the port where the second echo quantum state enters the unequal-arm interferometer is different from that in Example 1, the destructive interference light signal is emitted from another input port of the first beam splitter and then enters the second single-photon detector.

Embodiment 3

As shown in Figure 5, it is a schematic diagram of an improved embodiment 3 of a time phase coded quantum safe ranging radar device of the present invention. The device includes a master laser, a slave laser, a first beam splitter and a second beam splitter, a first single photon detector, a second single photon detector, a first circulator, a second circulator, an attenuator, a polarization beam splitter, a polarization scrambler, a telescope, and a target. The specific structure of the third embodiment is different from that of the second embodiment in that: the first circulator also includes a fourth port (i.e., the 4th port of the first circulator in Figure 5), and the optical transmission direction from the fourth port of the first circulator to the first port of the first circulator is conductive, replacing the function of the third circulator, so the third circulator can be omitted.

The specific working process and principle of the third embodiment are different from those of the second embodiment as follows:

The two sub-pulses emitted from the output port of the second beam splitter enter the first port of the first circulator, and then enter the slave laser for injection locking after being emitted from the second port of the first circulator, and three coding states are randomly generated.

The second echo component enters the fourth port of the first circulator, and enters the output port of the second beam splitter after being emitted from the first port of the first circulator.

The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (15)

1. A time-phase encoded quantum safety range radar apparatus, the apparatus comprising:

A primary laser for generating pulses of light having a period T;

The unequal arm interferometer module is used for splitting the optical pulse into two sub-pulses with time difference and interfering the second echo component to generate an interference optical signal and sending the interference optical signal to the second single photon detector;

A first circulator for transmitting the two sub-pulses to the slave laser and for transmitting the encoded states randomly output from the laser to the attenuator;

The slave laser is used for being injected and locked through the two sub-pulses under the drive of a drive signal, and outputting a coding state, wherein the coding state comprises a first time state of the sub-pulse under the Z base at a former time position, a second time state of the sub-pulse under the X base at a latter time position, and a phase state of the sub-pulse contained in the front and rear time positions under the X base;

the attenuator is used for attenuating the coded state to a preset intensity and generating a corresponding emission quantum state;

the second circulator is used for transmitting the emission quantum state to the telescope and transmitting the echo quantum state returned by the telescope to the polarization processing and beam splitting module;

A telescope for irradiating the target after expanding the emission quantum state, and for receiving the echo quantum state reflected by the target;

the polarization processing and beam splitting module is used for adjusting the polarization state of the echo quantum state, splitting the echo quantum state into a first echo component and a second echo component, and respectively sending the first echo component and the second echo component into the first single photon detector and the unequal arm interferometer module;

The first single photon detector and the second single photon detector are used for detecting a first echo component and an interference light signal respectively.

2. The time phase encoded quantum safety ranging radar apparatus of claim 1, wherein the unequal arm interferometer module comprises a first beam splitter, a second beam splitter, and a third circulator:

the two output ports of the first beam splitter are respectively connected with the two input ports of the second beam splitter through optical fibers with different lengths to form an unequal arm interferometer;

the first port, the second port and the third port of the third circulator are respectively and correspondingly connected with one of the input ports of the main laser and the first beam splitter and the second single photon detector;

The two output ports of the second beam splitter are respectively connected with the first port of the first circulator and one output port of the polarization processing and beam splitting module.

3. The time phase encoded quantum safety ranging radar apparatus of claim 1, wherein the unequal arm interferometer module comprises a first beam splitter, a second beam splitter, and a third circulator:

the two output ports of the first beam splitter are respectively connected with the two input ports of the second beam splitter through optical fibers with different lengths to form an unequal arm interferometer;

two input ports of the first beam splitter are respectively connected with the main laser and the second single photon detector;

The first port, the second port and the third port of the third circulator are respectively and correspondingly connected with one output port of the polarization processing and beam splitting module, one output port of the second beam splitter and the first port of the first circulator.

4. The time phase encoded quantum safety ranging radar apparatus of claim 1, wherein the first circulator further comprises a fourth port, and the unequal arm interferometer module comprises a first beam splitter, a second beam splitter, and a fourth port of the first circulator:

the two output ports of the first beam splitter are respectively connected with the two input ports of the second beam splitter through optical fibers with different lengths to form an unequal arm interferometer;

two input ports of the first beam splitter are respectively connected with the main laser and the second single photon detector;

the first port and the fourth port of the first circulator are respectively and correspondingly connected with one output port of the second beam splitter and one output port of the polarization processing and beam splitting module.

5. A time phase encoded quantum safety ranging radar apparatus according to claim 1 or 2 or 3 or 4, wherein the polarization processing and beam splitting module comprises a polarization controller and a third beam splitter:

the polarization controller is used for adjusting the polarization state of the echo quantum state into horizontal polarization, an input port of the polarization controller is used as an input port of the polarization processing and beam splitting module, and an output port of the polarization controller is connected with an input port of the third beam splitter;

The two output ports of the third beam splitter are respectively used as the two output ports of the polarization processing and beam splitting module.

6. A time phase encoded quantum safety ranging radar apparatus as claimed in claim 1 or 2 or 3 or 4, wherein the polarization processing and beam splitting module comprises a scrambler and a polarizing beam splitter:

the polarization scrambler is used for reducing the polarization degree of an echo quantum state to 0, an input port of the polarization scrambler is used as an input port of the polarization processing and beam splitting module, and an output port of the polarization scrambler is connected with an input port of the polarization beam splitter;

The two output ports of the polarization beam splitter are respectively used as the two output ports of the polarization processing and beam splitting module.

7. A time phase coded quantum safety ranging radar apparatus according to claim 1 or 2 or 3 or 4, wherein the time difference between the two sub-pulses produced by the unequal arm interferometer module is T/2.

8. A time phase coded quantum safety range radar device according to claim 1 or 2 or 3 or 4, wherein the operating frequency of the slave laser is 2 times the operating frequency of the master laser.

9. A time phase coded quantum safety range radar device according to claim 1 or 2 or 3 or 4, wherein the primary laser is an electro-absorption laser and the primary laser corresponding to the secondary laser producing a phase state is half the primary laser corresponding to the secondary laser producing a first time state or a second time state.

10. A time-phase coded quantum safety range radar device according to claim 1 or 2 or 3 or 4, wherein the probability of outputting the first and second time states from the laser is 1/4 and the probability of outputting the phase state is 1/2.

11. A time phase encoded quantum safety ranging radar apparatus according to claim 1 or 2 or 3 or 4, wherein the first echo component and the second echo component output from the two output ports of the polarization processing and beam splitting module have the same amplitude and polarization state.

12. A method of safe ranging, characterized in that the following steps are performed by a time-phase encoded quantum safe ranging radar apparatus according to any one of claims 1-11:

Step S1: the light pulse generated by the main laser is split into two sub-pulses by the unequal arm interferometer module and then injected into the auxiliary laser, 3 time phase coding emission quantum state sequences are randomly generated and used as detection signals of the quantum security radar;

step S2: the detection signal irradiates the target object, an echo quantum state is formed after the detection signal is reflected, and a first echo component and a second echo component are generated after the echo quantum state is subjected to polarization treatment and a beam splitting module;

step S3: the first echo component enters a first single photon detector to be detected, and a first detection sequence D1 is recorded; the second echo component returns to the unequal arm interferometer module to interfere, and the generated interference light signal enters a second single photon detector to be detected, and a second detection sequence D2 is recorded;

Step S4: carrying out shift cross-correlation operation on the emission quantum state sequence and the first detection sequence D1, and obtaining a target distance when the shift cross-correlation operation reaches a peak value;

step S5: and (3) matching the emission quantum state sequence with detection results of the first echo component and the second echo component respectively according to the target distance obtained in the step (S4), counting the Z-base error rate according to the first detection sequence D1, counting the X-base error rate according to the second detection sequence D2, obtaining the average error rates of the Z-base and the X-base, and judging that the target is deceptive-jamming when the average error rate is larger than an error rate threshold value.

13. The method for safe ranging as claimed in claim 12, wherein the statistical method of the Z-base error rate in step S5 is as follows:

step S5.1z: each element of the first detection sequence D1 is in one-to-one correspondence with each element of the emission quantum state sequence, so that two adjacent elements in the first detection sequence D1 are used as a group to respectively correspond to the previous time window and the next time window of the first single photon detector;

step S5.2z: counting detection counts C1E and C1L of front and rear two time windows in a first detection sequence D1 corresponding to a first time state in the emission quantum state sequence, and detection counts C2E and C2L of front and rear two time windows in the first detection sequence D1 corresponding to a second time state in the emission quantum state sequence;

Step S5.3z: the Z-base error rate ez= (c1l+c2e)/(c1e+c1l+c2e+c2l) is calculated.

14. The method for safe ranging as claimed in claim 12, wherein the statistical method of the X-base bit error rate in step S5 is as follows:

Step s5.1x: each element of the second detection sequence D2 is in one-to-one correspondence with each element of the emission quantum state sequence, so that two adjacent elements in the second detection sequence D2 are used as a group to respectively correspond to the previous time window and the next time window of the second single photon detector;

Step s5.2x: counting the detection count Cx of the latter time window in the second detection sequence D2 corresponding to the phase state in the emission quantum state sequence; counting detection counts Cs1 of a previous time window in a second detection sequence D2 corresponding to the phase state when the previous quantum state in the emission quantum state sequence is the first time state and the next quantum state is the phase state, and detection counts Cs2 of a previous time window in the second detection sequence D2 corresponding to the second time state when the previous quantum state in the emission quantum state sequence is the phase state and the next quantum state is the second time state;

step s5.3x: the X-base error rate ex=cx/[ 8 (Cs 1+ Cs 2) ].

15. The method according to claim 12, wherein the bit error rate threshold in the step S5 is 25%.