A quantum lidar based on time phase

Abstract

This invention provides a time-phase-based quantum lidar, which utilizes CMOS-compatible silicon-based optoelectronic integration technology to fabricate the transmitting and receiving chips. The advantages of chip-based integration include small size, light weight, and low power consumption, making it more practical for applications. The core chip for both quantum lidar and quantum secure communication systems, fabricated using integration technology, offers advantages such as small size, high precision, high speed, and low power consumption. This chip can be used for both quantum lidar and quantum secure communication.

Description

Technical Field

[0001] This invention relates to the field of optical imaging, and in particular to a quantum lidar based on time phase. Background Technology

[0002] The combination of quantum technology with lidar and optical communication has given rise to novel quantum lidar and quantum secure communication. Quantum lidar is a quantum sensor that modulates quantum information into lidar signals to emit or receive optical quantum signals, thereby achieving target detection. It can be used to detect, identify, and distinguish radio frequency stealth platforms and weapon systems, and theoretically boasts extremely long detection ranges, higher sensitivity, better concealment, and stronger anti-jamming capabilities, making it suitable for planetary defense and space exploration. Just as lidar can be used for space optical communication, quantum lidar can also be used for space quantum secure communication, ensuring confidentiality while also possessing acquisition, tracking, and alignment capabilities.

[0003] Currently, quantum lidar systems are built using discrete components, resulting in large system size and poor resistance to environmental interference. Summary of the Invention

[0004] In view of this, this embodiment of the invention provides a quantum lidar based on time phase.

[0005] This invention provides a time-phase-based quantum lidar, including a transmitting chip and a receiving chip.

[0006] The transmitting chip includes:

[0007] The first beam splitter is used to split the pulse light source into two beams, namely the first pulse light and the second pulse light;

[0008] A first time delay component, connected to the first beam splitter, is used to time delay the first pulse light;

[0009] A first phase-tuning component, connected to the first beam splitter, is used to configure an additional phase for the second pulsed light;

[0010] A first beam mixing component is connected to the first time delay component and the first phase adjustment component respectively, and is used to mix the first pulse light and the second pulse light to obtain a first pulse beam, the first pulse beam having two pulses;

[0011] A first optical phased array, connected to the first beam mixing component, is used to emit the first pulse beam into free space;

[0012] The receiving chip includes:

[0013] A second optical phased array is used to collect the first pulse beam;

[0014] The second beam splitter, connected to the second optical phased array, is used to split the first pulse beam into a third pulse beam and a fourth pulse beam.

[0015] The second time delay component, connected to the second beam splitter, is used to time delay the third pulse light;

[0016] The second phase-adjusting component, connected to the second beam splitter, is used to configure an additional phase for the fourth pulse beam;

[0017] The second beam mixing component is connected to the second time delay component and the second phase adjustment component respectively, and is used to mix the third pulse light and the fourth pulse light to obtain a second pulse beam, the second pulse beam having three pulses;

[0018] The second photodetector is connected to the second beam mixing component and is used to perform photoelectric conversion on the second pulse beam.

[0019] As an optional embodiment, the transmitting chip further includes a third phase-tuning component for configuring an additional phase on the first pulse beam, an amplitude modulator for balancing the amplitudes between optical pulses, a first photodetector for real-time online detection of the pulse information of the first pulse beam, and a first coupler for coupling the optical signal of the laser into the optical waveguide of the chip. The third phase-tuning component is connected to the first time delay component and the first beam mixing component, respectively. The amplitude modulator is connected to the first phase-tuning component and the first beam mixing component, respectively. The first photodetector is connected to the first beam mixing component. The fourth phase-tuning component is connected to the second beam splitter and the second time delay component, respectively. The second amplitude modulator is connected to the second beam splitter and the second phase-tuning component, respectively.

[0020] As an optional solution, the receiving chip further includes a second coupler for detecting optical signals to check the performance of the receiving chip, a fourth phase modulation component for configuring additional phase for the third pulse beam, and a second amplitude modulator for balancing the amplitude between optical pulses. The second coupler is connected to the second beam splitter, and the second photodetector is a balanced photodetector, specifically including two sub-photodetectors.

[0021] As an optional solution, the first time delay component and the second time delay component use the same time delay line and have the same delay time. The time delay line includes a 1×N optical switch, an N×1 optical switch and N first delay lines of different lengths in the middle. The 1×N optical switch and the N×1 optical switch randomly select the delay line according to external instructions.

[0022] As an optional solution, the time delay line includes a 1×4 optical switch and a 4×1 optical switch and four second delay lines that generate a fixed additional phase difference. The phase difference between adjacent double pulses is 0, π / 4, π / 2, and 3π / 4 within the principal complex angle of 0 to 2π.

[0023] As an optional embodiment, the transmitting chip further includes a third photodetector for photoelectric conversion when used as a receiving chip, the third photodetector being connected to the first beam splitter.

[0024] As an alternative, when performing quantum secure communication, the first optical phased array of the transmitting chip is replaced by a third coupler, which is connected to the second coupler by optical fiber.

[0025] This invention provides a time-phase-based quantum lidar, which utilizes CMOS-compatible silicon-based optoelectronic integration technology to fabricate the transmitting and receiving chips. The advantages of chip-based integration include small size, light weight, and low power consumption, making it more practical for applications. The core chip for both quantum lidar and quantum secure communication systems, fabricated using integration technology, offers advantages such as small size, high precision, high speed, and low power consumption. This chip can be used for both quantum lidar and quantum secure communication. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a quantum lidar based on time phase provided in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of a quantum lidar based on time phase provided in an embodiment of the present invention;

[0028] Figure 3 This invention provides a schematic diagram of another time-phase-based quantum lidar structure in an embodiment of the invention.

[0029] Figure 4 This is a schematic diagram of the time delay line structure in a quantum lidar based on time phase, provided in an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of the time delay line structure in a quantum lidar based on time phase, provided in an embodiment of the present invention.

[0031] Figure 6 This invention provides a schematic diagram of another time delay line structure in a quantum lidar based on time phase in an embodiment of the present invention;

[0032] Figure 7This is a schematic diagram of another quantum lidar based on time phase provided in an embodiment of the present invention;

[0033] Figure 8 This is a schematic diagram of another time-phase-based quantum lidar provided in an embodiment of the present invention.

[0034] Reference numerals: Transmitting chip 100, first beam splitter 101, first time delay component 102, first phase adjustment component 103, first beam mixing component 104, first optical phased array 105, third phase adjustment component 106, amplitude modulator 107, first photodetector 108, first coupler 109, third photodetector 110, third coupler 111;

[0035] The receiver chip 200, the second optical phased array 201, the second beam splitter 202, the second time delay component 203, the second phase adjustment component 204, the second beam mixing component 205, the second photodetector 206, the second coupler 207, the fourth phase adjustment component 208, and the second amplitude modulator 209.

[0036] 1×N optical switch 311, N×1 optical switch 313, delay line 312-1;

[0037] 1×4 optical switch 321 and 4×1 optical switch 323, second delay lines 322-1 to 322-4; Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0039] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0040] Combination Figure 1 and Figure 2 As shown, this embodiment of the invention provides a time-phase-based quantum lidar, including a transmitting chip 100 and a receiving chip 200.

[0041] The transmitter chip 100 includes:

[0042] The first beam splitter 101 is used to split the pulse light source into two beams, namely the first pulse light and the second pulse light;

[0043] The first time delay component 102 is connected to the first beam splitter 101 and is used to delay the first pulse light.

[0044] The first phase-adjusting component 103 is connected to the first beam splitter 101 and is used to configure an additional phase for the second pulse light.

[0045] The first beam mixing component 104 is connected to the first time delay component 102 and the first phase adjustment component 103 respectively, and is used to mix the first pulse light and the second pulse light to obtain a first pulse beam, the first pulse beam having two pulses;

[0046] The first optical phased array 105, connected to the first beam mixing component 104, is used to emit the first pulsed beam into free space. Specifically, the pulsed light source is coupled from the laser to the emitting chip 100 via a coupler, and then split into two beams by the first beam splitter 101, namely the first pulsed light and the second pulsed light, which follow two paths. In the first path, the first pulsed light passes through the delay line of the first time delay component 102, which introduces a certain time delay. In the second path, the second pulsed light passes through the first phase adjustment component 103, which adds a phase to the second pulsed laser. Then, the two beams are mixed by the first beam mixing component 104. At this point, each laser pulse becomes two, with the later pulse following the first path and the earlier pulse following the second path. The time difference between these two laser pulses is mainly caused by the time delay of the first path, which is required to be greater than the width of the light pulse so that the two light pulses can be clearly separated. The phase difference between them is controlled by the second path phase modulator. These two laser pulses enter the first optical phased array 105 and are emitted into free space.

[0047] The receiver chip 200 includes:

[0048] The second optical phased array 201 is used to collect the first pulse beam;

[0049] The second beam splitter 202 is connected to the second optical phased array and is used to split the first pulse beam to obtain a third pulse beam and a fourth pulse beam.

[0050] The second time delay component 203 is connected to the second beam splitter 202 and is used to delay the time of the third pulse light.

[0051] The second phase adjustment component 204 is connected to the second beam splitter 202 and is used to configure an additional phase for the fourth pulse light.

[0052] The second beam mixing component 205 is connected to the second time delay component 203 and the second phase adjustment component 204 respectively, and is used to mix the third pulse light and the fourth pulse light to obtain a second pulse beam, the second pulse beam having three pulses;

[0053] The second photodetector 206, connected to the second beam mixing component 205, is used to perform photoelectric conversion on the second pulse beam. Specifically, the dual pulse emitted by the transmitting chip 100 is reflected (or directly) by a spatial object and collected by the second optical phased array 201 of the receiving chip 200, and enters the optical waveguide. After passing through the second beam splitter 202, the second beam splitter 202 also splits the pulse beam into two paths, namely the third pulse beam and the fourth pulse beam. The first path is that the third pulse beam passes through the second time delay component 203, which produces the same time delay. The second path is that the fourth pulse beam passes through the second phase modulation component 204, which adds another phase to the pulse laser. Then, the two beams are mixed by the second beam mixing component 205. At this time, the optical signal of the dual pulse becomes three pulses, of which the middle optical pulse is the coherent superposition of two pulses. Its amplitude is determined by the phase added by the phase modulation components in the second paths of the transmitting chip 100 and the receiving chip 200.

[0054] Combination Figure 3 As shown, in one embodiment, the transmitting chip 100 further includes a third phase-adjusting component 106 for configuring an additional phase for the first pulse beam, an amplitude modulator 107 for balancing the amplitudes between optical pulses, a first photodetector 108 for real-time online detection of the pulse information of the first pulse beam, and a first coupler 109 for coupling the optical signal of the laser into the optical waveguide of the chip. The third phase-adjusting component 106 is connected to the first time delay component 102 and the first beam mixing component 104, respectively. The amplitude modulator 107 is connected to the first phase-adjusting component 103 and the first beam mixing component 104, respectively. The first photodetector 108 is connected to the first beam mixing component 104.

[0055] The coupler in this embodiment of the invention couples the optical signal from the laser into the optical waveguide of the silicon photonic chip. The first beam splitter 101 is a 2×2 optical hybrid beam splitter, which can split the light from the two waveguides at one end into the two waveguides at the other end. The first time delay component 102 generates a delay time greater than the width of the optical pulse. The first phase modulation component 103 and the third phase modulation component 106 are both phase modulators. Although theoretically only one phase modulator is needed to achieve the required function, having a phase modulator for each path can balance the phase and help reduce phase modulation power consumption. The presence of the amplitude modulator 107 is beneficial for balancing the amplitude between optical pulses. 400 is an optical phased array, which can radiate light from the chip into free space and change the radiation direction of the light through electronic control. The first photodetector 108 and the second photodetector 206 are photodetectors, which can be avalanche photodiodes (or single-photon detectors) or PIN photodetectors, and are not limited thereto.

[0056] Combination Figure 4 As shown, in one embodiment, the receiving chip 200 further includes a fourth phase-adjusting component 208 for configuring an additional phase for the third pulse beam, a second amplitude modulator 209 for balancing the amplitudes between optical pulses, a first photodetector 108 for real-time online detection of the pulse information of the first pulse beam, and a first coupler 109 for coupling the optical signal of the laser into the optical waveguide of the chip. The third phase-adjusting component 106 is connected to the first time delay component 102 and the first beam mixing component 104, respectively. The amplitude modulator 107 is connected to the first phase-adjusting component 103 and the first beam mixing component 104, respectively. The first photodetector 108 is connected to the first beam mixing component 104.

[0057] Combination Figure 4 As shown, in one embodiment, the receiving chip 200 further includes a second coupler 207 for detecting optical signals to check the performance of the receiving chip, a fourth phase modulation component 208 for configuring additional phase for the third pulse beam, and a second amplitude modulator 209 for balancing the amplitudes between optical pulses. The second coupler 207 is connected to the second beam splitter 202. The second photodetector 206 is a balanced photodetector, specifically including two sub-photodetectors. Compared with a single photodetector, the balanced photodetector has higher sensitivity. The fourth phase modulation component 208 is connected to the second beam splitter 202 and the second time delay component 203, respectively. The second amplitude modulator 209 is connected to the second beam splitter 202 and the second phase modulation component 204, respectively.

[0058] Combination Figure 5As shown, the first time delay component 103 and the second time delay component 203 use the same time delay line and have the same delay time. By taking advantage of the fact that the delay time is the same, the anti-interference ability, confidentiality and identifiability of the quantum lidar can be increased by changing the time delay. Specifically, the time delay line includes a 1×N optical switch 311, an N×1 optical switch 313 and N first delay lines 312-1…312-n of different lengths in the middle. The 1×N optical switch 311 and the N×1 optical switch 313 randomly select the delay line according to external instructions.

[0059] In this embodiment, since the middle pulse is the result of interference among the three pulses, its phase difference is controlled by the phase modulators of the transmitting and receiving chips. When used for quantum secure communication, the BB84 protocol requires rapid switching between four phases, while the B92 protocol requires rapid switching between two phases. The phase modulators on the transmitting chip 100 and the receiving chip 200 can employ... Figure 6 The structure shown consists of two optical switches 321 (1×4 and 4×1) and four parts 322 that generate fixed additional phase differences. These pre-set fixed additional phases can ensure that the phase difference between the two pulses generated by the transmitting chip is 0, π / 4, π / 2, and 3π / 4 respectively within the principal complex angle of 0 to 2π.

[0060] Combination Figure 6 As shown, the time delay line includes a 1×4 optical switch 321 and a 4×1 optical switch 323 and four second delay lines 322-1 to 322-4 that generate a fixed additional phase difference. The phase differences between adjacent double pulses are 0, π / 4, π / 2, and 3π / 4, respectively, within the principal complex angle of 0 to 2π.

[0061] Combination Figure 7 As shown, the transmitting chip 100 also includes a third photodetector 110 for photoelectric conversion when used as a receiving chip, and the third photodetector 110 is connected to the first beam splitter 101.

[0062] Combination Figure 8 As shown, during quantum secure communication, the first optical phased array of the transmitting chip 100 is replaced by a third coupler 111, and the third coupler 111 is connected to the second coupler 207 by optical fiber.

[0063] This invention provides a time-phase-based quantum lidar, which utilizes CMOS-compatible silicon-based optoelectronic integration technology to fabricate the transmitting and receiving chips. The advantages of chip-based integration include small size, light weight, and low power consumption, making it more practical for applications. The core chip for both quantum lidar and quantum secure communication systems, fabricated using integration technology, offers advantages such as small size, high precision, high speed, and low power consumption. This chip can be used for both quantum lidar and quantum secure communication.

[0064] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0065] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A quantum lidar based on time phase, characterized in that, Including transmitter chip and receiver chip, The transmitting chip includes: The first beam splitter is used to split the pulse light source into two beams, namely the first pulse light and the second pulse light; A first time delay component, connected to the first beam splitter, is used to time delay the first pulse light; A first phase-tuning component, connected to the first beam splitter, is used to configure an additional phase for the second pulsed light; A first beam mixing component is connected to the first time delay component and the first phase adjustment component respectively, and is used to mix the first pulse light and the second pulse light to obtain a first pulse beam, the first pulse beam having two pulses; A first optical phased array, connected to the first beam mixing component, is used to emit the first pulse beam into free space and to change the radiation direction of the light by means of electronic control. A third phase-adjusting component for configuring an additional phase on the first pulse beam and an amplitude modulator for balancing the amplitudes between optical pulses, wherein the third phase-adjusting component is connected to the first time delay component and the first beam mixing component respectively, and the amplitude modulator is connected to the first phase-adjusting component and the first beam mixing component respectively. The receiving chip includes: A second optical phased array is used to collect the first pulse beam; The second beam splitter, connected to the second optical phased array, is used to split the first pulse beam into a third pulse beam and a fourth pulse beam. The second time delay component, connected to the second beam splitter, is used to time delay the third pulse light; The second phase-adjusting component, connected to the second beam splitter, is used to configure an additional phase for the fourth pulse beam; The second beam mixing component is connected to the second time delay component and the second phase adjustment component respectively, and is used to mix the third pulse light and the fourth pulse light to obtain a second pulse beam, the second pulse beam having three pulses; The second photodetector is connected to the second beam mixing component and is used to perform photoelectric conversion on the second pulse beam; A fourth phase-adjusting component for configuring an additional phase on the third pulse beam and a second amplitude modulator for balancing the amplitudes between optical pulses, the fourth phase-adjusting component being connected to the second beam splitter and the second time delay component, respectively, and the second amplitude modulator being connected to the second beam splitter and the second phase-adjusting component, respectively. The first time delay component and the second time delay component use the same time delay line and have the same delay time.

2. The quantum lidar based on time phase according to claim 1, characterized in that, The transmitting chip also includes a first photodetector for real-time online detection of the pulse information of the first pulse beam and a first coupler for coupling the optical signal of the laser into the optical waveguide of the chip. The first photodetector is connected to the first beam mixing component.

3. The quantum lidar based on time phase according to claim 1, characterized in that, The receiving chip also includes a second coupler for detecting optical signals to check the performance of the receiving chip. The second coupler is connected to the second beam splitter. The second photodetector is a balanced photodetector, specifically including two sub-photodetectors.

4. The quantum lidar based on time phase according to claim 1, characterized in that, The time delay line includes a 1×N optical switch, an N×1 optical switch, and N first delay lines of different lengths in the middle. The 1×N optical switch and the N×1 optical switch randomly select the delay line according to external instructions.

5. The quantum lidar based on time phase according to claim 4, characterized in that, The time delay line includes a 1×4 optical switch and a 4×1 optical switch and four second delay lines that generate a fixed additional phase difference. The phase difference between adjacent double pulses is 0, π / 4, π / 2, and 3π / 4 within the principal complex angle of 0 to 2π.

6. The quantum lidar based on time phase according to claim 1, characterized in that, The transmitting chip also includes a third photodetector for photoelectric conversion when used as a receiving chip, the third photodetector being connected to the first beam splitter.

7. The quantum lidar based on time phase according to claim 3, characterized in that, In quantum secure communication, the first optical phased array of the transmitting chip is replaced by a third coupler, which is connected to the second coupler by optical fiber.

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