CN117217321B

CN117217321B - Quantum image generation device and method

Info

Publication number: CN117217321B
Application number: CN202311481961.4A
Authority: CN
Inventors: 安雪碧; 丁士俊; 周志伟; 李安
Original assignee: Hefei Si Zhen Chip Technology Co ltd
Current assignee: Hefei Si Zhen Chip Technology Co ltd
Priority date: 2023-11-09
Filing date: 2023-11-09
Publication date: 2024-01-30
Anticipated expiration: 2043-11-09
Also published as: CN117217321A

Abstract

The application discloses a quantum image generation device and a quantum image generation method, wherein the quantum image generation device comprises a basic image generation module, a first delay selection module, a second delay selection module, a first fusion operation module and a second fusion operation module; the basic pattern generation module correspondingly generates N node pattern units of a plurality of different time domains based on a plurality of pumping light pulses input from the outside, and carries out delay processing on photons in the N node pattern units of the different time domains through the delay selection unit so that photons with the same wavelength to be fused and connected reach the fusion operation module at the same time, and the fusion operation module carries out fusion operation on the photons to be fused and connected in the different N node pattern to expand and prepare a large-scale pattern. According to the method, the quantum image fusion connection of different time domains is expanded into a large-scale image, and the method can be realized by adopting fewer devices and smaller space under the requirement of forming the same large-scale quantum image, so that the limitation of the chip size is broken through, and the cost is saved.

Description

Quantum image generation device and method

Technical Field

The application belongs to the technical field of quantum information, and particularly relates to a quantum image generation device and a quantum image generation method.

Background

The image state has important application value in the field of quantum information, and is an important resource for quantum communication and quantum computing. The quantum image is a special quantum entangled state which can be described in a simple, visual and effective way through a mathematical graph, is not a specific quantum state, but is a quantum state, the intuitiveness and the feasibility of mathematical calculation greatly simplify the complexity of quantum entangled value measurement, and therefore, the quantum image is a basic resource for researching quantum calculation, quantum error correction, quantum walking and understanding the characteristics of the quantum entangled state.

In the graphics states, each vertex represents a quantum bit, each connecting line represents a correlation, different dot line combinations can form different graphics states, and more common graphics state types are a linear graphics state, a star graphics state, a horseshoe graphics state and an extensible two-dimensional grid graphics state. Of these pattern types, the linear pattern is the simplest and most basic pattern, and when other various patterns are studied, the linear pattern is often not separated, while the star pattern is a typical representative pattern, which uses one vertex as the center, and other vertices are all connected with the vertex, and as shown in fig. 1, other various patterns can be easily evolved from the star pattern.

The existing on-chip pattern generation technology generally adopts a laser light source, a beam splitter and a silicon waveguide coil to generate entangled photon pairs, and the quantum pattern scale is determined by the number of photons and the interconnection degree between photons, so that a large number of silicon waveguide coils and quantum logic gate optical devices are needed for preparing large-scale quantum patterns, and a large chip area is needed when the on-chip pattern generation technology is integrated, however, the chip size has process limitations, for example, the size of a silicon optical chip is the size of a mask plate of a photoetching machine at maximum, and therefore, the pattern scale generated by an on-chip pattern generation scheme can be limited by the chip size and is not easy to expand.

Disclosure of Invention

Based on the above, the present application provides a quantum image generating device and a generating method, which generate a plurality of N node image units in different time domains by using a basic image generating module, delay photons in the N node image units in different time domains by using a delay selecting unit to make photons with the same wavelength to be fused and connected arrive at a fusion operation module at the same time, and then fusion operation expansion is performed on photons to be fused and connected in different N node image units by using the fusion operation module to prepare a larger scale image, thereby breaking through the limitation of chip size. The specific scheme is as follows:

In a first aspect, the application discloses a quantum image generation device, which comprises a basic image generation module, a first delay selection module, a second delay selection module, a first fusion operation module and a second fusion operation module;

the basic pattern generation module generates M N node pattern units based on M pumping light pulses input from the outside and transmits the N node pattern units to the first delay selection module and the second delay selection module, wherein M isN is->Each N node pattern element comprising N photons, wherein N/2 photons have a wavelength +.>The other N/2 photon wavelength is +.>The basic pattern generation module is provided with N groups of output ports, and the front N/2 groups of output ports are used for outputting the output wavelength of +.>The post-N/2 group of output ports are used for outputting photons with the wavelength of +.>Each group of output ports comprising two output sub-ports;

first delay selection module and second delayThe selection modules comprise N delay selection units, and the delay selection units in the first delay selection module are used for receiving the wavelength of the received waveAnd delays the received photons by different times so that the wavelength of the connection to be fused in different N node patterns is +.>The photons of (a) arrive at the first fusion operation module at the same time, and a delay selection unit in the second delay selection module is used for receiving the wavelength of +. >And delays the received photons by different times so that the wavelength of the connection to be fused in different N node patterns is +.>Each delay selection unit is correspondingly connected with one output sub-port of the basic pattern generation module, each delay selection unit is provided with M output ports, and the M output ports of each delay selection unit respectively output photons of M N node pattern units in a one-to-one correspondence manner;

the first fusion operation module and the second fusion operation module are respectively provided with N groups of input ports and N groups of exit ports, each group of input ports is provided with M input sub-ports, each group of exit ports is provided with M exit sub-ports, the M input sub-ports of each group of input ports are respectively connected with the M output ports of the delay selection unit in a one-to-one correspondence manner, and the first fusion operation module is used for receiving the wavelength output by the first delay selection module and is provided withCarrying out fusion operation on photons to be fused and connected in different N node patterns to ensure that the photons corresponding to be fused and connected carry out path exchange to complete pattern scale expansion; the second fusion operation module is used for receiving the wavelength output by the second delay selection module as +.>And carrying out fusion operation on photons to be fused and connected in different N node patterns to ensure that the photons to be fused and connected carry out path exchange to complete pattern scale expansion.

Further, the basic pattern generation module includes a beam splitting module having N/2 output ends, N/2 50:50 beam splitters, N two-photon generation structures, N path distribution modules and a waveguide transmission module, where the beam splitting module is configured to averagely split a received pump light pulse into N/2 beams, and each output end of the beam splitting module is correspondingly connected to one 50: the two output ends of the 50 beam splitter and the 50:50 beam splitter are respectively connected with a two-photon generating structure, and the two-photon generating structure is used for generating light with the wavelength of respectivelyAnd->Each two-photon generating structure is connected with a path distribution module which is provided with an output upper end and an output lower end and is used for receiving the entangled photon pairs generated by the two-photon generating structure and setting the wavelength as +.>Is output from its output upper end, with wavelength +.>Is output from the lower output end thereof; the waveguide transmission module consists of N groups of waveguide transmission paths and at least (N/2) -1 path switching units, the path switching units are used for carrying out path switching on photons with the same wavelength on different waveguide transmission paths to form N node pattern units, the front N/2 groups of waveguide transmission paths form a first waveguide transmission unit, the rear N/2 groups of waveguide transmission paths form a second waveguide transmission unit, each group of waveguide transmission paths comprise 2 transmission waveguides, and the output lower ends of the path distribution modules are respectively connected with the transmission waveguides of the second waveguide transmission unit in sequence so as to enable the wavelength to be >The output upper ends of the path distribution modules are respectively connected with the transmission waveguides of the first waveguide transmission unit in sequence so as to enable the wavelength to be +.>Is transmitted to the first waveguide transmission unit.

Further, the delay selection unit consists of a 1 XM waveguide type input optical switch, M delay lines with sequentially equal-amount incremental lengths and M1 XM waveguide type output optical switches; the 1 XM waveguide type input optical switch is provided with M output ends, each output end of the switch is connected with the input end of one delay line, and the switch is used for adjusting the transmission path of input photons to enable the input photons to be transmitted to the corresponding delay line; the M delay lines with the equal-quantity increasing lengths sequentially delay the received photons by corresponding time respectively, and the equal-quantity increasing lengths of the delay lines are equal to the period of pumping light pulse output multiplied by the propagation speed of the photons on the delay lines; the output end of each delay line is connected with a 1 xM waveguide type output optical switch, and the 1 xM waveguide type output optical switch is provided with M output ends which respectively output photons of M N node pattern units in a one-to-one correspondence mode.

Further, a fusion operation structure is arranged on the first fusion operation module or/and the second fusion operation module, the total number of the fusion operation structures arranged on the two fusion operation modules is at least (M-1), and the fusion operation structure is used for exchanging a transmission path of a photon output from one delay selection unit with a transmission path of a photon output from the other delay selection unit.

Preferably, the first fusion operation module and the second fusion operation module are (MXN) x (MXN) waveguide type optical switches, and are formed by cross cascading (MXN-1) x (MXN/2) MZ interferometers according to a square structure.

Preferably, the two-photon generating structure is one of a helical waveguide coil, a silicon nitride micro-ring structure, or a periodically poled crystal waveguide.

Preferably, the path allocation module is a wavelength division demultiplexer or an optical filter.

Preferably, the splitting module is a 1× (N/2) MMI coupler.

Further, the 1 XM waveguide type input optical switch and the 1 XM waveguide type output optical switch are formed by cascading a plurality of MZ interferometers and are in a tree structure.

In a second aspect, the present application discloses a quantum image generating method, where the generating method is applied to the quantum image generating device, and the quantum image generating device includes a basic image generating module, a first delay selecting module, a second delay selecting module, a first fusion operating module and a second fusion operating module; the generating method comprises the following steps:

the basic pattern generation module generates M N node pattern units based on M pumping light pulses input from the outside, wherein each N node pattern unit comprises N/2 wavelengths Is +.2 wavelengths>And N/2 wavelengths are +.>Is transmitted to the first delay selection module, N/2 wavelengths are +.>Photon transmission to a second delay selection module;

the receiving wavelength of the delay selection unit in the first delay selection module isAnd delays the received photons by different times so that the wavelength of the connection to be fused in different N node patterns is +.>The photons of the (a) arrive at the first fusion operation module at the same time, and the receiving wavelength of a delay selection unit in the second delay selection module is +.>And to receive photonsThe delays of different times are such that the wavelength of the connection to be fused in the different N node patterns is +.>The photons of (a) arrive at the second fusion operation module at the same time;

the first fusion operation module receives the wavelength output by the first delay selection module as followsThe photons to be fused and connected in different N node patterns are fused, so that the corresponding photons to be fused and connected are subjected to path exchange to complete pattern scale expansion, and the second fusion operation module receives the wavelength output by the second delay selection module as +.>And carrying out fusion operation on photons to be fused and connected in different N node patterns to ensure that the photons to be fused and connected carry out path exchange to complete pattern scale expansion.

In general, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

the quantum image generating device comprises a basic image generating module, a first delay selecting module, a second delay selecting module, a first fusion operating module and a second fusion operating module; the basic pattern generation module correspondingly generates N node pattern units of a plurality of different time domains based on a plurality of pumping light pulses input from the outside, and carries out delay processing on photons in the N node pattern units of the different time domains through the delay selection unit so that photons with the same wavelength to be fused and connected reach the fusion operation module at the same time, and the fusion operation module carries out fusion operation expansion on the photons to be fused and connected in the different N node pattern to prepare a larger-scale pattern; based on the characteristic that the quantum image can be fused, connected and expanded through the fusion operation module, the quantum image fusion connection of different time domains is expanded into a larger-scale image through a time domain expansion method, and under the condition that the same large-scale quantum image requirement is formed, fewer devices and smaller space can be adopted to realize the method, so that the limitation of the chip size is broken through, and meanwhile, the resources and the cost are saved.

Drawings

In order to more clearly illustrate the present embodiments or the technical solutions in the prior art, the drawings that are required for the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a star pattern;

FIG. 2 is a schematic diagram of a quantum image generating device according to the present disclosure;

FIG. 3 is a schematic structural diagram of a quantum image generating device according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of a basic pattern generation module according to the embodiment of FIG. 3;

FIG. 5 is a schematic diagram of a basic pattern generation module according to another embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of a delay selection unit provided in the present application;

fig. 7 is a schematic structural diagram of a delay selection unit according to another embodiment of the present application;

FIG. 8 is a schematic diagram of a fusion operation structure for implementing fusion connection in the present application;

FIG. 9 is a schematic diagram of a fusion expansion performed by 2 fusion operation structures in the present application;

FIG. 10 is a schematic diagram of the fusion expansion of FIG. 3 to form a 12-node quantum graph;

FIG. 11 is a schematic structural diagram of a quantum image generating device according to another embodiment of the present disclosure;

FIG. 12 is a schematic diagram of the principle of forming a 12-node quantum graph based on the fusion expansion of FIG. 11;

FIG. 13 is a schematic structural diagram of a quantum image generating device according to another embodiment of the present disclosure;

FIG. 14 is a schematic diagram of the fusion expansion of FIG. 13 to form a 12-node quantum graph;

fig. 15 is a schematic structural diagram of a first fusion operation module and a second fusion operation module according to another embodiment of the present application;

FIG. 16 is a schematic diagram of a quantum image generating device according to the present application based on FIG. 15;

fig. 17 is a flowchart of a quantum image generation method provided in the present application.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures and detailed description are described in further detail below. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present application is not limited to the specific embodiments disclosed below.

In order to facilitate understanding and explanation of the technical solutions provided by the embodiments of the present application, the background art of the present application will be described first.

The image state has important application value in the field of quantum information, and is an important resource for quantum communication and quantum computing. The existing on-chip pattern generation technology generally adopts a laser light source, a beam splitter and a silicon waveguide coil to generate entangled photon pairs, and the quantum pattern scale is determined by the number of photons and the interconnection degree between photons, so that a large number of silicon waveguide coils and quantum logic gate optical devices are needed for preparing large-scale quantum patterns, and a large chip area is needed when the on-chip pattern generation technology is integrated, however, the chip size has process limitations, for example, the size of a silicon optical chip is the size of a mask plate of a photoetching machine at maximum, and therefore, the pattern scale generated by an on-chip pattern generation scheme can be limited by the chip size and is not easy to expand.

Based on the above, the application discloses a quantum image generating device, as shown in fig. 2, which comprises a basic image generating module, a first delay selecting module, a second delay selecting module, a first fusion operating module and a second fusion operating module.

The basic pattern generation module generates M N node pattern units based on M pumping light pulses input from the outside and transmits the N node pattern units to the first delay selection module and the second delay selection module, wherein M isN is->Each N node pattern element comprising N photons, wherein N/2 photons have a wavelength +.>The other N/2 photon wavelength is +.>The basic pattern generation module is provided with N groups of output ports, and the front N/2 groups of output ports are used for outputting the output wavelength of +.>The post-N/2 group of output ports are used for outputting photons with the wavelength of +.>Each set of output ports comprising two output sub-ports.

The basic pattern generation module generates an N-node pattern unit based on one pump light pulse, and generates N-node pattern units of M different time domains when M pump light pulses are sequentially input to the basic pattern generation module. The graphical element generated in this application has at least 4 nodes, The specific pattern unit has a number of nodes determined according to the structure of the basic pattern generation module, each node represents a quantum bit, and the generated N node pattern unit comprises N photons, and in the N photons, the wavelength of half of the photons is different from that of the other half of the photons, wherein N/2 photons are set as the wavelengthThe other N/2 photon wavelength is set as +.>. Specifically, the first N/2 groups of output ports of the basic pattern generation module are used for outputting the N node pattern units with the wavelength of +.>The latter N/2 group of output ports are used for outputting the photons with the wavelength of +.>Is a photon of (a) a photon of (b). Each set of output ports outputs one photon of an N-node pattern unit, each photon being output from one output sub-port of each set of output ports. N/2 wavelengths are->Is input to the first delay selection module, N/2 wavelengths are +.>Is input to the second delay selection module.

The first delay selection module and the second delay selection module both comprise N delay selection units, and the delay selection units in the first delay selection module are used for receiving the wavelength of N delay selection unitsAnd delays the received photons by different times so that the wavelength of the connection to be fused in different N node patterns is +. >Is identical to the photons of (2)When the first time reaches the first fusion operation module, the delay selection unit in the second delay selection module is used for receiving the wavelength of +.>And delays the received photons by different times so that the wavelength of the connection to be fused in different N node patterns is +.>And the photons of the N node pattern units are output by the M output ports of each delay selection unit in one-to-one correspondence.

Each delay selection unit delays photons transmitted to the delay selection unit by different time, wherein the delay selection unit comprises at least M delay paths, each delay path delays photons by different time, the delay of different time comprises no delay of photons, the delay time of the M delay paths can be respectively 0T, 1T and 2T … … (M-1) T, wherein T is the period of pumping light pulse output, 0T represents no delay of input photons, 1T represents delay of one pumping light pulse output period of the input photons, and the like. When photons in N node pattern units in different time domains generated based on different pump light pulses are input to the delay selection unit, the delay time is also different, so that the photons in the N node pattern units in different time domains can reach the first fusion operation module or the second fusion operation module at the same time. If a photon in the N-node pattern unit generated based on the first pump light pulse and a photon in the N-node pattern unit generated based on the third pump light pulse arrive at the first fusion operation module at the same time, it is necessary to perform path adjustment on the photon in the N-node pattern unit generated based on the first pump light pulse so as to transmit the photon onto the 2T delay path for 2T delay.

It is noted here that the nodes (photons) in the different N node pattern elements that do not need to be connected together in a fusion may or may not be delayed. When (when)Photons which do not need fusion connection do not do delay, photons can be output from a 0T delay path through regulation and control, and finally a large-scale pattern separated in time is obtained; when delaying photons which do not need fusion connection, the same delay is performed on N photons in the N node pattern units, and the delay time of the photons of the M N node pattern units is different, so that N/2 wavelengths areThe photons of (2) arrive at the first fusion operating module simultaneously, N/2 wavelengths are +.>And (3) the photons of the photon(s) arrive at the second fusion operation module at the same time, and finally, a large-scale image state in which all the photons are at the same time is obtained.

Each delay selection unit is provided with M output ports, and the M output ports of each delay selection unit respectively output photons of the M N node pattern units in a one-to-one correspondence mode. Specifically, M pump light pulses are input, and each delay selection unit has M output ports. Assuming that 4 pump light pulses are input, each delay selection unit is provided with 4 output ports, which are respectively named as a first output port, a second output port, a third output port and a fourth output port; generating a first N-node pattern unit based on a first pump light pulse, generating a second N-node pattern unit based on a second pump light pulse, generating a third N-node pattern unit based on a third pump light pulse, generating a fourth N-node pattern unit based on a fourth pump light pulse, outputting photons in the first N-node pattern unit from a first output port, outputting photons in the second N-node pattern unit from a second output port, outputting photons in the third N-node pattern unit from a third output port, and outputting photons in the fourth N-node pattern unit from a fourth output port after delay processing.

The first fusion operation module and the second fusion operation module are provided with N groups of input ports and N groups of output ports, each group of input ports is provided with M input sub-ports, each group of output ports is provided with M output sub-ports, and each group of input endsThe M input sub-ports of the port are respectively connected with the M output ports of the delay selection unit in a one-to-one correspondence manner, and the first fusion operation module is used for receiving the wavelength output by the first delay selection module as followsCarrying out fusion operation on photons to be fused and connected in different N node patterns to ensure that the photons corresponding to be fused and connected carry out path exchange to complete pattern scale expansion; the second fusion operation module is used for receiving the wavelength output by the second delay selection module as +.>And carrying out fusion operation on photons to be fused and connected in different N node patterns to ensure that the photons to be fused and connected carry out path exchange to complete pattern scale expansion.

Specifically, the first fusion operation module or the second fusion operation module in the application performs fusion operation on photons needing fusion connection, and directly outputs photons needing no fusion connection. The fusion operation is understood here as a path switching operation, which performs path switching on pairs of photons that need to be fusion connected, the path switching being performed between each pair of photons, each pair of photons referring to a photon in a different N-node pattern unit.

In one embodiment of the present application, m=3 and n=4 are set, and the structure of the quantum image generating device is shown in fig. 3. In this embodiment, 3 pump light pulses are input, and the basic pattern generation unit generates 4-node pattern units based on each pump light pulse, and generates 3 4-node pattern units in total, each 4-node pattern unit including 4 photons, wherein 2 photons have a wavelength ofThe other 2 photons have a wavelength of +.>The basic pattern generation module is provided with 4 groups of output ports, and the first 2 groups of output ports are used for outputting the signals with the wavelength of +.>The last 2 groups of output ports are used for outputting photons with the wavelength +.>The first delay selection module and the second delay selection module comprise 4 delay selection units, each delay selection unit is provided with 3 output ports, and the 3 output ports of each delay selection unit respectively output photons of 3 4-node pattern units in one-to-one correspondence. The first fusion operation module and the second fusion operation module are respectively provided with 4 groups of input ports and 4 groups of output ports, each group of input ports is provided with 3 input sub-ports, each group of output ports is provided with 3 output sub-ports, and the 3 input sub-ports of each group of input ports are respectively connected with the 3 output ports of the delay selection unit in a one-to-one correspondence manner.

In order to better understand the technical scheme of the application, the 3 pump light pulses which are sequentially input are respectively named as a pulse, b pulse and c pulse. The 4-node pattern unit includes 4 photons, respectively denoted as photon 1, photon 2, photon 3, and photon 4, and the 4 groups of output ports of the basic pattern generation module are respectively denoted as 1 st group of output ports, 2 nd group of output ports, 3 rd group of output ports, and 4 th group of output ports in sequence. Let photon 1 and photon 2 have a wavelength of l ₁ Photon 3 and photon 4 have a wavelength of l ₂ . The 4 photons included in the 4-node pattern unit generated based on the a pulse are named photons a1, a2, a3, and a4, the 4 photons included in the 4-node pattern unit generated based on the b pulse are named photons b1, b2, b3, and b4, and the 4 photons included in the 4-node pattern unit generated based on the c pulse are named photons c1, c2, c3, and c4. The 3 photons output from the 1 st group of output ports of the basic pattern generation module are denoted as a1, b1, and c1, the 3 photons output from the 2 nd group of output ports of the basic pattern generation module are denoted as a2, b2, and c2, the 3 photons output from the 3 rd group of output ports of the basic pattern generation module are denoted as a3, b3, and c3, and the 3 photons output from the 4 th group of output ports of the basic pattern generation module are denoted as a4, b4, and c4. The photons a1, b1, c1, a2, b2 and c2 are input to a first delay selection module, a3, b3 and c3 The photons a4, b4 and c4 are input to a second delay selection module, each delay selection module comprises 4 delay selection units, each delay selection unit is provided with 3 output ports respectively named as a first output port, a second output port and a third output port, the first output port of the delay selection unit is used for outputting photons in the 4-node pattern unit generated based on the pulse a, the second output port of the delay selection unit is used for outputting photons in the 4-node pattern unit generated based on the pulse b, and the third output port of the delay selection unit is used for outputting photons in the 4-node pattern unit generated based on the pulse c. Specifically, a1, a2, a3 and a4 are output from the first output port of the corresponding delay selection unit after being subjected to delay processing by the corresponding delay selection unit, b1, b2, b3 and b4 are output from the second output port of the corresponding delay selection unit after being subjected to delay processing by the corresponding delay selection unit, and c1, c2, c3 and c4 are output from the third output port of the corresponding delay selection unit after being subjected to delay processing by the corresponding delay selection unit.

In one embodiment of the present application, the basic pattern generation module includes a beam splitting module having N/2 output ends, N/2 50:50 beam splitters, N two-photon generation structures, N path distribution modules and a waveguide transmission module, where the beam splitting module is configured to averagely divide a received pump light pulse into N/2 beams, and each output end of the beam splitting module is respectively and correspondingly connected to one 50: the two output ends of the 50 beam splitter and the 50:50 beam splitter are respectively connected with a two-photon generating structure, and the two-photon generating structure is used for generating light with the wavelength of respectively Andeach two-photon generating structure is connected with a path distribution module which is provided with an output upper end and an output lower end and is used for receiving the entangled photon pairs generated by the two-photon generating structure and setting the wavelength as +.>Is output from its output upper end, with wavelength +.>Is output from the lower output end thereof; the waveguide transmission module consists of N groups of waveguide transmission paths and at least (N/2) -1 path switching units, the path switching units are used for carrying out path switching on photons with the same wavelength on different waveguide transmission paths to form N node pattern units, the front N/2 groups of waveguide transmission paths form a first waveguide transmission unit, the rear N/2 groups of waveguide transmission paths form a second waveguide transmission unit, each group of waveguide transmission paths comprise 2 transmission waveguides, and the output lower ends of the path distribution modules are respectively connected with the transmission waveguides of the second waveguide transmission unit in sequence so as to enable the wavelength to be>The output upper ends of the path distribution modules are respectively connected with the transmission waveguides of the first waveguide transmission unit in sequence so as to enable the wavelength to be +.>Is transmitted to the first waveguide transmission unit.

In the present application, it is preferable that the two-photon generating structure is one of a helical waveguide coil, a silicon nitride micro-ring structure, or a periodically polarized crystal waveguide, and entangled photon pairs are generated based on a nonlinear process. The path distribution module is a wavelength division demultiplexer or an optical filter. The beam splitting module is a 1× (N/2) MMI coupler and uniformly divides the input optical pulse into N/2 pulses.

Specifically, based on the embodiment of fig. 3 (m=3, n=4), the specific structure of the basic pattern generation module is shown in fig. 4, and a 4-node pattern unit is generated, and specifically includes a beam splitting module having 2 output ends, 2 50:50 beam splitters, 4 two-photon generation structures, 4 path distribution modules, and a waveguide transmission module. The beam splitting module equally divides the received pump light pulse into 2 beams, and two output ends of the beam splitting module are respectively and correspondingly connected with one 50:50 beam splitter, waveguide transmission module is made up of 4 groups of waveguide transmission paths and at least 1 path switching unit for the same wavelength light on different waveguide transmission pathsThe sub-processing path exchange to form a 4-node pattern unit, the first 2 groups of waveguide transmission paths form a first waveguide transmission unit, the second 2 groups of waveguide transmission paths form a second waveguide transmission unit, each group of waveguide transmission paths comprise 2 transmission waveguides, and the output lower ends of the path distribution modules are respectively connected with the transmission waveguides of the second waveguide transmission unit in sequence so as to enable the wavelength to be the same as the wavelengthThe output upper ends of the path distribution modules are respectively connected with the transmission waveguides of the first waveguide transmission unit in sequence so as to enable the wavelength to be +. >Is transmitted to the first waveguide transmission unit.

Here, for convenience of explanation, referring to fig. 4, the 2 50:50 splitters are respectively named as a first 50:50 splitter, a second 50:50 splitter in order from top to bottom, the 4 two-photon generating structures are respectively named as a first two-photon generating structure, a second two-photon generating structure, a third two-photon generating structure, and a fourth two-photon generating structure in order from top to bottom, the 4 path allocating modules are respectively named as a first path allocating module, a second path allocating module, a third path allocating module, and a fourth path allocating module in order from top to bottom, the 4 transmission waveguides in the first waveguide transmission unit are respectively named as a first transmission waveguide, a second transmission waveguide, a third transmission waveguide, and a fourth transmission waveguide in order from top to bottom, and the 4 transmission waveguides in the second waveguide transmission unit are respectively named as a fifth transmission waveguide, a sixth transmission waveguide, a seventh transmission waveguide, and an eighth transmission waveguide in order from top to bottom.

The beam splitting module averagely divides one received pumping light pulse into 2 beams, and transmits the 2 beams to the first 50:50 beam splitter and the second 50:50 beam splitter respectively, the first 50:50 beam splitter uniformly divides the received light pulse into 2 beams, and transmits the 2 beams to the first two-photon generating structure and the second two-photon generating structure respectively, and the second 50:50 beam splitter uniformly divides the received light pulse into 2 beams and transmits the 2 beams to the third 50:50 beam splitter respectively A two-photon generating structure and a fourth two-photon generating structure. The first two-photon generating structure or the second two-photon generating structure generates entangled photon pairs based on a nonlinear process. The third two-photon generating structure or the fourth two-photon generating structure generates entangled photon pairs based on a nonlinear process. It should be noted here that one of the first two-photon generating structure and the second two-photon generating structure generates entangled photon pairs and the two photons in the generated entangled photon pairs have different wavelengths, which are respectively denoted as wavelengthsAnd wavelength->. Similarly, one of the third two-photon generating structure and the fourth two-photon generating structure generates entangled photon pairs and the two photons in the generated entangled photon pairs have different wavelengths, which are respectively denoted as wavelength +.>And wavelength of. The entangled photon pairs generated by the first two-photon generating structure or the second two-photon generating structure are transmitted to the corresponding path distribution modules, and the entangled photon pairs generated by the third two-photon generating structure or the fourth two-photon generating structure are transmitted to the corresponding path distribution modules. In the application, the output upper end of the first path distribution module is connected with a first transmission waveguide in the first waveguide transmission unit, and the output lower end of the first path distribution module is connected with a fifth transmission waveguide in the second waveguide transmission unit; the output upper end of the second path distribution module is connected with a second transmission waveguide in the first waveguide transmission unit, and the output lower end of the second path distribution module is connected with a sixth transmission waveguide in the second waveguide transmission unit; the output upper end of the third path distribution module is connected with a third transmission waveguide in the first waveguide transmission unit, and the output lower end of the third path distribution module is connected with a seventh transmission waveguide in the second waveguide transmission unit; output upper end and the first path distribution module And the output lower end of the fourth path distribution module is connected with an eighth transmission waveguide in the second waveguide transmission unit. The connection is made so that the wavelength is +.>All 2 photons of (2) are input into the first waveguide transmission unit to make the wavelength +.>All 2 photons of (2) are input to the second waveguide transmission unit. In fig. 4, a path switching unit is provided in the first waveguide transmission unit, which switches the transmission path of the photons received by the second transmission waveguide with the transmission path of the photons received by the third transmission waveguide.

The principle of generating a 4-node pattern cell based on the structure of fig. 4 is explained below.

After the pump light pulse passes through the beam splitting module and the two 50:50 beam splitters, the quantum state can be expressed as:

in the method, in the process of the invention,represents the path from the upper end of the first 50:50 beam splitter output to the first two-photon generating structure, is->Representing the path from the lower output end of the first 50:50 beam splitter to the second two-photon generating structure,/->Represents the path from the second 50:50 beam splitter output upper end to the third two-photon generating structure, is->Representing the path from the second 50:50 beam splitter output lower end to the fourth two-photon-generating structure.

After two entangled photon pairs are generated through the 4 two-photon generating structures, the quantum state evolves as follows:

if the first two-photon generating structure generates entangled photon pairs, the wavelength is that after passing through the first path distribution moduleIs transmitted to the first transmission waveguide with a wavelength of +.>Is transmitted to a fifth transmission waveguide; if the second two-photon generating structure generates entangled photon pair, the wavelength is +.>Is transmitted to the second transmission waveguide with a wavelength of +.>Is transmitted to the sixth transmission waveguide; if the third two-photon generating structure generates entangled photon pairs, the wavelength is +.>Is transmitted to the third transmission waveguide with a wavelength of +.>Is transmitted to a seventh transmission waveguide; if the fourth two-photon generating structure generates entangled photon pair, the wavelength is +.>Is transmitted to the fourth transmission waveguide with a wavelength of +.>Is transmitted to the eighth transmission waveguide. Then after passing through the path distribution module, the measurement is carried outThe evolution of the sub-states is:

wherein 0 represents a transmission path of the first transmission waveguide, 1 represents a transmission path of the second transmission waveguide, 2 represents a transmission path of the third transmission waveguide, 3 represents a transmission path of the fourth transmission waveguide, 4 represents a transmission path of the fifth transmission waveguide, 5 represents a transmission path of the sixth transmission waveguide, 6 represents a transmission path of the seventh transmission waveguide, and 7 represents a transmission path of the eighth transmission waveguide.

After passing through the path switching unit in the first waveguide transmission unit, photons on the second transmission waveguide are switched with photon paths on the third transmission waveguide, i.e.And->Exchange, then the quantum state evolves as:

wherein,for the normalized state, two photons are shown to be simultaneously output from a set of waveguide transmission paths, which are screened out in the post-selection process, and for the invalid output, this is not considered in this application.Is a graphical quantum state.

In another embodiment of the present application, assuming that a 6-node pattern unit is generated, i.e., n=6, the structure of the corresponding basic pattern generation module is shown in fig. 5, and specifically includes a beam splitting module having 3 output ends, 3 50:50 beam splitters, 6 two-photon generation structures, 6 path distribution modules, and a waveguide transmission module. The beam splitting module is used for averagely dividing the received pump light pulseFor 3 bundles, three output ends of the three bundles are respectively and correspondingly connected with one 50: the two output ends of the 50 beam splitter and the 50:50 beam splitter are respectively connected with a two-photon generating structure, the waveguide transmission module consists of 6 groups of waveguide transmission paths and at least 2 path switching units, the first 3 groups of waveguide transmission paths form a first waveguide transmission unit, the second 3 groups of waveguide transmission paths form a second waveguide transmission unit, each group of waveguide transmission paths comprise 2 transmission waveguides, and the output lower ends of the path distribution modules are respectively and sequentially connected with the transmission waveguides of the second waveguide transmission unit so as to enable the wavelength to be the same as the wavelength The output upper ends of the path distribution modules are respectively connected with the transmission waveguides of the first waveguide transmission unit in sequence so as to enable the wavelength to be +.>Is transmitted to the first waveguide transmission unit. The procedure and principle of generating a 6-node pattern unit of this structure are similar to those of a 4-node pattern unit, and will not be described here again.

In the present application, the delay selection unit is composed of a 1×m waveguide type input optical switch, M delay lines with sequentially equal-increasing lengths, and M1×m waveguide type output optical switches, as shown in fig. 6, where the 1×m waveguide type input optical switch has M output ends, each output end is connected to an input end of one delay line, and is used for adjusting a transmission path of an input photon to transmit the input photon to the corresponding delay line; the M delay lines with the equal-quantity increasing lengths sequentially delay the received photons by corresponding time respectively, and the equal-quantity increasing lengths of the delay lines are equal to the period of pumping light pulse output multiplied by the propagation speed of the photons on the delay lines; the output end of each delay line is connected with a 1 xM waveguide type output optical switch, and the 1 xM waveguide type output optical switch is provided with M output ends which respectively output photons of M N node pattern units in a one-to-one correspondence mode.

Specifically, the 1×m waveguide type input optical switch and the 1×m waveguide type output optical switch are each composed of a cascade of MZ interferometers and are in a tree structure.

In one embodiment of the present application, when m=3 and n=4 are set, the corresponding delay selection unit is composed of a 1×3 waveguide type input optical switch, 3 delay lines with sequentially equal increasing lengths, and 3 1×3 waveguide type output optical switches, as shown in fig. 7, the 1×3 waveguide type input optical switch has 3 output terminals, the 1×3 waveguide type output optical switch has 3 output terminals, and the delay times of the 3 delay lines with sequentially equal increasing lengths are respectively 0T, 1T and 2T. Specifically, the 1×3 waveguide type input optical switch and the 1×3 waveguide type output optical switch are each composed of 3 MZ interferometer cascades and are in a tree structure. The 3 output ends of the 1 x 3 waveguide type input optical switch are sequentially and correspondingly connected with a 0T delay line, a 1T delay line and a 2T delay line. The 3 output ends of the 1×3 waveguide type output optical switch respectively output photons of 3N node pattern units, which can be specifically: the first output terminal of the 1 x 3 waveguide type output optical switch outputs photons of the first N-node pattern unit, the second output terminal of the 1 x 3 waveguide type output optical switch outputs photons of the second N-node pattern unit, and the third output terminal of the 1 x 3 waveguide type output optical switch outputs photons of the third N-node pattern unit. The first output ends of the three 1X 3 waveguide type output optical switches form a first delay output port, the second output ends of the three 1X 3 waveguide type output optical switches form a second delay output port, the third output ends of the three 1X 3 waveguide type output optical switches form a third delay output port, and the first delay output port, the second delay output port and the third delay output port are three output ports of a delay selection unit and are connected with three input sub-ports of a corresponding group of input ports in the fusion operation module in a one-to-one correspondence mode.

The operation of the delay selection unit in this embodiment is described below with reference to fig. 3 and 7.

After inputting three pulses of a pump light pulse, b pump light pulse and c pump light pulse, the basic pattern generation module sequentially generates 3 4-node pattern units based on the three pump light pulses, assuming that 6 wavelengths in the 3 4-node pattern units are l ₁ The photons of the (a) are simultaneously input into the first fusion operation module, so that corresponding time delay is required to be carried out on the photons in different 4-node pattern units respectively, and the 4-node pattern units generated based on the a pump light pulse are subjected toThe photons in the cells are 2T delayed, 1T delayed for photons in the 4-node pattern cells generated based on the b pump light pulses, and not delayed (0T delay) for photons in the 4-node pattern cells generated based on the c pump light pulses. Referring to fig. 3, assuming that an a1 photon in a 4-node pattern unit generated based on an a pump light pulse is output from a lower output sub-port of a1 st group output port thereof, an a2 photon is output from an upper output sub-port of a2 nd group output port thereof, a b1 photon in a 4-node pattern unit generated based on a b pump light pulse is output from a lower output sub-port of a1 st group output port thereof, a b2 photon is output from an upper output sub-port of a2 nd group output port thereof, a c1 photon in a 4-node pattern unit generated based on a c pump light pulse is output from a lower output sub-port of a1 st group output port thereof, and a c2 photon is output from an upper output sub-port of a2 nd group output port thereof, three photons a1, b1 and c1 are input to the same delay selection unit, but the times input to the delay selection units are different, and the equal interval times are all T; then three photons a2, b2 and c2 are all input to another delay selection unit, and likewise, the time input to the delay selection unit is different, and the equal difference interval time is T.

In order to better understand the technical scheme of the application, the transmission principle and process of three photons a1, b1 and c1 in the same delay selection unit are described below.

Through the regulation and control of a 1X 3 waveguide type input optical switch in the delay selection unit, a1 photon is input to a 2T delay path, b1 photon is input to a 1T delay path, and c1 photon is input to a 0T delay path. The specific regulation and control principle of the 1×3 waveguide type input optical switch is as follows: by adjusting the phase modulators of the 3 cascaded MZ interferometers separately, the incoming photons are transmitted to different paths. a1, b1 and c1 photons are respectively input to the corresponding connected 1×3 waveguide type output optical switches after corresponding delay, a1 photon is output from the first output end through the regulation and control of the corresponding 1×3 waveguide type output optical switch after 2T delay, b1 photon is output from the second output end through the regulation and control of the corresponding 1×3 waveguide type output optical switch after 1T delay, and c1 photon is output from the third output end through the regulation and control of the corresponding 1×3 waveguide type output optical switch after 0T delay, as shown in fig. 7. And finally, outputting a1 photon from a first delay output port of the delay selection unit, outputting b1 photon from a second delay output port of the delay selection unit, and outputting c1 photon from a third delay output port of the delay selection unit. The regulation and control principle of the 1×3 waveguide type output optical switch is the same as that of the 1×3 waveguide type input optical switch.

The transmission principle and process of three photons a2, b2 and c2 in another delay selection unit are similar to those described above. After delay treatment of a1, b1, c1, a2, b2 and c2, the six wavelengths areSimultaneously input to the first fusion manipulation module.

The above procedure is described for a wavelength of 4-node pattern elementsThe same delay is made for both photons of the same 4-node pattern element, the same wavelength is +.>The same delay is also performed on the two photons of a1, a2, a3 and a4, namely, 2T delay is performed on each of a1, b2, b3 and b4, 1T delay is performed on each of b1, b2, c3 and c4, 0T delay is performed on each of c1, c2, c3 and c4, a1, b1, c1, a2, b2 and c2 arrive at the first fusion operation module at the same time, a3, b3, c3, a4, b4 and c4 arrive at the second fusion operation module at the same time, and finally, a large-scale image state that 12 photons are all at the same time is obtained.

Of course, photons which do not need fusion connection in the 3 4-node pattern units can be delayed, so that photons which do not need delay are all output from the OT delay path through the regulation and control of the 1×3 waveguide type input optical switch. If the b1 photon and the a2 photon are fused (path exchange) in advance, the b1 photon and the a2 photon are required to be correspondingly delayed, so that the two photons arrive at the first fusion operation module at the same time, 2T delay is performed on the a2 photon, T delay is performed on the b1 photon, or T delay is performed on the a2 photon, the b1 photon is not delayed, and both delay modes can enable the two photons to arrive at the first fusion operation module at the same time.

In one embodiment of the present application, a fusion operation structure is provided on the first fusion operation module or/and the second fusion operation module, and the total number of the fusion operation structures provided on the two fusion operation modules is at least (M-1), and the fusion operation structure is used for exchanging the transmission path of the photon output from one delay selection unit with the transmission path of the photon output from the other delay selection unit. The (M-1) fusion operation structures can be arranged on the first fusion operation module or the second fusion operation module, or respectively arranged on the first fusion operation structure and the second fusion operation structure, and the specific arrangement mode can be set according to the fusion requirement of the nodes, so that the application is not limited specifically. The first fusion operation module or/and the second fusion operation module performs path exchange on photons needing fusion connection through the fusion operation structure, and directly outputs photons needing no fusion connection. When a plurality of pairs of photons need to be subjected to path switching, a corresponding number of fusion operation structures are needed to respectively realize fusion connection, wherein each pair of photons subjected to path switching refers to photons in different N node pattern units.

The principle of implementing fusion connection by using a specific fusion operation structure is shown in fig. 8. Photon 1 and photon 2 have two paths that can be input, namely path 0 and path 1, respectively, photon 1 and photon 2 are in a separated state when initially input into the system, and the quantum state of the initial input system is:

where subscripts 1 and 2 correspond to photons,0 in (2) represents path 0, ">1 in (2) represents path 1, path exchange is performed between path 1, which may be input by photon 1, and path 0, which may be input by photon, through a fusion operation structure, +.>And->After exchanging, the quantum state evolves into:

the quantum state is an entangled quantum state, so that the photons 1 and 2 are changed from a separation state to a quantum entangled state through the fusion operation structure, and fusion connection is completed.

The fusion operation structure can fuse two nodes (photons) in different N node pattern units together and keep connection with other nodes, so that the scale of the pattern can be expanded, and a larger-scale pattern can be output after the fusion operation structure. As shown in fig. 9, two 4-node star-shaped patterns can be expanded and fused to form an 8-node quantum pattern by respectively performing fusion operation through 2 fusion operation structures.

Referring to each fusion operation structure in the first fusion operation module and the second fusion operation module in fig. 3, the two fusion operation structures in the first fusion operation module can respectively realize that the path exchange of the b2 photon and the a2 photon is fused, and the path exchange of the c1 photon and the b2 photon is fused. The fusion operation structure in the second fusion operation module can realize the path exchange of the b3 photon and the a4 photon for fusion. Assuming that 3 4 node pattern units generated based on three pumping light pulses are all star-shaped patterns, after the fusion operation of the first fusion operation module and the second fusion operation module in fig. 3, the 3 4 node pattern units are expanded and fused into a 12 node quantum pattern, as shown in fig. 10, so that only one basic 4 node pattern generation module is utilized, and the quantum pattern of 12 nodes is generated by inputting three pumping light pulses, and the 3-time expansion of the pattern is realized.

The following formulas the expansion process of the 3 4-node pattern units.

As can be seen from the principle of generating a 4-node pattern cell based on fig. 4 and the derivation process of generating a basic pattern, the basic pattern generation module generates a 4-node pattern cell based on a pump light pulse with the following expression:

The expression of the 4-node pattern unit generated by the basic pattern generation module based on the b pump light pulse is:

the expression of the 4-node pattern unit generated by the basic pattern generation module based on the c pump light pulse is:

/>

the photons of the three 4-node pattern units generated based on the a pump light pulse, the b pump light pulse and the c pump light pulse are processed by the two delay selection modules and then input into the first fusion operation module and the second fusion operation module, wherein for convenience of explanation and explanation, the fusion operation process is still described by taking each fusion operation structure in the first fusion operation module and the second fusion operation module in fig. 3 as an example, and the fusion operation of the three groups of photons of the a2 photon and the b1 photon, the a4 photon and the b3 photon, and the c1 photon and the b2 photon, namely the path exchange of the b1 photon and the a2 photon, the path exchange of the c1 photon and the b2 photon, and the path exchange of the b3 photon and the a4 photon can be realized by the figure. After path exchange, the output quantum image has the expression:

the quantum state is a quantum state of a 12-node quantum sub-state formed.

And the method extends to the expansion of the N node pattern unit, so that the quantum pattern of M multiplied by N nodes can be output on the basis of an N node basic pattern generation module.

In another embodiment of the present application, it is assumed that the a2 photon in the 4-node pattern unit generated based on the a pulse is output from the upper output sub-port in the 2 nd group of output ports of the basic pattern generation module, and the a4 photon is output from the upper output sub-port in the 4 th group of output ports of the basic pattern generation module; b1 photons in the 4-node pattern unit generated based on the b pulse are output from a lower output sub-port in the 1 st group of output ports of the basic pattern generation module, and b3 photons are output from a lower output sub-port in the 3 rd group of output ports of the basic pattern generation module; the c1 photon in the 4-node pattern unit generated based on the c pulse is output from the upper output sub-port in the 1 st group of output ports of the basic pattern generation module, the c2 photon is output from the lower output sub-port in the 2 nd group of output ports of the basic pattern generation module, the c3 photon is output from the upper output sub-port in the 3 rd group of output ports of the basic pattern generation module, and the c4 photon is output from the lower output sub-port in the 4 th group of output ports of the basic pattern generation module, as shown in fig. 11. And 2 fusion operation structures are arranged in the first fusion operation module and the second fusion operation module, two fusion operation structures in the first fusion operation module perform fusion operation on two groups of photons, one fusion operation structure exchanges paths for b1 photons and c1 photons, and the other fusion operation structure exchanges paths for a2 photons and c2 photons. Two fusion operation structures in the second fusion operation module perform fusion operation on two groups of photons, wherein one fusion operation structure exchanges paths between b3 photons and c3 photons, and the other fusion operation structure exchanges paths between a4 photons and c4 photons. Assuming that 3 4 node pattern units generated based on three pump light pulses are all star-shaped patterns, after 4 fusion operation structures in the first fusion operation module and the second fusion operation module in fig. 11 are fused, the 3 4 node pattern units are expanded and fused into a 12 node quantum sub-pattern, as shown in fig. 12, so that 3 times expansion of a basic pattern is realized.

The number of the set fusion operation structures and the set position of each fusion operation structure in the application can be set according to the fusion requirements of the nodes in different basic image units. One node in the basic pattern may also be fused with nodes in other multiple basic pattern units, as shown in fig. 13, where a4 photon in the figure is fused with a c3 photon and b3 photon at the same time, that is, an a4 node in a4 node pattern unit generated based on a pulse is fused with a b3 node in a4 node pattern unit generated based on b pulse and a c3 node in a4 node pattern unit generated based on c pulse at the same time. It should be emphasized that the sequence of the fusion operation of the a4 photon with the c3 photon and the b3 photon is not limited, and the sequence of the fusion operation does not affect the fusion result. Meanwhile, in fig. 13, two groups of photons, namely an a2 photon and a c1 photon and an a3 photon and a b4 photon, are subjected to path exchange fusion, and a quantum image of a 12-node formed after the fusion operation is shown in fig. 14.

In the above embodiment, the two nodes in different basic graphics units perform the fusion operation, which is completed by performing path exchange through the fusion operation structure arranged in the first fusion operation module or the second fusion operation module, and once the position and the number of the fusion operation structures are set, only specific photon pairs can be subjected to the fusion operation, which has a certain limitation. Thus, in another embodiment of the present application, the first fusion operation module and the second fusion operation module are both (mxn) × (mxn) waveguide-type optical switches, and are composed of (mxn-1) × (mxn/2) MZ interferometers in a square-type structure cross-cascaded. The first fusion operation module and the second fusion operation module under the structure can perform fusion operation of two nodes between any two basic image states, and the application range and the applicability are wider. Assuming that the basic pattern generation module generates 3 4-node pattern units based on 3 pump light pulses input from the outside, the first fusion operation module and the second fusion operation module are 12×12 waveguide type optical switches, and are formed by 66 MZ interferometers in a square structure cross cascade, as shown in fig. 15. The 12×12 waveguide optical switch has 12 input ports and 12 output ports, the 12 input ports being a first input port, a second input port, and up to a twelfth input port in this order, taking the first fusion operation module as an example, referring to fig. 15, the first input port and the fourth input port are for receiving a1 photon output from the corresponding delay selection unit, the second input port and the fifth input port are for receiving b1 photon output from the corresponding delay selection unit, the third input port and the sixth input port are for receiving c1 photon output from the corresponding delay selection unit, the seventh input port and the tenth input port are for receiving a2 photon output from the corresponding delay selection unit, the eighth input port and the eleventh input port are for receiving b2 photon output from the corresponding delay selection unit, and the ninth input port and the eleventh input port are for receiving c2 photon output from the corresponding delay selection unit. Through unified regulation and control of the phases of 66 MZ interferometers, photons input by any input port can be output from any output port, and the purpose of path switching of the input photons is achieved. In fig. 15, the broken line indicates that the path switching is performed between the b1 photon input from the fifth input port and the a2 photon input from the seventh input port, and the merging operation of the two nodes is completed. The 12 input ports in the first fusion operation module are respectively connected with the 12 output ends of the first delay selection module in a one-to-one correspondence manner, and the 12 input ports in the second fusion operation module are respectively connected with the 12 output ends of the second delay selection module in a one-to-one correspondence manner, as shown in fig. 16. In the illustration, the first fusion operation module exchanges paths of the b1 photon and the a2 photon to finish fusion operation of two nodes. And the second fusion operation module exchanges paths of the b3 photon and the a4 photon to finish fusion operation of two nodes.

Based on the quantum image generating device provided in the embodiment of the present application, the present application further correspondingly provides a quantum image generating method, as shown in fig. 17, where the generating method includes:

s11, the basic pattern generation module generates M N node pattern units based on M pumping light pulses input from the outside, wherein each N node pattern unit comprises N/2 wavelengthsIs +.2 wavelengths>And N/2 wavelengths are +.>Is transmitted to the first delay selection module, N/2 wavelengths are +.>The photons are transmitted to a second delay selection module.

S12, the receiving wavelength of a delay selection unit in the first delay selection module isAnd delays the received photons by different times so that the wavelength of the connection to be fused in different N node patterns is +.>The photons of the (a) arrive at the first fusion operation module at the same time, and the receiving wavelength of a delay selection unit in the second delay selection module is +.>And delays the received photons by different times so that the wavelength of the connection to be fused in different N node patterns is +.>Simultaneously reaching the second fusion manipulation module.

S13, the first fusion operation module receives the wavelength output by the first delay selection module as followsThe photons to be fused and connected in different N node patterns are fused, so that the corresponding photons to be fused and connected are subjected to path exchange to complete pattern scale expansion, and the second fusion operation module receives the wavelength output by the second delay selection module as +. >And carrying out fusion operation on photons to be fused and connected in different N node patterns to ensure that the photons to be fused and connected carry out path exchange to complete pattern scale expansion.

The detailed process of each step is described in detail in the description of the related modules, and each step is not described herein.

From the above, it can be known that, based on the characteristic that the quantum image can be fused, connected and expanded through the fusion operation module, the method of time domain expansion expands the fusion connection of the quantum images of different time domains into a larger-scale image, and under the requirement of forming the same large-scale quantum image, the method can be realized by adopting fewer devices and smaller space, and saves resources and cost while breaking through the limitation of the chip size.

Claims

1. The quantum image generating device is characterized by comprising a basic image generating module, a first delay selecting module, a second delay selecting module, a first fusion operating module and a second fusion operating module;

the basic pattern generation module generates M N node pattern units based on M pumping light pulses input from the outside and transmits the N node pattern units to the first delay selection module and the second delay selection module, wherein M is N is->Each N-node pattern cell comprising N photons, wherein N/2 photons have a wavelength of λ1 and N/2 photons have a wavelength of λ2, the base pattern generation module having N groups of output ports, the first N/2 groups of output ports being for outputting photons having a wavelength of λ1, the last N/2 groups of output ports being for outputting photons having a wavelength of λ2, each group of output ports comprising two output sub-ports and each group of output ports being for outputting one photon in the N-node pattern cell, each photon being output from one output sub-port in each group of output ports;

the first delay selection module and the second delay selection module both comprise N delay selection units, the delay selection units in the first delay selection module are used for receiving photons with the wavelength of lambda 1 and delaying the received photons for different times, so that the photons with the wavelength of lambda 1 to be fused and connected in different N node patterns simultaneously reach the first fusion operation module, the delay selection units in the second delay selection module are used for receiving photons with the wavelength of lambda 2 and delaying the received photons for different times, so that the photons with the wavelength of lambda 2 to be fused and connected in different N node patterns simultaneously reach the second fusion operation module, each delay selection unit is correspondingly connected with one output sub-port of the basic pattern generation module and provided with M output ports, and the M output ports of each delay selection unit are respectively in one-to-one correspondence with the photons of M N node pattern units;

The first fusion operation module and the second fusion operation module are respectively provided with N groups of input ports and N groups of exit ports, each group of input ports is provided with M input sub-ports, each group of exit ports is provided with M exit sub-ports, the M input sub-ports of each group of input ports are respectively connected with the M output ports of the delay selection unit in a one-to-one correspondence manner, and the first fusion operation module is used for receiving photons with the wavelength of lambda 1 output by the first delay selection module and carrying out fusion operation on photons to be fused and connected in different N node patterns so as to lead the corresponding photons to be fused and connected to carry out path exchange to complete pattern scale expansion; the second fusion operation module is used for receiving the photons with the wavelength of lambda 2 output by the second delay selection module and carrying out fusion operation on the photons to be fused and connected in different N node patterns so as to lead the photons to be fused and connected to carry out path exchange to complete pattern scale expansion.

2. The quantum image generating device according to claim 1, wherein the basic image generating module comprises a beam splitting module having N/2 output ends, N/2 50:50 beam splitters, N two-photon generating structures, N path distributing modules and a waveguide transmission module, the beam splitting module is configured to averagely split the received pump light pulse into N/2 beams, and each output end of the beam splitting module is respectively connected to one 50: the two output ends of the 50 beam splitter are respectively connected with a two-photon generating structure, the two-photon generating structures are used for generating entangled photon pairs with the wavelengths of lambda 1 and lambda 2, each two-photon generating structure is connected with a path distribution module, the path distribution module is provided with an output upper end and an output lower end, and the path distribution module is used for receiving the entangled photon pairs generated by the two-photon generating structures, outputting photons with the wavelengths of lambda 1 from the output upper end and photons with the wavelengths of lambda 2 from the output lower end; the waveguide transmission module consists of N groups of waveguide transmission paths and at least (N/2) -1 path switching units, the path switching units are used for carrying out path switching on photons with the same wavelength on different waveguide transmission paths to form N node pattern units, the front N/2 groups of waveguide transmission paths form a first waveguide transmission unit, the rear N/2 groups of waveguide transmission paths form a second waveguide transmission unit, each group of waveguide transmission paths comprise 2 transmission waveguides, the lower output ends of the path distribution modules are respectively connected with the transmission waveguides of the second waveguide transmission unit in sequence so as to enable photons with the wavelength of lambda 2 to be transmitted to the second waveguide transmission unit, and the upper output ends of the path distribution modules are respectively connected with the transmission waveguides of the first waveguide transmission unit in sequence so as to enable photons with the wavelength of lambda 1 to be transmitted to the first waveguide transmission unit.

3. The quantum pattern generating device according to claim 1, wherein the delay selection unit is composed of a 1×m waveguide type input optical switch, M delay lines with sequentially equal increasing lengths, and M1×m waveguide type output optical switches; the 1 XM waveguide type input optical switch is provided with M output ends, each output end of the switch is connected with the input end of one delay line, and the switch is used for adjusting the transmission path of input photons to enable the input photons to be transmitted to the corresponding delay line; the M delay lines with the equal-quantity increasing lengths sequentially delay the received photons by corresponding time respectively, and the equal-quantity increasing lengths of the delay lines are equal to the period of pumping light pulse output multiplied by the propagation speed of the photons on the delay lines; the output end of each delay line is connected with a 1 xM waveguide type output optical switch, and the 1 xM waveguide type output optical switch is provided with M output ends which respectively output photons of M N node pattern units in a one-to-one correspondence mode.

4. The quantum image generating apparatus according to claim 1, wherein the first fusion operation module and/or the second fusion operation module are provided with fusion operation structures, the total number of the fusion operation structures provided on the two fusion operation modules is at least (M-1), and the fusion operation structures are used for exchanging the transmission path of the photon output from one delay selection unit with the transmission path of the photon output from the other delay selection unit.

5. The quantum pattern generating device according to claim 1, wherein the first fusion operation module and the second fusion operation module are (mxn) × (mxn) waveguide type optical switches, and each of the (mxn-1) × (mxn/2) MZ interferometers is formed by cross-cascading according to a square structure.

6. The quantum image generation device of claim 2 wherein the two-photon generation structure is one of a helical waveguide coil, a silicon nitride micro-ring structure, or a periodically poled crystal waveguide.

7. A quantum image generation device according to claim 2 wherein the path allocation module is a wavelength division demultiplexer or an optical filter.

8. The quantum image generation device of claim 2 wherein the beam splitting module is a 1× (N/2) MMI coupler.

9. A quantum pattern generating apparatus according to claim 3, wherein the 1 xm waveguide type input optical switch and the 1 xm waveguide type output optical switch are each composed of a cascade of MZ interferometers and are in a tree structure.

10. A quantum image generation method, which is characterized in that the generation method is applied to the quantum image generation device of any one of claims 1-9, and the quantum image generation comprises a basic image generation module, a first delay selection module, a second delay selection module, a first fusion operation module and a second fusion operation module; the generating method comprises the following steps:

The basic pattern generation module generates M N node pattern units based on M pumping light pulses input from the outside, each N node pattern unit comprises N/2 photons with the wavelength of lambda 1 and N/2 photons with the wavelength of lambda 2, the front N/2 groups of output ports in the basic pattern generation module output photons with the wavelength of lambda 1 and transmit the photons to the first delay selection module, the rear N/2 groups of output ports output photons with the wavelength of lambda 2 and transmit the photons to the second delay selection module, and each group of output ports outputs one photon in the N node pattern unit, and each photon is output from one output sub-port in each group of output ports;

the time delay selection unit in the first time delay selection module receives photons with the wavelength of lambda 1 and delays the received photons for different times, so that photons with the wavelength of lambda 1 to be fused and connected in different N node patterns simultaneously reach the first fusion operation module, and the time delay selection unit in the second time delay selection module receives photons with the wavelength of lambda 2 and delays the received photons for different times, so that photons with the wavelength of lambda 2 to be fused and connected in different N node patterns simultaneously reach the second fusion operation module;

the first fusion operation module receives the photons with the wavelength of lambda 1 output by the first delay selection module and carries out fusion operation on the photons to be fused and connected in different N node patterns so that the corresponding photons to be fused and connected carry out path exchange to complete pattern scale expansion, and the second fusion operation module receives the photons with the wavelength of lambda 2 output by the second delay selection module and carries out fusion operation on the photons to be fused and connected in different N node patterns so that the photons to be fused and connected carry out path exchange to complete pattern scale expansion.