A chip quantum random number generation device and method

Abstract

The application relates to the field of quantum information, and discloses a chipped quantum random number generation device and method. The device adopts a full-chip integrated architecture, and sequentially integrates a laser chip, a plasma polarization rotator, a plasma beam splitter and a photodetector, and realizes true random number generation through a single-photon branch path scheme. The laser chip outputs single-photon-level laser, which is incident to the beam splitter after being regulated by the rotator into a polarization state suitable for beam splitting requirements; single photons randomly select transmission paths in the beam splitter based on quantum scattering effects, are emitted from two output ends respectively and are detected correspondingly; through random triggering events of two-way detection signals, binary random sequences are converted, and chipped quantum random number output is realized. The device is miniaturized and has high integration, discards traditional discrete optical elements, has the characteristics of low cost, high stability and easy batch production, and can be widely applied to on-chip quantum computing, quantum communication and miniature encryption equipment and the like.

Description

Technical Field

[0001] This invention relates to the fields of quantum information technology and chip integration technology, and in particular to a chip-based quantum random number generation device and method. Background Technology

[0002] Quantum random number generators (QRNGs) utilize the inherent randomness of quantum mechanics (such as single-photon path selection and quantum scattering) to generate truly random numbers, and are core foundational devices in fields such as cryptography, quantum communication, and quantum computing. Traditional QRNG devices are mostly built using discrete optical components (such as independent lasers, free-space beam splitters, and external detectors), which suffer from problems such as large size, low integration, poor stability, and high cost, making it difficult to meet the application requirements of miniaturized and portable quantum devices.

[0003] While existing on-chip QRNG solutions attempt to integrate some optical components, they still have many shortcomings: some solutions do not integrate polarization control components, resulting in low conversion efficiency between photons and surface plasmon polaritons (SPPs); some solutions use dielectric waveguide beam splitters, which are limited by the diffraction limit, making it difficult to further reduce the device size; and some solutions have not achieved monolithic integration of the laser and detector, still relying on external optical coupling, which affects system stability and integration.

[0004] Plasma technology can confine light fields to scales far below the diffraction limit, providing an ideal approach for chip-based integration; while the mature development of laser chips and integrated detectors has laid the foundation for fully chip-integrated QRNGs. Therefore, designing a fully chip-based architecture based on "laser chip + plasma polarization rotator + plasma beam splitter + integrated PD" and realizing QRNG chip integration through a single-photon branching path scheme has become the key to overcoming the shortcomings of existing technologies. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention proposes a chip-based quantum random number generation device and method.

[0006] The technical solution of this invention is implemented as follows:

[0007] A chip-based quantum random number generation device includes a chip-based entropy source module, an ADC module, and a post-processing module. The chip-based entropy source module includes a laser chip, a plasma polarization rotator (PPR), a plasma polarization beam splitter (PPBS), and two photodetectors (PD1 and PD2) that are monolithically integrated in sequence. The components are interconnected in sequence through on-chip waveguides.

[0008] The laser output from the laser chip is directly coupled to the input waveguide of the PPR;

[0009] PPR is used to rotate and control the polarization state of the incident laser, converting the linearly polarized light output from the laser chip into a 45° linearly polarized state that is compatible with PPBS.

[0010] The PPBS and PPR are directly connected via an output waveguide, which includes a cross gold bar waveguide, a polarization selection grating, a central scattering grating, and an orthogonal polarization grating. The incident 45° linear polarization state is randomly separated into a horizontal polarization component and a vertical polarization component, which are then coupled to two orthogonal polarization gratings respectively.

[0011] PD1 and PD2 are chip-integrated single-photon avalanche diode detectors (SPADs), each directly coupled one-to-one to the two orthogonal output waveguides of the plasma polarization beamsplitter via an on-chip polarization-maintaining waveguide. PD1 is coupled to the output waveguide of the polarization grating transmitting horizontally polarized light, and PD2 is coupled to the output waveguide of the polarization grating transmitting vertically polarized light. The two detectors convert the received single-photon signal into an electrical pulse signal; PD1 corresponds to "0" in the binary sequence, and PD2 corresponds to "1" in the binary sequence.

[0012] The ADC module is used to acquire the electrical pulse signals of PD1 and PD2; the post-processing module is used to convert the raw data of the electrical pulse signals of PD1 and PD2 into true random numbers according to a predetermined algorithm.

[0013] Preferably, the laser chip is a single-photon level continuous-wave laser chip, outputting laser light with a wavelength of 780~850nm, an operating current higher than the operating threshold, and laser power attenuated to the single-photon level by the chip's built-in attenuation structure. The photon number distribution satisfies a Poisson distribution and the average photon number is [not specified]. .

[0014] Preferably, the PPR is fabricated on a chip substrate and includes a metal nanowaveguide and a periodic grating structure; the metal nanowaveguide is a gold bar waveguide with a width W1 and a height H1, and the periodic grating structure has a grating period T1 and a height H2, which is adjusted by adjusting the matching relationship between the grating period and the waveguide width.

[0015] Preferably, the polarization selective scattering grating is located on the input waveguide of the cross-gold bar waveguide and is a periodic metal grating with period T2 and height H4; the central scattering grating is located in the cross region of the cross-gold bar waveguide and is a third-order periodic grating, serving as a quantum scattering region based on the polarization-dependent scattering effect of surface plasmon polaritons (SPP).

[0016] Preferably, the chip substrate is made of quartz glass or silicon substrate, which provides support for all integrated components and has good optical transparency and thermal stability; the polarization-maintaining waveguide is an erbium-doped quartz waveguide or a silicon nitride waveguide with a polarization extinction ratio ≥20dB.

[0017] Preferably, the laser chip, PPR, PPBS, polarization-preserving waveguide, and two PDs are monolithically integrated using the same set of micro-nano fabrication processes. Specific processes include electron beam lithography (EBL), electron beam evaporation (EBE), plasma-enhanced chemical vapor deposition (PECVD), and a lift-off process. The metal structures of the gold bar waveguide and scattering grating are fabricated using an EBL+EBE+lift-off process, while the polarization-preserving waveguide is fabricated using a PECVD+EBL+etching process. The waveguide alignment deviation of each component is ≤±50nm, and the overall chip size is ≤5mm×5mm.

[0018] Preferably, the metal nanowaveguide of the PPR is a gold bar waveguide with a width W1=2μm and a height H1=70nm, and the grating period of the periodic grating structure is T1=500nm and the height H1=90nm.

[0019] Preferably, the input gold bar waveguide of the PPBS has a width W2=2μm and a height H3=70nm, and the polarization selective scattering grating is a 5th-order periodic metal grating (period T2=400nm, height H4=90nm); the widths of the two orthogonal output waveguides are both W2=2μm and H4=90nm.

[0020] Preferably, the surface of the polarization selective scattering grating of the PPBS is provided with a silicon dioxide protective film with a thickness of 5~10nm. This protective film is prepared by atomic layer deposition (ALD) process and is used to reduce the oxidation loss and environmental interference of the metal grating.

[0021] Preferably, the laser chip has a built-in temperature compensation unit, which is an integrated structure of a miniature platinum resistance temperature sensor and a semiconductor cooler (TEC). The temperature control accuracy is ≤ ±0.01℃, which can compensate for the influence of ambient temperature changes on the laser wavelength and output power in real time, ensuring the stability of single-photon excitation.

[0022] This invention also discloses a chip-based quantum random number generation method, comprising the following steps:

[0023] S1. Single-photon excitation: Activate the laser chip, set the operating current to 30~40mA, and output a continuous-wave laser with a wavelength of 780~850nm. After the laser is attenuated by the chip's built-in attenuation structure, the average number of photons is... It satisfies the single-photon excitation condition and is directly coupled to the input waveguide of the plasma polarization rotator;

[0024] S2. Polarization state manipulation: The plasma polarization rotator manipulates the polarization state of the incident laser through the interaction between its periodic grating structure and the metal nanowaveguide. Based on the SPP excitation requirements of the plasma beam splitter, the laser polarization state is rotated to 45° linear polarization.

[0025] S3. Quantum random beam splitting: The polarization-tuned laser is coupled to the input waveguide of the plasma beam splitter. The photon interacts with the free electrons on the surface of the gold bar waveguide and is converted into a single SPP that propagates along the waveguide. When the SPP propagates to the central scattering grating, it randomly selects a propagation path due to the quantum scattering effect. It has a 50% probability of propagating from the forward output arm and a 50% probability of propagating from the side output arm, thus realizing the random allocation of the branch path of the single photon.

[0026] S4. Single-photon detection and electrical pulse conversion: Two integrated SPAD detectors receive single-photon signals from the two output arms of the plasma beam splitter, respectively, and convert the photon signals into electrical pulse signals. When PD1 detects a photon and triggers, the output electrical pulse corresponds to the binary number "0"; when PD2 detects a photon and triggers, the output electrical pulse corresponds to the binary number "1". If both detectors trigger simultaneously or neither triggers, the signal is considered invalid and does not participate in sequence generation.

[0027] S5. Initial Sequence Generation: The ADC module acquires the electrical pulse signals of the two PDs. The post-processing module uses a post-selection algorithm to filter the valid signals, retaining only the electrical pulses triggered by a single detector, removing multiphoton interference and vacuum state signals, and generating the initial binary sequence.

[0028] S6. Sequence Optimization: The Von Neumann recursive extraction algorithm is used to eliminate bias and short-range correlation in the initial binary sequence: the sequence is split into adjacent bit pairs, "01" and "10" are retained, the split-mapping operation is repeated for the remaining bits, and finally the optimized quantum random number sequence is spliced ​​together.

[0029] Preferably, in step S3, the polarization separation process of the plasma polarization beam splitter satisfies the following: the separation efficiency of the horizontal polarization SPP and the vertical polarization SPP is ≥95%, the optical power deviation between the two polarized lights is ≤±3%, and the bias of the initial sequence is within the correctable range.

[0030] Preferably, in step S3, the transmission loss of SPP in the input and output waveguides of the plasma polarization beam splitter is calculated by the attenuation formula e^(-l / Lp), where the waveguide length l = 3~5μm, the SPP attenuation length Lp = 7~9μm, and the transmission efficiency ≥55%. The transmission loss can be compensated by fine-tuning the output power of the laser chip to ensure the number of effective single-photon signals.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. Fully integrated chip with high miniaturization: The laser, polarization rotator, beam splitter, and detector are all monolithically integrated on the same substrate, with an overall chip size of ≤5mm×5mm. This completely eliminates the need for traditional discrete optical components and external coupling structures, meeting the application requirements of portable and miniaturized quantum devices.

[0033] 2. High stability and low loss: On-chip waveguide interconnection avoids alignment deviation and loss caused by external optical coupling. The waveguide alignment deviation of each component is ≤ ±50nm, resulting in high optical signal transmission efficiency. The chip structure reduces the impact of environmental interference (such as vibration and temperature changes) on device performance, significantly improving operational stability.

[0034] 3. Process compatibility and easy mass production: All integrated components are prepared using mature electron beam lithography, electron beam evaporation and lift-off processes, which are compatible with existing semiconductor micro and nano fabrication processes, making mass production easier and reducing manufacturing costs. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the chip-based quantum random number generation device of the present invention;

[0036] Figure 2 This is a schematic diagram of the gold bar waveguide structure of the present invention;

[0037] Figure 3 This is a schematic diagram of the cross-gold bar waveguide structure of the present invention. Detailed Implementation

[0038] The present invention will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0039] like Figure 1 As shown, a chip-based quantum random number generation device includes a chip-based entropy source module, an ADC module, and a post-processing module. The chip-based entropy source module includes a laser chip, a plasma polarization rotator (PPR), a plasma polarization beam splitter (PPBS), and two photodetectors (PD) that are monolithically integrated in sequence. The components are interconnected through on-chip waveguides.

[0040] The laser chip is a single-photon level continuous-wave laser chip, outputting laser light with a wavelength of 780~850nm. The operating current is higher than the operating threshold, and the laser power is attenuated to the single-photon level by the chip's built-in attenuation structure. The photon number distribution follows a Poisson distribution, and the average photon number is... It is directly coupled to the input waveguide of the plasma polarization rotator;

[0041] like Figure 2As shown, the plasma polarization rotator (PPR) is fabricated on a chip substrate and includes a metal nanowaveguide and a periodic grating structure. The metal nanowaveguide is a gold bar waveguide with a width W1 and a height H1. The periodic grating structure has a grating period T1 and a height H2. By adjusting the matching relationship between the grating period and the waveguide width, the rotational control of the polarization state of the incident laser can be achieved, converting the linearly polarized light output from the laser chip into a 45° linearly polarized state that is compatible with the plasma polarization beam splitter.

[0042] like Figure 3 As shown, the plasma polarization beam splitter (PPBS) is directly connected to the plasma polarization rotator via an output waveguide. It includes a cross-gold bar waveguide, a polarization selection grating, a central scattering grating, and an orthogonal polarization grating. The cross-gold bar waveguide has a width of W2 and a height of H3. The polarization selection scattering grating, located on the input waveguide of the cross-gold bar waveguide, is a periodic metal grating with a period of T2 and a height of H4. The central scattering grating, located in the intersection region of the cross-gold bar waveguide, is a third-order periodic grating. As a quantum scattering region, based on the polarization-dependent scattering effect of surface plasmon polaritons (SPPs), it randomly separates the incident linearly polarized SPPs into horizontal and vertical polarization components, which are then coupled to two orthogonal polarization gratings. The two orthogonal polarization gratings are located on the two output waveguides of the cross-gold bar waveguide, each with a width of W2, a period of T2, and a height of H4.

[0043] The two photodetectors (PDs) are chip-integrated single-photon avalanche diode (SPAD) detectors, each directly coupled one-to-one to the two orthogonal output waveguides of the plasma polarization beamsplitter via on-chip polarization-maintaining waveguides. PD1 is coupled to the output waveguide of the polarization grating transmitting horizontally polarized light, and PD2 is coupled to the output waveguide of the polarization grating transmitting vertically polarized light. The detectors convert the received single-photon signal into an electrical pulse signal; PD1 corresponds to "0" in the binary sequence, and PD2 corresponds to "1" in the binary sequence.

[0044] The chip substrate is made of quartz glass or silicon substrate, which provides support for all integrated components and has good optical transparency and thermal stability; the polarization maintaining waveguide is an erbium-doped quartz waveguide or a silicon nitride waveguide with a polarization extinction ratio ≥20dB.

[0045] The ADC module is used to acquire the electrical pulse signals of PD1 and PD2; the post-processing module is used to convert the raw data of the electrical pulse signals of PD1 and PD2 into true random numbers according to a predetermined algorithm.

[0046] The laser chip, plasma polarization rotator, plasma polarization beam splitter, polarization-maintaining waveguide, and two photodiodes (PDs) are monolithically integrated using the same micro-nano fabrication process. Specific processes include electron beam lithography (EBL), electron beam evaporation (EBE), plasma-enhanced chemical vapor deposition (PECVD), and a lift-off process. The metal structures (gold bar waveguide and scattering grating) are fabricated using an EBL+EBE+lift-off process, while the polarization-maintaining waveguide is fabricated using a PECVD+EBL+etching process. The waveguide alignment deviation of each component is ≤±50nm, and the overall chip size is ≤5mm×5mm.

[0047] The metal nanowaveguide of the plasma polarization rotator is a gold bar waveguide with a width W1=2μm and a height H1=70nm, and a periodic grating structure with a grating period T1=500nm and a height H1=90nm.

[0048] The input gold bar waveguide of the plasma polarization beam splitter has a width of W2=2μm and a height of H3=70nm. The polarization selective scattering grating is a 5-order periodic metal grating (period T2=400nm, height H4=90nm); the two orthogonal output waveguides both have a width of W2=2μm and a height of H4=90nm.

[0049] The specific work process is as follows:

[0050] The device adopts a fully integrated chip architecture, which integrates the laser chip, plasma polarization rotator, plasma beam splitter and two integrated PDs on the same substrate through micro-nano technology, so as to realize on-chip transmission and processing of optical signals without the need for external optical components.

[0051] The laser chip is an on-chip integrated continuous-wave laser chip with an output wavelength of 780~850nm (this wavelength band matches the optical-to-SPP conversion efficiency of the plasma device), and an operating current of 30~40mA (above the lasing threshold to ensure stable output). The chip incorporates a thin-film attenuation structure to attenuate the laser power to the single-photon level, avoiding multiphoton interference and ensuring that the photon number distribution follows a Poisson distribution.

[0052] ,

[0053] Where α and n are the amplitude and photon number of the continuous optical signal, respectively, satisfying The output of the laser chip is directly coupled to the input waveguide of the plasma polarization rotator.

[0054] The plasma polarization rotator, a key component connecting the laser chip and the plasma beam splitter, is used to control the polarization state to adapt to the SPP excitation requirements. Its structure includes a gold bar waveguide and a periodic grating: the gold bar waveguide has a width of 2μm and a height of 70nm (ensuring efficient SPP transmission), while the periodic grating has a period of 500nm and a height of 90nm (polarization rotation is achieved through mode coupling between the grating and the waveguide). By optimizing the matching relationship between the grating period and the waveguide width, the original horizontally polarized light output from the laser chip can be converted into 45° linearly polarized light.

[0055] The core function of a plasma beamsplitter is to achieve random path allocation for single photons. Its structure includes a cross-gold bar waveguide, a polarization selection grating, a central scattering grating, and an orthogonal polarization grating. The two input and output arms of the cross-gold bar waveguide have the same width as the main waveguide (2μm), ensuring the continuity of SPP transmission. The central scattering grating is a third-order periodic grating (period 450nm, height 90nm), serving as the quantum scattering region. After incident photons are converted into SPP in the waveguide, they are transmitted to the central scattering grating. Due to the randomness of quantum mechanics, some SPP is transmitted to the output arm of the forward polarization grating, and some is reflected to the output arm of the lateral polarization grating, achieving random path selection for single photons. The two output arms of the plasma polarization beamsplitter are directly coupled to the input waveguides of two integrated photons (PDs), respectively, without external optical loss. 45° linearly polarized light undergoes random path selection through the plasma polarization beamsplitter, with equal probability of entering the two integrated PDs.

[0056] The integrated PD uses a chip-integrated SPAD detector. The two PDs correspond to the two output arms of the plasma beam splitter. When a single photon signal is received, an electrical pulse is output: PD1 triggers a binary "0", and PD2 triggers a binary "1", providing a direct physical carrier for the random number sequence.

[0057] Chip substrate: Quartz glass or silicon substrate is selected, with a thickness of 0.1~0.2mm, possessing good optical transparency (ensuring low-loss transmission of optical signals) and thermal stability (avoiding the impact of operating temperature changes on device performance). All integrated components are fabricated using the same micro-nano process, with an overall chip size ≤5mm×5mm, achieving miniaturization and high integration.

[0058] After the ADC acquires the electrical pulse signals of PD1 and PD2, it generates raw random bits, which are then converted into true random numbers by the post-processing module according to a predetermined algorithm.

[0059] A chip-based quantum random number generation method based on the above-mentioned device:

[0060] This method utilizes a fully integrated chip architecture and leverages the quantum randomness of single-photon branch paths, combined with signal processing algorithms, to generate highly random quantum random numbers. The specific steps are as follows:

[0061] S1. Single-photon excitation: Activate the laser chip, set the operating current to 30-40mA, and output a continuous-wave laser with a wavelength of 780-850nm. After the laser is attenuated by the chip's built-in attenuation structure, the average number of photons... It satisfies the single-photon excitation condition and is directly coupled to the input waveguide of the plasma polarization rotator.

[0062] S2. Polarization State Control: The plasma polarization rotator controls the polarization state of the incident laser through the interaction between its periodic grating structure and the metal nanowaveguide. Based on the SPP excitation requirements of the plasma beam splitter, the laser polarization state is rotated to 45° linear polarization.

[0063] S3, Quantum Random Beam Splitting: The polarization-tuned laser is coupled to the input waveguide of the plasma beam splitter. The photon interacts with the free electrons on the surface of the gold bar waveguide, converting it into a single SPP that propagates along the waveguide. When the SPP propagates to the central scattering grating, it randomly selects a propagation path due to the quantum scattering effect, with half the probability of propagating from the forward output arm and half the probability from the side output arm, thus achieving random allocation of the branch path for the single photon.

[0064] S4. Single-Photon Detection and Electrical Pulse Conversion: Two integrated SPAD detectors receive single-photon signals from the two output arms of the plasma beam splitter, respectively, and convert the photon signals into electrical pulse signals. When PD1 detects a photon and triggers, the output electrical pulse corresponds to the binary digit "0"; when PD2 detects a photon and triggers, the output electrical pulse corresponds to the binary digit "1". If both detectors trigger simultaneously (multi-photon interference) or neither triggers (vacuum state), the signal is considered invalid and does not participate in sequence generation.

[0065] S5. Initial Sequence Generation: The ADC module acquires the electrical pulse signals of the two PDs, and the post-processing module uses a post-selection algorithm to filter the valid signals—only retaining the electrical pulses triggered by a single detector, removing multiphoton interference and vacuum state signals, and generating the initial binary sequence.

[0066] S6. Sequence Optimization: The Von Neumann recursive extraction algorithm is used to eliminate bias and short-range correlation in the initial binary sequence. The sequence is split into adjacent bit pairs, and "01" (mapped to "0") and "10" (mapped to "1") are retained. The split-mapping operation is repeated for the remaining bits, and finally the optimized quantum random number sequence is spliced ​​together.

[0067] In step S3, the polarization separation process of the plasma polarization beam splitter satisfies the following conditions: the separation efficiency of the horizontally polarized SPP and the vertically polarized SPP is ≥95%, and the optical power deviation between the two polarized beams is ≤±3%, ensuring that the bias of the initial sequence is within the correctable range. In step S3, the transmission loss of the SPP in the input and output waveguides of the plasma polarization beam splitter is calculated using the attenuation formula e^(-l / Lp), where the waveguide length l = 3~5μm, the SPP attenuation length Lp = 7~9μm, and the transmission efficiency is ≥55%. The transmission loss can be compensated by fine-tuning the output power of the laser chip, ensuring the number of effective single-photon signals.

[0068] Based on the principles and embodiments of this invention, it can be seen that this invention integrates the laser, polarization rotator, beam splitter, and detector all on a single substrate, completely eliminating the need for traditional discrete optical components and external coupling structures, thus meeting the application requirements of portable and miniaturized quantum devices. On-chip waveguide interconnection avoids alignment deviations and losses caused by external optical coupling, with waveguide alignment deviations of each component ≤ ±50nm, resulting in high optical signal transmission efficiency. The chip-based structure reduces the impact of environmental interference (such as vibration and temperature changes) on device performance, significantly improving operational stability. All integrated components are fabricated using mature electron beam lithography, electron beam evaporation, and lift-off processes, making them compatible with existing semiconductor micro-nano fabrication processes, facilitating mass production, and reducing manufacturing costs.

Claims

1. A chip-based quantum random number generation device, characterized in that, It includes a chip-based entropy source module, an ADC module, and a post-processing module. The chip-based entropy source module includes a laser chip, a plasma polarization rotator (PPR), a plasma polarization beam splitter (PPBS), and two photodetectors (PD1 and PD2) that are integrated on a single chip in sequence. The components are interconnected in sequence through on-chip waveguides. The laser output from the laser chip is directly coupled to the input waveguide of the PPR; PPR is used to rotate and control the polarization state of the incident laser, converting the linearly polarized light output from the laser chip into a 45° linearly polarized state that is compatible with PPBS. The PPBS and PPR are directly connected via an output waveguide, which includes a cross gold bar waveguide, a polarization selection grating, a central scattering grating, and an orthogonal polarization grating. The incident 45° linear polarization state is randomly separated into a horizontal polarization component and a vertical polarization component, which are then coupled to two orthogonal polarization gratings respectively. PD1 and PD2 are chip-integrated single-photon avalanche diode detectors (SPADs), each directly coupled one-to-one to the two orthogonal output waveguides of the PPBS via an on-chip polarization-maintaining waveguide. PD1 is coupled to the polarization grating output waveguide transmitting horizontally polarized light, and PD2 is coupled to the polarization grating output waveguide transmitting vertically polarized light. The two detectors convert the received single-photon signal into an electrical pulse signal; PD1 corresponds to "0" in the binary sequence, and PD2 corresponds to "1" in the binary sequence. The ADC module is used to acquire the electrical pulse signals of PD1 and PD2; the post-processing module is used to convert the raw data of the electrical pulse signals of PD1 and PD2 into true random numbers according to a predetermined algorithm.

2. The chip-based quantum random number generation device according to claim 1, characterized in that, The laser chip is a single-photon level continuous-wave laser chip, outputting laser light with a wavelength of 780~850nm. The operating current is higher than the operating threshold, and the laser power is attenuated to the single-photon level by the chip's built-in attenuation structure. The photon number distribution follows a Poisson distribution, and the average photon number is... .

3. The chip-based quantum random number generation device according to claim 2, characterized in that, PPR is fabricated on a chip substrate and includes a metal nanowaveguide and a periodic grating structure. The metal nanowaveguide is a gold bar waveguide with a width W1 and a height H1. The periodic grating structure has a grating period T1 and a height H2. The matching relationship between the grating period and the waveguide width is adjusted.

4. The chip-based quantum random number generation device according to claim 2, characterized in that, The polarization selective scattering grating is located on the input waveguide of the cross-gold bar waveguide. It is a periodic metal grating with a period of T2 and a height of H4. The central scattering grating is located in the cross region of the cross-gold bar waveguide. It is a third-order periodic grating and serves as a quantum scattering region based on the polarization-dependent scattering effect of surface plasmon polaritons (SPP).

5. The chip-based quantum random number generation device according to claim 3, characterized in that, The chip substrate is made of quartz glass or silicon substrate, which provides support for all integrated components and has good optical transparency and thermal stability; the polarization maintaining waveguide is an erbium-doped quartz waveguide or a silicon nitride waveguide with a polarization extinction ratio ≥20dB.

6. The chip-based quantum random number generation device according to claim 4, characterized in that, The laser chip, PPR, PPBS, polarization-preserving waveguide, and two PDs are monolithically integrated using the same micro-nano fabrication process. The specific process includes electron beam lithography (EBL), electron beam evaporation (EBE), plasma-enhanced chemical vapor deposition (PECVD), and lift-off process. The metal structure of the gold bar waveguide and scattering grating is fabricated using the EBL+EBE+lift-off process, while the polarization-preserving waveguide is fabricated using the PECVD+EBL+etching process. The waveguide alignment deviation of each component is ≤±50nm, and the overall chip size is ≤5mm×5mm.

7. The chip-based quantum random number generation device according to claim 3, characterized in that, The PPR's metal nanowaveguide is a gold bar waveguide with a width W1=2μm and a height H1=70nm, and a periodic grating structure with a grating period T1=500nm and a height H1=90nm.

8. The chip-based quantum random number generation device according to claim 1, characterized in that, The input gold bar waveguide of the PPBS has a width of W2=2μm and a height of H3=70nm. The polarization selective scattering grating is a 5th-order periodic metal grating with a period of T2=400nm and a height of H4=90nm. The two orthogonal output waveguides both have a width of W2=2μm and a height of H4=90nm.

9. The chip-based quantum random number generation device according to claim 1, characterized in that, The polarization selective scattering grating of PPBS has a silicon dioxide protective film with a thickness of 5~10nm on its surface. This protective film is prepared by atomic layer deposition (ALD) process and is used to reduce the oxidation loss of metal grating and environmental interference.

10. The chip-based quantum random number generation device according to claim 1, characterized in that, The laser chip has a built-in temperature compensation unit, which is an integrated structure of a miniature platinum resistance temperature sensor and a semiconductor cooler (TEC). The temperature control accuracy is ≤ ±0.01℃, which can compensate for the influence of ambient temperature changes on laser wavelength and output power in real time, ensuring the stability of single-photon excitation.

11. A chip-based quantum random number generation method, employing the apparatus described in any one of claims 1-10, characterized in that, Includes the following steps: S1. Single-photon excitation: Activate the laser chip, set the operating current to 30~40mA, and output a continuous-wave laser with a wavelength of 780~850nm. After the laser is attenuated by the chip's built-in attenuation structure, the average number of photons is... It satisfies the single-photon excitation condition and is directly coupled to the input waveguide of the plasma polarization rotator; S2. Polarization state manipulation: The plasma polarization rotator manipulates the polarization state of the incident laser through the interaction between its periodic grating structure and the metal nanowaveguide. Based on the SPP excitation requirements of the plasma beam splitter, the laser polarization state is rotated to 45° linear polarization. S3. Quantum random beam splitting: The polarization-tuned laser is coupled to the input waveguide of the plasma beam splitter. The photon interacts with the free electrons on the surface of the gold bar waveguide and is converted into a single SPP that propagates along the waveguide. When the SPP propagates to the central scattering grating, it randomly selects a propagation path due to the quantum scattering effect. It has a 50% probability of propagating from the forward output arm and a 50% probability of propagating from the side output arm, thus realizing the random allocation of the branch path of the single photon. S4. Single-photon detection and electrical pulse conversion: Two integrated SPAD detectors receive single-photon signals from the two output arms of the plasma beam splitter, respectively, and convert the photon signals into electrical pulse signals. When PD1 detects a photon and triggers, the output electrical pulse corresponds to the binary digit "0"; when PD2 detects a photon and triggers, the output electrical pulse corresponds to the binary digit "1". If both detectors trigger simultaneously or neither triggers, the signal is considered invalid and does not participate in sequence generation. S5. Initial sequence generation: The ADC module acquires the electrical pulse signals of the two PDs, and the post-processing module uses a post-selection algorithm to filter the valid signals, retaining only the electrical pulses triggered by a single detector, removing multiphoton interference and vacuum state signals, and generating the initial binary sequence. S6. Sequence Optimization: The Von Neumann recursive extraction algorithm is used to eliminate bias and short-range correlation in the initial binary sequence: the sequence is split into adjacent bit pairs, "01" and "10" are retained, and the split-mapping operation is repeated for the remaining bits, and finally spliced ​​into the optimized quantum random number sequence.

12. The method according to claim 11, characterized in that, In step S3, the polarization separation process of the plasma polarization beam splitter satisfies the following requirements: the separation efficiency of the horizontal polarization SPP and the vertical polarization SPP is ≥95%, the optical power deviation between the two polarized lights is ≤±3%, and the bias of the initial sequence is ensured to be within the correctable range.

13. The method according to claim 11, characterized in that, In step S3, the transmission loss of SPP in the input and output waveguides of the plasma polarization beam splitter is calculated by the attenuation formula e^(-l / Lp), where the waveguide length l = 3~5μm, the SPP attenuation length Lp = 7~9μm, and the transmission efficiency ≥55%. The transmission loss can be compensated by fine-tuning the output power of the laser chip to ensure the number of effective single-photon signals.

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