Optical heterodyne entropy source for generating true random numbers, manufacturing method, chip and system

Abstract

The present disclosure relates to the field of information security technology, and specifically to an optical heterodyne entropy source, manufacturing method, chip and system for generating true random numbers. The optical heterodyne entropy source for generating true random numbers includes: a first tunable laser, a first optical beam splitter and a first photodetector arranged along a first optical path; a second tunable laser, a second optical beam splitter and a second photodetector arranged along a second optical path; an optical coupler; wherein the first optical beam splitter divides the first optical signal generated by the first tunable laser into two paths, one of which is introduced into the optical coupler, and the second optical signal generated by the second tunable laser is introduced into the optical coupler, and the optical coupler outputs a beat frequency signal, which is sequentially output through the second optical beam splitter and the second photodetector. The above technical solution realizes the superposition of the difference frequency signal of the dual lasers and the phase noise signal thereof, thereby improving the rate of generating random numbers.

Description

Technical Field

[0001] The present disclosure relates to the field of information security technology, and in particular to an optical heterodyne entropy source for generating true random numbers, a manufacturing method, a chip, and a system. Background Art

[0002] With the rapid development of information technology, data transmission and interaction are also increasing, bringing with it information security issues. Random number encryption, a classic information encryption technology, is widely used. Current random number generation methods are divided into two categories: pseudo-random number generation and true random number generation. Pseudo-random number generation uses a generation algorithm and an initial random number seed to generate a random number sequence. In essence, the random numbers obtained using this method are correlated and cannot meet the higher security requirements of encryption. True random number generation utilizes random phenomena in nature to generate corresponding random signals. Random phenomena primarily originate from real physical processes, such as various noise signals present in devices and systems. Random numbers generated using this method are highly unpredictable and suitable for higher security encryption.

[0003] For random number generators, the performance and scale of the device determine the speed and data volume of random number generation. Random number generators based on electronic devices often face significant challenges in performance and power consumption. In recent years, random number generators based on photonic devices have begun to be widely reported. These random number generators are characterized by high device speed and low electrical loss. However, currently reported random number generators based on photonic devices primarily utilize the phase noise of the laser light source itself as an entropy source, combined with optoelectronic devices such as modulators and detectors to generate true random number sequences. However, the generated random number rate is not fast enough. Summary of the Invention

[0004] In order to solve the problems in the related art, the embodiments of the present disclosure provide an optical heterodyne entropy source, a manufacturing method, a chip and a system for generating true random numbers.

[0005] In a first aspect, an embodiment of the present disclosure provides an optical heterodyne entropy source for generating true random numbers, including:

[0006] A first tunable laser, a first optical beam splitter, and a first photodetector arranged along a first optical path;

[0007] a second tunable laser, a second optical beam splitter, and a second photodetector arranged along a second optical path;

[0008] Optocoupler;

[0009] The first optical beam splitter divides the first optical signal generated by the first tunable laser into two paths, one of which is introduced into the optical coupler, and the second optical signal generated by the second tunable laser is introduced into the optical coupler. The optical coupler outputs a beat frequency signal, and the beat frequency signal is sequentially output through the second optical beam splitter and the second photodetector.

[0010] In one implementation of the present disclosure, it further includes:

[0011] A substrate is provided on which the first tunable laser, the first optical beam splitter, the first photodetector, the second tunable laser, the second optical beam splitter, the second photodetector and the optical coupler are integrated.

[0012] In one implementation of the present disclosure, the first tunable laser and the second tunable laser are stacked structures, wherein the layers from the bottom to the top are an n-type bottom layer, a gain layer, and a p-type cap layer; wherein the gain layer comprises a periodic grating structure; and / or,

[0013] The first optical beam splitter, the second optical beam splitter and the optical coupler are homoepitaxial layers formed on the substrate, and are obtained by etching the homoepitaxial layers; and / or,

[0014] The first photodetector and the second photodetector are stacked structures, with layers from the bottom to the top comprising an n-type bottom layer, an intrinsic absorption layer, and a p-type cap layer.

[0015] In one implementation of the present disclosure, the substrate, the first tunable laser, the first optical beam splitter, the first photodetector, the second tunable laser, the second optical beam splitter, the second photodetector and the optical coupler are made of III-V semiconductor materials.

[0016] In one implementation of the present disclosure, the first tunable laser and the second tunable laser are distributed feedback lasers or distributed Bragg reflector lasers; and / or,

[0017] The first optical beam splitter and the second optical beam splitter are 1×2 multimode interference couplers; and / or,

[0018] The first photodetector and the second photodetector are PIN-type photodetectors or single-row carrier photodetectors; and / or,

[0019] The optical coupler is a 2×1 multimode interference coupler.

[0020] In an implementation of the present disclosure, the frequency adjustable range of the first tunable laser and the second tunable laser exceeds 1 THz.

[0021] In one implementation of the present disclosure, the power of the first optical signal is twice the power of the second optical signal.

[0022] In a second aspect, the present disclosure provides a method for manufacturing an optical heterodyne entropy source, including:

[0023] providing a substrate;

[0024] An n-type bottom layer and a gain layer are sequentially grown epitaxially on a substrate, a periodic grating structure is formed on the gain layer by etching, and then a p-type cap layer is epitaxially grown on the gain layer;

[0025] Etching the n-type bottom layer, the gain layer and the p-type cap layer to form a first tunable laser and a second tunable laser;

[0026] Epitaxially growing an n-type bottom layer, an intrinsic absorption layer and a p-type cap layer on the substrate in sequence;

[0027] Etching the n-type bottom layer, the intrinsic absorption layer and the p-type cap layer on both sides to form a first photodetector and a second photodetector;

[0028] Homoepitaxial growth is performed on the substrate, and the homoepitaxial layer is etched to form a first optical beam splitter, a second optical beam splitter and an optical coupler.

[0029] In a third aspect, an embodiment of the present disclosure provides an optical heterodyne entropy source photonic integrated chip, comprising the optical heterodyne entropy source as described in any one of the first aspects.

[0030] In a fourth aspect, an embodiment of the present disclosure provides a true random number generator system, comprising a current comparator circuit and the optical heterodyne entropy source photon integrated chip as described in the third aspect;

[0031] The other path of the first optical signal is introduced into the first photodetector, and the first output current of the first photodetector is introduced into the current comparator circuit; and the second output current output by the second photodetector is introduced into the current comparator circuit;

[0032] The current comparator circuit is used to compare the first output current and the second output current and generate a random number sequence, and then output the random number sequence from an output terminal of the current comparator circuit.

[0033] The technical effects provided by the embodiments of the present disclosure may include the following beneficial effects:

[0034] According to the technical solution provided by the embodiment of the present disclosure, the optical heterodyne entropy source for generating true random numbers includes: a first tunable laser, a first optical beam splitter and a first photodetector arranged along a first optical path; a second tunable laser, a second optical beam splitter and a second photodetector arranged along a second optical path; an optical coupler; wherein the first optical beam splitter divides the first optical signal generated by the first tunable laser into two paths, one of which is introduced into the optical coupler, and the second optical signal generated by the second tunable laser is introduced into the optical coupler, and the optical coupler outputs a beat frequency signal, which is sequentially outputted through the second optical beam splitter and the second photodetector. In the above technical solution, based on the principle of optical heterodyne beat frequency, the superposition of the difference frequency signal of the dual lasers and their own phase noise signal is realized. By adjusting the frequency difference of the two laser signals, the phase noise of the laser can be improved, thereby increasing the rate of generating random numbers.

[0035] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Other features, objectives and advantages of the present disclosure will become more apparent through the following detailed description of non-limiting embodiments in conjunction with the accompanying drawings.

[0037] Figure 1 A schematic structural diagram of an optical heterodyne entropy source for generating true random numbers according to an embodiment of the present disclosure is shown.

[0038] Figure 2 The embodiment of the present disclosure is shown along Figure 1 Schematic diagram of the cross-sectional structure along the AB direction.

[0039] Figure 3 According to the embodiment of the present disclosure Figure 2 Flow chart for the fabrication of the structure shown in .

[0040] Figure 4 A schematic structural diagram of a true random number generator system according to an embodiment of the present disclosure is shown.

[0041] Figure 5a FIG. 4 shows a spectrum diagram of a beat signal according to an embodiment of the present disclosure.

[0042] Figure 5b A schematic diagram showing the test results of the autocorrelation sequence of the beat frequency signal according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0043] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. In addition, for the sake of clarity, parts not related to the description of the exemplary embodiments are omitted in the accompanying drawings.

[0044] In the present disclosure, it should be understood that terms such as "include" or "have" are intended to indicate the presence of features, numbers, steps, actions, components, parts, or combinations thereof disclosed in the present specification, and are not intended to exclude the possibility that one or more other features, numbers, steps, actions, components, parts, or combinations thereof exist or are added.

[0045] It should also be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] The random number generators based on photonic devices reported so far mainly use the phase noise of the laser light source itself as the entropy source, combined with modulators, detectors and other optoelectronic devices to achieve the generation of true random number sequences. The generated random number rate is not fast enough.

[0047] Taking the above-mentioned defects into consideration, the optical heterodyne entropy source for generating true random numbers provided by the present invention realizes the superposition of the difference frequency signal of the dual lasers and their own phase noise signal based on the principle of optical heterodyne beat frequency. By adjusting the frequency difference between the two laser signals, the phase noise of the laser can be improved, thereby increasing the rate of generating random numbers.

[0048] Figure 1 A schematic structural diagram of an optical heterodyne entropy source for generating true random numbers according to an embodiment of the present disclosure is shown.

[0049] like Figure 1 As shown, the optical heterodyne entropy source for generating true random numbers includes: a first tunable laser 11, a first optical beam splitter 12 and a first photodetector 13 arranged along a first optical path; a second tunable laser 14, a second optical beam splitter 15 and a second photodetector 16 arranged along a second optical path; and an optical coupler 17; wherein the first optical beam splitter 12 divides the first optical signal generated by the first tunable laser 11 into two paths, one of which is introduced into the optical coupler 17, and the second optical signal generated by the second tunable laser 14 is introduced into the optical coupler 17, and the optical coupler 17 outputs a beat frequency signal, and the beat frequency signal is output in sequence through the second optical beam splitter 15 and the second photodetector 16.

[0050] Specifically, the first tunable laser 11 includes an output end, and the first tunable laser 11 outputs a first optical signal. The first optical beam splitter 12 includes an input end, a first output end, and a second output end. Its input end is connected to the output end of the first tunable laser 11, and the first optical signal is split into two signals of equal power. One signal is output from the first output end of the first optical beam splitter 12, and the other signal is output from the second output end of the first optical beam splitter 12. The first photodetector 13 includes an input end and an output end. Its input end is connected to the first output end of the first optical beam splitter 12, and the first photodetector 13 converts the received signal into a current, which is then output from the output end of the first photodetector 13.

[0051] The second tunable laser 14 includes an output end, and the second tunable laser 14 outputs a second optical signal. The optical coupler 17 includes a first input end, a second input end, and an output end. The first input end of the optical coupler 17 is connected to the second output end of the first optical beam splitter 12, and the second input end of the optical coupler 17 is connected to the output end of the second tunable laser 14. The optical coupler 17 combines the signal received from the first optical beam splitter 12 and the second optical signal to obtain a beat signal. The second optical beam splitter 15 includes an input end, a first output end, and a second output end. The input end of the second optical beam splitter 15 is connected to the output end of the optical coupler 17, and the beat signal is divided into two beat signals of equal power. One beat signal is output from the first output end of the second optical beam splitter 15, and the other beat signal is output from the second output end of the second optical beam splitter 15. The second photodetector 16 includes an input end and an output end. Its input end is connected to the first output end of the second optical beam splitter 15 , and converts the received beat frequency signal into a current, which is output from the output end of the second photodetector 16 .

[0052] In one implementation of the present disclosure, the structures of the first tunable laser 11 and the second tunable laser 14 may be the same or different. The structures of the first optical beam splitter 12 and the second optical beam splitter 15 may be the same or different. The structures of the first photodetector 13 and the second photodetector 16 may be the same or different.

[0053] In one implementation of the present disclosure, the optical heterodyne entropy source for generating true random numbers further includes:

[0054] A substrate 10, on which the first tunable laser 11, the first optical beam splitter 12, the first photodetector 13, the second tunable laser 14, the second optical beam splitter 15, the second photodetector 16, and the optical coupler 17 are integrated. The material of the substrate 10 includes, but is not limited to, indium phosphide, gallium arsenide, and indium gallium arsenide.

[0055] By integrating the above-mentioned devices for generating true random numbers of optical heterodyne entropy sources on the same substrate using photonic integration technology, monolithic integration of the random number entropy source is achieved, which has the advantages of small size and low power consumption and is conducive to large-scale production.

[0056] In one implementation of the present disclosure, the first tunable laser 11, the first optical beam splitter 12, the first photodetector 13, the second tunable laser 14, the second optical beam splitter 15, the second photodetector 16 and the optical coupler 17 can be existing devices.

[0057] Specifically, the first tunable laser 11 and the second tunable laser 14 are distributed feedback lasers or distributed Bragg reflector lasers; and / or,

[0058] The first optical beam splitter 12 and the second optical beam splitter 15 are 1×2 multimode interference couplers; and / or,

[0059] The first photodetector 13 and the second photodetector 16 are PIN-type photodetectors or single-row carrier photodetectors; and / or,

[0060] The optical coupler 17 is a 2×1 multimode interference coupler.

[0061] In another embodiment of the present disclosure, the first tunable laser 11, the first optical beam splitter 12, the first photodetector 13, the second tunable laser 14, the second optical beam splitter 15, the second photodetector 16, and the optical coupler 17 can also be manufactured using a chip manufacturing process. The first tunable laser 11, the first optical beam splitter 12, the first photodetector 13, the second tunable laser 14, the second optical beam splitter 15, the second photodetector 16, and the optical coupler 17 are made of Group III-V semiconductor materials.

[0062] Specifically, the first tunable laser 11 and the second tunable laser 14 are stacked structures, with an n-type base layer, a gain layer, and a p-type cap layer, from bottom to top. The gain layer includes a periodic grating structure for selecting the laser output wavelength and achieving tuning. The n-type base layer can be made of indium phosphide, the gain layer can be made of indium gallium arsenide, and the p-type cap layer can be made of indium phosphide.

[0063] The first optical beam splitter 12, the second optical beam splitter 15 and the optical coupler 17 are formed by etching the homoepitaxial layer formed on the substrate 10. The first optical beam splitter 12, the second optical beam splitter 15 and the optical coupler 17 can be made of indium phosphide.

[0064] The first photodetector 13 and the second photodetector 16 are stacked structures, with an n-type base layer, an intrinsic absorption layer, and a p-type cap layer, from bottom to top. The n-type base layer may be made of indium phosphide, the intrinsic absorption layer may be made of indium gallium arsenide, and the p-type cap layer may be made of indium phosphide or indium gallium arsenide.

[0065] In one implementation of the present disclosure, the frequency adjustable range of the first tunable laser 11 and the second tunable laser 14 exceeds 1 THz, and the frequency of the noise signal generated can theoretically be as high as GHz, which greatly improves the random number generation speed.

[0066] In an implementation of the present disclosure, the power of the first optical signal is twice the power of the second optical signal, thereby making the beat frequency signal output by the optical coupler more stable.

[0067] Figure 2 The embodiment of the present disclosure is shown along Figure 1 Schematic diagram of the cross-sectional structure along the AB direction. Figure 3 The embodiment according to the present disclosure is shown Figure 2 Flow chart for the fabrication of the structure shown in .

[0068] Combine Figure 2 , Figure 3 As shown, Figure 2 The method for making the structure shown comprises:

[0069] A substrate 10 is provided, and an n-type bottom layer 110 and a gain layer 111 are sequentially grown on the substrate 10, a periodic grating structure is formed on the gain layer 111 by etching, and then a p-type cap layer 112 is epitaxially grown on the gain layer 111, as shown in FIG. Figure 3 (a) to Figure 3 (c) shown.

[0070] The n-type bottom layer 110, the gain layer 111 and the p-type cap layer 112 are etched to form the first tunable laser 11 of the ridge laser structure. Figure 3 (d) shown.

[0071] On the substrate 10, an n-type bottom layer 160, an intrinsic type absorption layer 161 and a p-type cap layer 162 are sequentially grown epitaxially. Figure 3 (e) shown.

[0072] The n-type bottom layer 160, the intrinsic absorption layer 161 and the p-type cap layer 162 on both sides are etched to form a second photodetector 16 with a ridge-type detector structure. Figure 3 (f) shown.

[0073] Homoepitaxial growth is performed on the substrate 10, and the homoepitaxial layer is etched to form the first optical beam splitter 12, the second optical beam splitter 15 and the optical coupler 17. Figure 3 (g) to Figure 3 (h) shown.

[0074] The epitaxial growth method includes but is not limited to metal organic chemical vapor deposition and molecular beam epitaxy. The etching method can be wet etching or dry etching.

[0075] It can be understood that the second tunable laser 14 has the same structure as the first tunable laser 11, and the first photodetector 13 has the same structure as the second photodetector 16. The second tunable laser 14 is formed while etching the first tunable laser 11, and the first photodetector 13 is formed while etching the second photodetector 16. Then, the first optical beam splitter 12 is etched in the direction of the first optical path, the second optical beam splitter 15 is etched in the direction of the second optical path, and the optical coupler 17 is etched between the first optical beam splitter 12 and the second optical beam splitter 15 to obtain the optical coupler 17. Figure 1 The optical heterodyne entropy source is shown.

[0076] Specifically, Figure 1 The method for making the optical heterodyne entropy source shown includes:

[0077] providing a substrate;

[0078] An n-type bottom layer and a gain layer are sequentially grown epitaxially on a substrate, a periodic grating structure is formed on the gain layer by etching, and then a p-type cap layer is epitaxially grown on the gain layer;

[0079] Etching the n-type bottom layer, the gain layer and the p-type cap layer to form a first tunable laser and a second tunable laser;

[0080] Epitaxially growing an n-type bottom layer, an intrinsic absorption layer and a p-type cap layer on the substrate in sequence;

[0081] Etching the n-type bottom layer, the intrinsic absorption layer and the p-type cap layer on both sides to form a first photodetector and a second photodetector;

[0082] Homoepitaxial growth is performed on the substrate, and the homoepitaxial layer is etched to form a first optical beam splitter, a second optical beam splitter and an optical coupler.

[0083] Based on the same or similar inventive concept, the present disclosure also provides an optical heterodyne entropy source photonic integrated chip, including any of the optical heterodyne entropy sources described above.

[0084] Figure 4 A schematic structural diagram of a true random number generator system according to an embodiment of the present disclosure is shown.

[0085] like Figure 4 As shown, a true random number generator system includes a current comparator circuit and an optical heterodyne entropy source photonic integrated chip. The optical heterodyne entropy source photonic integrated chip includes a substrate 10 and an optical heterodyne entropy source integrated on the substrate 10 for generating true random numbers. The optical heterodyne entropy source for generating true random numbers includes: a first tunable laser 11, a first optical beam splitter 12, and a first photodetector 13 arranged along a first optical path; a second tunable laser 14, a second optical beam splitter 15, and a second photodetector 16 arranged along a second optical path; and an optical coupler 17.

[0086] Among them, the first optical beam splitter 12 divides the first optical signal generated by the first tunable laser 11 into two paths, one of which is introduced into the optical coupler 17, and the second optical signal generated by the second tunable laser 14 is introduced into the optical coupler 17. The optical coupler 17 outputs a beat frequency signal, and the beat frequency signal is output in sequence through the second optical beam splitter 15 and the second photodetector 16.

[0087] Another path of the first optical signal is introduced into the first photodetector 13, and the first output current of the first photodetector 13 is introduced into the current comparator circuit; the second output current output by the second photodetector 16 is introduced into the current comparator circuit; the current comparator circuit is used to compare the first output current and the second output current and generate a random number sequence, and then output the random number sequence from the output end of the current comparator circuit.

[0088] The working principle of the true random number generator system to generate random numbers is as follows:

[0089] The first optical signal generated by the first tunable laser 11 has a frequency of f1 and an angular frequency of ω1. The second optical signal generated by the second tunable laser 14 has a frequency of f2 and an angular frequency of ω2. The power of the first optical signal input to the optical coupler 17 is P1 / 2, and the power of the second optical signal input to the optical coupler 17 is P2. For illustrative purposes, the present disclosure sets the power of the first optical signal to be twice the power of the second optical signal, i.e., P1 = 2P2.

[0090] The first output current of the first photodetector 13 is kP2, where k is the conversion rate of the photodetector.

[0091] The optical coupler 17 combines the first optical signal and the second optical signal and inputs them into the second photodetector 16 for optical heterodyne beat frequency. Based on the optical heterodyne principle, the input optical power of the second photodetector 16 can be expressed by the following formula:

[0092]

[0093] The second output current of the second photodetector 16 is

[0094] Where m is the spatial coupling coefficient of the optical coupler, which is between 0 and 1; ω1-ω2 is the angular frequency difference between the first optical signal and the second optical signal. is the phase difference between the first optical signal and the second optical signal.

[0095] The above equation shows that the time-domain phase perturbation of the second output current signal from the second photodetector is equal to the product of the laser's own phase noise and the angular frequency difference, resulting in a high perturbation frequency. The quality of the random number sequence is positively correlated with the perturbation frequency of the random signal's entropy source, thereby increasing the rate at which random numbers are generated.

[0096] Figure 5a FIG. 4 shows a spectrum diagram of a beat signal according to an embodiment of the present disclosure. Figure 5b A schematic diagram shows the test results of an autocorrelation sequence for a beat frequency signal according to an embodiment of the present disclosure. The spectrum plot allows the wavelength of each laser signal to be read, thereby calculating the frequency difference. An autocorrelation sequence is an autocorrelation operation performed on the input waveform. When the input waveform contains two frequency components, the resulting output waveform is a sinusoidal wave with a frequency equal to the difference between the two frequencies.

[0097] There is a corresponding relationship between the wavelength difference between the first optical signal and the second optical signal and the frequency obtained by the heterodyne beat frequency. The conversion relationship between the wavelength difference and the beat frequency is 0.08nm corresponding to 1GHz. Figure 5a As shown. The frequency of the autocorrelation sequence waveform of the beat signal is equal to the heterodyne beat frequency, as shown Figure 5b As shown. Combined Figure 5a as well as Figure 5b It can be seen that the frequency of the autocorrelation sequence of the beat signal is consistent with the beat frequency converted from the wavelength difference, which proves that the system can effectively generate high-frequency beat signals.

[0098] The above description is merely a preferred embodiment of the present disclosure and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this disclosure.

Claims

1. An optical heterodyne entropy source for generating true random numbers, characterized in that: include: A first tunable laser, a first optical beam splitter, and a first photodetector arranged along a first optical path; a second tunable laser, a second optical beam splitter, and a second photodetector arranged along a second optical path; Optocoupler; The first optical beam splitter splits the first optical signal generated by the first tunable laser into two paths, one of which is introduced into the optical coupler, and the second optical signal generated by the second tunable laser is introduced into the optical coupler. The optical coupler outputs a beat frequency signal, which is sequentially output through the second optical beam splitter and the second photodetector. The first tunable laser and the second tunable laser are stacked structures, and the layers from the bottom to the top are an n-type bottom layer, a gain layer and a p-type cover layer, wherein the gain layer includes a periodic grating structure; and / or, the first optical beam splitter, the second optical beam splitter and the optical coupler are homoepitaxial layers formed on a substrate, and the homoepitaxial layers are etched; and / or, the first photodetector and the second photodetector are stacked structures, and the layers from the bottom to the top are an n-type bottom layer, an intrinsic absorption layer and a p-type cover layer.

2. The optical heterodyne entropy source according to claim 1, characterized in that Also includes: A substrate is provided on which the first tunable laser, the first optical beam splitter, the first photodetector, the second tunable laser, the second optical beam splitter, the second photodetector and the optical coupler are integrated.

3. The optical heterodyne entropy source according to claim 1, characterized in that: The materials of the substrate, the first tunable laser, the first optical beam splitter, the first photodetector, the second tunable laser, the second optical beam splitter, the second photodetector and the optical coupler are III-V group semiconductor materials.

4. The optical heterodyne entropy source according to any one of claims 1 to 3, characterized in that: The first tunable laser and the second tunable laser are distributed feedback lasers or distributed Bragg reflector lasers; and / or, The first optical beam splitter and the second optical beam splitter are 1×2 multimode interference couplers; and / or, The first photodetector and the second photodetector are PIN-type photodetectors or single-row carrier photodetectors; and / or, The optical coupler is a 2×1 multimode interference coupler.

5. The optical heterodyne entropy source according to any one of claims 1 to 3, characterized in that: The frequency adjustable range of the first tunable laser and the second tunable laser exceeds 1 THz.

6. The optical heterodyne entropy source according to any one of claims 1 to 3, characterized in that: The power of the first optical signal is twice the power of the second optical signal.

7. The method for manufacturing an optical heterodyne entropy source according to claim 3, wherein: include: providing a substrate; An n-type bottom layer and a gain layer are sequentially grown epitaxially on a substrate, a periodic grating structure is formed on the gain layer by etching, and then a p-type cap layer is epitaxially grown on the gain layer; Etching the n-type bottom layer, the gain layer and the p-type cap layer to form a first tunable laser and a second tunable laser; Epitaxially growing an n-type bottom layer, an intrinsic absorption layer and a p-type cap layer on the substrate in sequence; Etching the n-type bottom layer, the intrinsic absorption layer and the p-type cap layer on both sides to form a first photodetector and a second photodetector; Homoepitaxial growth is performed on the substrate, and the homoepitaxial layer is etched to form a first optical beam splitter, a second optical beam splitter and an optical coupler.

8. An optical heterodyne entropy source photon integrated chip, characterized in that: Comprising the optical heterodyne entropy source as described in any one of claims 1-6.

9. A true random number generator system, characterized in that: comprising a current comparator circuit and the optical heterodyne entropy source photon integrated chip as claimed in claim 8; The other path of the first optical signal is introduced into the first photodetector, and the first output current of the first photodetector is introduced into the current comparator circuit; and the second output current output by the second photodetector is introduced into the current comparator circuit; The current comparator circuit is used to compare the first output current and the second output current and generate a random number sequence, and then output the random number sequence from an output terminal of the current comparator circuit.

Images