Perfect vortex beam super-structured surface vertical cavity surface emitting laser encryption chip

Abstract

The present application provides a perfect vortex beam superstructure surface vertical cavity surface emitting laser encryption chip, the chip comprises: a vertical cavity surface emitting laser VCSEL array comprising a plurality of independently drivable VCSEL units, each VCSEL unit in the plurality of VCSEL units is provided with a superstructure surface layer at the light emitting end face, and has different phases. A key control unit is used to generate a channel selection signal according to the information to be transmitted. A multi-channel electrically driven modulation unit is electrically connected with the key control unit and the plurality of VCSEL units respectively; the multi-channel electrically driven modulation unit is used to control the plurality of VCSEL units to convert the outgoing light beam into a perfect vortex beam with a target topological charge number according to the channel selection signal; and the perfect vortex beam with the target topological charge number is used to represent the information to be transmitted. It can be seen that the chip can generate a perfect vortex beam, effectively avoiding external encryption devices, significantly reducing the size and integration difficulty, and enabling high-speed, low-power, high-security physical layer encryption within the chip scale.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, and in particular to a perfect vortex beam metasurface vertical cavity surface-emitting laser encryption chip. Background Technology

[0002] With the rapid development of artificial intelligence, cloud computing, data centers, and high-performance computing, the requirements for bandwidth, speed, energy consumption, and security in communication systems are continuously increasing. Due to its advantages such as high bandwidth, low loss, and resistance to electromagnetic interference, optical communication has become a crucial technology in communication systems.

[0003] However, existing optical communication relies on upper-layer digital cryptographic algorithms or external encryption devices for secure transmission. While these methods have good versatility, they increase computational latency, system complexity, and energy consumption, and have limited protection against physical layer eavesdropping, link interception, and low-level signal analysis.

[0004] For example, external encryption devices typically rely on discrete optical components such as spatial light modulators, diffractive optical elements, lens groups, and polarization controllers. However, discrete optical components suffer from drawbacks such as large size, complex optical path debugging, and insufficient stability, making them difficult to directly embed into high-speed optical modules, data center server boards, or on-chip optical interconnect systems. Therefore, how to achieve high-speed, low-power, and highly secure physical layer encryption at the chip level is a technical problem that needs to be solved for secure optical communication transmission. Summary of the Invention

[0005] This invention provides a perfect vortex beam metasurface vertical cavity surface-emitting laser encryption chip, which achieves high-speed, low-power, and high-security physical layer encryption within the chip scale. The technical solution is as follows.

[0006] Firstly, a perfect vortex beam metasurface vertical-cavity surface-emitting laser encryption chip is provided, the chip comprising: A vertical cavity surface emission laser (VCSEL) array, comprising multiple independently driveable VCSEL units, wherein each VCSEL unit has a metasurface layer on its output end face, and the metasurface layers on the output end faces of the multiple VCSEL units have different phases. The key control unit is used to generate a channel selection signal based on the information to be transmitted. The multi-channel electrically driven modulation unit is electrically connected to the key control unit and multiple VCSEL units respectively, and the multi-channel electrically driven modulation unit corresponds one-to-one with the multiple VCSEL units; the multi-channel electrically driven modulation unit is used to control the multiple VCSEL units to convert the outgoing beam into a perfect vortex beam with the target topological charge number according to the channel selection signal; the perfect vortex beam with the target topological charge number is used to characterize the information to be transmitted.

[0007] Furthermore, the key control unit is specifically used to map the first key sequence to the arrangement and combination of multiple VCSEL units to obtain a channel selection signal; wherein, the first key sequence is obtained by encrypting the information to be transmitted.

[0008] Furthermore, the chip also includes: a key management module, which is used to digitally encrypt the information to be transmitted to obtain a first key sequence; the key management module is electrically connected to the key control unit.

[0009] Furthermore, the chip also includes an optical output interface, which is electrically connected to the VCSEL array for outputting a perfect vortex beam with the target topological charge.

[0010] Furthermore, the VCSEL unit sequentially includes: an N-type electrode, a gallium arsenide (GaAs) substrate, an N-type Bragg mirror, an oxide confinement aperture, a P-type Bragg mirror benzocyclobutene layer, and a P-type electrode; wherein, the metasurface layer is located between the N-type electrode and the gallium arsenide (GaAs) substrate.

[0011] Furthermore, when the number of multiple VCSEL units is greater than the number of topology load types, multiple VCSEL units correspond to the same type of topology load.

[0012] Furthermore, the multi-channel electrically driven modulation unit includes a field-programmable gate array (FPGA).

[0013] Furthermore, the number of multiple VCSEL units is 4 raised to the power of M, where M is a positive integer greater than or equal to 1.

[0014] Furthermore, the operating wavelength of the VCSEL array is any one of 850 nm to 1550 nm.

[0015] Furthermore, multiple VCSEL units correspond to different topology loads, with the topology load ranging from -N to +N, where N is an integer greater than or equal to 1.

[0016] The perfect vortex beam metasurface vertical cavity surface-emitting laser encryption chip provided by this invention has at least the following technical advantages: By setting up a vertical-cavity surface-emitting laser (VCSEL) array, which includes multiple independently driveable VCSEL units, and each VCSEL unit having a metasurface layer on its output end face, the metasurface layers on the output end faces of the multiple VCSEL units have different phases. A key control unit generates a channel selection signal based on the information to be transmitted. A multi-channel electrically driven modulation unit controls the multiple VCSEL units to convert the emitted beam into a perfect vortex beam with the target topological charge number based on the channel selection signal. The perfect vortex beam with the target topological charge number is used to characterize the information to be transmitted. Therefore, this chip can generate a perfect vortex beam, effectively avoiding external encryption devices, significantly reducing size and integration difficulty, and enabling high-speed, low-power, and high-security physical layer encryption within the chip scale.

[0017] In addition, the metasurface layers on the light-emitting end faces of multiple VCSEL units have different phases, and multiple VCSEL units can correspond to different topological charges. In this way, by selecting multiple VCSEL units for arbitrary combination and controlling the working timing of multiple VCSEL units, dynamic programmable control can be achieved. The control method is simple and the response speed is fast. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of a perfect vortex beam profile generated by a single VCSEL unit integrating a metasurface layer, provided as an embodiment of the present invention; Figure 2 This is a schematic diagram showing different topological charge numbers corresponding to different VCSEL units provided in embodiments of the present invention; Figure 3 This is a schematic diagram illustrating the selection of channels in a VCSEL array, as provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0021] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0022] This invention provides a perfect vortex beam metasurface vertical-cavity surface-emitting laser (VCSEL) encryption chip. The chip may include: a vertical-cavity surface-emitting laser (VCSEL) array, a key control unit, and a multi-channel electrically driven modulation unit. The multi-channel electrically driven modulation unit is electrically connected to the key control unit and multiple VCSEL units respectively, with each multi-channel electrically driven modulation unit corresponding to one of the multiple VCSEL units.

[0023] The VCSEL array comprises multiple independently driveable VCSEL cells. Each VCSEL cell has a metasurface layer on its light-emitting end face, and these metasurface layers have different phases. The phase of the metasurface layer includes a vortex phase term. = · ( ), where l is the topological charge number. For example, depending on the VCSEL epitaxial material, optical communication application scenario, and metasurface material system, the operating wavelength of the VCSEL array can be any one of 850 nm to 1550 nm, such as 850 nm, 940 nm, 980 nm, 1310 nm, and 1550 nm. In practical applications, the operating wavelength of the VCSEL array is 960 nm. For example, Figure 1 This is a schematic diagram illustrating the generation of a perfect vortex beam using a structure with an integrated metasurface layer in a single VCSEL unit, as provided in an embodiment of the present invention. Figure 1 As shown, the VCSEL unit sequentially includes: an N-type electrode 1, a gallium arsenide (GaAs) substrate 3, an N-type Bragg mirror 4, an oxide confinement aperture 5, a P-type Bragg mirror 6, a benzocyclobutene layer 7, and a P-type electrode 8; wherein, the metasurface layer 2 is located between the N-type electrode 1 and the gallium arsenide (GaAs) substrate 3.

[0024] The metasurface layer 2 is composed of subwavelength artificial micro / nano structures. By designing the size, shape, orientation, or arrangement period of the structural units, precise control of the phase, amplitude, polarization, and wavefront of the optical field can be achieved within an extremely thin thickness. Integrating the metasurface layer directly onto the output end face of a vertical-cavity surface-emitting laser allows for the direct generation of the target optical field at the light source, effectively avoiding the problems of large size, high cost, and poor stability associated with external encryption devices.

[0025] In one example, based on the metasurface layer design capabilities, mode sorting capabilities, and link transmission conditions, multiple VCSEL units correspond to different topology payload numbers, ranging from -N to +N, where N is an integer greater than or equal to 1. For example, if N=5, then the topology payload number ranges from -5 to +5. See also... Figure 2 As shown, l=1 to l=5 represent different orbital angular momentum topological charges and their corresponding perfect vortex beam planar phase distributions. Furthermore, depending on the chip area, driver circuit size, and communication capacity requirements, the number of multiple VCSEL units can be a power of 4, where M is a positive integer greater than or equal to 1. For example, the number of multiple VCSEL units can be 4, 8, 16, 32, 64, 128, or 256. In practical applications, the number of multiple VCSEL units is 128. Additionally, when the number of multiple VCSEL units exceeds the number of topological charge types, the multiple VCSEL units correspond to the same type of topological charge. This effectively improves output power, provides redundant channels, enables parallel data stream transmission, or constructs channel-topological charge joint encoding.

[0026] The key control unit is used to generate a channel selection signal based on the information to be transmitted. Specifically, the key control unit maps a first key sequence to an arrangement of multiple VCSEL units to obtain the channel selection signal; the first key sequence is obtained by encrypting the information to be transmitted. For example, the key control unit establishes a dynamic mapping relationship between the information to be transmitted, the topological payload, multiple VCSEL units, time slices, and the output optical field mode. For example, within a certain key period, the bit groups "00", "01", "10", and "11" can be mapped to l=-1, l=+1, l=-2, and l=+2, respectively. In the next key period, this mapping can be changed according to the pseudo-random key sequence. For instance, in the next key period, the bit groups "000", "001", "010", "011", "100", "101", "110", and "111" can be set to correspond to l=-4, l=-3, l=-2, l=-1, l=+1, l=+2, l=+3, and l=+4, respectively; thus, dynamic spatial encryption is achieved. In this way, the key sequence may correspond to different topological payloads in different time slices. If the interceptor does not have the key sequence, it is difficult to directly recover the transmitted information from the observed light field pattern. Then, according to the above mapping relationship, the information to be transmitted is converted into a ciphertext spatial light field. The encrypted spatial optical field can be represented by a single topological charge perfect vortex beam, or by the superposition of multiple topological charge modes, the parallel emission of multiple VCSEL units, or the joint representation of multiple time-slice sequences.

[0027] Therefore, this invention utilizes orbital angular momentum topological charge number as the physical layer encryption dimension, enabling the information to be transmitted not only to be represented by intensity, time, or wavelength, but also by the ciphertext spatial optical field, thus improving the coding dimension and security of the optical communication system. Furthermore, the orthogonality between orbital angular momentum modes with different topological charge numbers allows for parallel transmission of multiple VCSEL units, enabling the transmission of multiple ciphertext data streams in the same optical path, thereby improving communication capacity and spectral efficiency.

[0028] The multi-channel electrically driven modulation unit controls multiple VCSEL units (such as controlling the on / off state, modulation amplitude, modulation frequency, and modulation timing of multiple VCSEL units) according to the channel selection signal to convert the emitted beam into a perfect vortex beam with the target topological charge; the perfect vortex beam with the target topological charge is used to characterize the information to be transmitted. For example, the multi-channel electrically driven modulation unit includes a field-programmable gate array (FPGA). The FPGA is responsible for receiving the upper-layer data stream, performing frame synchronization, generating the channel selection signal, and driving the VCSEL array. Referring to Figure 3, the FPGA array 9 performs channel selection on the VCSEL array 10. Here, 11 represents a CCD or external light field detection unit, which can be used to observe, calibrate, or verify the output light field.

[0029] Among them, perfect vortex beams are a special type of orbital angular momentum beams whose annular intensity radius is weakly correlated with or approximately independent of the topological charge number under certain conditions. Compared to ordinary Laguerre-Gaussian vortex beams, perfect vortex beams are more suitable for multiplexing and detecting multiple topological charge number modes because different topological charge number modes are more similar in spatial dimensions, which helps reduce the complexity of the receiver's optical system and improve the consistency of multi-mode transmission.

[0030] Orbital angular momentum beams are a special type of optical field with a helical phase distribution, whose phase factor can typically be expressed as exp(ilθ), where l is the topological charge number. Orbital angular momentum modes with different topological charges are orthogonal under ideal conditions and can serve as independent information channels or coding dimensions. Multiplexing orbital angular momentum modes enables the transmission of multiple parallel data streams in the same optical path, thereby improving communication capacity. Encoding using topological charge numbers can also construct a spatial encryption dimension that differs from traditional intensity, wavelength, and polarization coding.

[0031] In summary, the chip provided by this invention can generate a perfect vortex beam, effectively avoiding external encryption devices, significantly reducing size and integration difficulty, and enabling high-speed, low-power, and high-security physical layer encryption within the chip scale.

[0032] Furthermore, the metasurface layers on the light-emitting ends of multiple VCSEL units have different phases, and multiple VCSEL units can correspond to different topological charges. Thus, by selecting multiple VCSEL units for arbitrary combinations and controlling their operating timing, dynamic programmable control is achieved, resulting in a simple control method and fast response speed. Dynamic programmable control refers to using electronic control to select different VCSEL units or combinations of different VCSEL units to output perfectly vortex beams with different topological charges or combinations of topological charges, rather than relying on physical changes to the metasurface structure during operation.

[0033] In some embodiments, the chip further includes a key management module; the key management module is electrically connected to the key control unit. The key management module is responsible for generating, storing, or loading key sequences and distributing the key sequences to the key control unit. Exemplarily, the key management module is used to digitally encrypt the information to be transmitted to obtain a first key sequence. Exemplarily, the digital encryption can employ digital encryption algorithms such as AES, RSA, SM2, or SM4. Thus, this invention can work in conjunction with digital encryption algorithms to construct a hybrid security system combining physical layer encryption and digital layer encryption, improving comprehensive protection against link eavesdropping, pattern interception, and computational attacks. Furthermore, after obtaining the first key sequence (first-layer ciphertext) through digital encryption, the first key sequence is then mapped to an orbital angular momentum topological charge sequence to form a second-layer ciphertext. This results in higher information transmission security.

[0034] In some embodiments, the chip further includes an optical output interface electrically connected to the VCSEL array for outputting a perfect vortex beam with a target topological charge. During multi-channel parallel transmission, multiple data streams can be assigned to different topological charge modes or to different VCSEL array regions. Multiple encrypted optical fields are coupled to the same free-space link, fiber optic link, or optical module system via the optical output interface, achieving orbital angular momentum mode multiplexing transmission.

[0035] This invention provides a perfect vortex beam metasurface vertical-cavity surface-emitting laser (VCSEL) encryption chip, which can be realized through semiconductor laser technology, micro-nano fabrication technology, electron beam exposure, photolithography, etching, thin film deposition, and chip packaging. This chip can serve as an independent transmitter encryption light source or be integrated into optical modules, high-speed interconnect devices for data centers, military secure communication equipment, government private network communication equipment, and financial security communication systems. This invention provides a perfect vortex beam metasurface VCSEL encryption chip that achieves perfect vortex beam generation, orbital angular momentum encoding, multi-channel parallel transmission, and ciphertext spatial modulation. It has a clear engineering implementation path and application value, and possesses good industrial practicality. This invention provides a perfect vortex beam metasurface VCSEL encryption chip that utilizes the orthogonality of orbital angular momentum modes and the radius stability of a perfect vortex beam to achieve multi-channel parallel optical encryption transmission. It has advantages such as small size, high integration, large transmission capacity, fast modulation speed, high key dimension, and strong anti-eavesdropping capability, and can be used in scenarios such as data center optical interconnects, military intranets, government private networks, financial communications, and high-security optical modules.

[0036] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0037] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A perfect vortex beam metasurface vertical-cavity surface-emitting laser encryption chip, characterized in that, The chip includes: A vertical cavity surface-emitting laser (VCSEL) array, comprising multiple independently driveable VCSEL units, wherein each VCSEL unit has a metasurface layer on its light-emitting end face, and the metasurface layers on the light-emitting end faces of the multiple VCSEL units have different phases. A key control unit, which is used to generate a channel selection signal based on the information to be transmitted; A multi-channel electrically driven modulation unit is electrically connected to the key control unit and the plurality of VCSEL units respectively, and the multi-channel electrically driven modulation unit corresponds one-to-one with the plurality of VCSEL units; the multi-channel electrically driven modulation unit is used to control the corresponding plurality of VCSEL units to convert the outgoing beam into a perfect vortex beam with a target topological charge number according to the channel selection signal; the perfect vortex beam with the target topological charge number is used to characterize the information to be transmitted.

2. The chip according to claim 1, characterized in that, The key control unit is specifically used to map the first key sequence to the arrangement combination of the plurality of VCSEL units to obtain the channel selection signal; wherein, the first key sequence is obtained by encrypting the information to be transmitted.

3. The chip according to claim 2, characterized in that, The chip also includes: A key management module is provided, which is used to digitally encrypt the information to be transmitted to obtain the first key sequence; the key management module is electrically connected to the key control unit.

4. The chip according to any one of claims 1-3, characterized in that, The chip also includes: An optical output interface, which is electrically connected to the VCSEL array, is used to output a perfect vortex beam with the target topological charge.

5. The chip according to claim 1, characterized in that, The VCSEL unit sequentially comprises: an N-type electrode, a GaAs substrate, an N-type Bragg mirror, an oxide confinement hole, a P-type Bragg mirror, a benzocyclobutene layer, and a P-type electrode; wherein the metasurface layer is located on the surface of the GaAs substrate.

6. The chip according to claim 1, characterized in that, When the number of VCSEL units is greater than the number of topology load types, the multiple VCSEL units correspond to the same type of topology load.

7. The chip according to claim 1, characterized in that, The multi-channel electrically driven modulation unit includes a field-programmable gate array (FPGA).

8. The chip according to claim 1, characterized in that, The number of the plurality of VCSEL units is a power of 4, where M is a positive integer greater than or equal to 1.

9. The chip according to claim 1, characterized in that, The operating wavelength of the VCSEL array is any one of 850 nm to 1550 nm.

10. The chip according to claim 1, characterized in that, The multiple VCSEL units correspond to different topology loads, and the topology load ranges from -N to +N, where N is an integer greater than or equal to 1.

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