Controllable adjustment method and system for motion state of spatial optical soliton

Abstract

The application discloses a controllable adjustment method and system for a spatial optical soliton motion state, and belongs to the optical field, and comprises the following steps: periodically modulating a transverse refractive index and a nonlinear coefficient in an optical lattice; constructing a nonlinear Schrodinger equation for describing a light beam transmission characteristic based on the optical lattice subjected to the periodic modulation; solving the nonlinear Schrodinger equation by using an equivalent particle method to obtain an optical soliton center position; and based on the optical soliton center position, completing controllable adjustment of the spatial optical soliton motion state through numerical simulation verification. The application periodically modulates the transverse refractive index and the nonlinear coefficient in the optical lattice, derives a new nonlinear Schrodinger equation, solves the nonlinear Schrodinger equation by using the equivalent particle method, analyzes several states of the optical soliton transmission in the optical lattice, and verifies the correctness of the equation through numerical simulation, so that the motion trajectory control problem of the optical soliton transmission in the optical lattice is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of optics, and particularly relates to a controllable adjustment method and system for a spatial optical soliton motion state. BACKGROUND

[0002] Controlling the transmission characteristics and evolution behavior of light waves has been an important topic in optical research. When the nonlinear effect of a medium and its diffraction effect are balanced, the light beam remains unchanged in shape during transmission, forming a spatial optical soliton. This excellent characteristic makes the optical soliton have good application in all-optical switching, all-optical photonic devices, etc. An optical lattice is a structure with periodically varying refractive index, and many phenomena that do not occur in ordinary media occur when light waves are transmitted in the optical lattice. The parameter modulation of the optical lattice can effectively control the transmission behavior of the optical soliton.

[0003] Therefore, it is necessary to design a controllable adjustment method and system for a spatial optical soliton motion state for the problem of controlling the motion trajectory of the optical soliton during transmission in the optical lattice. SUMMARY

[0004] The purpose of the present application is to provide a controllable adjustment method and system for a spatial optical soliton motion state to solve the problems in the prior art. The transverse refractive index and nonlinear coefficient are periodically modulated by the optical lattice, a new nonlinear Schrodinger equation is derived, the nonlinear Schrodinger equation is solved by using the equivalent particle method, several states of the transmission of the optical soliton in the optical lattice are analyzed, and the correctness of the equation is verified by numerical simulation.

[0005] According to one aspect of the present application, a controllable adjustment method for a spatial optical soliton motion state is provided, comprising:

[0006] periodically modulating the transverse refractive index and nonlinear coefficient in the optical lattice;

[0007] constructing a nonlinear Schrodinger equation for describing the transmission characteristics of the light beam based on the periodically modulated optical lattice;

[0008] solving the nonlinear Schrodinger equation by using the equivalent particle method to obtain the center position of the optical soliton;

[0009] based on the center position of the optical soliton, the controllable adjustment of the motion state of the spatial optical soliton is completed by numerical simulation verification.

[0010] Further, the periodic modulation comprises:

[0011] using a self-focusing Kerr-type nonlinear medium with a nonlinear coefficient to form a transmission medium, and the transverse refractive index also periodically changes.

[0012] Furthermore, the modulation function in the nonlinear Schrödinger equation represents the effect of the optical lattice, and different values ​​of the modulation function correspond to different nonlinear effects.

[0013] Furthermore, the equivalent particle method is used to solve the nonlinear Schrödinger equation, including:

[0014] The spatial solitons propagating in the medium are represented as quasiparticles, and the equation is derived through the law of conservation of energy;

[0015] The equation is solved to obtain the center position of the optical soliton, and the motion state of the optical soliton in the one-dimensional periodically modulated optical lattice is determined.

[0016] Furthermore, the numerical simulation verification includes:

[0017] By changing the parameters such as incident angle, waveguide parameters, shape factor, and lattice strength, the transmission state of optical solitons in the optical lattice can be adjusted;

[0018] By adjusting the incident angle, shape factor and lattice strength of the optical soliton, the number of solitons captured by the channel can be quantitatively controlled.

[0019] According to one aspect of the present invention, a controllable adjustment system for the motion state of a spatial optical soliton is provided, comprising:

[0020] A periodic modulation module, used to periodically modulate the transverse refractive index and nonlinear coefficient in the optical lattice;

[0021] A nonlinear Schrödinger equation building module, which is used to construct the nonlinear Schrödinger equation for describing the propagation characteristics of optical beams based on a periodically modulated optical lattice;

[0022] Nonlinear Schrödinger equation solving module, used to solve the nonlinear Schrödinger equation using the equivalent particle method to obtain the center position of the optical soliton;

[0023] The numerical simulation verification module is used to complete the controllable adjustment of the motion state of spatial optical solitons through numerical simulation verification based on the center position of the optical soliton.

[0024] According to one aspect of the present invention, there is provided an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the controllable adjustment method for the motion state of a spatial optical soliton when executing the computer program.

[0025] According to one aspect of the present invention, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the steps of the controllable adjustment method of the motion state of a spatial optical soliton are implemented.

[0026] According to one aspect of the present invention, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the steps of the method for controllably adjusting the motion state of a spatial optical soliton.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. This invention proposes a controllable method for regulating the motion state of spatial optical solitons. By periodically modulating the transverse refractive index and nonlinear coefficient through an optical lattice, a new nonlinear Schrödinger equation is derived. The equivalent particle method is used to solve the nonlinear Schrödinger equation, achieving the purpose of controlling the movement trajectory of optical solitons and providing a new approach for optical switches.

[0029] 2. The present invention proposes a controllable adjustment method for the motion state of spatial optical solitons. By analyzing several motion states of optical solitons transmitted in an optical lattice and numerically verifying the correctness of the nonlinear Schrödinger equation, the problem of controlling the motion trajectory of optical solitons during transmission in an optical lattice is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 This is a flowchart of an embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of an optical lattice according to an embodiment of the present invention;

[0033] Figure 3 is a schematic diagram of a lateral modulation lattice model according to an embodiment of the present invention;

[0034] Figure 4 This is a numerical simulation diagram of soliton propagation in a medium according to an embodiment of the present invention;

[0035] Figure 5 Graph showing the effects of different parameters on the captured channel according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] like Figure 1 As shown, an embodiment of the present invention provides a method for controllably adjusting the motion state of spatial optical solitons, comprising periodically modulating the transverse refractive index and nonlinear coefficient in an optical lattice; constructing a nonlinear Schrödinger equation for describing the transmission characteristics of a light beam based on the periodically modulated optical lattice; solving the nonlinear Schrödinger equation using an equivalent particle method to obtain the center position of the optical soliton; and completing controllably adjusting the motion state of spatial optical solitons through numerical simulation verification based on the center position of the optical soliton.

[0038] Specifically, if Figure 2 As shown, the embodiment of the present invention provides a schematic diagram of the optical lattice and the photonic lattice structure. Since light waves are electromagnetic waves, their motion equations satisfy Maxwell's equations. The nonlinear Schrödinger equation is derived from Maxwell's equations, as shown in formula (1):

[0039] (1)

[0040] in, represents a beam in space, is the slowly varying envelope amplitude of the beam, is the incident intensity, is the normalized beam width on the horizontal axis, is the initial width of the incident beam, is the longitudinal coordinate normalized to the diffraction length, where is the vertical coordinate; is the diffraction length, where is the speed of light, is the linear refractive index; is the nonlinear length, where is the nonlinear refractive index, is the beam frequency, ,in is the modulation depth of the linear refractive index; describes the distribution of the linear refractive index, is the modulation period, where ,when This shows that there is no nonlinear effect. When , it indicates that it contains self-focusing Kerr nonlinearity. When it is explained that the self-defocusing Kerr nonlinearity is included; is the modulation function, representing the effect of the lattice.

[0041] Specifically, modulating the refractive index will affect the optical soliton transmission characteristics, and modulating the nonlinear coefficient will also affect the optical soliton transmission characteristics. The embodiment of the present invention combines these two influencing factors and modulates the refractive index and the nonlinear coefficient at the same time. To achieve periodic modulation of the optical nonlinear coefficient, the nonlinear coefficients are used. and The transmission medium is composed of a self-focusing Kerr-type nonlinear medium, and its transverse refractive index also changes periodically. When a light beam propagates in this medium, its transmission characteristics can be described by the nonlinear Schrödinger equation (NLSE), as shown in Equation (2):

[0042] (2)

[0043] in, is the potential function, which describes the periodic modulation of the nonlinear coefficient; is the lattice function, describing the transverse nonlinear coefficient, where , is the lattice strength. The spatial distribution of the modulation function is the lattice model. The lateral modulation lattice model is as follows Figure 3 As shown. At the same time, the nonlinear Schrödinger equation can be transformed into formula (3):

[0044] (3)

[0045] Specifically, the spatial soliton propagating in the medium can be represented as a quasiparticle, which can be approximated as:

[0046] (4)

[0047] in, , is the number of channels where the optical soliton is located, is the shape factor, is the phase, is the angle of incidence, is an imaginary number, is the initial state of the optical soliton before it enters the optical lattice. According to the law of energy conservation, the following formula can be obtained:

[0048] (5)

[0049] in, For energy, Yes Perform the derivation.

[0050] By solving equation (5), the center position of the optical soliton can be obtained as follows:

[0051] (6)

[0052] Optical solitons can be regarded as equivalent particles moving in the optical lattice. Equation (6) represents the evolution equation of the center position of the beam, which is equivalent to the position of the particle for the equivalent particle. The evolution of the axis is equivalent to the acceleration of the particle for the equivalent particle.

[0053] Specifically, by integrating, we can derive the evolution of the center position of the light beam, that is, the motion state of the optical soliton in the one-dimensional periodically modulated optical lattice. The critical angle is the incident angle at which the optical soliton can just pass through the lattice channel. , the formula is as follows:

[0054] (7)

[0055] in, is the angle of incidence, is the vertical coordinate normalized to the diffraction length.

[0056] The critical angle can be calculated as follows:

[0057] (8)

[0058] in, are the waveguide parameters.

[0059] Specifically, the motion trajectory of the center of the integral beam in the lattice satisfies the following equation (9):

[0060] (9)

[0061] in, is the incident angle of the light beam, The increase in represents an increase in the particle's kinetic energy for the equivalent particle. At low kinetic energy, the particle remains in the central channel (i.e., the beam oscillates around the central channel). When the initial kinetic energy is greater than the height of the barrier, the particle leaves the central channel and begins to move along the structure. Therefore, there is a value of the incident angle that separates the two regions. The critical value of the incident angle that separates the two modes of motion is called the critical angle. .when When the light beam is in the central channel, Periodic oscillation at point Pass through the center channel.

[0062] Specifically, the results of theoretical analysis are verified by numerical simulation. The propagation of optical solitons in the medium is as follows: Figure 4 As shown, it can be divided into three situations:

[0063] Distortion-free propagation: When the input beam width is comparable to the modulation period, as can be seen from Figure (a), the spatial soliton is almost unaffected by the transverse modulation. As long as the incident angle is much larger than the critical angle, it can propagate without distortion, just like in a homogeneous medium.

[0064] Oscillation in the central channel: When the modulation period is relatively large, as described in Figure (b), the spatial soliton is captured when it is incident on the central channel of the lattice and propagates oscillatingly along the center of the lattice.

[0065] Trapped in a channel: When the incident angle is greater than the critical angle, as shown in Figure (c), the soliton loses some energy when passing through the lattice channel, which causes the soliton to be trapped in a certain channel. The position of the trapped soliton can be evaluated by the size of the trapped channel, where Solitons are trapped in Department, Defined as the captured channel.

[0066] like Figure 5 As shown in FIG, the embodiment of the present invention provides the influence of different parameters on the trapped channel. The soliton radiates slowly during the propagation process, and its propagation angle gradually decreases. Then the soliton is trapped in a lattice channel. The nonlinear system with energy loss can be regarded as a damping system, and the motion of the soliton can be regarded as a damped motion. and form factor It is a parameter that can be changed by adjusting the incident soliton. and lattice strength Representing the linear and nonlinear lattice strengths, respectively, they produce similar images. By varying the soliton's incident angle and shape factor as well as the lattice strength of the optical lattice, the number of solitons trapped in the channel can be quantitatively controlled.

[0067] The implementation of each embodiment of the present invention is based on programmed processing performed by a device with processor functionality. Therefore, in practical engineering, the technical solutions and functions of each embodiment of the present invention are packaged into various modules. Based on this reality, and in addition to the aforementioned embodiments, an embodiment of the present invention provides a system for controllably regulating the motion state of spatial optical solitons. This system is used to implement a method for controllably regulating the motion state of spatial optical solitons described in the aforementioned method embodiments.

[0068] The system includes: a periodic modulation module for periodically modulating the transverse refractive index and nonlinear coefficient in the optical lattice; a nonlinear Schrödinger equation construction module for constructing a nonlinear Schrödinger equation for describing the light beam transmission characteristics based on the periodically modulated optical lattice; a nonlinear Schrödinger equation solving module for solving the nonlinear Schrödinger equation using the equivalent particle method to obtain the center position of the optical soliton; and a numerical simulation verification module for completing the controllable adjustment of the motion state of the spatial optical soliton through numerical simulation verification based on the center position of the optical soliton.

[0069] An embodiment of the present invention provides a controllable regulation system for the motion state of spatial optical solitons. Addressing the problem of controlling the motion trajectory of optical solitons during transmission within an optical lattice, the system employs several modules to periodically modulate the transverse refractive index and nonlinear coefficient through the optical lattice, deriving a new nonlinear Schrödinger equation. The nonlinear Schrödinger equation is solved using the equivalent particle method. By analyzing several states of optical solitons transmitting within the optical lattice and numerically verifying the correctness of the nonlinear Schrödinger equation, the problem of controlling the motion trajectory of optical solitons during transmission within the optical lattice is solved.

[0070] Based on the same inventive concept as the aforementioned embodiment, an embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions, thereby realizing a controllable adjustment method for the motion state of a spatial optical soliton as proposed in the aforementioned embodiment.

[0071] An embodiment of the present invention also provides a computer-readable storage medium storing a computer program. When executed by a processor, the program is used to control the trajectory of optical solitons, addressing the problem of controlling the trajectory of optical solitons during transmission within an optical lattice. The storage medium can be any non-volatile storage device, such as a hard disk, solid-state drive, flash drive, or optical disk, and is used to store the computer program code and necessary data files. The stored computer program includes a periodic modulation module, a nonlinear Schrödinger equation construction module, a nonlinear Schrödinger equation solution module, and a numerical simulation verification module.

[0072] The present invention also provides a computer program product comprising instructions that, when executed on a computer, fully or partially implements the controllable adjustment method for the motion state of a spatial optical soliton according to the above-described embodiment. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device.

[0073] Finally, it should be noted that the above specific embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above specific embodiments and is susceptible to numerous variations. Any simple modifications, equivalent variations, and modifications to the above specific embodiments based on the technical essence of the present invention shall be deemed to fall within the scope of protection of the present invention.

Claims

1. A method for controllable regulation of the motion state of spatial optical solitons, characterized in that: include: Periodic modulation of the lateral refractive index and nonlinear coefficient in optical lattices; The periodic modulation is: using a self-focusing Kerr-type nonlinear medium with a nonlinear coefficient to form a transmission medium, and at the same time the transverse refractive index is also periodically changed; Based on the periodically modulated optical lattice, a nonlinear Schrödinger equation is constructed to describe the propagation characteristics of the light beam. The modulation function in the nonlinear Schrödinger equation represents the effect of the optical lattice, and different values ​​of the modulation function correspond to different nonlinear effects. The nonlinear Schrödinger equation is solved using the equivalent particle method to obtain the center position of the optical soliton. Specifically, the spatial soliton propagating in the medium is represented as a quasiparticle, and an equation is derived using the law of conservation of energy. The center position of the optical soliton is obtained by solving the equation, and the motion state of the optical soliton in the one-dimensional periodically modulated optical lattice is determined. Based on the center position of the optical soliton, the controllable adjustment of the motion state of the spatial optical soliton is completed through numerical simulation verification. The numerical simulation verification includes: adjusting the transmission state of the optical soliton in the optical lattice by changing parameters such as the incident angle, waveguide parameters, shape factor, and lattice strength; and quantitatively controlling the number of solitons captured by the channel by adjusting the incident angle, shape factor, and lattice strength of the optical soliton.

2. A controllable adjustment system for the motion state of a spatial optical soliton, applied to the controllable adjustment method for the motion state of a spatial optical soliton according to claim 1, characterized in that: include: A periodic modulation module, used to periodically modulate the transverse refractive index and nonlinear coefficient in the optical lattice; A nonlinear Schrödinger equation building module, which is used to construct the nonlinear Schrödinger equation for describing the propagation characteristics of optical beams based on a periodically modulated optical lattice; Nonlinear Schrödinger equation solving module, used to solve the nonlinear Schrödinger equation using the equivalent particle method to obtain the center position of the optical soliton; The numerical simulation verification module is used to complete the controllable adjustment of the motion state of spatial optical solitons through numerical simulation verification based on the center position of the optical soliton.

3. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for controllably adjusting the motion state of spatial optical solitons according to claim 1 are implemented.

4. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for controllably adjusting the motion state of spatial optical solitons according to claim 1 are implemented.

5. A computer program product comprising instructions, characterized in that When the method is run on a computer, the computer is enabled to execute the steps of the method for controllably adjusting the motion state of spatial optical solitons as claimed in claim 1 .

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