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

Abstract

The invention discloses a controllable adjustment method and system for the motion state of a space optical soliton, and belongs to the field of optics, and the method comprises the steps: carrying out the periodic modulation of a transverse refractive index and a nonlinear coefficient in an optical lattice; constructing a nonlinear Schrodinger equation for describing light beam transmission characteristics based on the periodically modulated optical lattice; solving the nonlinear Schrodinger equation by using an equivalent particle method to obtain an optical soliton center position; and based on the center position of the optical soliton, the controllable adjustment of the motion state of the space optical soliton is completed through numerical simulation verification. According to the method, the transverse refractive index and the nonlinear coefficient are periodically modulated through the optical lattice, a new nonlinear Schrodinger equation is deduced and obtained, the nonlinear Schrodinger equation is solved through an equivalent particle method, several states of transmission of optical solitons in the optical lattice are analyzed, the correctness of the equation is verified through numerical values, and the nonlinear Schrodinger equation is obtained. The problem of motion trail control when optical solitons are transmitted in optical lattices is solved.

Description

Technical Field

[0001] The invention belongs to the field of optics, and in particular relates to a controllable adjustment method and system for the motion state of a spatial optical soliton. Background Art

[0002] Controlling the transmission characteristics and evolution behavior of light waves has always been an important topic in optical research. During the transmission of a light beam, when the nonlinear effect of the medium is balanced with its diffraction effect, the light beam maintains its shape and is transmitted, forming a spatial optical soliton. This excellent characteristic makes optical solitons have great applications in all-optical switches and all-optical photonic devices. An optical lattice is a structure with a periodic change in refractive index. When light waves are transmitted in an optical lattice, many phenomena that do not occur in ordinary media will occur. Parameter modulation of the optical lattice can effectively regulate the transmission behavior of optical solitons.

[0003] Therefore, it is necessary to design a controllable adjustment method and system for the motion state of spatial optical solitons in order to control the motion trajectory of optical solitons when they are transmitted in an optical lattice. Summary of the invention

[0004] The purpose of the present invention is to provide a controllable adjustment method and system for the motion state of spatial optical solitons in view of the problems existing in the prior art. The transverse refractive index and the nonlinear coefficient are periodically modulated by an optical lattice, a new nonlinear Schrödinger equation is derived, the nonlinear Schrödinger equation is solved using the equivalent particle method, several states of optical solitons transmitted in an optical lattice are analyzed, and the correctness of the equation is verified by numerical values.

[0005] According to one aspect of the present invention, a method for controllably adjusting the motion state of a spatial optical soliton is provided, comprising:

[0006] Periodic modulation of the lateral refractive index and nonlinear coefficients in optical lattices;

[0007] Based on the periodically modulated optical lattice, a nonlinear Schrödinger equation is constructed to describe the propagation characteristics of the light beam.

[0008] The nonlinear Schrödinger equation is solved 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 through numerical simulation verification.

[0010] Further, periodic modulation is performed, including:

[0011] The transmission medium is composed of a self-focusing Kerr-type nonlinear medium with a nonlinear coefficient, and the transverse refractive index also changes periodically.

[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] Representing the spatial soliton propagating in the medium as a quasiparticle, 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, there is provided a controllable adjustment system for the motion state of a spatial optical soliton, comprising:

[0020] A periodic modulation module, used for periodically modulating 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 a light beam 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 of the motion state of a spatial optical soliton when executing the computer program.

[0025] According to one aspect of the present invention, there is provided a computer-readable storage medium storing a computer program, wherein 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, there is provided a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the steps of the controllable adjustment method for the motion state of a spatial optical soliton.

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

[0028] 1. The present invention proposes a controllable adjustment method for the motion state of a spatial optical soliton. By periodically modulating the transverse refractive index and the 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, thereby achieving the purpose of controlling the moving trajectory of the optical soliton and providing a method for optical switching.

[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 motion trajectory control 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0031] Figure 1 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 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 influence of different parameters on the captured channel according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work 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 a spatial optical soliton, including periodically modulating the transverse refractive index and the 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 a spatial optical soliton through numerical simulation verification based on the center position of the optical soliton.

[0038] Specifically, Figure 2 As shown, the embodiment of the present invention provides a schematic diagram of the structure of an optical lattice and a photonic lattice. Since light waves are electromagnetic waves, their motion equations satisfy the Maxwell equations. The nonlinear Schrödinger equation is derived from the Maxwell 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 indicates that there is no nonlinear effect. When , it means that it contains self-focusing Kerr nonlinearity. When it indicates that self-defocusing Kerr nonlinearity is involved; 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 simultaneously. To achieve periodic modulation of the optical nonlinear coefficient, the nonlinear coefficients are used to be 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, describing the periodic modulation of the nonlinear coefficients; is the lattice function, describing the lateral 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 equation (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 channel number where the optical soliton is located, is the shape factor, is the phase, is the incident angle, 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 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 incident angle, is the longitudinal 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 the equivalent particle indicates an increase in the particle's kinetic energy. At a small kinetic energy, the particle is 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 beam is in the central channel, The 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 lateral modulation and can propagate without distortion just like in a homogeneous medium as long as the incident angle is much larger than the critical angle.

[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, the embodiment of the present invention provides the influence of different parameters on the captured channel. The soliton radiates slowly during the propagation process, and its propagation angle gradually decreases. Then the soliton is captured in a lattice channel. The nonlinear system with energy loss can be regarded as a damping system, and the movement of the soliton can be regarded as a damped motion. and form factor is a parameter that can be changed by adjusting the incident soliton. and lattice strength Representing linear and nonlinear lattice strengths, respectively, they will have similar images. By changing the incident angle and shape factor of the soliton and the lattice strength of the optical lattice, the number of solitons captured by the channel can be quantitatively controlled.

[0067] The implementation basis of each embodiment of the present invention is to implement programmed processing through a device with a processor function. Therefore, in engineering practice, the technical solutions and functions of each embodiment of the present invention are encapsulated into various modules. Based on this reality, on the basis of the above embodiments, an embodiment of the present invention provides a controllable adjustment system for the motion state of a spatial optical soliton, which is used to execute a controllable adjustment method for the motion state of a spatial optical soliton in the above method embodiment.

[0068] The system includes: a periodic modulation module, which is used to periodically modulate the transverse refractive index and nonlinear coefficient in the optical lattice; a nonlinear Schrödinger equation construction module, which is used to construct a nonlinear Schrödinger equation for describing the transmission characteristics of a light beam based on the periodically modulated optical lattice; a nonlinear Schrödinger equation solving module, which is used to solve the nonlinear Schrödinger equation using an equivalent particle method to obtain the center position of the optical soliton; and a numerical simulation verification module, which is used to complete 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] A controllable adjustment system for the motion state of a spatial optical soliton provided by an embodiment of the present invention aims at solving the problem of motion trajectory control of an optical soliton when it is transmitted in an optical lattice. The system adopts several modules to periodically modulate the transverse refractive index and the nonlinear coefficient through the optical lattice, derives a new nonlinear Schrödinger equation, solves the nonlinear Schrödinger equation using the equivalent particle method, analyzes several states of optical solitons transmitted in an optical lattice, and numerically verifies the correctness of the nonlinear Schrödinger equation, thereby solving the problem of motion trajectory control of an optical soliton when it is transmitted in an optical lattice.

[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, the memory being used to store computer-executable instructions, and the processor being used to execute computer-executable instructions, to implement a controllable adjustment method for the motion state of a spatial optical soliton as proposed in the aforementioned embodiment.

[0071] The embodiment of the present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, it is used to control the moving trajectory of the optical soliton and solve the problem of controlling the moving trajectory of the optical soliton when it is transmitted in the optical lattice. The storage medium can be any non-volatile storage device such as a hard disk, a solid-state hard disk, a flash disk, an optical disk, etc., which is used to store computer program codes 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 embodiment of the present invention also provides a computer program product containing instructions, which, when executed on a computer, generates in whole or in part a controllable adjustment method for the motion state of a spatial optical soliton according to the above 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 pointed out that the above specific embodiments are only representative examples of the present invention. Obviously, the present invention is not limited to the above specific embodiments, and there are many variations. Any simple modification, equivalent changes and modifications made to the above specific embodiments based on the technical essence of the present invention should be considered to belong to the protection scope of the present invention.

Claims

1. A controllable adjustment method for the motion state of a spatial optical soliton, characterized in that: include: Periodic modulation of the lateral refractive index and nonlinear coefficients in optical lattices; Based on the periodically modulated optical lattice, a nonlinear Schrödinger equation is constructed to describe the propagation characteristics of the light beam. The nonlinear Schrödinger equation is solved using the equivalent particle method to obtain the center position of the optical soliton. 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.

2. The controllable adjustment method of the motion state of a spatial optical soliton according to claim 1, characterized in that: Perform periodic modulation, including: The transmission medium is composed of a self-focusing Kerr-type nonlinear medium with a nonlinear coefficient, and the transverse refractive index also changes periodically.

3. The controllable adjustment method of the motion state of a spatial optical soliton according to claim 1, characterized in that: 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.

4. The controllable adjustment method of the motion state of a spatial optical soliton according to claim 1 is characterized in that: Solve the nonlinear Schrödinger equation using the equivalent particle method, including: Representing the spatial soliton propagating in the medium as a quasiparticle, the equation is derived through the law of conservation of energy; 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.

5. The controllable adjustment method of the motion state of a spatial optical soliton according to claim 1, characterized in that: The numerical simulation verification includes: 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; 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.

6. A controllable regulation system for the motion state of spatial optical solitons, characterized in that: include: A periodic modulation module, used for periodically modulating the transverse refractive index and nonlinear coefficient in the optical lattice; A nonlinear Schrödinger equation building module, which is used to construct a nonlinear Schrödinger equation for describing the propagation characteristics of a light beam 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.

7. 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 any one of claims 1 to 5 are implemented.

8. 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 described in any one of claims 1 to 5 are implemented.

9. 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 described in any one of claims 1 to 5.

Images