阅读说明：本技术 基于超材料谐振体的转弯光开关控制方法及光开关 (Turning optical switch control method based on metamaterial resonator and optical switch ) 是由 董国艳 郑姝慧 于 2019-11-11 设计创作，主要内容包括：一种基于零折射率超材料谐振体的转弯光开关控制方法及光开关；所述方法是将两束频率相同、同轴且相干的入射光分别从超材料阵列的两侧正入射,通过改变其中一束入射光与超材料阵列的相对位置来改变两束入射光之间的相位差,使其在超材料阵列中发生相长或相消,实现光开关的开关特性及光开关的90°转弯；所述光开关包括固定光源、移动光源和超材料阵列,固定光源和移动光源分别设置在超材料阵列的两侧,且与超材料阵列之间均设置有透镜；固定光源、移动光源、透镜和超材料阵列沿同一光轴线方向设置。本发明结构简单、低损耗、高集成度、工作波长可以选择并且集光开关和分束器功能于一体。(A turning optical switch control method based on a zero-refractive-index metamaterial resonator and an optical switch; the method comprises the steps that two beams of coaxial and coherent incident light with the same frequency are respectively normally incident from two sides of a metamaterial array, the phase difference between the two beams of incident light is changed by changing the relative position of one beam of the incident light and the metamaterial array, so that the two beams of the incident light are constructive or destructive in the metamaterial array, and the switching characteristic of an optical switch and the 90-degree turning of the optical switch are realized; the optical switch comprises a fixed light source, a movable light source and a metamaterial array, wherein the fixed light source and the movable light source are respectively arranged on two sides of the metamaterial array, and a lens is arranged between the fixed light source and the metamaterial array; the fixed light source, the movable light source, the lens and the metamaterial array are arranged along the same optical axis direction. The invention has simple structure, low loss, high integration, selectable working wavelength and integrated functions of the light collecting switch and the beam splitter.)

1. A turning optical switch control method based on a zero-refractive-index metamaterial resonator is characterized by comprising the following steps:

two beams of coaxial and coherent incident light with the same frequency are respectively normally incident into the zero-refractive-index metamaterial array from two sides, the two beams of incident light interfere in the array, and two paths of symmetrical radiation beams are generated in the direction perpendicular to the incident optical axis;

the relative position of one beam of incident light and the metamaterial array is changed, so that the phase of the incident light reaching the metamaterial is changed, the phase difference between the two beams of incident light is changed, the two beams of incident light are constructive or destructive in the metamaterial array, the switching characteristic of the optical switch is realized, and the 90-degree turning function of the optical switch is realized because the incident light and the emergent light of the light beams are positioned in two mutually perpendicular directions.

2. The method for controlling a turning optical switch based on the zero-refractive-index metamaterial resonator as claimed in claim 1, wherein: when the phase difference of the two beams of incident light is 0, the interference phase lengthening occurs, and the optical switch is turned on; when the phase difference of the two beams is pi, the interference cancellation occurs, and the optical switch is turned off.

3. The method for controlling a turning optical switch based on the zero-refractive-index metamaterial resonator as claimed in claim 1, wherein: the metamaterial array is rectangular in shape.

4. The method for controlling a turning optical switch based on the zero-refractive-index metamaterial resonator as claimed in claim 1, wherein: the zero index metamaterial is any effective refractive index n_eff0 material.

5. The method for controlling a turning optical switch based on the zero-refractive-index metamaterial resonator as claimed in claim 1, wherein: the working frequency corresponding to the zero-refractive-index metamaterial is determined by the structural properties of the metamaterial.

6. An optical switch, characterized by: the device comprises a fixed light source, a movable light source and a metamaterial array, wherein the fixed light source and the movable light source are respectively arranged on two sides of the metamaterial array, and a lens is arranged between the fixed light source and the metamaterial array; the fixed light source, the movable light source, the lens and the metamaterial array are arranged along the same axial direction.

7. The optical switch of claim 6, wherein: the lens is a convex lens and is used for converging the conical divergent light beams emitted by the laser into parallel light beams.

8. The optical switch of claim 6, wherein: and an optical receiving device is arranged in the emergent light direction of the metamaterial array and is connected with a photoelectric detection system.

Technical Field

The invention relates to a control method of a 90-degree turning optical switch and the optical switch, belonging to the technical field of optical switches.

Background

The optical switch is an important photonic integrated device, fully utilizes the interaction of photons and media to realize the effective control of on and off of an optical transmission process, and has very wide application prospects in the fields of optical communication, optical calculation, rapid optical information processing and the like. In recent years, research on optical switches has been the focus of attention, and photonic crystals having a unique band propagation characteristic provide a new method for developing photonic devices, which allows miniaturization of the devices and flexible control of the transmission characteristics of light waves.

The metamaterial is an equivalent uniform artificial composite structure or composite material with extraordinary physical properties which are not possessed by materials in nature, and is a material which is composed of artificially constructed microstructures and has the integral electromagnetic property described by equivalent dielectric constant and equivalent magnetic permeability. The photonic crystal is a dielectric microstructure artificial metamaterial with the photonic band gap characteristic and the refractive index of which is periodically changed, and the period of the structural change is in the same order of magnitude as the wavelength of light. According to the accidental degeneracy of the monopole mode and the dipole mode, the two-dimensional (2D) photonic crystal with a square or triangular lattice structure can realize cone-shaped linear dispersion characteristics in the center of the Brillouin zone, and is a triple degeneracy state with the wave vector k being 0. According to the effective medium theory, a photonic crystal can be regarded as an equivalent double-zero refractive index material with zero wave number and infinite wavelength at the dirac-like point frequency. Similarly, the zero-refractive-index property can be realized in the artificial metamaterial composed of metal and dielectric through mechanisms such as Mie resonance and plasma resonance.

At present, the commonly used optical switching method is to introduce waveguides, microcavities or other defects in the photonic crystal structure, and then to realize the switching function of the optical switch by adjusting the structural parameters or using a nonlinear material with large third order, and this method has strict requirements on the properties of the constituent materials and the crystal structure.

Disclosure of Invention

Aiming at the defects in the existing optical switch, the invention provides a turning optical switch control method based on a zero-refractive-index metamaterial resonator, and simultaneously provides an optical switch which is simple in structure, low in loss, high in integration degree, selectable in working wavelength and integrated in functions of a light collecting switch and a beam splitter.

The invention discloses a turning optical switch control method based on a metamaterial resonator, which comprises the following steps:

two beams of coaxial and coherent incident light with the same frequency are respectively normally incident into the metamaterial array from two sides (left and right sides) of the zero-refractive-index metamaterial array (one beam is fixed incident light, the other beam is mobile incident light), the two beams of incident light interfere in the metamaterial array, and two paths of symmetrical radiation beams are generated in the direction perpendicular to an incident light axis.

The relative position of one beam of incident light and the metamaterial array is changed, so that the phase of the beam of incident light reaching the metamaterial is changed, the phase difference between the two beams of incident light is changed, the two beams of incident light are subjected to constructive and destructive effects in the metamaterial array, and the switching characteristic of the optical switch is realized. Since the incidence and the emergence of the light beams are in two mutually perpendicular directions, the 90-degree turning function of the optical switch is realized.

When the phase difference of the two beams of incident light is 0, the interference phase lengthening occurs, and the optical switch is turned on; when the phase difference of two incident lights is pi, the interference cancellation occurs, and the optical switch is turned off.

The metamaterial array is rectangular, and the lattice structure can be square, triangular and the like.

The zero index metamaterial is any effective refractive index n_effThe material 0 may be a photonic crystal composed of a non-metallic dielectric material, or may have a metamaterial structure composed of a material such as a metal, ferrite, or ferroelectric.

The working frequency corresponding to the zero-refractive-index metamaterial is determined by the structural properties of the metamaterial.

The optical switch for realizing the method adopts the following technical scheme:

the optical switch comprises a fixed light source, a movable light source and a metamaterial array, wherein the fixed light source and the movable light source are respectively arranged on two sides of the metamaterial array, and a lens is arranged between the fixed light source and the metamaterial array; the fixed light source, the movable light source, the lens and the metamaterial array are arranged along the same optical axis direction.

The lens is a convex lens and is used for converging the conical divergent light beams emitted by the laser into parallel light beams.

And an optical receiving device is arranged in the emergent light direction of the metamaterial array and connected with a photoelectric detection system.

The optical receiving device and the photoelectric detection system are used for measuring the transmissivity of the metamaterial array in the vertical direction, and the whole structure is vertically symmetrical, so that only one direction can be measured.

The invention designs an optical switch system by utilizing a metamaterial with zero refractive index characteristic. Compared with the existing optical switch system, the optical switch system has the following characteristics:

1. the invention utilizes the principle of interference constructive and interference destructive in the metamaterial array interference phenomenon, does not need to introduce waveguides, micro-cavities and defects in a photonic crystal structure or adjust structural parameters to realize the method like a common optical switch, and has simple structure, easy integration and lower cost;

2. the incident direction of the light source and the realization direction of the optical switch are mutually vertical, namely the incident direction and the emergent direction of the light beam are in two mutually vertical directions, so that the 90-degree turning function of the optical switch is realized;

3. the emergent light path is two paths of symmetrical radiation beams, the light collecting switch and the beam splitter are integrated, and the upper and lower beams of radiation light have the same light transmission characteristics of period, frequency, amplitude, phase and the like;

4. the invention can increase or reduce the structural parameters of the zero-refractive-index metamaterial in equal proportion and correspondingly change the magnitude of the frequency of the light source, so that the optical switch system can be suitable for occasions with different size requirements;

5. the invention can make the optical switch work in different working wave bands to realize the switch effect by setting the zero-refractive index metamaterials with different structures and different parameters, and the method can be suitable for the full wave range of the electromagnetic wave.

Drawings

FIG. 1 is a schematic diagram of a turning optical switch control method based on a metamaterial resonant body in the invention.

Fig. 2 is a schematic diagram of a possible lattice structure of the metamaterial array used in the present invention, and the array is rectangular. (a) A tetragonal lattice structure, and (b) a triangular lattice structure.

Fig. 3 is a transmission spectrum in the vertical direction of the metamaterial array in example 1, the solid line represents the transmission spectrum when the optical switch is in the on state, and the dotted line represents the transmission spectrum when the optical switch is in the off state.

In the figure: 1. fixing a light source; 2. a left lens; 3. moving the light source; 4. a right lens; 5. an array of metamaterials; 6. an optical receiving device; 7. a photoelectric detection system.

Detailed Description

The 90-degree turning optical switch control method based on the metamaterial resonator is realized by a fixed light source 1, a movable light source 3, two lenses (a left lens 2 and a right lens 4), a metamaterial array 5, an optical receiving device 6, a photoelectric detection system 7 and other components as shown in figure 1. The above components are also part of the turn light switch.

The left side and the right side of the metamaterial array 5 are respectively provided with a fixed light source 1 and a movable light source 3, a left lens 2 is arranged between the fixed light source 1 and the metamaterial array 5, and a right lens 4 is arranged between the movable light source 3 and the metamaterial array 5. An optical receiving device 6 is arranged in the emergent light direction of the metamaterial array 5, the optical receiving device 6 is connected with a photoelectric detection system 7, and the photoelectric detection system 7 can adopt a photoelectric detector, which is the prior art. The fixed light source 1, the movable light source 3, the left lens 2, the right lens 4 and the metamaterial array 5 are arranged along the x-ray axis direction, and the optical receiving device 6 and the photoelectric detection system 7 are arranged along the y-ray axis direction.

The fixed light source 1 and the movable light source 3 are used for emitting light beams with required frequency, and the two light beams are incident light with the same frequency, coaxial and coherent.

The left lens 2 and the right lens 4 are convex lenses for converging the conical divergent light beams emitted from the laser into parallel light beams. After being converged by the lens, the cone-shaped light beams emitted from the laser become parallel light beams with the width substantially equal to that of the metamaterial array 5 and are incident into the metamaterial array.

The metamaterial array 5 can be of different lattice structures such as square, triangle and the like (as shown in fig. 2), and the array shape is rectangular, so that the phase of incident light is kept unchanged when the incident light propagates, and the light is amplified. The metamaterial array 5 is a zero-index metamaterial and is any effective index n_eff0, the material may be a non-metallic dielectric materialThe formed photonic crystal can also be a metamaterial structure formed by materials such as metal, ferrite, ferroelectric and the like. The operating frequency corresponding to the zero index metamaterial is determined by the structural properties of the metamaterial.

Light emitted by the fixed light source 1 and the movable light source 3 enters the metamaterial array 5 to interfere after being converged by the lens, the phase of the light emitted by the movable light source 3 relative to the light emitted by the fixed light source 1 is adjusted by changing the position of the movable light source 3, the phase difference between the two beams of light is changed, the interference of the two beams of incident light in the metamaterial array is controlled to be constructive or destructive, and the phase difference can be circularly modified from 0 to 2 pi so as to be used for switching the state of the interference constructive or destructive. When the phase difference of the two beams is 0, the interference phase lengthening occurs, and the optical switch is turned on; when the phase difference of the two beams is pi, the interference cancellation occurs, and the optical switch is turned off, so that the switching effect of the optical switch is realized. Since the incidence and the emergence of the light beams are in two mutually perpendicular directions, the 90-degree turning function of the optical switch is realized.

The incident direction of the light source is the x-ray axis direction, but the realization direction of the optical switch is the y-ray axis direction, so that the optical switch has a 90-degree turning function, and the upper and lower symmetrical radiation beams can be split.

The optical receiving device 6 and the photoelectric detection system 7 are used for measuring the transmissivity in the vertical direction of the metamaterial array, and the whole structure is vertically symmetrical, so that only one direction can be measured.

The optical receiving device 6 is used for receiving the emergent light of the metamaterial array 5 in the vertical direction, so that the transmittance of the emergent light of the metamaterial in the vertical direction can be detected conveniently. The optical receiving device 6 may employ a lens.

The photoelectric detection system 7 is used for measuring the transmittance value of the light in the vertical direction of the metamaterial array 5.

In order to further illustrate the different transmittances of the metamaterial array when the phase difference of two beams of light is 0 and pi respectively, the transmission characteristics of the metamaterial array when the phase difference of two beams of incident light is 0 and pi respectively are disclosed below. The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.