A selectively excited half-dislocation dual optical microcavity

Abstract

The present invention discloses a selectively excited half-dislocation dual optical microcavity, comprising a ferrite cylindrical half-dislocation array, a parallel plate waveguide and an electromagnetic absorption material. The method for forming the ferrite cylindrical half-dislocation array is as follows: first, ferrite cylinders are arranged in a rectangular lattice to form a photonic crystal, and the photonic crystal is divided into an upper and lower sub-lattice. Then, a half-row of ferrite cylinders is embedded along the centerline of the upper sub-lattice, and finally, the position of the cylinders at the interface between the upper and lower sub-lattices is adjusted to obtain two half-dislocation microcavities. The half-dislocation array is placed between the parallel plate waveguides; the four boundaries are all covered with electromagnetic absorption material; and the direction of the external magnetic field is perpendicular to the array plane. The selectively excited dual optical microcavity achieves selective excitation in a mirror-symmetric structure by breaking the time reversal symmetry through an external magnetic field. The selective excitation mechanism of the half-dislocation dual optical microcavity proposed by the present invention has the advantages of simple principle, compact structure, high excitation ratio, low electromagnetic loss, and strong anti-interference ability.

Description

Technical Field

[0001] The invention relates to the field of photonic crystals and photonic devices, and in particular to a selectively excited half-dislocation dual optical microcavity. Background Art

[0002] Optical microcavities have been extensively studied for their ability to concentrate energy through resonance within extremely small volumes. They play an irreplaceable role in optical sensing and light-matter interactions, and are widely used in optical devices such as microlasers, photonic frequency combs, and integrated photonic devices. Optical microcavities primarily include Fabry-Perot microcavities, whispering gallery microcavities, and photonic crystal microcavities. Photonic crystal microcavities are known for their high Q and low loss. Traditional photonic crystal microcavities rely on artificial point defects. However, these point defect microcavities are extremely fragile, and even slight manufacturing errors or misalignments can lead to significant mode frequency shifts and Q degradation. Furthermore, due to mirror symmetry, if a system contains multiple identical microcavities, all will be excited simultaneously at the same frequency, limiting their application. Summary of the Invention

[0003] Purpose of the invention: In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a half-dislocation dual optical microcavity that can be selectively excited. Based on a rectangular lattice of ferrite cylinders, two half-dislocation optical microcavities are constructed by embedding half a row of ferrite cylinders. The external magnetic field is used to break the time reversal symmetry to achieve selective excitation. The invention has the advantages of simple structure, high excitation ratio, and strong anti-interference ability.

[0004] Technical solution: To achieve the above-mentioned purpose of the invention, the present invention provides a selectively excited half-dislocation dual optical microcavity, comprising a ferrite cylinder half-dislocation array, a parallel plate waveguide and an electromagnetic absorption material. The ferrite cylinder half-dislocation array is formed by the following method: first, ferrite cylinders are arranged in a rectangular lattice to form a photonic crystal, and the photonic crystal is divided into an upper and lower sub-lattice; then, a half-row of ferrite cylinders is embedded along the centerline of the upper sub-lattice, and the embedded half-row of ferrite cylinders squeezes the ferrite cylinders on both sides of the centerline of the upper sub-lattice, causing the cylinders on both sides to move to the left and right directions respectively; at the same time, the ferrite cylinders at the junction of the upper and lower sub-lattices produce lattice dislocations due to squeezing; the positions of the ferrite cylinders at the junction are adjusted according to the squeezing deformation to obtain a pair of half-dislocation microcavities located at the junction of the upper and lower sub-lattices; the half-dislocation array formed by the upper and lower sub-lattices is placed between the parallel plate waveguides; the four boundaries are covered with electromagnetic absorption material; and the direction of the external magnetic field is perpendicular to the array plane.

[0005] Preferably, the photonic crystal formed by arranging the ferrite cylinders in a rectangular lattice comprises at least 22 rows of ferrite cylinders.

[0006] Preferably, the ferrite cylindrical half dislocation array satisfies mirror symmetry, and the lattice constant in the length direction of the rectangular lattice arrangement is twice the lattice constant in the width direction.

[0007] Preferably, the two half-dislocation microcavities are located on the left and right sides of the center line respectively. By embedding half a row of ferrite cylinders into the upper sub-lattice along the center line, the additionally embedded ferrite cylinders cause extrusion deformation of the ferrite cylinders on both sides of the center line of the upper sub-lattice, and also cause lattice dislocation at the interface between the upper and lower sub-lattices, forming two half-dislocation microcavities with openings facing upward.

[0008] Preferably, the ferrite cylinders in the ferrite cylinder array are yttrium iron garnet (YIG) cylinders.

[0009] Preferably, the two half-dislocation microcavities in the ferrite cylindrical half-dislocation array are located on either side of a center line of the array, and the two half-dislocation microcavities are mirror-symmetrical along the center line of the array.

[0010] Preferably, the electromagnetic excitation source is placed above or below the middle row of ferrite cylinders.

[0011] Preferably, the electromagnetic excitation source is a point source, which is placed at the center of the line connecting the two half-dislocation optical microcavities.

[0012] Preferably, the detection source is placed at the geometric center of the half-dislocation optical microcavity.

[0013] Preferably, a single optical microcavity is selectively excited by adjusting the direction of the magnetic field.

[0014] Working principle: The selective excitation of the half-dislocation dual optical microcavity proposed in the present invention first constructs a ferrite cylinder array based on a rectangular lattice, and constructs a half-dislocation dual-cavity structure by embedding half a row of ferrite cylinders, obtaining a pair of optical microcavities with mirror symmetry. Then, an external magnetic field is used to break the time reversal symmetry of the system, and a pair of degenerate photon bound states in the microcavity undergoes energy level splitting, resulting in an imbalance in the photon energy in the two microcavities, forming selective excitation of a single microcavity. Finally, the selective excitation of the dual optical microcavity is related to the direction of the external magnetic field. Adjusting the direction of the external magnetic field (such as rotating it 180°) can excite the optical microcavity on either side.

[0015] Beneficial Effects: Compared with existing technologies, the proposed half-dislocation dual optical microcavity with selective excitation has a simple structure, enabling selective excitation of a single optical microcavity. It boasts advantages such as a simple principle, compact structure, high excitation ratio, low electromagnetic loss, and strong anti-interference capabilities. Due to its topological protection, the half-dislocation microcavity requires low manufacturing precision, is immune to disorder and defects, and is suitable for various integrated photonic devices. Because the ferrite cylinder array is scale-invariant, the operating frequency can be ported to the terahertz or optical bands by simply changing its geometric dimensions, demonstrating its broad applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 3D model structure diagram of an embodiment of the present invention.

[0017] Figure 2 Schematic diagram of the construction of a half-dislocation ferrite cylinder array according to an embodiment of the present invention.

[0018] Figure 3 This is a diagram of the electric field distribution of an embodiment of the present invention when a point source is excited by a magnetic field directed inward along a straight surface.

[0019] Figure 4 This is a diagram of the electric field distribution of an embodiment of the present invention when a point source is excited by a magnetic field directed outward along a straight surface.

[0020] Figure 5 1 is an electromagnetic transmission spectrum of different half-dislocation optical microcavities in the embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings and specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. After reading this invention, modifications to various equivalent forms of the present invention made by those skilled in the art fall within the scope defined by the appended claims.

[0022] An embodiment of the present invention discloses a selectively excited half-dislocation dual optical microcavity, comprising a ferrite cylinder half-dislocation array 1, a parallel plate waveguide 2, and an electromagnetic absorption boundary 3. The ferrite cylinder half-dislocation array is a structure formed by arranging ferrite cylinders in a rectangular lattice and embedding a half-row of ferrite cylinders along the centerline. The formation method is as follows: first, ferrite cylinders are arranged in a rectangular lattice to form a photonic crystal, and the photonic crystal is divided into two sub-lattices, an upper sub-lattice and an lower sub-lattice. Then, a half-row of ferrite cylinders is embedded along the centerline of the upper sub-lattice. The embedded half-row of ferrite cylinders squeezes the ferrite cylinders on both sides of the centerline of the upper sub-lattice, causing the cylinders on both sides to move to the left and right directions, respectively. At the same time, the ferrite cylinders at the junction of the upper and lower sub-lattices produce lattice dislocations due to the squeezing. The positions of the ferrite cylinders at the junction are adjusted according to the squeezing deformation to obtain a pair of half-dislocation microcavities located at the junction of the upper and lower sub-lattices. In this embodiment, two half-dislocation microcavities are located in the middle of the left and right regions, respectively, divided by the center line. A microcavity with an upward opening is formed by embedding half a row of ferrite cylinders into the upper sublattice and then adjusting the position of the ferrite cylinders at the interface between the upper sublattice and the upper and lower sublattices. The ferrite half-dislocation column array is surrounded by electromagnetic absorption material on all four sides. The ferrite cylinder half-dislocation array and the electromagnetic absorption material are both positioned between two parallel plate waveguides. In this embodiment, the parallel plate waveguide is a metal aluminum plate. The sample dimensions are 264 mm × 324 mm × 10 mm.

[0023] like Figure 1 As shown in FIG, a selectively excited half-dislocation dual optical microcavity design proposed in an embodiment of the present invention is based on a two-dimensional half-dislocation array. The ferrite cylinder is mainly composed of yttrium iron garnet (YIG), with a relative dielectric constant of 15.26 and a saturation magnetization of 1884 Gauss. The lattice constants of the ferrite cylinder array along the x-direction and y-direction are a and b, respectively. x and a y , a y =2*a x (In this example, a x =12mm, a y =24mm). Ferrite cylinder height h = 0.83a x , the radius of the dielectric column r=0.16a x The half-dislocation array is surrounded by electromagnetic absorption material to prevent unnecessary electromagnetic leakage.

[0024] like Figure 2 As shown in the figure, the construction process of the ferrite cylindrical half-dislocation array is as follows: (1) Construct a ferrite cylindrical array based on a rectangular lattice. The array satisfies the translational symmetry, and the lattice constants along the x-direction and y-direction are a and b respectively. x and a y(2) A pair of half-dislocation optical microcavities 4 with mirror symmetry is constructed by inserting half a row of ferrite cylinders 5 along the center line of the rectangular array. The electromagnetic wave is excited by a point source 6. The electromagnetic excitation source is placed above or below the middle row of ferrite cylinders, and the detection source is placed at the geometric center of the half-dislocation optical microcavity.

[0025] Figure 3 It shows that in the selectively excited half-dislocation dual optical microcavity design proposed in the present invention, when the direction of the external magnetic field is perpendicular to the array plane and outward (+z-axis direction), the electric field intensity of the left half-dislocation optical microcavity (white trapezoidal area) is significantly higher than that of the right half-dislocation optical microcavity.

[0026] Figure 4 It shows that in the selectively excited half-dislocation dual optical microcavity design proposed in the present invention, when the direction of the external magnetic field is perpendicular to the array plane and inward (-z axis direction), the electric field intensity of the right half-dislocation optical microcavity (white trapezoidal area) is significantly higher than that of the left half-dislocation optical microcavity.

[0027] Figure 5 The electromagnetic transmission spectra of different half-dislocation optical microcavities in the selectively excited half-dislocation dual optical microcavity design proposed in this invention are shown. At a frequency of f = 12.25 GHz (black arrow), the direction of the external magnetic field is perpendicular to the array plane and outward ( Figure 5 The transmission spectrum S21 of the left half-dislocation optical microcavity (solid line) is significantly higher than that of the right half-dislocation optical microcavity (dashed line). When the external magnetic field is perpendicular to the array plane and inward ( Figure 5 The transmission spectrum S21 of the right half-dislocation optical microcavity (dashed line) is significantly higher than that of the left half-dislocation optical microcavity (solid line).

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A selectively excited half-dislocation dual optical microcavity, characterized in that: The invention comprises a ferrite cylinder half-dislocation array, a parallel plate waveguide and an electromagnetic absorption material. The ferrite cylinder half-dislocation array is formed by the following method: first, ferrite cylinders are arranged in a rectangular lattice to form a photonic crystal, wherein the photonic crystal is divided into an upper and a lower sub-lattice; then, a half-row of ferrite cylinders is embedded along the centerline of the upper sub-lattice, and the embedded half-row of ferrite cylinders squeezes the ferrite cylinders on both sides of the centerline of the upper sub-lattice, causing the cylinders on both sides to move to the left and right directions respectively; at the same time, the ferrite cylinders at the junction of the upper and lower sub-lattices produce lattice dislocations due to the squeezing; the positions of the ferrite cylinders at the junction are adjusted according to the squeezing deformation to obtain a pair of half-dislocation microcavities located at the junction of the upper and lower sub-lattices; the half-dislocation array formed by the upper and lower sub-lattices is placed between the parallel plate waveguides; the four boundaries are all covered with electromagnetic absorption material; the direction of the external magnetic field is perpendicular to the array plane; and a single optical microcavity is selectively excited by adjusting the direction of the magnetic field.

2. The selectively excited half-dislocation dual optical microcavity according to claim 1, characterized in that: The photonic crystal formed by arranging the ferrite cylinders in a rectangular lattice has at least 22 rows of ferrite cylinders.

3. The selectively excited half-dislocation dual optical microcavity according to claim 1, characterized in that: The ferrite cylindrical half dislocation array satisfies mirror symmetry, and the lattice constant in the length direction of the rectangular lattice arrangement is twice the lattice constant in the width direction.

4. The selectively excited half-dislocation dual optical microcavity according to claim 1, characterized in that: The two half-dislocation microcavities are respectively located on the left and right sides of the midline. By embedding half a row of ferrite cylinders into the upper sub-lattice along the midline, the additionally embedded ferrite cylinders cause extrusion deformation of the ferrite cylinders on both sides of the midline of the upper sub-lattice, and also cause lattice dislocation at the interface between the upper and lower sub-lattices, forming two half-dislocation microcavities with openings facing upward.

5. The selectively excited half-dislocation dual optical microcavity according to claim 1, characterized in that: The ferrite cylinder is a yttrium iron garnet cylinder.

6. The selectively excited half-dislocation dual optical microcavity according to claim 1, characterized in that: The two half-dislocation microcavities in the ferrite cylindrical half-dislocation array are respectively located on two sides of the array centerline, and the two half-dislocation microcavities are mirror-symmetrical along the array centerline.

7. The selectively excited half-dislocation dual optical microcavity according to claim 1, characterized in that: The electromagnetic excitation source is a point source placed at the center of the line connecting the two half-dislocation optical microcavities.

8. The selectively excited half-dislocation dual optical microcavity according to claim 1, characterized in that: The detection source is placed at the geometric center of the half-dislocation optical microcavity.

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