CN102520480A - Multi-medium-coupling three-dimensional photonic crystal and method for designing and manufacturing multi-medium-coupling three-dimensional photonic crystal - Google Patents

Abstract

The invention discloses a multi-medium coupled three-dimensional photonic crystal and a design and manufacture method thereof, which is a multi-medium coupled three-dimensional photonic crystal which has an ultra-wide bandgap within a wide frequency and is easy to manufacture. The multi-medium coupling three-dimensional photonic crystal according to the present invention periodically includes a variety of dielectric materials with different dielectric constants. The photonic crystal includes two forms of periodic stacking and crossing, and is prepared by rapid prototyping combined with multi-step injection molding. The photonic crystal in the present invention contains more than two dielectric materials, and the dielectric between multiple dielectric materials The constant ratio (refractive index ratio) strengthens the Bragg scattering and obtains a wider band gap than that of a single dielectric material photonic crystal.

Description

Multimedia coupling three-dimensional photonic crystal and its design and manufacture method

technical field

The invention relates to a multi-media coupled three-dimensional photonic crystal and a design and manufacture method thereof. Specifically, it refers to a three-dimensional photonic crystal containing two or more dielectric materials.

Background technique

Photonic crystal refers to a composite structural material whose dielectric constant (or refractive index) is three-dimensionally arranged in three-dimensional space. Yablornovitch and John independently proposed the concept of photonic crystals in 1987 when they studied the suppression of atomic spontaneous emission and light localization respectively. Similar to traditional crystal materials, when the dielectric constant is modulated in three-dimensional space, it will present an energy band structure similar to that of solid-state electronic crystals, and electromagnetic waves with energy in the band gap will not be able to propagate in this structure. When the working electromagnetic wave frequency is in the optical band, it is customary to call it a photonic crystal or a photonic bandgap structure. When the working electromagnetic wave frequency is in the microwave frequency range, it is customary to call it an electromagnetic bandgap structure. For the convenience of research, the concept of "photonic crystal" is uniformly used.

The most basic characteristics of photonic crystals are photonic band gap and photonic localization. In addition, the researchers also discovered slow-wave and ultra-slow-wave transmission and negative refraction in photonic crystals. Various new applications of photonic crystals are based on these novel and peculiar properties of the photonic crystal structure itself. Mirrors, optical waveguides, and resonant cavities are a few fundamental areas of application of photonic crystals. Since the photonic crystal has a band gap characteristic, a reflective mirror with a reflectivity close to 100% can be obtained through reasonable design. Based on the mirror design, it is easy to obtain a variety of high-efficiency filters (such as low-pass filters, high-pass filters, band-pass filters, extremely narrow-band filters, etc.). Starting from the reflector, various polarizers can be obtained by utilizing the different bandgap characteristics of TE and TM polarization in photonic crystals. Excellent optical waveguides can be obtained by introducing appropriate line defects in the mirror design. By introducing appropriate point defects into the mirror design, resonators with high quality factors can be obtained. For the realization of these properties of photonic crystals, a wider band gap is more conducive to controlling the transmission of electromagnetic waves in a wider range.

The bandgap of photonic crystals can be controlled by changing the structure, filling ratio, and high-low dielectric ratio. There have been many research reports on different three-dimensional structures, such as wood pile structure and diamond structure photonic crystal. And Kirihara et al.'s article "Controlling the Transmission of Electromagnetic Waves by Changing the Period of Electromagnetic Crystals" (SolidState Communications, 124, 2002, pages 135-139) studied the effect of stretching the diamond structure period on the bandgap of photonic crystals. The essence is By changing the filling rate of the photonic crystal structure to control the electromagnetic bandgap, a photonic crystal with a wider bandgap is obtained after stretching. The article "Preparation of Millimeter Wave Electromagnetic Bandgap Crystals Using Microwave Dielectric Powder" (Joural of American Ceramics Society, Issue 9, 2009, pp. 371-378) studied the effects of microwave dielectric materials with different dielectric constants on the electromagnetic bandgap. Influence. However, based on the limitation of manufacturing technology, the photonic crystals in the above studies only contain two kinds of dielectric materials, high and low, and there are no research reports on photonic crystals containing more than two kinds of dielectric materials. This is due to the complexity of the three-dimensional structure, coupled with the inconsistencies in the molding, drying, and sintering processes of multiple dielectric materials included at the same time, making it very difficult to manufacture.

Contents of the invention

The purpose of the present invention is to provide a multi-medium coupling three-dimensional photonic crystal and its design and manufacture method.

Technical scheme of the present invention is realized like this:

Multi-medium coupling three-dimensional photonic crystals periodically include a variety of dielectric materials with different dielectric constants, and the photonic crystals include two forms of periodic stacking and crossing:

Periodically stacked multi-medium coupled three-dimensional photonic crystal refers to: divide the three-dimensional photonic crystal structure into two or more parts on average, fill each part with media with different dielectric constants, and finally form Photonic crystals with constant media;

Periodically intersecting multi-medium three-dimensional photonic crystal refers to: in the photonic crystal with periodic three-dimensional structure, the first layer is filled with the first medium, the second layer is filled with the second medium, and the third layer is filled with the first medium , the fourth layer is filled with the second medium, and so on; or each layer is cross-filled with different media; or two media are nested and filled to form a multi-media photonic crystal.

The three-dimensional structure includes a three-dimensional columnar diamond structure, a spherical diamond structure, a derivative of the diamond structure, and a wood pile structure.

The dielectric materials used include all ceramic materials, liquid materials and ultra-low temperature metal materials; the multi-media coupling refers to the respective coupling of a variety of media with different dielectric constants between ceramic materials, between liquid materials or between ultra-low temperature metal materials, or ceramics Various media are coupled between materials, liquid materials and ultra-low temperature metal materials.

A method for manufacturing a multi-media coupled three-dimensional photonic crystal, comprising the following steps:

First, CAD software is used for structural design based on electromagnetic theory, and resin models are manufactured by light-curing rapid prototyping, and ceramic slurry or liquid materials and ultra-low temperature metal materials are prepared;

Secondly, the multi-media coupling three-dimensional photonic crystal was prepared by multi-step injection molding method;

For periodically stacked photonic crystals, the casing for injection molding is designed in a connected manner. The structure corresponding to each dielectric material has a grouting port and a communication port. The height of the communication port is parallel to the highest point of the structure occupied by the corresponding medium. . After injecting one kind of medium slurry, seal the grouting port and the connecting port with plasticine, then carry out the injection molding of the second medium, and so on, finally obtain the multi-media three-dimensional photonic crystal.

For photonic crystals with nested structures, the upper middle of the injection molded shell is separated by a partition according to the type of medium, one side is used for the injection molding of the structure corresponding to the first medium, and the other side is used for the structure corresponding to the second medium. Injection molding, and finally obtain a multi-medium coupled three-dimensional photonic crystal.

Compared with the traditional three-dimensional photonic crystal, the present invention has the following characteristics:

1. the photonic crystal among the present invention comprises two or more dielectric materials, and the dielectric constant ratio (refractive index ratio) between multiple dielectric materials strengthens Bragg scattering, obtains the bandgap wider than single dielectric material photonic crystal;

②Using rapid prototyping mold combined with multi-step injection molding method to solve the forming problem of multi-medium coupling photonic crystal, give full play to the advantages of light-cured rapid prototyping in design and manufacturing, and lay a solid foundation for the development of photonic crystal to device.

The features of the present invention will be more clearly shown through the following descriptions of the accompanying drawings and specific embodiments.

Description of drawings

Figure 1 shows three dielectric photonic crystals with periodically stacked diamond structures

Figure 2 is three kinds of dielectric photonic crystals with periodic cross diamond structure

Figure 3 Three dielectric photonic crystals with periodically nested diamond structures

Figure 4 Periodic cross wood pile structure of multiple dielectric photonic crystals

Fig. 5 is a schematic diagram of a method for manufacturing a multi-media coupling photonic crystal according to Embodiment 1

Fig. 6 is a schematic diagram of a method for manufacturing a multi-media coupling photonic crystal according to Embodiment 3

Detailed ways

Example 1

Accompanying drawing 1 is the multiple dielectric photonic crystal of periodic lamination diamond structure. Select a variety of suitable dielectric materials (dielectric constants are ε ₁ , ε ₂ , ε ₃ ...), and use rapid prototyping and multi-step gel injection molding to prepare multi-media coupling photonic crystals. In Figure 1, the first periodic layer is the first medium with a dielectric constant of ε _1. When the first medium is about to solidify, inject the second medium ε ₂ into the second periodic layer. When the second medium is about to solidify When injecting the third medium ε ₃ into the third periodic layer, and so on, the photonic crystal containing multiple mediums can be prepared as shown in Fig. 1 . The prepared multi-medium coupling photonic crystal can be a multi-medium coupling photonic crystal containing a resin structure, and can also be a pure ceramic photonic crystal after drying, degreasing and sintering.

Example 2

Accompanying drawing 2 is three kinds of dielectric photonic crystals with periodic intersecting diamond structure. Select two suitable dielectric materials (dielectric constants ε ₁ , ε ₂ ), and use rapid prototyping and multi-step gel injection molding to prepare multi-media coupled photonic crystals. In Figure 2, the first periodic layer is the first medium with a dielectric constant of ε _1. When the first medium is about to solidify, inject the second medium ε ₂ into the second periodic layer. When the second medium is about to solidify When the third periodic layer is injected with the first medium ε ₁ , when the third periodic layer medium is about to solidify, the second medium ε ₂ is re-injected into the fourth periodic layer, and so on. Periodically crossed diamond-structured photonic crystals containing three media. The prepared multi-medium photonic crystal can be a multi-medium coupled photonic crystal containing a resin structure and two media, or a pure ceramic photonic crystal containing two kinds of ceramics and air after drying, degreasing and sintering.

Example 3

Accompanying drawing 3 is three kinds of dielectric photonic crystals with periodically nested diamond structures. Select two suitable dielectric materials (dielectric constants ε ₁ , ε ₂ ), and use rapid prototyping and multi-step gel injection molding to prepare multi-media coupled photonic crystals. The diamond structure is shelled by CAD software to obtain a multi-media diamond structure model composed of an air diamond structure, a resin diamond structure, and an air anti-diamond structure nested with each other. Inject the first medium ε ₁ into the air diamond structure in Figure 3, and then inject the second medium ε ₂ into the air anti-diamond structure, and after vacuum freeze-drying, it is composed of medium ε ₁ , resin and medium ε ₂ A Periodically Nested Diamond Structure Containing Three Dielectrics Three Dielectric Coupling Photonic Crystals

Example 4

Accompanying drawing 4 is a photonic crystal coupled with multiple media with a periodic cross wood pile structure. Select two suitable dielectric materials (dielectric constants ε ₁ , ε ₂ ), and use rapid prototyping and multi-step gel injection molding to prepare multi-media coupled photonic crystals. Adjacent long cylinders of each layer are respectively injected with two different dielectric materials ε ₁ and ε ₂ , and the long cylinders corresponding to the upper layer and the long cylinders corresponding to the lower layer are connected to each other. The prepared multimedia photonic crystal may be a multimedia photonic crystal containing a resin structure and two media, or may be a pure ceramic photonic crystal containing two ceramics and air after drying, degreasing and sintering.

Example 5

The method for manufacturing a multi-media coupling photonic crystal according to Embodiment 1. 1 shown in attached drawing 5 is the grouting port of the first medium; 2 is the connecting port, the function is to ensure that the first medium can only reach the designed structural height; 3 and 4 are the first and second medium respectively , 5 is the resin model, 6 is the casing for grouting. The specific implementation method is to inject the prepared first medium slurry from 1. When the height of the slurry reaches the height of the 2 communication port, the excess slurry will flow out from 2. At this time, use plasticine to block the 1 and 2 ports. Hold, quickly inject the prepared slurry 2 from the top of the model. The upper shell is wider, and this design has two functions. One is that when the first medium slurry is injected, after the slurry reaches the middle height, the excess slurry will flow to the gap next to it, and finally flow out from the second port. Avoid flowing into the upper structure; second, when the second medium slurry is injected from the top of the model, the slurry will flow out from all sides, try to make the slurry downward evenly, and avoid the second medium slurry from concentrating on a certain point and squeezing downward The first medium, so that the two media are mixed together, after the grouting is completed, it is solidified and freeze-dried to obtain a multi-medium coupling photonic crystal containing a resin structure and two media, which can also be degreased and sintered. Pure ceramic photonic crystals of both ceramic and air.

Example 6

The method for manufacturing a multi-media coupling photonic crystal according to Embodiment 3. The structure shown in accompanying drawing 6 is the structure of Fig. 3 plus a shell, and a partition is used to separate the diamond structure and the anti-diamond structure. First, the slurry of the first medium ε ₁ is injected into the air diamond structure; then the second medium ε ₂ is injected into the anti-diamond structure, and the two medium slurries are solidified and freeze-dried to obtain the medium ε ₁ Multimedia coupled three-dimensional photonic crystals of ε ₂ and resin three media.

Claims (6)

1. multimedium coupling three-D photon crystal is characterized in that, has periodically comprised the dielectric material of multiple differing dielectric constant in the multimedium coupling three-D photon crystal, comprises two kinds of forms of cyclical layer superimposition intersection in the said photonic crystal:

Periodically range upon range of multimedium coupling three-D photon crystal is meant: three-dimensional photon crystal structure is equally divided into two parts or more parts; In each part, fill the medium of differing dielectric constant respectively, form the photonic crystal that contains multiple differing dielectric constant medium simultaneously at last;

The multimedium three-D photon crystal that periodically intersects is meant: will have in the photonic crystal of periodicity three-dimensional structure; Ground floor is filled first kind of medium, and the second layer is filled second kind of medium, and the 3rd layer recharges first kind of medium; The 4th layer recharges second kind of medium, by that analogy; Or intersection is filled different medium in each layer; Perhaps the mutually nested filling of two media forms the multimedium photonic crystal.

2. three-D photon crystal according to claim 1 is characterized in that, said three-dimensional structure comprises the redundant organism of three-dimensional column diamond lattic structure and spherical diamond lattic structure and diamond lattic structure, yard structure.

3. three-D photon crystal according to claim 1 is characterized in that the used medium material comprises all stupaliths, fluent material and ultralow temperature metal material; The coupling of said multimedium is meant between the stupalith, the medium of multiple differing dielectric constant is coupled separately between the fluent material or between the ultralow temperature metal material, or multiple medium intercouples between stupalith, fluent material and the ultralow temperature metal material.

4. the manufacturing approach of multimedium coupling three-D photon crystal may further comprise the steps:

At first adopt CAD software to carry out structural design and utilize photocureable rapid shaping to make resin mould according to electromagnetic theory, and preparation ceramic size or fluent material, ultralow temperature metal material;

Secondly, adopt the multistep injection molding to prepare multimedium coupling three-D photon crystal;

5. method according to claim 4; It is characterized in that; Be directed to periodically range upon range of photonic crystal; Injection molding is carried out the communication type design with shell, and every kind of corresponding structure of dielectric material has a grouting port and a connected entrance, and the height of connected entrance is parallel with the peak of the shared structure of corresponding medium.Behind a kind of dielectric paste injection molding, seal grouting port and connected entrance with plasticine, carry out the injection molding of second kind of medium then, by that analogy, finally obtain the multimedium three-D photon crystal.

6. method according to claim 4; It is characterized in that; To with the photonic crystal of mutually nested structure, separate with dividing plate by the medium kind in the middle of the superstructure with the injection molding shell, Yi Bian be used for the injection molding of first kind of medium counter structure; Another side is used for the injection molding of second kind of medium counter structure, finally obtains multimedium coupling three-D photon crystal.

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