Distributed Bragg reflector resonant cavity based on plasmon supermolecules

Abstract

The invention discloses a plasmon supermolecule-based distributed Bragg reflector resonant cavity, which comprises a plasmon supermolecule distributed Bragg reflector and a dielectric cavity, and is characterized in that the plasmon supermolecule distributed Bragg reflector takes a gold nanoparticle supermolecule array layer and a dielectric layer as repetitive units, the number of the repetitive units is 1-100, the gold nanostructure supramolecular unit is formed by densely arranging N gold nanoparticles, and the distributed Bragg reflector resonant cavity is of a sandwich structure composed of two plasmon supramolecular distributed Bragg reflectors and a medium cavity. The resonant cavity has excellent performances of small cavity length, high quality factor, deep resonant depth and the like. Therefore, the distributed Bragg reflector resonant cavity of the plasmon supermolecule array can effectively improve the performance of a photoelectric device and reduce the size of the device at the same time.

Description

Technical Field

[0001] The invention relates to the field of optoelectronic devices, and in particular to a distributed Bragg reflector resonant cavity based on plasmon supramolecules. Background Art

[0002] A distributed Bragg reflector is a structure in which a layer of high refractive index material and a layer of low refractive index material are alternately stacked. The thickness of each layer is an odd multiple of a quarter of the optical wavelength. Reflection occurs at the interface of two different materials. The reflection at the interface is in phase. Therefore, in theory, a reflectivity of more than 99% can be achieved by stacking a certain number of layers. One type of distributed Bragg reflector is based on dielectric materials, mainly including some oxides, nitrides, and fluorides. These materials are combined into a Bragg reflector, and the refractive index difference can be relatively large. Therefore, a dielectric Bragg reflector only needs a combination of more than ten pairs of high and low refractive index materials to achieve a reflection of more than 99%, and the high reflection bandwidth is about 100nm. However, dielectric Bragg reflectors are often accompanied by certain absorption losses and scattering losses.

[0003] The other type is a distributed Bragg reflector based on semiconductor materials, mainly including III-V semiconductor material systems such as InP, GaAs, and GaN. In these material systems, since the growth technology is limited by lattice matching, two lattice-matched materials with different band gaps (different refractive indices) must be selected to form a Bragg reflector. The refractive index difference between high and low refractive index materials of Bragg reflectors based on semiconductor materials is small, usually Δn / n<15%. Therefore, more pairs (20-80) need to be stacked to achieve high reflection, and the high reflection bandwidth is narrow. In addition, the more stacked layers, the higher the process requirements.

[0004] For these traditional Bragg reflectors, due to the limitation of the material refractive index, if high reflection is to be achieved, the reflector thickness is relatively large, usually requiring a thickness of several microns to more than ten microns, and the high reflection bandwidth of the reflector is relatively small, which reduces the process tolerance of device preparation. The resonant cavity formed by the Bragg reflector based on traditional materials has a long total cavity length, which will be unfavorable for the miniaturization of the device. Summary of the invention

[0005] Technical problem: The purpose of the present invention is to provide a distributed Bragg reflector resonant cavity based on plasmon supramolecules to solve the problem that the distributed Bragg reflector made of traditional materials is thick and the resonant cavity based on the reflector made of traditional materials is too large, which is not conducive to device miniaturization.

[0006] Technical solution: A distributed Bragg reflector resonant cavity based on plasmon supramolecular of the present invention comprises: a plasmon supramolecular distributed Bragg reflector and a dielectric cavity, wherein the plasmon supramolecular distributed Bragg reflector comprises a gold nanoparticle supramolecular array layer and a dielectric layer as repeating units, the number of repeating units being 1 to 100, the gold nanoparticle supramolecular array layer being an array structure in which gold nanostructure supramolecular units are arranged in a tetragonal lattice or a hexagonal lattice, the gold nanostructure supramolecular unit being composed of N gold nanoparticles densely arranged, N being an integer in the range of 1 to 10 12 The distributed Bragg reflector resonant cavity is a sandwich structure consisting of two plasmon supramolecular distributed Bragg reflectors and a dielectric cavity.

[0007] In the plasmon supramolecular distributed Bragg reflector, the array period of the gold nanoparticle supramolecular array layer is greater than 20nm; the spacing between the gold nanostructure supramolecular units is 1-10 6 nm.

[0008] The shape of the gold nanostructure supramolecular unit includes circle, quadrilateral, hexagon or octagon.

[0009] The gold nanoparticles in the gold nanostructure supramolecular unit can be replaced by silver nanoparticles.

[0010] The gap between the gold nanoparticles is 1-10 nm.

[0011] The shapes of the gold nanoparticles in the gold nanostructure supramolecular unit include sphere, cylinder, cube or regular octahedron; the size of the gold nanoparticles is 20-100nm.

[0012] The real part of the effective refractive index of the gold nanoparticle supramolecular array layer in the infrared band is greater than 4, and the imaginary part of the effective refractive index approaches 0.

[0013] The dielectric cavity comprises an active dielectric cavity and a passive dielectric cavity.

[0014] The length of the dielectric cavity corresponding to the fundamental mode resonance mode in the distributed Bragg reflector resonant cavity is 1-3 μm; the resonance mode is located in the infrared band and has a deep resonance depth.

[0015] The upper and lower Bragg reflectors of the distributed Bragg reflector resonant cavity are both composed of two repeating units, and the total length of the resonant cavity is 2-5 μm.

[0016] Beneficial effects: Compared with the existing technology, the present invention has the following advantages:

[0017] 1. A plasmonic supramolecular distributed Bragg reflector is proposed, which uses a gold nanoparticle supramolecular array layer with a high effective refractive index and a dielectric layer with a low refractive index as the repeating unit layer. Compared with the Bragg reflector of traditional materials, the Bragg reflector composed of the gold nanoparticle supramolecular array layer and the dielectric layer has a large refractive index difference. By stacking fewer layers, higher reflection and a large high reflection bandwidth can be achieved, which provides a new strategy for miniaturization and tunable devices.

[0018] 2. A distributed Bragg reflector resonant cavity based on plasmonic supramolecules is proposed. Due to the high reflective properties of the gold nanoparticle supramolecule array layer / dielectric layer reflector, a distributed Bragg reflector of a few layers of plasmonic supramolecules can easily form a resonant cavity with a short cavity length and a deep resonance depth. This distributed Bragg reflector resonant cavity based on plasmonic supramolecules can be used in optoelectronic devices to effectively reduce the size of the device while improving its performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of a distributed Bragg reflector resonant cavity based on plasmon supramolecules of the present invention.

[0020] The figure includes: a plasmon supramolecular distributed Bragg reflector 100 , a repeating unit 10 , a dielectric layer 11 , a gold nanoparticle supramolecular array layer 12 , a gold nanostructure supramolecular unit 121 , and a dielectric cavity 200 . DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0022] See also Figure 1 The distributed Bragg reflector resonant cavity based on plasmon supramolecular of the present invention comprises: a plasmon supramolecular distributed Bragg reflector and a dielectric cavity, wherein the plasmon supramolecular distributed Bragg reflector is composed of a gold nanoparticle supramolecular array layer 12 and a dielectric layer 11 as a repeating unit 10, the number of the repeating units is 1 to 100, the gold nanoparticle supramolecular array layer is an array structure in which gold nanostructure supramolecular units are arranged at a certain interval in a tetragonal lattice or a hexagonal lattice, and the gold nanostructure supramolecular unit is composed of N gold nanoparticles densely arranged, N is an integer, and the value range is 1 to 10. 12 The resonant cavity is a sandwich structure consisting of two plasmon supramolecular distributed Bragg reflectors 100 and one dielectric cavity 200.

[0023] The technical solution provided by the embodiment of the present invention adopts a gold nanoparticle supramolecular array layer with a high effective refractive index and a dielectric layer with a low refractive index as the repeating unit layer of the Bragg reflector. Compared with the Bragg reflector of traditional materials, the Bragg reflector composed of the gold nanoparticle supramolecular array layer and the dielectric layer has a large refractive index difference, and a higher reflection and a large high reflection bandwidth can be achieved by stacking a smaller number of layers, which provides a new strategy for the miniaturization of devices and adjustable devices. Due to its high reflection characteristics, a few-layer plasmon nanostructure patterned supramolecular array distributed Bragg reflector is easy to form a resonant cavity with a short cavity length and a deep resonance depth. This distributed Bragg reflector resonant cavity based on plasmon supramolecular is applied in optoelectronic devices, which can effectively reduce the size of the device while improving the performance of the device.

[0024] In an embodiment, the period of the supramolecular unit array is greater than 20 nm.

[0025] In the embodiment, the spacing between supramolecular units is 1-10 6 nm.

[0026] In the embodiment, the shape of the supramolecular unit includes circle, quadrilateral, hexagon or octagon.

[0027] In the embodiment, the gold in the gold nanoparticles can be replaced by silver or aluminum.

[0028] In the embodiment, the particle shape of the gold nanoparticles includes sphere, cylinder, cube or regular octahedron.

[0029] In the embodiment, the size of the gold nanoparticles is 20-100 nm.

[0030] In the embodiment, the gap between the gold nanoparticles is 1-10 nm.

[0031] In an embodiment, the effective refractive index of the gold nanoparticle supramolecular array layer in the infrared band is greater than 4.

[0032] In the embodiment, the loss of the gold nanoparticle supramolecular array layer in the infrared band approaches to zero.

[0033] In an embodiment, the novel resonant cavity includes the above-mentioned plasmon supramolecular distributed Bragg reflector.

[0034] In the embodiment, the dielectric cavity in the novel resonant cavity includes an active dielectric cavity and a passive dielectric cavity.

[0035] In the embodiment, the length of the dielectric cavity corresponding to the first-order resonance mode in the novel resonant cavity is 1-3 μm.

[0036] In the embodiment, the resonance mode of the resonant cavity is located in the infrared band and has a deep resonance depth.

[0037] In the embodiment, the upper and lower Bragg reflectors of the novel resonant cavity are both composed of two unit layers, and the total length of the resonant cavity is 2-5 μm.

Claims

1. A distributed Bragg reflector resonant cavity based on plasmon supramolecules, characterized in that: include: A plasmon supramolecular distributed Bragg reflector (100) and a dielectric cavity (200), wherein the plasmon supramolecular distributed Bragg reflector (100) comprises a gold nanoparticle supramolecular array layer (12) and a dielectric layer (11) as repeating units (10), the number of the repeating units (10) being 1 to 100, the gold nanoparticle supramolecular array layer (12) being an array structure in which gold nanostructure supramolecular units (121) are arranged in a tetragonal lattice or a hexagonal lattice, and the gold nanostructure supramolecular unit is composed of N gold nanoparticles densely arranged, where N is an integer ranging from 1 to 10. 12 The distributed Bragg reflector resonant cavity is a sandwich structure consisting of two plasmon supramolecular distributed Bragg reflectors (100) and a dielectric cavity (200).

2. The distributed Bragg reflector resonant cavity based on plasmon supramolecules according to claim 1, characterized in that: In the plasmon supramolecular distributed Bragg reflector (100), the array period of the gold nanoparticle supramolecular array layer (12) is greater than 20 nm; the spacing between the gold nanostructure supramolecular units (121) is 1-10 6 nm.

3. The distributed Bragg reflector resonant cavity based on plasmon supramolecules according to claim 2, characterized in that: The shape of the gold nanostructure supramolecular unit (121) includes a circle, a quadrilateral, a hexagon or an octagon.

4. The distributed Bragg reflector resonant cavity based on plasmon supramolecules according to claim 3, characterized in that: The gold nanoparticles in the gold nanostructure supramolecular unit (121) can be replaced by silver nanoparticles.

5. The distributed Bragg reflector resonant cavity based on plasmon supramolecules according to claim 1, characterized in that: The gap between the gold nanoparticles is 1-10 nm.

6. The distributed Bragg reflector resonant cavity based on plasmon supramolecules according to claim 4, characterized in that: The gold nanoparticles in the gold nanostructure supramolecular unit (121) have shapes including sphere, cylinder, cube or regular octahedron; and the size of the gold nanoparticles is 20-100 nm.

7. The distributed Bragg reflector resonant cavity based on plasmon supramolecules according to claim 1, characterized in that: The real part of the effective refractive index of the gold nanoparticle supramolecular array layer (12) in the infrared band is greater than 4, and the imaginary part of the effective refractive index approaches 0.

8. The distributed Bragg reflector resonant cavity based on plasmon supramolecules according to claim 1, characterized in that: The dielectric cavity (200) comprises an active dielectric cavity and a passive dielectric cavity.

9. The distributed Bragg reflector resonant cavity based on plasmon supramolecules according to claim 1, characterized in that: The length of the dielectric cavity corresponding to the fundamental mode resonance mode in the distributed Bragg reflector resonant cavity is 1-3 μm; the resonance mode is located in the infrared band and has a deep resonance depth.

10. The distributed Bragg reflector resonant cavity based on plasmon supramolecules according to claim 1, characterized in that: The upper and lower Bragg reflectors of the distributed Bragg reflector resonant cavity are both composed of two repeating units (10), and the total length of the resonant cavity is 2-5 μm.

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