Infrared waveband vanadium dioxide optical switch

Abstract

An infrared wave band vanadium dioxide optical switch is characterized in that: a uniform metal film layer is plated on a base layer, a vanadium dioxide layer is plated on the metal film layer, and a periodic T-shaped metal nanorod structure is made on the vanadium dioxide layer by using exposure and development technology, so that the infrared wave band vanadium dioxide optical switch is obtained. By using the phase change characteristic of vanadium dioxide, the 'on' and 'off' states can be controlled by heating or cooling the vanadium dioxide film layer through power supply, so that the function of the optical switch is realized; by adjusting the polarization state, the double-channel tuning reflection spectrum energy can be realized; the present application is easy to implement, avoids the moving parts of the mechanical switch, not only realizes the function of the optical switch, but also realizes the tuning of the double-channel spectrum intensity through polarization control, and can be widely applied in the fields of optical instruments, optical detection, optical measurement and biomedicine.

Description

Technical Field

[0001] This invention relates to an infrared vanadium dioxide optical switch, specifically to utilizing the phase transition properties of vanadium dioxide to achieve the function of an optical switch, and polarization control to achieve dual-channel tuned reflection spectrum energy tuning function, which can be applied to the fields of optical instruments, optical detection, optical measurement and biomedicine.

[0002] By utilizing the phase transition properties of vanadium dioxide, the "on" and "off" states can be controlled by heating or cooling the vanadium dioxide film, thus achieving the function of an optical switch. By adjusting the azimuth angle, dual-channel tuned reflection spectral energy can be achieved. This invention is easy to implement, avoids the moving parts of mechanical switches, and not only achieves the function of an optical switch, but also achieves dual-channel spectral intensity tuning through polarization control. It can be widely used in optical instruments, optical detection, optical measurement, and biomedicine. Background Technology

[0003] Optical switches, as passive optoelectronic devices, are the core components of optical switching and one of the main factors affecting the performance of optical networks. They primarily realize functions such as routing selection, wavelength selection, and optical cross-connection at the optical layer. Classified according to switching principles, they mainly include thermo-optical switches, electro-optical switches, and mechano-optical switches. The performance of optical switches is mainly reflected in extinction ratio, polarization sensitivity, switching time, and switching size. Furthermore, in fields such as biological research, the required spectrum is usually obtained by passing a light source through an optical filter. The spectrum can affect biological growth and control biological developmental transitions; spectral optical parameters play a crucial role in biological growth and development. Therefore, optical switches that can not only achieve "on" and "off" states but also have adjustable spectral parameters are essential devices for scientific and technological research related to spectral parameters in communication and biology. One prior art example of an optical switch is the Chinese invention patent "A Miniature Vanadium Dioxide Optical Switch," patent application number: 200310111202.5. This optical switch has many advantages, but it still has some fundamental shortcomings: the spectrum obtained by this optical switch has unadjustable spectral parameters, unknown operating wavelength, poor optical switching flexibility, and thus limits the application range of the optical switch. Summary of the Invention

[0004] To overcome the aforementioned shortcomings of existing technologies, this invention discloses an infrared-band vanadium dioxide optical switch. It not only possesses a simple structure, allowing control of the "on" and "off" states through heating or cooling of the vanadium dioxide film to achieve the function of an optical switch, but also allows for the adjustment of the energy distribution of the dual-channel reflection spectrum by changing the polarization state of the incident light. This infrared-band vanadium dioxide optical switch is a novel energy and wavelength-tunable optical switch designed based on the surface plasmon resonance effect and the phase transition characteristics of vanadium dioxide.

[0005] An infrared vanadium dioxide photoswitch is characterized by: depositing a uniform metal film on a substrate, depositing a vanadium dioxide layer on the metal film, and then fabricating a periodic T-shaped metal nanorod structure on the vanadium dioxide layer using exposure and development techniques, thereby obtaining a T-shaped infrared vanadium dioxide photoswitch.

[0006] The T-shaped metal nanorod structure consists of two parallel metal nanorods I and two parallel metal nanorods II, with the directions of metal nanorods I and II perpendicular to each other.

[0007] An infrared-band vanadium dioxide optical switch is characterized by the following: the VO2 thin film is semiconductor when the temperature is below the phase transition temperature, corresponding to the "on" state; while when the temperature is above the phase transition temperature, the film system transforms into a metallic state, exhibiting total internal reflection characteristics, corresponding to the "off" state. This phase transition characteristic is reversible. Utilizing this principle, the "on" and "off" states can be controlled by electrically heating or cooling the vanadium dioxide film, thus achieving the function of an optical switch.

[0008] The dual-channel spectral intensity can be tuned by controlling the polarization of vanadium dioxide light in the infrared band.

[0009] Preferably, the uniform metal film is an Al film.

[0010] Preferably, the uniform T-shaped metal nanorod material is silver.

[0011] Compared with existing technologies, the advantages and positive effects of this invention are: Based on the surface plasmon resonance effect and utilizing a four-layer structure, optical switching is achieved through the modulation of the vanadium dioxide phase transition. The purpose of rapidly tuning the reflection spectrum energy in two channels is achieved by adjusting the polarization state. It is convenient to implement and easy to control, and can be widely applied in optical instruments, optical detection, optical measurement, and biomedicine. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a vanadium dioxide optical switch structure in the infrared band; wherein: 1 is a metal nanorod structure layer, 2 is a vanadium dioxide layer, 3 is a metal layer, and 4 is a substrate layer.

[0013] Figure 2 This is a front view of an infrared vanadium dioxide optical switch structure, showing the distribution of the upper surface metal nanorod structure layer. Nanorod I has a length of l1 and a width of w1, with a spacing of d1 between two nanorods I; nanorod II has a length of l2 and a width of w2, with a spacing of d2 between two nanorods II, and a distance of d3 between adjacent metal nanorods I and II.

[0014] Figure 34 represents the "on" and "off" states of vanadium dioxide during different phase transitions under different polarizations. Figure 3 In the TM state, vanadium dioxide in the semiconductor state has a reflection valley resonance wavelength of 4270nm and a reflectivity of 0.13%. When heated, VO2 exhibits a metallic state, the reflection valley disappears, and the average reflectivity in the range of 2000-6000nm is 85.2%. Figure 4 The reflection valley of vanadium dioxide in the semiconductor state under the TE state is 2643nm; when heated, VO2 exhibits a metallic state, the reflection valley disappears, and the average reflectivity in the range of 2000-6000nm is 73.9%.

[0015] Figure 5 This invention relates to the reflection spectrum characteristics of a light source in air with an incident angle of 0°, but with different polarization angles (0°, 30°, 45°, 60°, 90°), at different wavelength channels. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, these embodiments are not intended to limit the present invention. Any similar structures and similar variations of the present invention should be included in the protection scope of the present invention.

[0017] A vanadium dioxide optical switch in the infrared band, the specific parameters of the embodiment are as follows: Figure 2 As shown.

[0018] The specific steps are as follows:

[0019] 1. A uniform metallic Al film with a thickness of 250 nm was deposited on the SiO2 substrate using an electronic evaporation method.

[0020] 2. A uniform vanadium dioxide film with a thickness of 70 nm is deposited on a metallic Al film using an electronic evaporation method.

[0021] 3. A uniform Ag film with a thickness of 120 nm was deposited on the vanadium dioxide film using an electronic evaporation method.

[0022] 4. A certain thickness of photoresist was deposited on a vanadium dioxide film using spin coating and dried. Periodic T-shaped Ag rod structures were then fabricated using photolithography, exposure, development, and etching techniques. Nanorod I has a length of l1 = 530 nm, a width of w1 = 40 nm, and a spacing of d1 = 60 nm between two nanorods I. Nanorod II has a length of l2 = 280 nm, a width of w2 = 50 nm, and a spacing of d2 = 100 nm between two nanorods II. The distance between adjacent metal nanorods I and II is d3 = 80 nm. The period of the periodic T-shaped structure is 600 nm in both directions parallel to metal nanorod I and metal nanorod II.

[0023] This is how we obtain... Figure 1 The diagram shows the structure of a vanadium dioxide optical switch in the infrared band with a T-shaped structure.

[0024] By heating or cooling the vanadium dioxide film with electricity, the "on" and "off" states can be controlled, thus achieving the function of an optical switch.

[0025] By changing the azimuth angle to adjust the polarization state, the narrowband reflection spectrum of different channels can be changed, achieving the function of dual-channel spectral energy tuning.

[0026] Figure 2 and 3 It refers to the "on" and "off" states of vanadium dioxide during different phase transitions under different polarizations. Figure 2 In the TM state, vanadium dioxide in the semiconductor state has a reflection valley resonance wavelength of 4270nm and a reflectivity of 0.13%. When heated, VO2 exhibits a metallic state, the reflection valley disappears, and the average reflectivity in the range of 2000-6000nm is 85.2%. Figure 3 The reflection valley of vanadium dioxide in the semiconductor state under the TE state is 2643nm; when heated, VO2 exhibits a metallic state, the reflection valley disappears, and the average reflectivity in the range of 2000-6000nm is 73.9%.

[0027] Figure 4 This invention presents the reflectance spectral characteristics of the filter at different wavelengths (2643nm and 4270nm) under different polarization angles (0°, 30°, 45°, 60°, 90°) at a 0° incident angle in air. As shown in the figure, the resonant wavelength of the filter at a 0° polarization azimuth angle is 4270nm, and the resonant wavelength at a 90° azimuth angle is 2643nm. Furthermore, the reflectance at the resonant wavelength is close to 100% at both 0° and 90° azimuth angles. At a 45° azimuth angle, the reflectance is approximately 50% at wavelengths of 2643nm and 4270nm. The energy of the reflected spectrum changes linearly with the azimuth angle from 0° to 90° in both channels. This invention successfully achieves the function of tuning the spectrum using a dual-channel spectral energy tuned filter.

Claims

1. A vanadium dioxide optical switch in the infrared band, characterized in that: A uniform metal film is deposited on the substrate, and a vanadium dioxide layer is deposited on the metal film. Then, a periodic T-shaped metal nanorod structure is fabricated on the vanadium dioxide layer using exposure and development techniques, thus obtaining an infrared vanadium dioxide photoswitch. The T-shaped metal nanorod structure consists of two parallel metal nanorods I and two parallel metal nanorods II, with the directions of metal nanorods I and II perpendicular to each other.

2. The infrared vanadium dioxide optical switch as described in claim 1, characterized in that: By applying electricity to heat or cool the vanadium dioxide film, the "on" and "off" states can be controlled, thus realizing the function of an optical switch.

3. The infrared vanadium dioxide optical switch as described in claim 1, characterized in that: Dual-channel spectral intensity tuning is achieved through polarization control of vanadium dioxide optical switching in the infrared band.

4. The infrared vanadium dioxide optical switch as described in claim 1, characterized in that: By controlling the phase transition and polarization state of vanadium dioxide, spectral modulation and light switching functions in the infrared band were achieved.

5. The infrared vanadium dioxide optical switch as described in claim 1, characterized in that: The uniform metal film is an Al film.

6. The infrared vanadium dioxide optical switch as described in claim 5, characterized in that: The T-shaped metal nanorod material is silver.

7. The infrared vanadium dioxide optical switch as described in claim 6, characterized in that: The Al film thickness is 250 nm, the vanadium dioxide film thickness is 70 nm, the T-type silver nanorod thickness is 120 nm, and the length of nanorod I is... l 1 = 530 nm, width is w 1 = 40 nm, the distance between the two nanorods I is d 1 = 60 nm; the length of nanorod II is l 2 = 280 nm, width is w 2 = 50 nm, the distance between the two nanorods II is d 2 = 100 nm, the distance between adjacent metal nanorod I and metal nanorod II is d 3 = 80 nm.

8. The infrared vanadium dioxide optical switch as described in claim 7, characterized in that: The periodic T-shaped metal nanorod structure has a period of 600 nm in both directions parallel to metal nanorod I and metal nanorod II.

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