Visible light dynamically tunable hyperspectral resolution filter based on dielectric elastomers

Abstract

The application discloses a visible light dynamic tunable hyperspectral resolution filter based on a dielectric elastomer and belongs to the technical field of filters.The filter comprises a quartz substrate, one-dimensional photonic crystals, a defect layer, a band-pass layer and an ITO layer.The quartz substrate is located at the bottom layer;two axis-symmetrical one-dimensional photonic crystals are located on the upper layer of the quartz substrate, and the symmetry axis is the defect layer between the two one-dimensional photonic crystals;the band-pass layer is located at the uppermost layer;and the ITO layer is symmetrically attached to the two sides of the two one-dimensional photonic crystals.The application has the advantages of simple structure, high peak transmittance and narrow-band spectrum, wide tunable range, high color filter purity and fast wavelength tuning.

Description

Technical Field

[0001] This invention belongs to the field of optical filter technology, and specifically relates to a visible light dynamically tunable high spectral resolution optical filter structure based on a dielectric elastomer. Background Technology

[0002] Color filters are optical devices that play a vital role in many industrial fields, such as spectroscopic instruments, imaging sensors, and displays. The accuracy and sensitivity of many optical systems used in these fields are primarily determined by these optical devices.

[0003] Generally, optical filters come in two types: reflective filters and transmissive filters. Typically, reflective filters are achieved using perfect absorbers, where the wavelengths they filter are completely absorbed. Conversely, transmissive filters achieve their filtering function by allowing the desired wavelengths to pass through. Compared to reflective filters, transmissive filters are more suitable for applications such as displays, charge-coupled devices, and hyperspectral imaging.

[0004] For transmission filters, a key characteristic for achieving high precision and resolution is the quality factor, or full width at half the maximum transmission spectrum (FWHM). Furthermore, the filter's transmittance is also an important property to consider. This is because higher transmittance means better utilization of incident light energy, which helps reduce power dissipation and obtain high-intensity signals in optical systems using these filters.

[0005] From classic RGB Bayer filters to multi / hyperspectral integrated color filter arrays (CFAs), filter-type spectrometers have become a key technology for remote sensing spectral imaging. They enable the miniaturization of bulky spectrometers, making them compact and portable devices.

[0006] In addition, tunable filter type spectrometers usually use liquid crystal as the tunable material. However, due to the limitations of the liquid crystal material itself, the tunable range is not wide enough and the colors are not pure enough, thus limiting the spatial resolution of the spectrometer. Summary of the Invention

[0007] This invention addresses the problems of insufficient tunability, complex and bulky structure, and low purity of filtered light color in current tunable filters by proposing a visible light dynamically tunable high spectral resolution filter structure based on a dielectric elastomer.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] Visible light dynamically tunable high spectral resolution filter based on dielectric elastomer includes a quartz substrate, a one-dimensional photonic crystal, a defect layer, a bandpass layer, and an ITO layer.

[0010] The quartz substrate is located at the bottom layer; two axisymmetric one-dimensional photonic crystals are located on the upper layer of the quartz substrate, with the axis of symmetry being the defect layer between the two one-dimensional photonic crystals; the bandpass layer is located at the top layer; and the ITO layer is symmetrically attached to both sides of the two one-dimensional photonic crystals.

[0011] The one-dimensional photonic crystal structure is [BA]. n C[AB] n , where n represents the number of photonic crystal periods on both sides of the defect layer, and n is 3; the materials that make up the photonic crystal [AB] are a high refractive index material layer and a low refractive index material layer, respectively, and C represents the defect layer.

[0012] Preferably, the defect layer C is made of a dielectric elastomer with a thickness of 120 nm.

[0013] Preferably, the substrate is made of quartz.

[0014] Preferably, the bandpass layer is formed by alternating layers of dielectric materials TiO2 and SiO2 four times, wherein the thickness d1 of TiO2 is 96 nm and the thickness d2 of SiO2 is 106 nm.

[0015] Preferably, the high refractive index material A is GaP, and the thickness d4 is 38 nm.

[0016] Preferably, the low refractive index material B is SiO2 with a thickness d3 of 98 nm.

[0017] Preferably, the ITO layer material is indium tin oxide with a thickness of 120 nm.

[0018] The present invention has the following beneficial effects:

[0019] A dynamically tunable high spectral resolution filter for the visible light band is fabricated by combining the electrically controlled deformation properties of dielectric elastomer (DE) materials with photonic crystals. It has a simple structure, high peak transmittance and narrow band spectrum, wide tunability range, high color purity, and fast wavelength tuning. It has promising applications in spectral imaging, optical detection, optical measurement, and biomedicine. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the filter in the embodiment;

[0021] Figure 2 The transmission diagrams are shown in the examples under TE and TM polarized light incident light.

[0022] Figure 3 The diagram shows the transmission spectrum as a function of DE in the example. Detailed Implementation

[0023] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0024] like Figure 1 As shown, the visible light dynamically tunable hyperspectral resolution filter based on dielectric elastomer includes a substrate 1, a finite one-dimensional photonic crystal 2 composed of two different non-metallic dielectric materials arranged in a periodic alternation, a defect layer 3, a bandpass layer 4, and a semiconductor transparent conductive film ITO layer 5.

[0025] The quartz substrate 1 is located at the bottom layer; two axisymmetric one-dimensional photonic crystals 2 are located on the upper layer of the quartz substrate 1, with the axis of symmetry being the defect layer 3 between the two one-dimensional photonic crystals; the bandpass layer 4 is located at the top layer; and the ITO layer 5 is symmetrically attached to both sides of the two one-dimensional photonic crystals.

[0026] Specifically, the one-dimensional photonic crystal structure is [BA]. n C[AB] n , where n represents the number of photonic crystal periods on both sides of the defect layer, and n is 3; C represents the defect layer; the materials A and B that make up the photonic crystal [AB] are GaP, a high-refractive-index material, and SiO2, a low-refractive-index material, respectively, with thicknesses of 38 nm and 98 nm.

[0027] The material of defect layer 3 is dielectric elastomer DE, with a thickness of 120 nm.

[0028] The substrate material is quartz; the bandpass layer is formed by alternating layers of dielectric materials TiO2 and SiO2 four times, with the thickness d1 of TiO2 being 96 nm and the thickness d2 of SiO2 being 106 nm.

[0029] The ITO layer material is indium tin oxide, and the thickness is 120 nm.

[0030] By applying a voltage to the indium tin oxide (ITO) semiconductor transparent conductive film layers on both sides of the filter, a dielectric elastomer (DE) material is driven, thereby shifting the center wavelength to a longer wavelength band.

[0031] When light is incident on a filter, it is blocked and reflected by the large complete photonic bandgap. Only defect modes formed by defect states with high quality factors due to the defect layer can allow waves of a specific frequency to pass through the photonic bandgap. The smaller the frequency range of the defect modes, the narrower the transmission peak. In addition, by matching the bandgap layer formed by the bandpass layer and the photonic crystal, peaks outside the desired wavelength range can be suppressed, thereby effectively improving the color purity of the filtered light.

[0032] Example:

[0033] When light is incident perpendicularly, for the filter structure described above, under this incident condition, the polarization state of the incident light is changed. The result is as follows: Figure 2 As shown in the figure, the transmission spectrum of this invention under TE and TM polarized light incident at 609 nm is a simulated diagram. It can be seen from the figure that the transmission spectrum characteristic curve does not change when the polarization state of the incident light is changed, indicating that this structure is polarization-independent.

[0034] By applying different voltages to the dielectric elastomer (DE) in the filter through the transparent electrode ITO layer, the dielectric elastomer can undergo longitudinal deformation, thereby changing the center wavelength of the filter and achieving a dynamically tunable effect. Figure 3 As shown, a dynamic tunable range of 450nm-650nm can be achieved.

[0035] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A visible light dynamically tunable high spectral resolution filter based on a dielectric elastomer, characterized in that, It includes a quartz substrate, a one-dimensional photonic crystal, a defect layer, a bandpass layer, and an ITO layer; the quartz substrate is located at the bottom layer; two axisymmetric one-dimensional photonic crystals are located on the upper layer of the quartz substrate, with the axis of symmetry being the defect layer between the two one-dimensional photonic crystals; the bandpass layer is located at the top layer; and the ITO layer is symmetrically attached to both sides of the two one-dimensional photonic crystals.

2. The visible light dynamically tunable high spectral resolution filter based on a dielectric elastomer according to claim 1, characterized in that, The one-dimensional photonic crystal structure is [BA]. n C[AB] n , where n represents the number of photonic crystal periods on both sides of the defect layer, and n is 3; the materials that make up the photonic crystal [AB] are a high refractive index material layer and a low refractive index material layer, respectively, and C represents the defect layer.

3. The visible light dynamically tunable high spectral resolution filter based on a dielectric elastomer according to claim 2, characterized in that, The defect layer C is made of a dielectric elastomer with a thickness of 120 nm.

4. The visible light dynamically tunable high spectral resolution filter based on a dielectric elastomer according to claim 3, characterized in that, The bandpass layer is formed by alternating layers of dielectric materials TiO2 and SiO2 four times, wherein the thickness d1 of TiO2 is 96 nm and the thickness d2 of SiO2 is 106 nm.

5. The visible light dynamically tunable high spectral resolution filter based on a dielectric elastomer according to claim 4, characterized in that, The high refractive index material A is GaP, and its thickness d4 is 38 nm.

6. The visible light dynamically tunable high spectral resolution filter based on a dielectric elastomer according to claim 5, characterized in that, The low-refractive-index material B is SiO2, and its thickness d3 is 98 nm.

7. The visible light dynamically tunable high spectral resolution filter based on a dielectric elastomer according to claim 6, characterized in that, The ITO layer material is indium tin oxide, and the thickness is 120 nm.

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