Weak light spectroscopy device and spectrometer

Abstract

The present application belongs to the field of spectral equipment, and provides a weak light spectrum measuring device and a spectrometer, which comprises a substrate and at least two detection units arranged on the upper surface of the substrate, one detection unit comprising a light modulation micro-nano structure unit and a superconducting nanowire single-photon detector unit. The light modulation micro-nano structure unit can realize certain modulation effect on the spectrum of incident light, and the superconducting nanowire single-photon detector unit is used for detecting the modulated photons or itself also serves as a light modulation structure together with the existing light modulation micro-nano structure unit to generate spectral modulation effect on the photons and detect the photons, so that each detection unit has the characteristics of wide spectrum detection, the spectrum can be measured by using the method of calculating spectrum reconstruction, and the utilization rate of photons is greatly improved. The resonance effect of the light modulation micro-nano structure itself also has the effect of enhancing the detection efficiency of the superconducting nanowire single-photon detector, and shortening the measurement time.

Description

Technical Field

[0001] This invention relates to the field of spectroscopic equipment technology, and in particular to a weak light spectral measurement device and a spectrometer. Background Technology

[0002] As a commonly used optical information sensing technology, spectral measurement has been widely applied in various technical fields after years of development. Single-photon level weak light spectral measurement has important applications in scientific research, environmental monitoring, and remote sensing. However, current methods for weak light spectral measurement generally rely on tunable narrowband filters, such as monochromators, in conjunction with single-photon detectors. Spectral measurement is achieved by scanning different wavelengths point-by-point and measuring the photon count rate corresponding to each wavelength. During the measurement process, photons outside the filter passband cannot be detected, resulting in low photon utilization, long measurement time, and difficulty in integrating device functions, severely limiting the practical application of this technology. Summary of the Invention

[0003] This invention provides a weak light spectral measurement device and spectrometer to solve the defects of low photon utilization and long measurement time when using an adjustable narrowband filter with a single photon detector for weak light spectral measurement in the prior art, thereby achieving the effect of improving photon utilization and shortening measurement time.

[0004] This invention provides a weak light spectral measurement device, comprising a substrate and at least two detection units disposed on the upper surface of the substrate, wherein each detection unit comprises: a light modulation micro / nano structure unit, including a base plate and a plurality of modulation holes disposed on the base plate, the plurality of modulation holes being arranged in a two-dimensional pattern structure; and a superconducting nanowire single-photon detector unit, including at least one superconducting nanowire, the superconducting nanowire being arranged in a two-dimensional pattern structure, and the longitudinal projection of the superconducting nanowire being interspersed between the plurality of modulation holes.

[0005] According to the present invention, a weak light spectral measurement device includes a plurality of detection units comprising modulation apertures with at least two structural parameters, and / or, modulation apertures with at least two two-dimensional patterned structures, and / or, superconducting nanowires with at least two two-dimensional patterned structures.

[0006] According to the present invention, a weak light spectral measurement device is provided, wherein the base plate is located on the upper surface of the substrate, and the superconducting nanowire single-photon detector unit is disposed on the upper surface of the base plate.

[0007] According to a weak light spectral measurement device provided by the present invention, a buffer layer is provided between the base plate and the superconducting nanowire single-photon detector unit, and one of the base plate and the superconducting nanowire single-photon detector unit is located on the lower surface of the buffer layer, and the other is located on the upper surface of the buffer layer.

[0008] According to a weak light spectral measurement device provided by the present invention, when the base plate is located on the lower surface of the buffer layer, the bottom of the buffer layer is filled with the modulation hole.

[0009] According to a weak light spectral measurement device provided by the present invention, when the superconducting nanowire single-photon detector unit is located on the lower surface of the buffer layer, the bottom of the buffer layer is filled with the gaps between the superconducting nanowires.

[0010] According to the present invention, in a weak light spectral measurement device, the buffer layer is made of a low refractive index material.

[0011] According to the present invention, a weak light spectral measurement device is provided, wherein the substrate is made of silicon, germanium, germanium-silicon material, silicon compound, germanium compound, metal or III-V group material, wherein the silicon compound includes silicon nitride, silicon dioxide or silicon carbide.

[0012] According to the present invention, a weak light spectral measurement device is provided, wherein the superconducting nanowire is made of niobium nitride, niobium titanium nitride, tungsten silicon, molybdenum silicon, or magnesium diboride.

[0013] The present invention also provides a spectrometer, including a weak light spectral measurement device as described in any of the above claims.

[0014] The weak light spectral measurement device provided by this invention includes a substrate and at least two detection units disposed on the upper surface of the substrate. Each detection unit includes a light modulation micro / nanostructure unit and a superconducting nanowire single-photon detector unit. The light modulation micro / nanostructure unit can modulate the incident light spectrum. The superconducting nanowire single-photon detector unit is used to detect photons after being modulated by the light modulation micro / nanostructure unit, or it can also act as a light modulation structure itself, working together with the existing light modulation micro / nanostructure unit to modulate the spectrum of photons and detect them. This allows each detection unit to have a wide-spectrum detection characteristic. Compared with the traditional scheme of using a narrowband filter with a single-photon detector, the weak light spectral measurement device provided by this invention can use a computational spectral reconstruction method to measure the spectrum, greatly improving photon utilization. Furthermore, the resonant effect of the light modulation micro / nanostructure itself also enhances the detection efficiency of the superconducting nanowire single-photon detector, shortening the measurement time.

[0015] Furthermore, the present invention also provides a spectrometer that, due to having the weak light spectral measurement device described above, has the same advantages as described above. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is an exploded view of the weak light spectral measurement device with the superconducting nanowire single-photon detector unit provided by the present invention mounted on the upper surface of the substrate.

[0018] Figure 2 This is a cross-sectional view of the weak light spectral measurement device provided by the present invention, which is a superconducting nanowire single-photon detector unit disposed on the upper surface of a base plate.

[0019] Figure 3 This is an exploded view of the weak light spectral measurement device provided by the present invention, in which the base plate is set at the bottom of the buffer layer and the superconducting nanowire single-photon detector unit is set at the top of the buffer layer.

[0020] Figure 4 This is a cross-sectional view of the weak light spectral measurement device provided by the present invention, in which the base plate is set at the bottom of the buffer layer and the superconducting nanowire single-photon detector unit is set at the top of the buffer layer.

[0021] Figure 5 This is an exploded view of the weak light spectral measurement device provided by the present invention, in which the base plate is set on the top of the buffer layer and the superconducting nanowire single-photon detector unit is set at the bottom of the buffer layer.

[0022] Figure 6 This is a cross-sectional view of the weak light spectral measurement device provided by the present invention, in which the base plate is set on the top of the buffer layer and the superconducting nanowire single-photon detector unit is set at the bottom of the buffer layer.

[0023] Figure label:

[0024] 100: Substrate;

[0025] 200: Detection unit; 200a: First detection unit; 200b: Second detection unit;

[0026] 200c: Third detection unit; 200d: Fourth detection unit; 210: Optical modulation micro / nano structure unit;

[0027] 211: Base plate; 212: Modulation aperture; 220: Superconducting nanowire single-photon detector unit;

[0028] 221: Superconducting nanowires;

[0029] 300: Buffer layer. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0031] The following is combined Figures 1 to 6 The present invention describes a weak light spectral measurement device.

[0032] This invention provides a weak light spectral measurement device, comprising a substrate 100 and a detection unit 200, wherein at least two detection units 200 are provided, and both are disposed on the upper surface of the substrate 100. Each detection unit 200 includes a light modulation micro / nano structure unit 210 and a superconducting nanowire single-photon detector unit 220.

[0033] The optical modulation micro / nano structure unit 210 includes a substrate 211 and multiple modulation holes 212. These modulation holes 212 are etched onto the substrate 211 and distributed according to a specific pattern, forming a one-dimensional or two-dimensional patterned structure. The multiple modulation holes 212 modulate the spectrum of the incident light, including but not limited to light scattering, absorption, diffraction, reflection, interference, surface plasmon resonance, and other effects. Simultaneously, the resonance effect of the optical modulation micro / nano structure unit 210 can enhance the absorption efficiency of the superconducting nanowire 221 at certain wavelengths, shortening the measurement time.

[0034] The superconducting nanowire single-photon detector unit 220 includes at least one superconducting nanowire 221, which is also a micro / nano-scale structure, corresponding to the aforementioned optical modulation micro / nano-structure unit 210. The superconducting nanowire 221 can extend into various shapes, forming one-dimensional or two-dimensional patterned structures. In the longitudinal projection view of the detector unit 200, the projection of the two-dimensional patterned structure formed by the superconducting nanowire 221 is interspersed within the gaps between the projections of the multiple modulation holes 212. The superconducting nanowire single-photon detector unit 220 is used to detect photons modulated by the optical modulation micro / nano-structure unit 210, or the superconducting nanowire single-photon detector unit 220 itself also serves as an optical modulation structure, working together with the existing optical modulation micro / nano-structure unit 210 to spectrally modulate photons and detect them.

[0035] In summary, a light-modulated micro / nano structure unit 210 and a superconducting nanowire single-photon detector unit 220 constitute a detector unit 200. Each detector unit 200 possesses broad-spectrum detection characteristics. Compared to the traditional scheme of using a narrowband filter with a single-photon detector, the weak light spectral measurement device provided by this invention can measure the spectrum using a computational spectral reconstruction method, greatly improving photon utilization. Furthermore, the resonant effect of the light-modulated micro / nano structure itself also enhances the detection efficiency of the superconducting nanowire single-photon detector, shortening the measurement time.

[0036] In one embodiment of the present invention, the plurality of detection units 200 described above include at least two types of detection units 200 with different structural parameters. The structural parameters can be the cross-sectional shape or size of the modulation aperture 212, or the arrangement of the two-dimensional patterned structure of the modulation aperture 212, or the arrangement of the two-dimensional patterned structure formed by the superconducting nanowires 221. Some exemplary specific structural parameters will be described in the following embodiments, and will not be detailed here.

[0037] A light-modulated micro / nano structure unit 210 and a superconducting nanowire single-photon detector unit 220 constitute a detector unit 200. By utilizing the principle of reconstructive spectral measurement and by using light-modulated micro / nano structure units 210 with different structural parameters to achieve differentiated superconducting nanowire single-photon detector spectral responses, high-accuracy spectral reconstruction is achieved.

[0038] In one embodiment of the present invention, both the modulation aperture 212 and the superconducting nanowire 221 can be disposed on the base plate 211, which is disposed on the substrate 100. See also Figure 1 Four detection units 200 can be set on a base plate 211, which can be the first detection unit 200a, the second detection unit 200b, the third detection unit 200c and the fourth detection unit 220d respectively.

[0039] The first detection unit 200a can be located in the lower left quarter of the base plate 211. The modulation aperture 212 can have a rectangular cross-section and be arranged in a horizontal and vertical array. A superconducting nanowire 221 extending vertically is set on the left side of the left column of modulation apertures 212, the right side of the right column of modulation apertures 212, and between two adjacent columns of modulation apertures 212. Adjacent superconducting nanowires 221 are connected end to end by connecting lines. After connection, multiple superconducting nanowires 221 extend into a serpentine structure and are interspersed between multiple columns of modulation apertures 212.

[0040] The second detection unit 200b can be located in the upper left quarter of the base plate 211. The modulation apertures 212 can have a circular cross-section and are arranged in a horizontal and vertical array. The superconducting nanowires 221 first pass around a modulation aperture 212 in the lower right corner, then around three modulation apertures 212 surrounding that modulation aperture 212, then around five adjacent modulation apertures 212, and finally around the seven outermost modulation apertures 212. The superconducting nanowires 221 form a serpentine structure, interlacing between multiple modulation apertures 212.

[0041] The third detection unit 200c can be set in the upper right quarter of the base plate 211. The cross-sectional shape of the modulation hole 212 of the third detection unit 200c is different from that of the first detection unit 200a. It is set as a circular structure, and the distribution of the superconducting nanowires 221 is rotated by ninety degrees relative to the superconducting nanowires 221 in the first detection unit 200a.

[0042] The fourth detection unit 220d can be located in the lower right quarter of the base plate 211. The modulation aperture 212 has a circular cross-section, and multiple modulation apertures 212 are arranged in a ring, with four modulation apertures 212 in the inner ring and ten modulation apertures 212 in the outer ring. Superconducting nanowires 221 are respectively arranged between the inner and outer rings, and on the outer side of the outer ring, all of which are ring-shaped superconducting nanowires 221. Two vertical superconducting nanowires 221 are arranged between the four modulation apertures 212 in the inner ring, and four horizontal superconducting nanowires 221 are arranged between the ten modulation apertures 212 in the outer ring, forming... Figure 1 The structure shown.

[0043] The cross-sectional shape of the modulation aperture 212, the number of modulation apertures 212, the size of the modulation apertures 212, the distribution of the modulation apertures 212, and the distribution of the superconducting nanowires 221 in the various detection units 200 described above are merely exemplary and do not limit the scope of protection of the present invention. For example, the cross-sectional shape of the modulation aperture 212 is not limited to circular, rectangular, or other shapes, but can also be any other achievable shape such as regular polygons or ellipses.

[0044] See Figure 2As can be seen, the base plate 211 is disposed on the upper surface of the substrate 100, and the superconducting nanowire 221 is directly disposed on the upper surface of the base plate 211.

[0045] In another embodiment of the present invention, a buffer layer 300 may be provided between the aforementioned base plate 211 and the superconducting nanowire single-photon detector unit 220, which can be said to include four layers. Taking one detector unit 200 as an example, see [link to documentation]. Figure 3 and Figure 4 From top to bottom, they can be identified as superconducting nanowire single-photon detector unit 220, buffer layer 300, base plate 211, and substrate 100.

[0046] See Figure 3 The superconducting nanowires 221 can have the same distribution as the superconducting nanowires 221 in the first detection unit 200a described above. The modulation holes 212 can be various shapes such as circular, rectangular, and elliptical, and can be arranged in an array. As long as it is observed in the longitudinal projection, the projection of the superconducting nanowires 221 is interspersed in the gaps between the projections of the multiple modulation holes 212.

[0047] The optical modulation micro / nanostructure unit 210 shown in this embodiment can be any micro / nanostructure with optical modulation function. For a detection unit 200, the optical modulation micro / nanostructure unit 210 has different reflectivities for photons of different wavelengths. The reflected photons are detected by the superconducting nanowire single-photon detector unit 220 above. Different detector units 200 will have different spectral responses, thereby realizing reconstructive spectral measurement. Furthermore, due to the buffer layer 300, the optical modulation micro / nanostructure unit 210 and the superconducting nanowire single-photon detector unit 220 can form an optical resonant cavity, further enhancing the detection efficiency of the superconducting nanowire single-photon detector unit 220.

[0048] In this embodiment, the buffer layer 300 is made of a low-refractive-index material, such as silicon dioxide or a polymer. See also... Figure 4 The bottom of the buffer layer 300 matches the base plate 211, and the bottom surface of the buffer layer 300 is in contact with the upper surface of the base plate 211 at the corresponding position. The bottom of the buffer layer 300 extends downward and fills each modulation hole 212 at the position corresponding to the modulation hole 212 of the base plate 211. In this way, the difference in refractive index between the buffer layer 300 and air can prevent it from affecting the modulation of the light modulation micro / nano structure unit 210.

[0049] In another embodiment of the invention, see Figure 5 and Figure 6 Taking a detection unit 200 as an example, from top to bottom it can be a base plate 211, a buffer layer 300, a superconducting nanowire single-photon detector unit 220 and a substrate 100.

[0050] See Figure 5 The superconducting nanowires 221 can have the same distribution as the superconducting nanowires 221 in the first detection unit 200a described above. The modulation holes 212 can be various shapes such as circular, rectangular, and elliptical, and can be arranged in an array. As long as it is observed in the longitudinal projection, the projection of the superconducting nanowires 221 is interspersed in the gaps between the projections of the multiple modulation holes 212.

[0051] The optical modulation micro / nanostructure unit 210 shown in this embodiment can be any micro / nanostructure with optical modulation function. For a detection unit 200, the optical modulation micro / nanostructure unit 210 has different transmittances for photons of different wavelengths. The transmitted photons are detected by the superconducting nanowire single-photon detector unit 220 below, and different detector units 200 will have different spectral responses, thereby realizing reconstructive spectral measurement. Furthermore, due to the buffer layer 300, the optical modulation micro / nanostructure unit 210 and the superconducting nanowire single-photon detector unit 220 can form an optical resonant cavity, further enhancing the detection efficiency of the superconducting nanowire single-photon detector unit 220.

[0052] In this embodiment, the buffer layer 300 is made of a low-refractive-index material, such as silicon dioxide or a polymer. See also... Figure 6 The bottom of the buffer layer 300 is attached to the upper surface of the substrate 100 on which the superconducting nanowires 221 are disposed. The bottom of the buffer layer 300 wraps around the outside of the superconducting nanowires 221. The bottom of the buffer layer 300 is attached to the substrate 100, and the bottom of the buffer layer 300 fills the gap between two adjacent superconducting nanowires 221. This can prevent the difference in refractive index between the buffer layer 300 and air from affecting the absorption of photons by the superconducting nanowires 221.

[0053] The weak light spectral measurement device provided by this invention includes, but is not limited to, one-dimensional and two-dimensional photonic crystals, surface plasmon resonances, metamaterials, and metasurfaces. Specific materials may include silicon, germanium, germanium-silicon materials, silicon compounds, germanium compounds, metals, and III-V group materials. Silicon compounds include, but are not limited to, silicon nitride, silicon dioxide, and silicon carbide.

[0054] The material of the superconducting nanowire single-photon detector unit 220 can be any material suitable for fabricating superconducting nanowire single-photon detectors, such as niobium nitride, niobium titanium nitride, etc.

[0055] The present invention also provides a spectrometer that includes the weak light spectral measurement device described above, and therefore also has the same advantages as described above.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A weak light spectral measurement device, characterized in that, The device includes a substrate and at least two detection units disposed on the upper surface of the substrate, wherein each detection unit includes: The optical modulation micro / nano structure unit includes a base plate and a plurality of modulation holes disposed on the base plate, wherein the plurality of modulation holes are arranged in a two-dimensional pattern structure; A superconducting nanowire single-photon detector unit includes at least one superconducting nanowire, which is arranged in a two-dimensional pattern structure, and the longitudinal projection of the superconducting nanowire is interspersed between multiple modulation holes. The plurality of the detection units include modulation apertures with at least two structural parameters, and / or, modulation apertures with at least two two-dimensional patterned structures, and / or, superconducting nanowires with at least two two-dimensional patterned structures. The base plate is located on the upper surface of the substrate, and the superconducting nanowire single-photon detector unit is disposed on the upper surface of the base plate; A buffer layer is provided between the base plate and the superconducting nanowire single-photon detector unit, and one of the base plate and the superconducting nanowire single-photon detector unit is located on the lower surface of the buffer layer, while the other is located on the upper surface of the buffer layer.

2. The weak light spectral measurement device according to claim 1, characterized in that, When the base plate is located on the lower surface of the buffer layer, the bottom of the buffer layer is filled with the modulation hole.

3. The weak light spectral measurement device according to claim 1, characterized in that, When the superconducting nanowire single-photon detector unit is located on the lower surface of the buffer layer, the bottom of the buffer layer is filled with the gaps between the superconducting nanowires.

4. The weak light spectral measurement device according to any one of claims 1 to 3, characterized in that, The buffer layer is made of a low refractive index material.

5. The weak light spectral measurement device according to claim 1, characterized in that, The base plate is made of silicon, germanium, germanium-silicon materials, silicon compounds, germanium compounds, metals, or group III-V materials, wherein silicon compounds include silicon nitride, silicon dioxide, or silicon carbide.

6. The weak light spectral measurement device according to claim 1, characterized in that, The superconducting nanowires are made of materials including niobium nitride, niobium titanium nitride, tungsten silicon, molybdenum silicon, or magnesium diboride.

7. A spectrometer, characterized in that, Including the weak light spectral measurement device as described in any one of claims 1 to 6.

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