Circular dichroism measurement device, circular dichroism measurement method, and program

Abstract

To provide a circular dichroism measuring device, a circular dichroism measuring method, and a program capable of evaluating the chirality of a small amount of a target sample easily with high sensitivity.SOLUTION: A CD spectrometer 100 includes: a Topological PhC 50 having first photonic structures 51, 53 and a second photonic structure 52 different in topology, and topological edges 54, 55 expressing a topological edge state capable of propagating an optical vortex at an interface of a boundary between the first photonic structures 51, 53 and the second photonic structure 52; and a Spectrometer 4 dropping a sample 10 on the topological edges and measuring the propagation of the optical vortex on the topological edges in a single direction depending on an optical spin state.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a circular dichroism measurement device, a circular dichroism measurement method, and a program that utilize topological photonics. [Background technology]

[0002] Many biomolecules, such as proteins and DNA, have mirror image asymmetry, or chirality, and therefore, evaluation of chirality is an important issue from the perspectives of drug discovery and biocompatible materials. Chiral molecules exhibit different refractive indices and absorption characteristics for left-handed and right-handed circularly polarized light. The different refractive indices are indicated by optical rotational dispersion (ORD), and the different absorption characteristics are indicated by circular dichroism (CD). Measuring optical rotational dispersion (ORD) or circular dichroism (CD) allows for the characterization and identification of each molecule. Circular polarization occurs when the phases of orthogonal electric field vectors are shifted by a quarter wavelength, and there are left-handed circularly polarized light (El) and right-handed circularly polarized light (Er).

[0003] Figure 14 is a diagram explaining optical rotatory dispersion (ORD) and angle of rotation (α). The left diagram of Figure 14 shows circularly polarized light (solid circle) and incident light (solid thick arrow) before passing through an optically active substance, and the left diagram of Figure 14 shows circularly polarized light (solid circle) and transmitted light (solid thick arrow) after passing through an optically active substance. In Figure 14, linearly polarized light in the Y-axis direction that rotates to the left is called left-handed, and linearly polarized light that rotates to the right is called dextrorotatory. Here, the rotation angle α indicates the angle of rotation, and + or - indicates the direction of rotation. Optically active substances are substances that have mirror-image isomers. They have the property of rotating the plane of polarization of linearly polarized light, known as optical rotation (OR), and the wavelength dependence of this property is called optical rotatory dispersion (ORD).

[0004] FIG. 15 is a diagram illustrating circular dichroism (CD). Circular dichroism (CD) is a phenomenon in which a difference in absorbance occurs between left-handed circularly polarized light (El) and right-handed circularly polarized light (Er) in the absorption wavelength range of an optically active substance when the substance absorbs circularly polarized light. Circular polarization occurs when the phases of orthogonal wave vectors (electric field vectors) are shifted by a quarter wavelength. Elliptical polarization is expressed as the sum of El and Er when their intensities are different.

[0005] CD measurement detects the difference in absorption between left and right circularly polarized light by passing them through an optically active sample. The transmitted light becomes circularly polarized due to the difference in absorption between the left and right circularly polarized light, and this phenomenon of unequal absorption is called circular dichroism (CD) and is expressed by the ellipticity θ. As structural analysis tools using circular dichroism (CD), CD spectrometer and CD luminescence have been put to practical use. The CD spectrometer measures the asymmetry of light absorption for left-handed and right-handed circularly polarized light. CD luminescence measures the circular polarization asymmetry in fluorescence emission. Circular dichroism (CD) has been established as a powerful research tool for structural analysis of biomolecules, including the a-helical structure, which is a typical chiral structure of proteins.

[0006] Patent documents 1 and 2 describe a circular dichroism measurement device that periodically generates left-handed and right-handed circularly polarized light using a photoelastic modulator or the like, irradiates the light onto a sample, and detects the intensity of the light transmitted through the sample in synchronization with the modulation frequency.

[0007] Patent Document 3 describes a circular dichroism fluorescence microscope that irradiates a specimen with left-handed circularly polarized light and detects fluorescence emitted from the specimen.

[0008] Patent Document 4 describes optical phase modulators such as photoelastic modulators and Pockels cells as circular polarization modulators that generate circularly polarized light. It is known that the modulation of circular polarization modulators contains distortion components. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-13064 [Patent Document 2] International Publication No. 2006 / 085606 [Patent Document 3] International Publication No. 2007 / 088947 [Patent Document 4] Patent No. 3341928 Summary of the Invention [Problem to be solved by the invention]

[0010] However, such conventional circular dichroism measurement devices have the following problems with both CD spectrometers and CD luminescence.

[0011] Issues with conventional CD spectrometers (1) A relatively large amount of sample is required. (2) Measurement accuracy cannot be guaranteed for heterogeneous samples with low optical transparency, such as living tissues and cells, i.e., samples with strong optical scattering. (3) Using conventional measurement equipment, it is difficult to analyze local regions within cells or tissues or the spatial distribution of chirality.

[0012] Issues with conventional CD luminescence Although it is possible to directly measure the chirality of molecules locally under a microscope, the sensitivity is poor.

[0013] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a circular dichroism measurement device, a circular dichroism measurement method, and a program that can evaluate the chirality of a small amount of target sample with high sensitivity and ease. [Means for solving the problem]

[0014] In order to solve the above-mentioned problems, the circular dichroism measurement device of the present invention is a circular dichroism measurement device that measures the chirality of a sample using circular dichroism, and is characterized by comprising: a topological photonic crystal having a first photonic structure and a second photonic structure with different topologies, and a topological edge that exhibits a topological edge state in which an optical vortex can propagate at the interface between the first photonic structure and the second photonic structure, and a measurement unit that drops a sample onto the topological edge and measures that the optical vortex of the topological edge propagates in a single direction depending on the optical spin state. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a circular dichroism measurement device, a circular dichroism measurement method, and a program that can easily evaluate the chirality of a small amount of target sample with high sensitivity. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram illustrating the structure of a topological edge (topological edge state waveguide) used in a circular dichroism measurement device of the present invention. [Figure 2] FIG. 2 is a Brillouin zone diagram showing the structure of a nanohole having C6v symmetry in the circular dichroism measurement device of the present invention. [Figure 3] FIG. 1 is a plan view showing the configuration of a circular dichroism measurement device according to a first embodiment of the present invention. [Figure 4] FIG. 1 is a diagram showing the device structure of a Si photonics chip in a circular dichroism measurement device according to a first embodiment of the present invention. [Figure 5] FIG. 1 is a plan view showing a circular dichroism measurement device according to a first embodiment of the present invention. [Figure 6] FIG. 10 is a diagram showing the device structure of a Si photonics chip in a circular dichroism measurement device according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing a propagation mode distribution of the topological transmission line of the element structure shown in FIG. 6. [Figure 8] FIG. 10 is a plan view showing the structure of a circular dichroism measurement device according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a diagram showing the device structure of a Si photonics chip in a circular dichroism measurement device according to a second embodiment of the present invention. [Figure 10] 1 is a diagram showing an outline of a circular dichroism measurement device of the present invention. FIG. [Figure 11] 1 is a diagram showing an outline of a circular dichroism measurement device of the present invention. FIG. [Figure 12] FIG. 12 is a diagram illustrating a circular dichroism measurement process performed by the circular dichroism measurement apparatus of FIG. 11. [Figure 13] FIG. 1 is a hardware configuration diagram illustrating an example of a computer that realizes the functions of the circular dichroism measurement device according to each embodiment of the present invention. [Figure 14] FIG. 1 is a diagram illustrating optical rotatory dispersion (ORD) and angle of rotation (α). [Figure 15] FIG. 1 is a diagram illustrating circular dichroism (CD). DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (Explanation of the principle) Attempts to trace the topology of electron systems in topological insulators and Weyl semimetals to photon systems are called topological photonics and have been making rapid progress in recent years. Topological insulators are materials that are insulating with an energy gap in the bulk, but have gapless metallic states at their edges (edges in two-dimensional systems, surfaces in three-dimensional systems).

[0018] In particular, the honeycomb lattice arrangement of the dielectric 6vThe emergence of Z2 topology (a class in the classification of topological structures possessed by electronic wave functions) in structures obtained by applying deformations with symmetry (symmetry that overlaps when rotated by 60°) makes it possible to realize topological edge states capable of transmitting optical vortices.

[0019] Topological photonics is an attempt to trace the topological concept of electronic systems to photon systems, and in particular, to explore the "dielectric arrangement" of dielectrics in a honeycomb lattice arrangement. 6v By changing the topology while maintaining symmetry, it is possible to create two types of photonic crystals (PhCs) with different topologies.

[0020] There are two types of photonic crystals (PhCs): Trivial Photonic Crystals and Topological Photonic Crystals. A trivial photonic crystal is a "trivial" (ordinary) photonic structure whose bulk is an insulator with an energy gap, while a topological photonic crystal is a photonic structure whose interior is an insulator with an energy gap but whose edges are in a bandgapless metallic state.

[0021] It is known that optical vortex modes propagate at the interface between these two photonic crystals (PhCs) (topological transmission line), making this a promising method for controlling optical vortices within optical circuits.

[0022] <Topological Edge Design> FIG. 1 is a diagram illustrating the structure of a topological edge (topological edge state waveguide) 20 used in a circular dichroism measurement apparatus according to a first embodiment of the present invention (Si-based topological edge state waveguide used in simulation). As shown in Figure 1, the topological edge 20 has a photonic structure (Trivial photonic structure) 11 whose bulk is an insulator with an energy gap, a topological photonic structure (Topological photonic structure) 12 whose interior is an insulator with an energy gap and whose edge is in a gapless metallic state, and a topological edge (Topological edge) 13 that exhibits a topological edge state in which optical vortex propagation is possible at the boundary between the photonic structure 11 and the topological photonic structure 12.

[0023] <Photonic Structure> Photonic Structure (Trivial PhC) 11 is C 6v The structure is such that first dielectrics 111 having symmetry are arranged in a triangular lattice pattern (for example, with a period a=800 nm). The topological photonic structure (Topological PhC) 12 is a structure arranged in a triangular lattice shape (for example, with a period a=800 nm).

[0024] The first dielectric 111 is formed on an SOI (Silicon-On-Insulator) wafer by nanometers (nm, 1 nm = 10) arranged in a triangular lattice (period a = 800 nm) unit cell 121. -9 m) Use structure. The second dielectric 112 uses a nanostructure in which cells 122 (unit cells) are arranged in a triangular lattice pattern (period a=800 nm) on an SOI wafer (for example, Si film thickness 220 nm) 131. Nanoholes 111a of first dielectric 111 and nanoholes 112a of second dielectric 112 have different parameters, namely, distance r from the center of honeycomb lattice cells 121, 122 to the center of nanoholes 111a, 112a and length l of one side of the nanohole (described later).

[0025] In a topological photonics system, a topological edge state occurs at the interface between two types of photonic structures where the length of one side of the triangle in the honeycomb dielectric part and the distance from the center of the cell are slightly different, and light propagates through it. Depending on the direction of rotation of the optical vortex, light propagates in only one direction, either left or right. In Figure 1, a topological edge mode is manifested at the topological edge 13 at the boundary between photonic structure 11 and topological photonic structure 12. The optical state (topological edge state) that arises at the interface between the two regions created by the topological photonic structure 12 only allows light with specific polarization and optical vortices, and these specific polarization and optical vortices have propagation direction dependence.

[0026] <C 6v Symmetrical nanohole structure Figure 2 shows the C 6v 1 is a Brillouin Zone diagram (schematic image of a unit cell in the reciprocal space) showing the structure of a symmetric nanohole. Take the nanohole 111a in the first dielectric 111 of the photonic structure 11 as an example. The nanohole 112a in the second dielectric 112 of the topological photonic structure 12 also has a similar structure. As shown in the right diagram of Figure 2, the center of the honeycomb lattice cell 121 is taken as the Γ point, which is the center (origin) of the Brillouin zone. The highly symmetrical points of the Brillouin zone are point M (the center of a rectangular surface), point K (the center of an edge connecting two rectangular surfaces), point A (the center of a hexagonal surface), point H (an end point), and point L (the center of an edge connecting a hexagonal surface and a rectangular surface).

[0027] As shown in the left diagram of FIG. 2, the Si film 133 is made up of honeycomb lattice cells 121 and C 6vSymmetrical nanoholes 111a are formed. A photonic structure consisting of the remaining Si film 133 and the nanoholes 111a opened in the Si film 133 forms the first dielectric 111 of the photonic structure 11. The left diagram in Fig. 2 is a diagram of the cell 121 of the photonic structure 11 viewed obliquely from above in front of the top surface, with the SiO2 insulating film 132 below the opened nanoholes 111a exposed. 2, the parameters of the nanohole 111a are the distance r from the center of a cell 121 (Γ point) of the honeycomb lattice to the center of the nanohole 111a and the length l of one side of the nanohole 111a. The central angle between the cells 121 of adjacent nanoholes 111a is π / 3. In the case of the nanohole 111a of the photonic structure 11, for example, r=240 nm and l=240 nm. In addition, in the case of the nanohole 112a of the topological photonic structure 12, for example, r=290 nm and l=250 nm. Furthermore, as shown in the left diagram of FIG. 2, the distances a1 and a2 between the centers (Γ points) of adjacent regular hexagonal cells 121 are the same (here, a1=a2=800 nm≡a).

[0028] <Topological Photonics> Topological photonics is a phenomenon in which unidirectional light propagation occurs at the interface between two photonic structures with different topologies, depending on the optical spin state (i.e., whether the light is right- or left-handed circularly polarized). The propagation direction of light propagating at the interface between two photonic structures with different topologies is uniquely determined by the circular polarization: right- or left-handed circular polarization.

[0029] (First embodiment) 3 to 5 are diagrams showing the structure of a circular dichroism measurement device according to a first embodiment of the present invention, Fig. 3 is a plan view showing the configuration of the circular dichroism measurement device according to the first embodiment, as seen from directly above. In topological photonics, unidirectional light propagation occurs at the interface between two photonic structures with different topologies, depending on the optical spin state (i.e., whether the light is left- or right-handed circularly polarized light). The circular dichroism measurement device of this embodiment is an example applied to a CD spectrometer that measures the asymmetry of light absorption for left-handed circularly polarized light.

[0030] [Overall configuration] As shown in FIG. 3, the CD spectrometer 100 (circular dichroism measurement device) includes a Si photonics chip 40, a topological PhC 50 (topological photonic crystal (PhC)) (topological region) having two photonic structures with different topologies arranged on the Si photonics chip 40, and Si waveguides 60 (60a to 60d) (waveguides) that propagate light in the TE mode (transverse electric mode) / TM mode (transverse magnetic mode) in the topological PhC 50.

[0031] The CD spectrometer 100 includes an ASE (Amplified Spontaneous Emission) light source 1 (light source) arranged outside the Si photonics chip 40, a 3 dB coupler 2 (distributor) that distributes light from the ASE light source 1, optical fibers 3 (3 a, 3 b) that transmit light from the 3 dB coupler 2 to input Si waveguides 60 (60 a, 60 b), optical fibers 3 (3 c, 3 d) that transmit light from the output Si waveguides 60 (60 c, 60 d) to a spectrometer 4, and a spectrometer 4 that measures the light from the optical fibers 3 (3 c, 3 d).

[0032] ASE light source 1 consists of a rare-earth doped fiber, a pumping laser diode (LD), an optical filter, and an optical isolator. The rare-earth doped fiber generates spontaneous emission light inside. The optical filter transmits the pumping light and reflects the ASE light. The isolator transmits the light traveling forward and blocks the light traveling backward. ASE light source 1 amplifies and outputs the spontaneous emission light generated within the rare-earth doped optical fiber, making it a high-brightness, broadband, low-coherence light source with excellent output stability. In addition, because ASE light source 1 generates light within the optical fiber, it has the advantage that light from the light source can be input into optical fiber 3 with low loss.

[0033] The 3dB coupler2 is an optical fiber coupler that can multiplex and demultiplex optical signals. The 3dB coupler2 splits the light from the ASE light source1 in half, i.e., the splitting ratio is 1:1. When the splitting ratio is 1:1, the optical power is halved (-3dB), which is why it is called a 3dB coupler.

[0034] Spectrometer 4 measures the electromagnetic spectrum of light. It splits light into wavelengths using a spectroscopic element, and measures the intensity by receiving the light separated by wavelength with a detector.

[0035] The spectrometer 4 drops the sample 10 onto the topological edges 54 and 55, and measures that the optical vortices at the topological edges 54 and 55 propagate in a single direction depending on the optical spin state.

[0036] Spectrometer 4 measures the asymmetry of optical absorption for left-handed circularly polarized light. Spectrometer 4 measures the transmission spectrum propagating through topological edges 54 and 55 by changing the propagation direction.

[0037] The Si photonics chip 40 is a silicon chip of 10 mm x 10 mm. The Si photonics chip 40 has a topological PhC 50 and a Si waveguide 60 that introduces and extracts light to and from the topological edge.

[0038] [Element structure] FIG. 4 is a diagram showing the device structure of a Si photonics chip 40 of a CD spectrometer 100 (circular dichroism measurement device) (a schematic image of a proposed device). As shown in Figures 3 and 4, Topological PhC 50 has first photonic structures 51, 53 of a first topology (see region A in Figure 3), a second photonic structure 52 of a second topology (see region B in Figure 3) that is different from the first topology, a first topological edge 54 that exhibits a topological edge state that allows optical vortex propagation at the interface between the first photonic structure 51 and the second photonic structure 52, and a second topological edge 55 that exhibits a topological edge state that allows optical vortex propagation at the interface between the second photonic structure 52 and the first photonic structure 53.

[0039] The first photonic structures 51, 53 and the second photonic structure 52 may be any combination of photonic structures as long as they are two photonic structures with different topologies. For example, if one of the first photonic structures 51, 53 and the second photonic structure 52 is a trivial photonic structure, the other is a topological photonic structure.

[0040] Any one of the first photonic structures 51, 53 and the second photonic structure 52 is configured as a topological photonic structure. In this case, the topological photonic structure may include a dielectric material having symmetry (see FIG. 2) within the arranged cells.

[0041] In addition, topological photonic structures are 6v The structure may be one in which regular hexagonal unit cells of a dielectric material containing nanoholes having symmetry (see FIG. 2) are arranged in a triangular lattice, or may be a topological structure represented by Z2 topology.

[0042] 3 and 4, the first photonic structures 51 and 53 (see region A in FIG. 3) are topological photonic structures, i.e., topological photonic structures whose interiors are insulators with energy gaps and whose edges are in a gapless metallic state. Also, the second photonic structure 52 (see region B in FIG. 3) is a trivial photonic structure whose bulk is an insulator with an energy gap.

[0043] The first photonic structure 51, the second photonic structure 52, and the first photonic structure 53 each have a rectangular shape of, for example, 10 × 10 μm. In this case, the Topological PhC 50 consisting of the first photonic structure 51, the second photonic structure 52, and the first photonic structure 53 has a rectangular shape of 10 × 30 μm. The total length of the first topological edge 54 and the second topological edge 55 is 10 μm.

[0044] As described above, the Topological PhC 50 is extremely small, measuring 10 × 30 μm, making it difficult to handle the Topological PhC 50 alone (cutting out only the Topological PhC 50). Furthermore, because the Topological PhC 50 is extremely small, it is also difficult to introduce / extract light into / from the first topological edge 54 and the second topological edge 55. Meanwhile, the Si photonics chip 40 is, for example, 10 × 10 mm in size. Therefore, the Topological PhC 50 is placed on the Si photonics chip 40, and the Si photonics chip 40 is used as the object of handling in the CD spectrometer 100 (circular dichroism measurement device).

[0045] In this embodiment, a topological PhC 50 is mounted on a Si photonics chip 40, and a low-loss optical waveguide (Si waveguide 60) is formed in the Si photonics chip 40, and the input and output sides of the first topological edge 54 and the second topological edge 55 are connected to the Si waveguide 60. The other end of the Si waveguide 60 extends to the opposing side of the Si photonics chip 40 to serve as an optical input and output portion of the Si photonics chip 40.

[0046] The first topological edge 54 has the Si waveguide 60a connected to its input side and the Si waveguide 60c connected to its output side, and the second topological edge 55 has the Si waveguide 60b connected to its input side and the Si waveguide 60d connected to its output side.

[0047] The Si waveguide 60a is connected to an optical fiber 3a, which is connected to one output terminal of a 3dB coupler 2. The Si waveguide 60b is connected to an optical fiber 3b, which is connected to the other output terminal of the 3dB coupler 2.

[0048] The Si waveguide 60c is connected to an optical fiber 3c, which is connected to one input terminal of the spectrometer 4. The Si waveguide 60d is connected to an optical fiber 3d, which is connected to the other input terminal of the spectrometer 4.

[0049] The 3 dB coupler 2 splits the light from the ASE light source 1 (light source) into two halves, one of which is introduced into the Si waveguide 60 a of the Si photonics chip 40 via the optical fiber 3 a, and the other is introduced into the Si waveguide 60 b of the Si photonics chip 40 via the optical fiber 3 b.

[0050] The path along which light introduced into the Si waveguide 60a of the Si photonics chip 40 propagates in an optical vortex pattern through the first topological edge 54 of the Si photonics chip 40, passes through the Si waveguide 60c, and is output to the optical fiber 3c outside the Si photonics chip 40 is called a “first path” (see the open arrow in FIG. 3 ), and the path along which light introduced into the Si waveguide 60b of the Si photonics chip 40 propagates in an optical vortex pattern through the first topological edge 55 of the Si photonics chip 40, passes through the Si waveguide 60d, and is output to the optical fiber 3d outside the Si photonics chip 40 is called a “second path” (see the open arrow in FIG. 3 ). The CD spectrometer 100 is characterized by having two paths, a “first path” and a “second path”, in the Si photonics chip 40.

[0051] The CD spectrometer 100 measures the transmission spectrum of a topological transmission line by changing the propagation direction. One method for changing the propagation direction is to provide first photonic structures 51 and 53 and a second photonic structure 52 with different topologies in a Topological PhC 50, and arrange a first topological edge 54 and a second topological edge 55 in close proximity. Then, a sample (10) (see Figure 4) is dropped onto the top surfaces of both the first topological edge 54 and the second topological edge 55. In this way, by simultaneously using two topological transmission lines arranged in parallel in advance, an effect similar to that of changing the propagation direction of a topological transmission line can be obtained.

[0052] As shown in Figures 3 and 4, the first topological edge 54 and the second topological edge 55 of the Topological PhC 50 are arranged close to each other. In the case of Figures 3 and 4, the Topological PhC 50 has a first photonic structure 51, a second photonic structure 52, and a first photonic structure 53 arranged in this order, and the area of ​​the second photonic structure 52 sandwiched between the first photonic structure 51 and the first photonic structure 53 (see area B in Figure 3) is reduced, thereby bringing the first topological edge 54 and the second topological edge 55 close to each other. This allows even a small amount of sample (specimen 10) (see Figure 4) dropped on the Topological PhC 50 to cover the top surfaces of both the first topological edge 54 and the second topological edge 55.

[0053] Because the Topological PhC 50 itself is extremely small and the first topological edge 54 and the second topological edge 55 are arranged closely on the Topological PhC 50, the Si waveguides 60 (60a to 60d) for introducing light into the first topological edge 54 and the second topological edge 55 are located close to each other. On the other hand, the other ends of the Si waveguides 60 (60a to 60d) are input / output terminals of the optical fibers 3 connected to the Si photonics chip 40, and an appropriate distance is maintained between them to improve handling during connection of the optical fibers 3. From the above, the Si waveguides 60 (60a to 60d) on the Si photonics chip 40 are formed to be curved in an S-order shape at the introduction position into the Topological PhC 50, as shown in Fig. 3. The Si waveguides 60 (60a to 60d) are formed to maintain appropriate intervals on the input / output sides to the outside of the Si photonics chip 40.

[0054] Here, since the Si waveguide 60 (60a to 60d) can propagate light with extremely low loss, there is no restriction on the overall length of the Si waveguide 60 (60a to 60d), in other words, on the size of the Si photonics chip 40. As shown in FIG. 3, the Si photonics chip 40 is an image in which a topological PhC 50 is inserted at the midpoint of the waveguide of a Si waveguide 60 (60a to 60d).

[0055] The operation of the CD spectrometer 100 configured as described above will now be described. In the CD spectrometer 100, light from one light source (ASE light source 1) is split into two by a 3 dB coupler 2, and the two are introduced into Si waveguides 60 (60a, 60b) of a Si photonics chip 40 through optical fibers 3 (3a, 3b). The Si waveguides 60 (60a, 60b) guide the input light to the topological PhC 50 with low loss, and introduce the light into the first topological edge 54 and the second topological edge 55 of the topological PhC 50, respectively.

[0056] As described above, the first topological edge 54 and the second topological edge 55 of the Topological PhC 50 are arranged close to each other, and a sample (specimen 10) (see Figure 4) is dropped onto the Topological PhC 50 so as to cover the top surfaces of the first topological edge 54 and the second topological edge 55. Here, an SiO2 film (not shown) is placed on the Topological PhC 50 to protect the top surfaces of the first topological edge 54 and the second topological edge 55. The sample (specimen 10) is dropped onto this SiO2 film. The sample (specimen 10) dropped onto the SiO2 film is washed after measurement. Dropping the sample (specimen 10) while the chip is protected by a thin SiO2 film prevents damage to the device sample.

[0057] Since the first photonic structures 51 and 53 (see region A in FIG. 3) and the second photonic structure 52 (see region B in FIG. 3) have different topologies, light stands out strongly at the interface between region A and region B. In the <first pass> (see arrow a in Figure 4), the left side of the first topological edge 54 of the Topological PhC 50 (the left side when viewing the Si photonics chip 40 in Figure 3 from above; the same notation applies below) is Region A, and the right side is Region B. Since the left side of the propagation direction is Region A and the right side is Region B, right-handed circularly polarized light is dominant, and right-handed circularly polarized light passes (propagates) through the first topological edge 54.

[0058] In the second path (see arrow b in Figure 4), the left side of the second topological edge 55 of Topological PhC 50 is Region B, and the right side is Region A. Since Region B is on the left side and Region A is on the right side relative to the propagation direction, left-handed circularly polarized light is dominant, and left-handed circularly polarized light passes (propagates) through the second topological edge 55. That is, the optical vortex propagating through the first topological edge 54 in the <first pass> is right-handed circularly polarized light, and the optical vortex propagating through the second topological edge 55 in the <second pass> is left-handed circularly polarized light.

[0059] The output light from the first topological edge 54 and the second topological edge 55 of the Topological PhC 50 is output to the Si waveguide 60 (60c, 60d) of the Si photonics chip 40, guided by the low-loss Si waveguide 60 (60c, 60d), and input to the Spectrometer 4 via the optical fiber 3 (3c, 3d) connected to the other end of the Si waveguide 60 (60c, 60d). Spectrometer 4 measures the asymmetry of light absorption for left-handed circularly polarized light.

[0060] [Variations] 5 is a diagram showing the device structure of the Si photonics chip 40 of the CD spectrometer 100A (circular dichroism measurement device), in which the same components as those in FIG. As shown in FIG. 5, the CD spectrometer 100A has a topological photonics chip 50A on a Si photonics chip 40. Topological PhC50A has a first photonic structure 51 of a first topology (see region A in Figure 5), second photonic structures 52, 56 of a second topology (see region B in Figure 5) that is different from the first topology, a first topological edge 54 that exhibits a topological edge state that allows optical vortex propagation at the interface between the first photonic structure 51 and the second photonic structure 56, and a second topological edge 55 that exhibits a topological edge state that allows optical vortex propagation at the interface between the second photonic structure 52 and the first photonic structure 51.

[0061] The first photonic structure 51 (see region A in FIG. 5) is a topological photonic structure, i.e., a topological photonic structure in which the interior is an insulator with an energy gap and its edges are in a gapless metallic state. The second photonic structures 52 and 56 (see region B in FIG. 5) are trivial photonic structures in which the bulk is an insulator with an energy gap.

[0062] The first topological edge 54 has the Si waveguide 60b connected to its input side and the Si waveguide 60d connected to its output side, and the second topological edge 55 has the Si waveguide 60a connected to its input side and the Si waveguide 60c connected to its output side.

[0063] The path along which light introduced into the Si waveguide 60a of the Si photonics chip 40 propagates in an optical vortex pattern through the first topological edge 54 of the Si photonics chip 40, passes through the Si waveguide 60c, and is output to the optical fiber 3c outside the Si photonics chip 40 is called a “first path” (see the open arrow in Figure 5 ), and the path along which light introduced into the Si waveguide 60b of the Si photonics chip 40 propagates in an optical vortex pattern through the first topological edge 55 of the Si photonics chip 40, passes through the Si waveguide 60d, and is output to the optical fiber 3d outside the Si photonics chip 40 is called a “second path” (see the open arrow in Figure 5 ).

[0064] In the above configuration, the CD spectrometer 100A splits light from one light source (ASE light source 1) into two by a 3 dB coupler 2 and introduces the split light into Si waveguides 60 (60a to 60d) of the Si photonics chip 40 through optical fibers 3 (3a, 3b). The Si waveguides 60 (60a, 60b) guide the input light to the topological PhC 50 with low loss, and introduce the light into the first topological edge 54 and the second topological edge 55 of the topological PhC 50, respectively.

[0065] Since the first photonic structure 51 (see region A in FIG. 5) and the second photonic structures 52 and 56 (see region B in FIG. 5) have different topologies, light stands out strongly at the interface between region A and region B. In the <first path>, the left side of the second topological edge 55 of Topological PhC 50A is Region B, and the right side is Region A. Therefore, left-handed circularly polarized light passes (propagates) through the second topological edge 55. In the <second pass>, the left side of the first topological edge 54 of the Topological PhC 50A is Region A, and the right side is Region B. Therefore, right-handed circularly polarized light passes (propagates) through the first topological edge 54. That is, the optical vortex propagating through the first topological edge 54 in the <second pass> is right-handed circularly polarized light, and the optical vortex propagating through the second topological edge 55 in the <first pass> is left-handed circularly polarized light.

[0066] The output light from the first topological edge 54 and the second topological edge 55 of the Topological PhC 50A is output to the Si waveguide 60 (60c, 60d) of the Si photonics chip 40, guided by the low-loss Si waveguide 60 (60c, 60d), and input to the Spectrometer 4 via the optical fiber 3 (3c, 3d) connected to the other end of the Si waveguide 60 (60c, 60d). Spectrometer 4 measures the asymmetry of light absorption for left-handed circularly polarized light. The CD spectrometer that measures the asymmetry of light absorption for left-handed circularly polarized light has been described above.

[0067] [effect] As described above, the CD spectrometer 100 (circular dichroism measurement device) according to the first embodiment comprises a Topological PhC 50 having first photonic structures 51, 53 and second photonic structure 52 with different topologies, topological edges 54, 55 that exhibit a topological edge state in which optical vortex propagation is possible at the interface between the first photonic structures 51, 53 and the second photonic structure 52, and a Spectrometer 4 that drops a sample 10 onto the topological edge and measures that the optical vortex of the topological edge propagates in a single direction depending on the optical spin state.

[0068] Of the first photonic structures 51, 53 and the second photonic structure 52, one is a photonic structure (Trivial photonic structure) whose bulk is an insulator with an energy gap, and the other is a first topological photonic structure (Topological photonic structure) whose interior is an insulator with an energy gap and whose edges are in a gapless metallic state.

[0069] The CD spectrometer100 measures the transmission spectrum of a topological transmission line by changing the direction of propagation. By measuring the asymmetry of light absorption for left- and right-handed circularly polarized light, the CD spectrometer100 can determine the intensity difference between left-handed and right-handed circularly polarized light. The CD spectrometer100 can identify the active material simply by dropping a sample and observing the intensity difference.

[0070] The CD spectrometer100 overcomes the problems of conventional CD spectrometers: (1) a relatively large amount of sample is required; (2) measurement accuracy cannot be guaranteed for heterogeneous samples with low optical transparency, such as living tissues and cells, i.e., samples with strong light scattering properties; and (3) analysis of local regions within cells or tissues or the spatial distribution of chirality is difficult with conventional measuring devices. The CD spectrometer100 enables highly sensitive and easy evaluation of the chirality of target samples.

[0071] In the CD spectrometer 100, the topological edges 54 and 55 are configured as follows: the first topological edge 54 that generates a topological edge state in which optical vortex propagation is possible at the interface between the first photonic structures 51 and 53 arranged on the left side in top view and the second photonic structure 52 arranged on the right side; and the second photonic structure 52 that is close to the first topological edge 54 and generates a topological edge state in which optical vortex propagation is possible at the interface between the second photonic structure 52 arranged on the left side in top view and the first photonic structures 51 and 53 arranged on the right side. and a second topological edge 55 that emits light from a light source, wherein light from a light source is divided into two halves, one of which is introduced into the first topological edge 54 and the other of which is introduced into the second topological edge 55, and a sample 10 is dropped onto the top surfaces of both the first topological edge 54 and the second topological edge 55 so as to cover them, and a spectrometer 4 measures the difference in intensity between the output light from the first topological edge 54 and the output light from the second topological edge 55 to measure the asymmetry of light absorption for left-handed and right-handed circularly polarized light.

[0072] In this way, by simultaneously using two topological transmission lines arranged in parallel in advance, it is possible to obtain the same effect as changing the propagation direction of the topological transmission line. In particular, since measurement accuracy equivalent to that of a measurement method in which the propagation direction is changed (or even higher, given the simultaneousness of the measurement conditions) can be obtained in a single measurement, the speed of identifying the chirality of the sample 10 can be significantly improved. In addition, there are no restrictions on how the Si photonics chip 40 with two topological transmission lines can be used. This has the advantage of being highly compatible and compatible with the CD luminescence 200 described below.

[0073] (Second embodiment) The circular dichroism measurement device according to the second embodiment of the present invention is an example applied to CD luminescence, which measures the circular polarization asymmetry in fluorescent light. 6 and 7 are explanatory diagrams illustrating the principle of a circular dichroism measurement device according to a second embodiment of the present invention. Fig. 6 is a diagram showing the device structure of a Si photonics chip of a CD luminescence (circular dichroism measurement device) (schematic image of a proposed device), and Fig. 7 is a diagram showing the propagation mode distribution of the topological transmission line of the device structure shown in Fig. 6. In explaining Fig. 6 and Fig. 7, the same components as those in Fig. 1 are assigned the same reference numerals. In topological photonics, unidirectional light propagation occurs at the interface between two photonic structures with different topologies, depending on the optical spin state (i.e., either left- or right-handed circular polarization). CD luminescence measures the circular polarization asymmetry in fluorescence emission. CD luminescence uses a fluorescent sample (Sample 10).

[0074] As shown in FIG. 6, a fluorescent sample (specimen 10) is dropped onto the interface at the boundary between photonic structures with different topologies. CD luminescence is achieved by irradiating the chip surface with pumping light 30 (excitation light) from above, perpendicular to the surface, to cause the sample 10 to fluoresce. Pumping light 30 uses light to raise electrons from a lower energy level of atoms or molecules to a higher energy level (optical pumping).

[0075] Figure 7 shows the propagation mode distribution of the topological transmission line when the fluorescent light emitted from Sample (sample 10) is right-circularly polarized. When Pumping light 30 is irradiated to Sample (sample 10) to cause it to emit fluorescent light, if the fluorescent light from Sample (sample 10) is right-circularly polarized, an optical vortex propagates on the topological transmission line 13 in the direction indicated by arrow c in Figures 6 and 7. On the other hand, if the fluorescent light from Sample (sample 10) is left-circularly polarized, an optical vortex propagates on the topological transmission line 13 in the direction indicated by arrow d in Figure 7.

[0076] The fluorescent light is extracted from the left and right topological transmission lines, and the power ratio of the light extracted from the left and right topological transmission lines is measured. This allows us to determine the difference between right-handed and left-handed circularly polarized light in the fluorescent light (the circular polarization ratio of the fluorescent light).

[0077] 8 is a plan view showing the structure of a circular dichroism measurement device according to a second embodiment of the present invention, in which the same components as those in FIG. The circular dichroism measurement device of this embodiment is an example applied to CD luminescence, which measures the circular polarization asymmetry in fluorescent light.

[0078] As shown in FIG. 8, the CD luminescence 200 (circular dichroism measurement device) includes a Si photonics chip 40, a topological PhC 50A (topological photonic crystal (PhC)) (topological region) having two photonic structures with different topologies arranged on the Si photonics chip 40, and Si waveguides 60 (60a to 60d) (waveguides) that propagate light in the TE mode (Transverse Electric mode) / TM mode (Transverse Magnetic mode) in the topological PhC 50A. Spectrometer 4 measures the circular polarization asymmetry in the fluorescent emission.

[0079] The device structure of the Si photonics chip 40 used in the CD luminescence 200 (circular dichroism measurement device) is the same as that of the Si photonics chip 40 in the CD spectrometer 100 (circular dichroism measurement device). Because the device structure of the Si photonics chip 40 is the same, it is possible to support both the CD spectrometer and the CD luminescence system simply by switching the path to the Si photonics chip 40.

[0080] 9 is a diagram showing the device structure of the Si photonics chip 40 of the CD luminescence 200 (circular dichroism measurement device) (schematic image of a proposed device). The same components as in FIG. 4 are assigned the same reference numerals. As shown in Figure 9, Topological PhC 50A has first photonic structures 51, 53 of a first topology (see region A in Figure 9), a second photonic structure 52 of a second topology (see region B in Figure 9) that is different from the first topology, a first topological edge 54 that exhibits a topological edge state that allows optical vortex propagation at the interface between first photonic structure 51 and second photonic structure 52, and a second topological edge 55 that exhibits a topological edge state that allows optical vortex propagation at the interface between second photonic structure 52 and first photonic structure 53.

[0081] The first photonic structures 51, 53 and the second photonic structure 52 may be any combination of photonic structures as long as they are two photonic structures with different topologies. For example, if one of the first photonic structures 51, 53 and the second photonic structure 52 is a trivial photonic structure, the other is a topological photonic structure.

[0082] In the case of Fig. 9, the first photonic structures 51 and 53 (see region A in Fig. 9) are topological photonic structures, i.e., topological photonic structures in which the interior is an insulator with an energy gap and the edges are in a gapless metallic state. Also, the second photonic structure 52 (see region B in Fig. 3) is a trivial photonic structure in which the bulk is an insulator with an energy gap.

[0083] The operation of the CD luminescence 200 configured as above will now be described. CD luminescence200 utilizes the phenomenon in which the direction of the optical vortex propagating along the topological transmission line is uniquely determined depending on whether the fluorescent light from the sample (sample 10) is right- or left-circularly polarized by irradiating it with pumping light30. For this reason, only one topological transmission line on the topological PhC50A (topological region) is required. 8 and 9, CD luminescence 200 uses a first topological edge 54 that allows optical vortex propagation at the interface between first photonic structure 51 (see region A in FIG. 9) of the first topology and second photonic structure 52 (see region B in FIG. 9). Note that a second topological edge 55 that allows optical vortex propagation may also be used at the interface between second photonic structure 52 and first photonic structure 53.

[0084] As shown in FIG. 9, a fluorescent sample (specimen 10) is dropped onto the interface at the boundary between photonic structures with different topologies. In CD luminescence 200, pumping light 30 (excitation light) is irradiated perpendicularly to the chip surface from above to cause sample (sample 10) to emit fluorescence. When pumping light 30 is irradiated to cause sample (sample 10) to emit fluorescence, if the fluorescence emitted from sample (sample 10) is right-handed circularly polarized light, an optical vortex propagates on topological transmission line 54 in the direction indicated by arrow d in Figure 9. Also, if the fluorescence emitted from sample (sample 10) is left-handed circularly polarized light, an optical vortex propagates on topological transmission line 54 in the direction indicated by arrow e in Figure 9. When the second topological edge 55 is used, and when the sample (sample 10) is irradiated with pumping light 30 to emit fluorescence, if the fluorescence emitted from the sample (sample 10) is right-circularly polarized, an optical vortex propagates on the topological transmission line 55 in the direction indicated by arrow g in Fig. 9. On the other hand, if the fluorescence emitted from the sample (sample 10) is left-circularly polarized, an optical vortex propagates on the topological transmission line 55 in the direction indicated by arrow f in Fig. 9.

[0085] The fluorescent light is extracted from both ends of the topological transmission line 54, and the spectrometer 4 measures the power ratio of the light extracted from the topological transmission line 54. This allows us to determine the difference between right-handed and left-handed circularly polarized light in the fluorescent light (the circular polarization ratio of the fluorescent light).

[0086] [Variations] (1) 10 is a diagram showing the device structure of the Si photonics chip 40 of the CD luminescence 200A (circular dichroism measurement device). The same components as those in FIGS. 5 and 8 are denoted by the same reference numerals. As shown in FIG. 10, CD luminescence 200A has Topological PhC 50A on a Si photonics chip 40. Topological PhC50A has a first photonic structure 51 of a first topology (see region A in Figure 9), second photonic structures 52, 56 of a second topology (see region B in Figure 9) that is different from the first topology, a first topological edge 54 that exhibits a topological edge state that allows optical vortex propagation at the interface between the first photonic structure 51 and the second photonic structure 56, and a second topological edge 55 that exhibits a topological edge state that allows optical vortex propagation at the interface between the second photonic structure 52 and the first photonic structure 51.

[0087] In the above configuration, when the sample (sample 10) is irradiated with pumping light 30 to emit fluorescence, if the fluorescence emitted from the sample (sample 10) is right-handed circularly polarized light, an optical vortex propagates along the topological transmission line 55 toward the Si waveguide 60c shown in Fig. 10. On the other hand, if the fluorescence emitted from the sample (sample 10) is left-handed circularly polarized light, an optical vortex propagates along the topological transmission line 55 toward the Si waveguide 60a shown in Fig. 10.

[0088] The fluorescent light is extracted from both ends of the topological transmission line 55, and the spectrometer 4 measures the power ratio of the light extracted from the topological transmission line 54. This allows us to determine the difference between right-handed and left-handed circularly polarized light in the fluorescent light (the circular polarization ratio of the fluorescent light).

[0089] (2) As described above, the CD luminescence 200 requires at least one topological transmission line on the Topological PhC 50A. From this perspective, the Topological PhC 50A can also be configured to include only the first photonic structure 51 and the second photonic structure 52 (or the first photonic structure 51 and the second photonic structure 56) with different topologies. In this case, the Topological PhC 50A is inserted at the midpoint of the waveguide of one Si waveguide 60. Furthermore, since there is only one topological transmission line, the number of Si waveguides 60 can be reduced, which has the advantage that a structure for bending the Si waveguide 60 is not required. However, since the Si photonics chip is no longer compatible, it becomes difficult to support both CD spectrometer and CD luminescence systems by switching the path.

[0090] [effect] As described above, the CD luminescence 200 (circular dichroism measurement device) according to the second embodiment drops the sample 10 containing a fluorescent substance onto the topological edges 54 and 55, irradiates the upper surface of the topological edge on which the dropped sample 10 rests with excitation light, causing the sample 10 to fluoresce, and the spectrometer 4 measures the circular polarization asymmetry in the fluorescent emission by measuring that the fluorescent emission propagates in a single direction depending on whether it is left-handed or right-handed circularly polarized light.

[0091] This allows us to drop a target sample (sample 10) onto the Topological PhC50A (topological photonics chip) and evaluate the propagation characteristics in that state, thereby making it relatively easy to evaluate the chirality of the target sample while maintaining sensitivity at a constant level.

[0092] Although the CD luminescence 200 has a weak luminescence intensity, the size of the Topological PhC50 (10 x 10 microns in the AB part) is small, so even weak luminescence can be output to the optical fiber 3 while maintaining its intensity. Also, because the size of the Topological PhC50 is small, only a small amount of sample needs to be dropped.

[0093] The CD luminescence200 overcomes the problems inherent in conventional CD luminescence: (1) a relatively large amount of sample is required, (2) measurement accuracy cannot be guaranteed for samples with low optical transparency, and (3) sensitivity is poor when measuring local molecular chirality under microscopic observation. The CD luminescence200 enables highly sensitive and easy evaluation of the chirality of target samples.

[0094] Combining the first and second embodiments with existing microspectroscopic techniques makes it possible to realize a "microcircular dichroism spectrometer" (see FIG. 11) that can "locally measure" molecular chirality.

[0095] [Device overview] 11 is a diagram showing an outline of the circular dichroism measurement device S of the present invention. The circular dichroism measurement device S is compatible with both the CD spectrometer 100 (see FIG. 3) and the CD luminescence 200 (see FIG. 8) systems. As shown in FIG. 11 , the circular dichroism measurement device S includes a microscope 310, a mounting stage 311 on which a Si photonics chip 40 is placed, an irradiation optical system 312 that drops a sample 10 to be measured onto the topological pH 50 of the Si photonics chip 40 and irradiates the sample 10 with pumping light 30, and a circular dichroism measurement device main body 320.

[0096] The microscope 310 performs microscopic observation of the sample 10 in conjunction with the measurement of chirality by the circular dichroism measurement device S. The illumination optical system 312 generates pumping light 30 and illuminates the sample 10 of the Topological PhC 50 vertically from above.

[0097] The circular dichroism measurement device main body 320 includes a touch panel display unit 321, a power button 330, a CD spectrometer selection button 340 (switching unit), a CD luminescence selection button 350 (switching unit), and an optical fiber connection terminal 360.

[0098] The touch panel display unit 321 is an LCD display unit with a touch panel, and is composed of an LCD display or an organic EL (Electro-Luminescence) display, a white LED backlight, various drivers, etc. The touch panel is also a pointing device for specifying any position on the display screen of the LCD display unit. The touch panel detects each operation when the user presses, slides, or releases their finger on the upper surface.

[0099] Setting conditions, measurement results, analysis results, etc. in the CD spectrometer mode and CD luminescence mode are displayed on the touch panel display unit 321. Detailed settings of the setting conditions can be made using software keys displayed on the touch panel.

[0100] The CD spectrometer selection button 340 is pressed to select the CD spectrometer mode, and the CD luminescence selection button 350 is pressed to select the CD luminescence mode. When the selection buttons 340 and 350 are pressed, the touch panel display unit 321 displays the setting conditions and measurement status of the functions corresponding to each mode. The selection buttons 340 and 350 are toggle switches, and one of the modes is selected. Note that, as will be described later, when automatic switching of the mode selection is executed, the settings made by the selection buttons 340 and 350 are reserved.

[0101] [flowchart] Fig. 12 is a diagram showing the circular dichroism measurement process of the circular dichroism measurement apparatus S of Fig. 11. The circular dichroism measurement apparatus S corresponds to both the CD spectrometer 100 (see Fig. 3) and the CD luminescence 200 (see Fig. 8) systems. After the system is started, in step S1, the Si photonics chip 40 is placed on the mounting table 311 (see FIG. 11). In step S2, a sample is dropped onto the topological PhC 50 of the Si photonics chip 40. Alternatively, the Si photonics chip 40 with the sample dropped onto the topological PhC 50 may be prepared in advance and placed on the stage 311.

[0102] In step S3, the CD spectrometer mode / CD luminescence mode is selected by pressing the CD spectrometer selection button 340 or the CD luminescence selection button 350 (see FIG. 11). If the CD spectrometer mode is selected, in step S4, the circular dichroism measurement device S functions as the CD spectrometer 100. When the software execution key on the touch panel of the touch panel display unit 321 is touched, the CD spectrometer 100 irradiates the ASE light source 1 (see FIGS. 3 and 5).

[0103] In step S5, the 3 dB coupler 2 (see FIGS. 3 and 5) distributes the light from the ASE light source 1 and introduces it into the Si waveguides 60 (60 a, 60 b) of the Si photonics chip 40 through optical fibers 3 (3 a, 3 b). The output light from the first topological edge 54 and the second topological edge 55 of the topological PhC 50 is output to the Si waveguides 60 (60 c, 60 d) of the Si photonics chip 40 and input to the spectrometer 4 via the optical fibers 3 (3 c, 3 d). In step S6, the spectrometer 4 (see FIGS. 3 and 5) measures the asymmetry of light absorption for left-handed circularly polarized light, and the process proceeds to step S9.

[0104] When the CD luminescence mode is selected in step S3 above, the circular dichroism measurement device S functions as the CD luminescence 200. When the software execution key on the touch panel of the touch panel display unit 321 is touched, the irradiation optical system 312 (see FIG. 11) of the CD luminescence 200 generates the pumping light 30 and irradiates the sample 10 of the Topological PhC 50 with the pumping light 30 vertically from above. In step S8, the spectrometer 4 (see FIGS. 8 and 10) measures the circular polarization asymmetry in the fluorescent light, and the process proceeds to step S9.

[0105] In step S9, a CPU (Central Processing Unit) 901 (switching unit) in FIG. 13 (described later) determines whether or not to switch modes. If the mode is to be switched, the process returns to step S3. If the mode is not switched, the measurement results, analysis results, etc. in the CD spectrometer mode or CD luminescence mode are output, and the processing of this flow ends. The measurement results, analysis results, etc. are output by displaying them on the touch panel display unit 321, recording them on the recording medium 912 (see FIG. 13), printing them on a printer or the like via the media I / F 907 (see FIG. 13), transmitting the measurement data via the communication I / F 906 (see FIG. 13), etc.

[0106] The Si photonics chip 40 can be used in the same manner for both the CD spectrometer 100 and the CD luminescence 200. By simply switching the external path of the Si photonics chip 40, it can be used for both the CD spectrometer 100 and the CD luminescence 200. The circular dichroism measurement device S can be operated in both the CD spectrometer mode and the CD luminescence mode by operating the CD spectrometer selection button 340 and the CD luminescence selection button 350 .

[0107] [Hardware configuration] In the circular dichroism measurement devices according to the first and second embodiments, circular dichroism distribution processing is realized by a computer 900, which is a physical device configured as shown in FIG. 13, for example. 13 is a hardware configuration diagram showing an example of a computer that realizes the functions of a circular dichroism measurement device. The computer 900 has a CPU 901 (switching unit), a ROM (Read Only Memory) 902, a RAM 903, an HDD (Hard Disk Drive) 904, an input / output I / F (Interface) 905, a communication I / F 906, and a media I / F 907.

[0108] The CPU 901 operates based on a program stored in the ROM 902 or the HDD 904, and controls each processing unit of the circular dichroism measurement device shown in Fig. 11. The ROM 902 stores a boot program executed by the CPU 901 when the computer 900 is started up, programs related to the hardware of the computer 900, and the like.

[0109] The CPU 901 functions as a switching unit that switches the path to the Si photonics chip 40, and switches between a CD spectrometer mode that measures the asymmetry of light absorption for left-handed circularly polarized light and a CD luminescence mode that measures the circular polarization asymmetry in fluorescent light. The spectrometer 4 (see Figures 3, 5, 8, and 10) measures the chirality of the sample based on the mode switched by the CPU 901.

[0110] The CPU 901 controls an input device 910 such as a mouse or keyboard and an output device 911 such as a display via an input / output I / F 905. The CPU 901 acquires data from the input device 910 via the input / output I / F 905 and outputs measured and analyzed data to the output device 911.

[0111] The HDD 904 stores programs executed by the CPU 901 and data used by the programs. The communication I / F 906 receives data from other devices via a communication network (e.g., NW (Network) 920) and outputs the data to the CPU 901, and also transmits data generated by the CPU 901 to other devices via the communication network.

[0112] The media I / F 907 reads a program or data stored in the recording medium 912 and outputs it to the CPU 901 via the RAM 903. The CPU 901 loads a program related to a target process from the recording medium 912 onto the RAM 903 via the media I / F 907, and executes the loaded program. The recording medium 912 is an optical recording medium such as a DVD (Digital Versatile Disc) or a PD (Phase Change Rewritable Disc), a magneto-optical recording medium such as an MO (Magneto Optical disc), a magnetic recording medium, a conductive memory tape medium, a semiconductor memory, or the like.

[0113] For example, when the computer 900 functions as the circular dichroism measurement device according to the first and second embodiments, the CPU 901 of the computer 900 executes a program loaded onto the RAM 903 to realize the function of the circular dichroism measurement device. The HDD 904 stores data in the RAM 903. The CPU 901 reads and executes a program related to a target process from a recording medium 912. Alternatively, the CPU 901 may read a program related to a target process from another device via a communication network (NW 920).

[0114] The present invention is not limited to the above-described embodiments, but includes other modifications and applications within the scope of the claims.

[0115] Furthermore, the above-described embodiments and modifications have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0116] In addition, in the above embodiments, the names "circular dichroism measurement device" and "circular dichroism measurement method" are used, but this is for convenience of explanation, and the name of the device invention may also be "circular dichroism measurement device," "microscopic circular dichroism spectrometer," "chirality evaluation device," etc. Furthermore, the name of the method invention may also be "chirality evaluation method," etc. [Explanation of symbols]

[0117] 1 ASE(Amplified Spontaneous Emission) light source 2 3dB coupler (divider) 3, 3a to 3d Optical fiber (route) 4 Spectrometer (measurement unit) 10 Sample (target sample) 11 Trivial photonic structure 12 Topological photonic structure 13 Topological edge 30 Pumping light 40Si photonics chip 50,50A Topological PhC (Topological Photonic Crystal (PhC)) (Topological Area) 51 First Photonic Structure 52,56 Second photonic structure 54 First Topological Edge 55 Second Topological Edge 60,60a~60d Si waveguide (optical waveguide) 100,100A CD spectrometer (circular dichroism measurement device) 200,200A CD luminescence (circular dichroism measurement device) 310 Microscope 312 Irradiation optical system 320 Circular dichroism measurement device 340 CD spectrometer selection button (switching section) 350 CD luminescence selection button (switching part) 901 CPU (switching unit) S Circular dichroism measurement device

Claims

1. A circular dichroism measurement device that measures the chirality of a sample using circular dichroism, a topological photonic crystal having a first photonic structure and a second photonic structure having different topologies, and a topological edge that exhibits a topological edge state that allows optical vortex propagation at the interface between the first photonic structure and the second photonic structure; a measurement unit that drops a sample onto the topological edge and measures that the optical vortex of the topological edge propagates in a single direction depending on the optical spin state. A circular dichroism measurement device characterized by:

2. Among the first photonic structure and the second photonic structure, One is a photonic structure (Trivial photonic structure) in which the bulk is an insulator with an energy gap, The other is the first topological photonic structure, which is an insulator with an energy gap inside and a gapless metallic state at its edges.

2. The circular dichroism measurement device according to claim 1 .

3. The measurement unit measures the asymmetry of light absorption for left-handed circularly polarized light.

2. The circular dichroism measurement device according to claim 1 .

4. The measurement unit changes the propagation direction of the transmission spectrum that has propagated through the topological edge and measures it.

2. The circular dichroism measurement device according to claim 1 .

5. The measurement unit measures the circular polarization asymmetry in the fluorescent light emitted from the sample.

2. The circular dichroism measurement device according to claim 1 .

6. The topological edge is a first topological edge that exhibits a topological edge state in which optical vortex propagation is possible at the interface between the first photonic structure arranged on the left side in top view and the second photonic structure arranged on the right side; a second topological edge that exhibits a topological edge state in which optical vortex propagation is possible at an interface between the second photonic structure that is located on the left side in top view and the first photonic structure that is located on the right side, the second topological edge being adjacent to the first topological edge; light from a light source is divided into halves, one half of the light is introduced into the first topological edge, and the other half of the light is introduced into the second topological edge; Dropping a sample onto the top surfaces of both the first topological edge and the second topological edge, The measurement unit The difference in intensity between the output light from the first topological edge and the output light from the second topological edge is measured to measure the asymmetry of light absorption for left-handed circularly polarized light.

2. The circular dichroism measurement device according to claim 1 .

7. Dropping a sample containing a fluorescent material onto the topological edge; irradiating an upper surface of the topological edge on which the dropped sample is placed with excitation light to cause the sample to emit fluorescence; The measurement unit Measure circular polarization asymmetry in fluorescence emission by measuring whether the fluorescence emission propagates in a single direction depending on whether the fluorescence emission is left- or right-handed.

2. The circular dichroism measurement device according to claim 1 .

8. The optical spin state is either right-handed or left-handed circularly polarized light.

2. The circular dichroism measurement device according to claim 1 .

9. and a Si photonics chip having the topological photonic crystal and an optical waveguide for introducing and guiding light to and from the topological edge.

2. The circular dichroism measurement device according to claim 1 .

10. a path connecting the optical waveguide of the Si photonics chip and an input terminal of the measurement unit; a switching unit that switches the path, the switching unit switches between a CD spectrometer mode that measures the asymmetry of light absorption with respect to left-handed circularly polarized light and a CD luminescence mode that measures the circularly polarized asymmetry in fluorescent light; The measurement unit measures the chirality of the sample based on the mode switched by the switching unit.

10. The circular dichroism measurement device according to claim 9.

11. The topological photonic structure comprises a dielectric material with symmetry within the arranged cells.

2. The circular dichroism measurement device according to claim 1 .

12. The photonic structure that is the topological photonic structure out of the first photonic structure or the second photonic structure is C ６ｖ The structure is composed of regular hexagonal unit cells of a dielectric material containing symmetrical nanoholes arranged in a triangular lattice.

2. The circular dichroism measurement device according to claim 1 .

13. The photonic structure that is the topological photonic structure out of the first photonic structure or the second photonic structure is Z ２ It is a topological structure expressed by topology.

2. The circular dichroism measurement device according to claim 1 .

14. A circular dichroism measurement method for a circular dichroism measurement device that measures the chirality of a sample using circular dichroism, comprising: a topological photonic crystal having a first photonic structure and a second photonic structure having different topologies, and a topological edge that exhibits a topological edge state in which optical vortex propagation is possible at an interface between the first photonic structure and the second photonic structure; Dropping a sample onto the topological edge; and measuring that the optical vortex at the topological edge propagates in a single direction depending on the optical spin state. A circular dichroism measurement method characterized by:

15. A circular dichroism measurement method for a circular dichroism measurement device that measures the chirality of a sample using circular dichroism, comprising: a topological photonic crystal having a first photonic structure and a second photonic structure having different topologies, and a topological edge that exhibits a topological edge state in which optical vortex propagation is possible at an interface between the first photonic structure and the second photonic structure; The topological edge is a first topological edge that exhibits a topological edge state in which optical vortex propagation is possible at the interface between the first photonic structure arranged on the left side in top view and the second photonic structure arranged on the right side; a second topological edge that exhibits a topological edge state in which optical vortex propagation is possible at an interface between the second photonic structure that is located on the left side in top view and the first photonic structure that is located on the right side, the second topological edge being close to the first topological edge; Dividing the light from the light source into two; introducing one half of the light into the first topological edge and the other half of the light into the second topological edge; Dropping a sample onto the top surfaces of both the first topological edge and the second topological edge; measuring an intensity difference between the output light from the first topological edge and the output light from the second topological edge to measure the asymmetry of light absorption for left-handed circularly polarized light; A circular dichroism measurement method characterized by:

16. A circular dichroism measurement method for a circular dichroism measurement device that measures the chirality of a sample using circular dichroism, comprising: a topological photonic crystal having a first photonic structure and a second photonic structure having different topologies, and a topological edge that exhibits a topological edge state in which optical vortex propagation is possible at an interface between the first photonic structure and the second photonic structure; Dropping a sample containing a fluorescent material onto the topological edge; Irradiating an upper surface of the topological edge on which the dropped sample is placed with excitation light to cause the sample to emit fluorescence; measuring the circular polarization asymmetry in the fluorescent emission by measuring that the fluorescent emission propagates in a single direction depending on the left or right circular polarization. A circular dichroism measurement method characterized by:

17. A program for causing a computer to function as the circular dichroism measurement device according to any one of claims 1 to 13.

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