Optical component, optical device, and optical system
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-08-13
Smart Images
Figure JP2025045842_13082026_PF_FP_ABST
Abstract
Description
Optical Component, Optical Device, Optical System
[0001] The present disclosure relates to optical components and the like that can be used in various fields such as astronomical observations and material analysis.
[0002] Conventionally, in various fields such as astronomical observations and material analysis, a spectroscopic device that spectrally separates light by wavelength, receives the light with a detector, and measures the intensity has been used. For example, in the field of astronomical observations, an observation method called area spectroscopy that can simultaneously observe two-dimensional spatial information and spectral information is known. As optical systems used to achieve area spectroscopy, a microlens array type, a fiber bundle type, an image slicer type, etc. are known.
[0003] Patent Document 1 describes an image slicer type optical device provided with a slice mirror. FIG. 11A is a plan view of the slice mirror described in Patent Document 1, and FIG. 11B is a perspective view. The slice mirror includes a plurality of rectangular reflecting surfaces 2a. In order to divide the observation light incident on the reflecting surface 2a from the space on the object surface side and reflect it in different directions, each of the reflecting surfaces 2a faces a different direction.
[0004] Japanese Patent Application Laid-Open No. 2022-96461
[0005] The image slicer type is known to have a simple optical system configuration, little loss of spatial information, and high spatial resolution even in a narrow field of view. In the image slicer type, a slice mirror, a collimating mirror, etc. are combined to form an area spectroscopy system. The slice mirror is a mirror that divides the focal plane image of a telescope into a plurality of elongated images. The collimating mirror is a mirror for rearranging the partial images that are divided by the slice mirror and reflected in different directions respectively.
[0006] Not limited to the example of Patent Document 1, in the image slicer type, the alignment accuracy between the slice mirror arranged on the optical path of the observation light and the optical element (for example, a collimating mirror) arranged on the optical path of the reflected light from the slice mirror is important for improving the performance of area spectroscopy.
[0007] However, precisely aligning and fixing the slice mirror with other optical elements (e.g., collimating mirrors) is not easy, leading to decreased manufacturing yield and increased manufacturing costs for optical systems. Furthermore, during operation of the spectroscopic system, vibrations, shocks, etc., easily cause misalignment between the slice mirror and other optical elements (e.g., collimating mirrors), making it difficult to stably maintain spectral accuracy.
[0008] One of the problems that the embodiments disclosed herein and in the drawings aim to solve is to provide a technology advantageous for achieving high spectral accuracy in, for example, an image slicer type optical device. However, the problems that the embodiments disclosed herein and in the drawings aim to solve are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems.
[0009] A first aspect of the present disclosure is an optical component comprising a substrate made of a solid material transparent to light of a wavelength used, the optical component comprising: an incident portion for injecting light into the interior of the substrate; a first reflecting portion for dividing the light incident from the incident portion into a plurality of light beams and reflecting them in different directions within the substrate; a second reflecting portion for reflecting each of the plurality of light beams reflected by the first reflecting portion to change the optical path within the substrate; and an exiting portion for emitting each of the plurality of light beams reflected by the second reflecting portion to the outside of the substrate.
[0010] This disclosure provides a technology that is advantageous for achieving high spectral accuracy in, for example, an image slicer type optical device. Other features and advantages of this disclosure will become apparent from the following description with reference to the accompanying drawings.
[0011] A schematic cross-sectional view showing the configuration of an optical system equipped with optical components according to the embodiment. A schematic optical path diagram showing the optical path of observed light in the optical system. A schematic cross-sectional view of the first optical component cut along the optical axis of the incident observed light. A schematic optical path diagram showing the optical path of the light beam within the first optical component. A schematic perspective plan view of the first optical component viewed through from the side of the incident optical system along the Z-plus direction. A schematic cross-sectional view showing the form of the first optical component manufactured by injection molding or glass molding. A schematic cross-sectional view showing the form of the first optical component manufactured by cutting. A cross-sectional view showing an example of the shape of the reflective surface of the first reflector. A cross-sectional view showing another example of the shape of the reflective surface of the first reflector. A cross-sectional view showing another example of the shape of the reflective surface of the first reflector. A cross-sectional view showing another example of the shape of the reflective surface of the first reflector. A schematic cross-sectional view of the second optical component cut along the optical axis of the incident light beam. An enlarged view of the spectroscopic section equipped with numerous fine gratings. A schematic cross-sectional view showing an example of a second optical component in which the lens and the spectral section are provided on different substrates. A schematic perspective plan view of the second optical component viewed from the side of the detection section along the Z-minus direction. A schematic cross-sectional view illustrating a second optical component in which the spectral section and lens are arranged in this order on a single substrate in the direction of light beam propagation. A schematic cross-sectional view illustrating a second optical component in which the spectral section and lens are arranged on different substrates in this order on different substrates in the direction of light beam propagation. A schematic cross-sectional view illustrating a second optical component in which the lens and spectral section are provided on separate substrates and the lens and spectral section are arranged facing each other. A schematic cross-sectional view illustrating another second optical component in which the lens and spectral section are provided on separate substrates and the lens and spectral section are arranged facing each other. A plan view of the slice mirror described in Patent Document 1. A perspective view of the slice mirror described in Patent Document 1.
[0012] Optical components, optical systems, etc., according to embodiments of this disclosure will be described with reference to the drawings. The embodiments shown below are illustrative, and for example, the details of the configuration can be modified as appropriate by those skilled in the art without departing from the spirit of this disclosure.
[0013] In the drawings referenced in the following descriptions of embodiments and examples, elements indicated by the same reference numerals shall have the same function unless otherwise specified. If multiple identical elements are shown in a drawing, the assignment of reference numerals and their descriptions may be omitted.
[0014] Furthermore, since drawings may be schematically represented for the sake of illustration and explanation, the shape, size, and arrangement of elements shown in the drawings may not strictly correspond to those of actual objects.
[0015] In the following explanation, for example, when we refer to the "X-plus direction," it refers to the same direction as the X-axis arrow in the illustrated Cartesian coordinate system, and when we refer to the "X-minus direction," it refers to the direction 180 degrees opposite to the direction indicated by the X-axis arrow in the illustrated Cartesian coordinate system. Furthermore, when we simply refer to the "X direction," it refers to the direction parallel to the X-axis, regardless of whether it is the same as or different from the direction indicated by the illustrated X-axis arrow. The same applies to directions other than X.
[0016] [Embodiment 1] (Configuration of the optical system) Figure 1 is a schematic cross-sectional view showing the configuration of an optical system equipped with optical components according to the embodiment. As shown in Figure 1, the optical system includes an incident optical system 101, an optical device 400 which is a surface spectrometer, a detection unit 300, and an information processing device 500.
[0017] The incident optical system 101 may be, for example, a telescope if the optical system is for astronomical observation, or for example, a microscope if the optical system is for materials analysis. The incident optical system 101 is not limited to these examples; an appropriate optical system may be installed depending on the object being observed.
[0018] The optical device 400 is an optical device for spectrally analyzing an incident light image in a two-dimensional spatial region and a spectral region, and comprises a case 350 as an exterior component, a first optical component 100, and a second optical component 200. The first optical component 100 and the second optical component 200 are positioned and fixed in predetermined positions within the case 350 via spacers 352 and housed in the case 350.
[0019] The case 350 not only serves as a structure that maintains the mechanical strength of the optical device 400, but can also function as a cover that prevents dust and unwanted external light from entering the interior. The case 350 includes an entrance window for introducing light incident from the entrance optical system 101 into the optical device 400, and an exit window for emitting the light spectrally separated from the optical device 400 toward the detection unit 300. The entrance window and exit window may be openings or members made of a material transparent to the light being observed.
[0020] The optical device 400 may be equipped with a light-shielding member 351 to suppress the generation of unwanted stray light. The light-shielding member 351 has a window that allows only the desired light beam to pass through. The window may be an opening (e.g., a slit) or a window member made of a material transparent to the desired light beam. The light-shielding member 351 with the window may be placed, for example, between the incident optical system 101 and the first optical component 100, between the first optical component 100 and the second optical component 200, between the second optical component 200 and the detection unit 300, etc.
[0021] The first optical component 100, as an optical component according to this embodiment, comprises a substrate made of a solid material that is transparent at the wavelength of light to be observed (usage wavelength). The substrate is provided with an incident portion 113, a first reflective portion 122 as a split mirror, a second reflective portion 112 as a collimating mirror, and an output portion 123 for emitting the light reflected by the second reflective portion. For convenience of illustration, the first reflective portion 122 and the second reflective portion 112 illustrated in Figure 1 each have two reflective surfaces, but the number of reflective surfaces is not limited to two. Preferably, the second reflective portion 112 collimates each reflected light beam so that it is parallel to the Z direction, but it is not necessarily strictly parallel. The specific configuration of the first optical component 100 will be described in detail later.
[0022] The second optical component 200 comprises a substrate made of a solid material that is transparent at the wavelength of light to be observed (usage wavelength). The substrate is provided with a lens section 212 for controlling the light beam emitted from the individual emission sections 123 of the first optical component 100, and a spectrometer section 222 for spectrally separating the light beam according to its wavelength. The specific configuration of the second optical component 200 will be described in detail later.
[0023] The detection unit 300 includes a light-receiving sensor 311 that detects light spectrally separated by the optical device 400. The light-receiving sensor 311 is an imaging device equipped with a two-dimensional light-receiving surface that is sensitive to the wavelength band of the light to be observed, and transmits the measurement results to the information processing device 500. For example, a CMOS image sensor or a CCD sensor can be used as the light-receiving sensor 311.
[0024] The information processing device 500 is a computer that performs information processing related to surface spectroscopy. Based on the measurement results of the light receiving sensor 311, it calculates two-dimensional spatial information and spectral information about the incident light. When the light receiving sensor 311 captures a video, the information processing device 500 can also acquire the time-dependent changes in the two-dimensional spatial information and spectral information. Based on the output signal of the light receiving sensor 311, the information processing device 500 acquires spectral image data of the incident light and performs information processing such as storing it in a memory unit, transmitting it to an external computer via a network, analyzing the observed object through image processing, and displaying the analysis results.
[0025] Next, the optical path of the observed light in the optical system according to the embodiment will be described. Figure 2 is a schematic optical path diagram showing the optical path of the observed light in the optical system shown in Figure 1.
[0026] The incident optical system 101 controls the light that enters the incident section 113. The observation light 2, i.e., the light beam from the object being observed, travels along the Z-positive direction via the incident optical system 101 with the first reflecting section 122 in focus, and enters the base body of the first optical component 100 from the incident section 113. The observation light 2 that enters through the incident optical system 101 may be a focused light beam or a light beam with high parallelism.
[0027] The first reflecting section 122 has multiple reflective surfaces with different reflection directions, and divides the light incident from the incident section 113 into multiple light beams and reflects them internally in different directions. The observed light is divided into multiple light images by the first reflecting section 122, and these multiple light beams 3 travel through the base of the first optical component 100 in different directions. A second reflecting section 112 is positioned on the optical path of each of the light beams 3 traveling in different directions. Each of the second reflecting sections 112 has a reflective surface that internally reflects the incident light beam 3. The internally reflected light travels through the base of the first optical component 100 in the Z-positive direction as a collimated light beam 4. The light beams 4 whose optical paths have been changed by the second reflecting sections 112 are emitted from the exit section 123 to the outside of the first optical component 100.
[0028] The light beam 5 emitted from the first optical component 100 is incident on the second optical component 200. The second optical component 200 includes a lens section 212 that focuses the incident light beam 5 onto the light-receiving surface of the light-receiving sensor 311, and a spectrometer 222 that spectrally separates the light beam 5 in the frequency domain. As a result, each light beam 5 is spectrally separated by the spectrometer 222 and irradiated onto the light-receiving surface of the light-receiving sensor 311. Here, the control of light by the lens section 212 is focusing (concentrating), but it may also be diverging.
[0029] Thus, in the optical system according to this embodiment, the observed light 2 is spatially spectrally separated by the first optical component 100, spectrally separated in the frequency domain by the second optical component 200, and detected by the detection unit 300.
[0030] (First Optical Component) Next, the first optical component 100 will be described in more detail. In the cross-sectional views shown in Figures 1 and 2, examples are shown in which the first reflector 122 and the second reflector 112 each have two reflective surfaces. However, in the following, drawings may be shown in which the first reflector 122 and the second reflector 112 do not have two reflective surfaces. The number of reflective surfaces of the first reflector 122 and the second reflector 112 of the first optical component is not limited to the examples shown in the drawings and can be appropriately changed according to the spatial resolution (resolution) of the surface spectroscopy to be achieved.
[0031] Figure 3A is a schematic cross-sectional view of the first optical component 100, cut along the optical axis OA of the incident observation light. The optical axis OA can be represented by a straight line passing through the incident portion 113 and the first reflecting portion 122. The optical axis OA extends in the Z direction along the Z axis. The X direction is perpendicular to the Z direction, and the Y direction is perpendicular to both the Z and Y directions. Figure 3B is a schematic optical path diagram showing the optical path of the light beam in the cross-section of Figure 3A. Figure 4 is a schematic perspective view of the first optical component 100, viewed from the side of the incident optical system 101 along the incident direction of the observation light (Z-positive direction). As shown in Figures 3A and 4, the multiple reflective surfaces of the second reflecting portion 112 are located in the X-positive and X-minus directions with respect to the optical axis OA. In other words, the optical axis OA is located between at least two reflective surfaces in the X direction. Furthermore, the multiple reflective surfaces of the second reflector 112 include two or more (three in this example) reflective surfaces in the X-positive direction and two or more (three in this example) reflective surfaces in the X-minus direction with respect to the optical axis OA. Also, as can be seen from Figure 4, the multiple reflective surfaces of the second reflector 112 exist in the Y-positive and Y-minus directions with respect to the optical axis OA. In other words, the optical axis OA is located between at least two reflective surfaces in the Y direction. Furthermore, the multiple reflective surfaces of the second reflector 112 include two or more (three in this example) reflective surfaces in the Y-positive direction and two or more (three in this example) reflective surfaces in the Y-minus direction with respect to the optical axis OA. Here, we have described the X and Y directions, but the same applies to two mutually orthogonal directions (diagonal directions) that are perpendicular to the optical axis OA and oblique to the X and Y directions. In this way, a mirror array is employed in which reflective surfaces (mirrors) are arranged in a one-dimensional or two-dimensional (two-dimensional in this example) manner.
[0032] The first optical component 100 comprises a substrate made of a solid material that is transparent at the wavelength of the light to be observed. For example, if the light to be observed is visible light, the substrate can be made of plastic or optical glass used in general optical applications. In the case of a part of the near-infrared region close to visible light, it is possible to make the substrate out of plastic or optical glass used in general optical applications. The refractive index of these plastics and optical glass may be less than 2.0. In the case of infrared light with longer wavelengths, the substrate can be made out of germanium, calcium fluoride, barium fluoride, zinc selenide, zinc sulfide, chalcogenide glass, etc., which are generally known as optical materials for infrared applications. In the case of ultraviolet light with a wavelength shorter than visible light, polycarbonate, acrylic, optical glass, quartz, calcium fluoride (CaF) ２ The substrate can be constructed using materials such as ). To ensure optical performance, the substrate of the first optical component 100 can also be made of a solid material with a refractive index of 2.0 or higher at the wavelength of light to be observed (usage wavelength).
[0033] In Figure 3A, the main surface on the side where the incident part 113 that causes the observation light 2 to enter the base is located is conveniently referred to as the first main surface 111, and the main surface on the side where the exit part 123 that causes the light beam 4 to exit from the base is located is conveniently referred to as the second main surface 121. In other words, the surface visible when viewing the first optical component 100 in a plan view from the direction in which the observation light 2 is incident (Z-positive direction) is conveniently called the first main surface 111, and the surface on the opposite side of the base material from the first main surface is conveniently called the second main surface 121. The incident part 113 and the second reflecting part 112 as a collimating mirror are located on the first main surface 111, and the second main surface 121 is located where the first reflecting part 122 as a splitting mirror and the exit part 123 that emits the light reflected by the second reflecting part 112 are located.
[0034] As shown in Figure 4, when the first optical component 100 is viewed through a plane from the direction in which the observation light 2 is incident (Z-positive direction), the first reflecting part 122, acting as a split mirror, is positioned within the aperture of the incident part 113. The second reflecting part 112 and the output part 123 are positioned around the first reflecting part 122. In this example, 54 second reflecting parts 112 are positioned around the first reflecting part 122. The first reflecting part 122 has 54 reflective surfaces, although not necessarily clear in Figure 4, for splitting the observation light 2 and reflecting it toward the 54 second reflecting parts 112.
[0035] As shown in Figure 3B, the observed light 2, i.e., the light beam from the object being observed, travels along the Z-positive direction, passes through the incident optical system 101 with the first reflecting section 122 in focus, and enters the base body of the first optical component 100 through the incident section 113. To suppress light loss during incidence, it is preferable to provide an anti-reflective coating on the substrate surface of the incident section 113. The anti-reflective coating can be one of those generally called AR coatings. For example, a thin film containing at least one of magnesium fluoride, silicon oxide, aluminum oxide, zirconium oxide, tantalum oxide, or titanium oxide can be provided. Alternatively, for example, an anti-reflective coating may be provided in which a large number of fine protrusions are formed and the effective refractive index gradually changes along the thickness direction of the film.
[0036] The first reflective section 122 has multiple (54 in this example) reflective surfaces with different reflection directions, and divides the light incident from the incident section 113 into multiple light beams and reflects them internally in different directions within the substrate. The normal directions (directions in which the normal to the reflective surface extends) of each of the multiple (54 in this example) reflective surfaces of the first reflective section 122 with different reflection directions may be nonparallel. To suppress losses during internal reflection, it is preferable to provide a reflective film on the substrate surface of the first reflective section 122. The reflective film may be a thin film formed by a film-forming means such as vapor deposition. For example, it may be a metallic reflective film made of silver, aluminum, gold, etc., or it may be a dielectric multilayer film in which the refractive index and film thickness of multiple layers are adjusted according to the reflection wavelength. If the refractive index of the substrate is sufficiently high (for example, refractive index 2.0 or higher), the first reflective section 122 and the second reflective section 112 can also be constructed by total internal reflection at the interface between the solid material and the atmosphere (air), in which case the reflective film can be omitted.
[0037] In the examples shown in Figures 3A and 3B, each reflective surface of the first reflecting section 122 is configured to have a concave cross-sectional shape, and each light beam 3 reflected by the reflective surface travels toward the second reflecting section 112 while being focused.
[0038] However, the shape of the internal reflection surface of the first reflecting section 122 is not limited to this example. Figure 6A shows an enlarged view of the reflection surface in Figures 3A and 3B, but as shown in Figure 6B, the first reflecting section 122 may have flat surfaces instead of concave surfaces, which connect to form a convex surface. Furthermore, multiple reflection surfaces may be arranged not only along the X direction but also along the Y direction. As shown in Figure 6C, curved mirrors with different surface orientations may be arranged along the Y direction, or as shown in Figure 6D, flat mirrors with different surface orientations may be arranged along the Y direction. In addition, multiple reflection surfaces with different surface orientations may be arranged two-dimensionally along both the X and Y directions.
[0039] Furthermore, if the individual reflective surfaces are curved, the first reflective section 122 may be a convex mirror instead of a concave mirror, as shown in Figure 6E. When the individual reflective surfaces are convex, the focused observation light 2 input from the incident optical system 101 can be magnified and reflected by the first reflective section 122. In that case, by making the second reflective section 112 a concave mirror with an appropriate curvature, the light beam 4 reflected by the second reflective section 112 can be made into a substantially parallel light beam.
[0040] The first reflector 122 divides the optical image of the observed light into multiple beams 3, which travel through the substrate of the first optical component 100 in different directions. A second reflector 112 is positioned along the optical path of each of the light beams 3 traveling in different directions. Each second reflector 112 internally reflects the incident light beam 3. The internally reflected light travels through the substrate of the first optical component 100 in the Z-plus direction as a light beam 4 with a changed (collimated) optical path. The normal directions (directions in which the normal to the reflective surface extends) of each of the multiple (54 in this example) reflective surfaces of the second reflector 112, each with a different reflection direction, may be nonparallel. To suppress losses during internal reflection, it is preferable to provide a reflective film on the substrate surface of the second reflector 112. The reflective film may be a thin film formed by a film deposition method such as vapor deposition. For example, it may be a metallic reflective film made of silver, aluminum, gold, etc., or a dielectric multilayer film in which the refractive index and film thickness of multiple layers are adjusted according to the reflection wavelength. In the example of Figures 3A and 3B, each reflective surface of the second reflective section 112 is configured to have a concave cross-sectional shape, but the shape of the reflective surface is not limited to this, and may be a flat surface, for example. Each reflective surface of the second reflective section 112 may have a reflective surface shape with a larger curvature than each reflective surface of the first reflective section 122. Separation parts may be provided between the multiple reflective surfaces of the second reflective section 112 to divide the reflective surfaces. This separation part may be a convex portion 151 provided on the substrate as shown in Figure 5A, or a concave portion 152 provided on the substrate as shown in Figure 5B. It is preferable to adopt a convex portion 151 as shown in Figure 5A in that it does not obstruct the optical path within the substrate. Furthermore, even if the convex portion 151 and the concave portion 152 are covered with a reflective film, a part of the substrate or an air gap will exist between the reflective surfaces, so they can function as a separation part.
[0041] The light beam 4 whose optical path is changed within the substrate by the second reflecting portion 112 is emitted from the emitting portion 123 as a light beam 5 to the outside of the first optical component 100. In the emitting portion 123, the substrate may be a flat surface or a curved surface as shown in the figure. In order to suppress the light quantity loss during emission, it is preferable to provide an antireflection film on the surface of the base material of the emitting portion 123. Generally, those referred to as AR coating can be applied to the antireflection film. For example, a thin film containing at least any one of magnesium fluoride, silicon oxide, aluminum oxide, zirconium oxide, tantalum oxide, and titanium oxide can be provided. Further, for example, an antireflection film in which a large number of fine protrusions are formed and the effective refractive index gradually changes along the thickness direction of the film may be provided.
[0042] (Manufacturing method of the substrate of the first optical component) The first optical component 100 according to the embodiment is produced with a substrate using a solid material that is transparent at the wavelength of the light to be observed. However, as described above, different solid materials can be used depending on the wavelength. When producing the first optical component 100 with an optical resin material used for plastic lenses or the like, for example, it can be integrally molded by an injection molding method using a mold. That is, the substrate can be an injection molded resin molded body. Further, when producing the first optical component 100 with an optical glass material used for glass lenses or the like, for example, it can be integrally molded by a glass molding method using a mold.
[0043] In the case of the injection molding method or the glass molding method, a mold having a molding surface with the optical surface shape of the first optical component inverted is manufactured, and the molten resin or glass is injected and cooled and solidified to form the substrate of the first optical component. The gate for injecting the molten resin or glass can be arranged, for example, at a plurality of positions on the mold surface for molding the first main surface. Also, in some cases, the first main surface may be molded with a mold combining a plurality of insert molds. If traces such as gate marks and boundary marks of insert molds are formed on the optical surfaces of the optical functional parts such as the incident portion 113, the first reflecting portion 122, the second reflecting portion 112, and the emitting portion 123, the optical performance of the first optical component 100 may deteriorate.
[0044] Therefore, as shown in the cross-sectional shape in FIG. 5A, in the case of an injection molding method or a glass molding method, the mold is configured such that such traces exist (become apparent) at positions where they do not optically affect, that is, between the optical surfaces of the optical functional parts.
[0045] Further, when manufacturing the first optical component 100 from a brittle material for optical use, the base body of the first optical component 100 can be manufactured as an integral body by cutting the base material. In the case of cutting, the cutting tool is relatively moved while being in contact with the base material for machining. However, traces reflecting the cutting edge shape of the cutting tool can be formed at the start or end position of the cutting. If such traces are formed on the optical surfaces of the optical functional parts such as the incident part 113, the first reflection part 122, the second reflection part 112, and the exit part 123, the optical performance of the first optical component 100 may deteriorate.
[0046] Therefore, as shown in the cross-sectional shape in FIG. 5B, it is desirable to set the movement locus of the cutting tool during cutting such that the traces of the cutting are present (become apparent) at positions where they do not optically affect, that is, between the optical surfaces of the optical functional parts.
[0047] As described above, the first optical component 100 according to the embodiment is formed integrally with an incident part 113, a first reflection part 122, a second reflection part 112, and an exit part 123 as optical functional parts on a base body made of a solid material that is transparent at the wavelength of light to be observed. Since it is a single component in which the optical functional parts are integrated with the base body made of a solid material, there is no need to adjust the assembly positions of the respective optical functional parts when assembling the spectroscopic device, and an improvement in manufacturing yield and a reduction in manufacturing cost are achieved. Further, since it is an integrated component, during the operation of the spectroscopic device, the relative positions of the optical functional parts such as the incident part 113, the first reflection part 122, the second reflection part 112, and the exit part 123 do not shift due to vibration, impact, etc., and high spectroscopic accuracy can be stably maintained. For example, even when receiving an impact or vibration from the outside, the positional relationship between the first main surface 111 and the second main surface 121 is suppressed from fluctuating in both the XY direction and the Z direction. For this reason, changes in the XY direction position of the light beam 5 emitted from the exit part 123 and the cross-sectional shape 6 (FIG. 6B) of the light beam are unlikely to occur.
[0048] (Second Optical Component) Next, the second optical component 200 will be described in more detail. In the cross-sectional views shown in Figures 1 and 2, an example is shown in which the second optical component 200 has two sets of lens units 212 and spectral units 222. However, in the following description, drawings in which the number of sets of lens units 212 and spectral units 222 is not two may be referred to. The number of sets of lens units 212 and spectral units 222 in the second optical component is not limited to the example shown and can be changed as appropriate depending on the spatial resolution (resolution) of the surface spectroscopy to be achieved.
[0049] Figure 7A is a schematic cross-sectional view of the second optical component 200, cut along the optical axis of the incident light beam 5 (Figure 2). The second optical component 200 has a lens portion 212 and a spectral portion 222, corresponding to each portion of the light beam reflected by the second reflecting portion 112 of the first optical component 100 and emitted from the emission portion 123. Figure 7B shows an enlarged view of one of the spectral portions 222, illustrating the numerous fine grooves provided in the spectral portion 222.
[0050] The lens section 212 and the spectrometer section 222 are arranged in correspondence with the second reflecting section 112, as illustrated in Figure 4. Figure 8 is a schematic perspective view of the second optical component 200, viewed from the side of the detection section 300 (Figure 1) along the Z-minus direction. The cross-sectional shape when the second optical component 200 is cut may differ depending on the position and direction of the cut, but Figure 7A shows the cross-sectional shape when cut along the X direction at a position that includes six sets of lens section 212 and spectrometer section 222.
[0051] The second optical component 200 comprises a substrate made of a solid material that is transparent at the wavelength of the light to be observed. For example, if the light to be observed is visible light, the substrate can be made of plastic or optical glass used in general optical applications. In the case of a part of the near-infrared region close to visible light, it is possible to make the substrate out of plastic or optical glass used in general optical applications. In the case of infrared light with longer wavelengths, the substrate can be made out of germanium, calcium fluoride, barium fluoride, zinc selenide, zinc sulfide, chalcogenide glass, etc., which are generally known as optical materials for infrared applications. In the case of ultraviolet light with a wavelength shorter than visible light, polycarbonate, acrylic, optical glass, quartz, calcium fluoride (CaF) can be used. ２ It is possible to construct the base using materials such as ).
[0052] The lens portion 212 has a curvature suitable for efficiently diffracting the light beam 5 (Figure 3B) emitted from the first optical component 100 in the spectral portion 222 and forming an image on the light-receiving surface of the light-receiving sensor 311. Although a convex lens is shown as an example in the figure, the lens portion 212 can also be a concave lens depending on the optical path design of the optical system.
[0053] The light beam incident on the lens portion 212 enters the base body of the second optical component 200. To suppress light loss during incidence, it is preferable to provide an anti-reflective coating on the surface of the lens portion 212. The anti-reflective coating can be one of those generally called AR coatings. For example, a thin film containing at least one of magnesium fluoride, silicon oxide, aluminum oxide, zirconium oxide, tantalum oxide, or titanium oxide can be provided. Alternatively, for example, an anti-reflective coating may be provided in which numerous fine protrusions are formed and the effective refractive index gradually changes along the thickness direction of the film.
[0054] The light beam incident from the lens section 212 passes through the inside of the base of the second optical component 200 and exits from the spectral section 222. The spectral section 222 spectrally separates the light beam in the frequency domain (spectrum) as schematically shown in Figure 2. The spectral section 222 has a diffraction grating, and spectral separation can be performed using this diffraction grating. The specifications of the spectral section 222 can be set according to the desired spectral performance. Specifically, the grating pitch, the apex angle of the grating, the angle of the base surface forming the grating, the blaze angle of the grating formed on the base surface, etc., are set as appropriate.
[0055] Figure 7A shows a preferred example in which the lens portion 212 and the spectral portion 222 are integrally formed on a single substrate, but the configuration of the second optical component 200 is not limited to this. For example, as shown in Figure 7C, the lens portion 212 and the spectral portion 222 may be provided on different substrates. To suppress light loss, it is preferable to provide an anti-reflective coating similar to that described above on the surfaces facing each other between the different substrates (the exit surface of the substrate having the lens portion 212 and the incident surface of the substrate having the spectral portion 222). When the lens portion 212 and the spectral portion 222 are provided on different substrates, the two substrates may be spaced apart as shown in Figure 7C, or they may be in contact with each other, or they may be integrated using an adhesive, for example.
[0056] Figure 7A shows an example where the lens section 212 and the spectral section 222 are arranged in this order in the direction of light beam propagation (Z-positive direction), but the configuration of the second optical component 200 is not limited to this. That is, in the optical path of the light beam spatially divided (spectrometrically) by the first optical component 100, the lens section 212 does not necessarily have to be placed upstream of the spectral section 222.
[0057] Figure 9A is a cross-sectional view showing an example in which the spectral section 222 and the lens section 212 are arranged in this order on a single substrate in the direction of light beam propagation (Z-positive direction). Figure 9B is a cross-sectional view showing an example in which the spectral section 222 and the lens section 212, arranged in this order, are provided on different substrates. To suppress light loss, it is preferable to provide an anti-reflective coating similar to that described above on the surfaces facing each other between the different substrates (the exit surface of the substrate having the spectral section 222 and the incident surface of the substrate having the lens section 212). The two substrates may be arranged spaced apart as shown in Figure 9B, but they may also be in contact with each other, or they may be integrated using an adhesive, for example.
[0058] Furthermore, it is not necessary to position the lens portion 212 or the spectral portion 222 of the second optical component facing the emission portion 123 of the first optical component 100. Nor is it necessary to position the lens portion 212 or the spectral portion 222 of the second optical component facing the light receiving sensor 311.
[0059] As illustrated in Figures 10A and 10B, the lens portion 212 and the spectral portion 222 may be provided on separate substrates, and the separate substrates may be arranged so that the lens portion 212 and the spectral portion 222 face each other. This has the advantage that the optically functional parts, the lens portion 212 and the spectral portion 222, are less likely to come into contact with foreign matter on the outside of the second optical component 200. Furthermore, it is preferable to provide an anti-reflective coating similar to that described above on the incident surface of the second optical component 200 facing the emission portion 123 of the first optical component 100, and on the emission surface of the second optical component 200 facing the light receiving sensor 311, in order to suppress light loss.
[0060] As explained with reference to Figure 1, the second optical component 200 is precisely positioned and fixed relative to the first optical component 100 via a spacer 352. Therefore, during operation of the spectrometer, no displacement of the relative position to the first optical component 100 occurs due to vibration, shock, etc., making it possible to stably maintain high spectral accuracy.
[0061] Furthermore, if the lens section 212 and the spectroscopic section 222 are integrally formed on a single substrate made of a solid material that is transparent at the wavelength of light to be observed, there is no need to adjust the assembly position of the lens section 212 and the spectroscopic section 222 when assembling the spectrometer. This improves manufacturing yield and reduces manufacturing costs. In addition, during operation of the spectrometer, vibration, shock, etc., will not cause a shift in the relative position of the lens section 212 and the spectroscopic section 222, making it possible to stably maintain high spectral accuracy.
[0062] [Comparative Example] As a comparative example, a conventional surface spectrometer was prepared, which assembled a slice mirror and a collimating mirror that were prepared as separate parts. As an example, an optical device 400 (Figure 1), which is a surface spectrometer, was prepared, which includes the first optical component 100 shown in Figure 3A and the second optical component 200 shown in Figure 7A.
[0063] For the comparative example and the example spectrometers, observation light was incident using the same incident optical system, and the output light emitted from the spectrometer was detected using the same detection unit. A two-dimensional image sensor with a pixel pitch of 5 μm was used as the detection unit, and the same acceleration (impact) was applied to the comparative example and the example spectrometers using an acceleration tester, and the change (error) in spectral performance was evaluated. Specifically, accelerations of 1G and 2G were applied from the acceleration tester, and the imaging results of spectral images before and after the application of acceleration were compared.
[0064] In the embodiment, there was no change in the image captured of the output light emitted from the surface spectrometer before and after applying an acceleration of 1G. Similarly, there was no change in the image captured of the output light emitted from the surface spectrometer before and after applying an acceleration of 2G. From this, it can be seen that even when acceleration was applied, the positional shift of the light beam emitted from the surface spectrometer was less than one pixel pitch (5 μm). In the embodiment, the first reflector 122 and the second reflector 112, which greatly affect spectral accuracy, are integrated with the base of the first optical component, and it can be evaluated that no change occurred in spectral performance even when subjected to acceleration (impact).
[0065] In contrast, in the comparative example, at least a portion of the image captured from the output light emitted from the surface spectrometer was shifted by approximately 10 μm (equivalent to 2 pixels) before and after applying a 1G acceleration, and by approximately 30 μm (equivalent to 6 pixels) before and after applying a 2G acceleration.
[0066] The spectral performance of an optical system depends on the spatial and chromatic resolution of the surface spectrometer and the resolution of the image sensor. In the comparative example, it was found that the application of acceleration caused a shift of, for example, two to three bands in wavelength resolution.
[0067] These results indicate that, when the spectrometer is actually operated, the example is less prone to misalignment of the optical elements compared to the comparative example, thus enabling the stable maintenance of high spectral accuracy.
[0068] [Other Embodiments] This disclosure is not limited to the embodiments and examples described above, and many modifications are possible within the technical concept of this disclosure. For example, all or part of the different embodiments and examples described above may be combined and implemented.
[0069] Furthermore, if this specification contains a statement such as "A is B," even if it omits a statement such as "A is not B," it can be said that this specification discloses that "A is not B." This is because the statement "A is B" implies that the case where "A is not B" is being considered.
[0070] The optical components, optical devices, optical systems, etc. disclosed herein are useful as techniques for achieving high spectral accuracy in various fields such as astronomical observation and materials analysis.
[0071] The present invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are attached to make the scope of the invention public.
[0072] This application claims priority based on Japanese Patent Application No. 2025-019634, filed on 7 February 2025, and all of its contents are incorporated herein by reference.
[0073] 2... Observation light / 2a... Reflecting surface / 3... Light beam / 4... Light beam / 5... Light beam / 6... Cross-sectional shape of the light beam / 100... First optical component / 101... Incident optical system / 111... First main surface / 112... Second reflecting part / 113... Incident part / 121... Second main surface / 122... First reflecting part / 123... Outgoing part / 151... Convex part / 152... Concave part / 200... Second optical component / 212... Lens part / 222... Spectroscopic part / 300... Detection part / 311... Light receiving sensor / 350... Case / 351... Light shielding member / 352... Spacer / 400... Optical device / 500... Information processing device
Claims
1. An optical component comprising a substrate made of a solid material transparent to light of a wavelength used, the optical component comprising: an incident part for injecting light into the interior of the substrate; a first reflecting part for splitting the light incident from the incident part into a plurality of light beams and reflecting them in different directions within the substrate; a second reflecting part for reflecting each of the plurality of light beams reflected by the first reflecting part to change the optical path within the substrate; and an exiting part for emitting each of the plurality of light beams reflected by the second reflecting part to the outside of the substrate.
2. The optical component according to claim 1, wherein the second reflecting portion has a plurality of reflecting surfaces including at least two reflecting surfaces, and the straight line is located between the two reflecting surfaces in a direction perpendicular to the straight line passing through the incident portion and the first reflecting portion.
3. The optical component according to claim 1 or 2, wherein the first reflecting portion has a plurality of reflective surfaces, and the normal directions of each of the plurality of reflective surfaces of the first reflecting portion are nonparallel to each other, and / or the second reflecting portion has a plurality of reflective surfaces, and the normal directions of each of the plurality of reflective surfaces of the second reflecting portion are nonparallel to each other.
4. The optical component according to any one of claims 1 to 3, wherein the first reflective portion comprises a reflective film formed on the surface of the substrate, and / or the second reflective portion comprises a reflective film formed on the surface of the substrate.
5. The optical component according to any one of claims 1 to 4, wherein the incident portion comprises an anti-reflective coating formed on the surface of the substrate, and / or the output portion comprises an anti-reflective coating formed on the surface of the substrate.
6. The optical component according to any one of claims 1 to 5, wherein the solid material is a material having a refractive index of less than 2.0 at the wavelength of use, and / or the solid material is a resin material.
7. The optical component according to any one of claims 1 to 6, wherein the first reflecting portion has a plurality of reflective surfaces, each of which of the plurality of reflective surfaces of the first reflecting portion is a flat surface, and / or the second reflecting portion has a plurality of reflective surfaces, each of which of the plurality of reflective surfaces of the second reflecting portion is a concave surface.
8. The optical component according to any one of claims 1 to 7, wherein the second reflective portion has a plurality of reflective surfaces, and the substrate has convex or concave portions between the plurality of reflective surfaces of the second reflective portion.
9. The optical component according to any one of claims 1 to 8, wherein the substrate is an injection-molded resin molded body.
10. An optical device comprising an optical component according to any one of claims 1 to 9, and an exterior component for housing the optical component.
11. The optical apparatus according to claim 10, further comprising a spectrometer for spectrally separating each of the plurality of light beams.
12. The optical apparatus according to claim 11, wherein the spectroscopic unit has a diffraction grating.
13. The optical device according to claim 11, wherein the optical component comprising the substrate is a first optical component, and further comprises a second optical component into which a plurality of light beams emitted from the first optical component are incident, the first optical component and the second optical component are housed in the exterior component, and the second optical component has the spectral section.
14. The optical apparatus according to claim 13, wherein the second optical component comprises a substrate made of a solid material transparent to light of the wavelength used.
15. The optical apparatus according to claim 14, wherein the solid material of the second optical component is a resin material.
16. The optical apparatus according to claim 14, wherein the second optical component has a lens portion that controls each of the plurality of light beams emitted from the emission portion.
17. The optical device according to claim 14, wherein a light-shielding member is disposed between the first optical component and the second optical component, the member having a window that transmits each of the plurality of light beams emitted from the emission section.
18. The optical device according to claim 14, wherein a light-shielding member is provided, which has a window that transmits each of the plurality of light beams emitted from the second optical component.
19. An optical system comprising an optical component according to any one of claims 1 to 9, and an incident optical system for controlling the light incident on the incident portion.
20. An optical system comprising an optical component according to any one of claims 1 to 9, and a light receiving sensor that receives a plurality of light beams emitted from the emission unit.