JP4348160B2 - Spectrometer - Google Patents

Description

  The present invention relates to a spectrometer that splits input light, and more particularly, to a spectrometer having a diffraction grating in a slab waveguide.

  Near-infrared light spectroscopy technology can be applied to the measurement of biological substances such as sugar chains, blood sugar, urea, and environmental substances such as carbon dioxide and NOx (nitrogen oxide), as well as agriculture and food. It can be applied to component analysis in all fields such as manufacturing.

  Light in the near-infrared region having a wavelength of about 1 to 4 μm can generally be separated by spectroscopy using reflection on a diffraction grating or Fourier transform infrared spectroscopy (FTIR method). In particular, spectroscopy using a diffraction grating is used in various fields because the structure of the apparatus used in this spectroscopy is simple.

  As a spectroscope using a diffraction grating, for example, as shown in FIG. 11, a lens 51 for collecting near-infrared light emitted from a light source 50 on a diffraction grating 52 and light L reflected by the diffraction grating 52 are detected. What is provided with the detector 54 for doing is known. In this spectroscope, when the light collected by the lens 51 is reflected by the diffraction grating 52, the reflection angle of the reflected light L is measured by moving the position of the detector 54. Yes. That is, in this spectroscope, the wavelength of light incident on the spectroscope is specified by the angle of the light L reflected by the diffraction grating 52.

  However, in this spectrometer, the wavelength resolution of light cannot be sufficiently obtained unless the distance between the diffraction grating 52 and the detector 54 is increased and the positioning accuracy of the detector 54 is not increased by a complicated driving mechanism. There was a problem. Therefore, it is difficult to reduce the size of such a spectroscope, and even the size of the spectroscope is limited to the desktop size.

On the other hand, a spectroscope in which a diffraction grating is formed in a slab waveguide by applying micromachine technology is known (see, for example, Non-Patent Document 1). In this spectroscope, a diode array (detector) is disposed at a position where light dispersed by the diffraction grating is collected. Therefore, this spectroscope can be miniaturized because it is not necessary to move the detector in order to detect the dispersed light.
Takanori Kiyokura, Spectroscopic Research Vol. 51, No. 1, Volume 23-25 “Development and application of micro-spectrometers using micromachine technology” (2002)

  By the way, this spectrometer can be further miniaturized if the distance between the diffraction grating and the detector is shortened, but if the distance between the diffraction grating and the detector is shortened, the wavelength resolution of the light is lowered. There is. Therefore, in this spectrometer, in order to maintain the necessary wavelength resolution of light, it is necessary to have a size of at least about 29 mm × 14 mm, and it is difficult to further reduce the size.

  Accordingly, an object of the present invention is to provide a spectroscope that can be downsized while maintaining a high wavelength resolution of light.

The invention according to claim 1 for solving the above-mentioned problem is a spectroscope in which input light is dispersed by a diffraction grating formed in a slab type waveguide, and among the light dispersed by the diffraction grating. A first channel waveguide having a base end disposed so as to cut out and propagate only light belonging to a predetermined band, and a waveguide disposed adjacent to the first channel waveguide. the a resonator you resonate in a narrow band than the predetermined band belonging to a predetermined band, is arranged to sandwich between the resonator of the first channel waveguide, the resonance in the resonator And a second channel waveguide through which the transmitted light is extracted and propagated.

  In this spectroscope, when the light separated by the diffraction grating is drawn out to the second channel waveguide through the first channel waveguide and the resonator, the resonator has the light at a constant wavelength interval due to the resonance phenomenon. And outputs the light to the second channel waveguide. That is, in this spectrometer, the resonator disperses part of the spectrum having a predetermined band with high accuracy. In addition, since the wavelength resolution of light by spectroscopy in such a resonator does not depend on the distance between the detector and the diffraction grating as in the conventional spectrometer, according to the spectrometer of the present invention, the detector and Even if the distance from the diffraction grating is reduced to achieve miniaturization, the wavelength resolution can be maintained high.

  The invention described in claim 2 is the spectrometer according to claim 1, further comprising a heater for heating the waveguide of the resonator.

  In this spectroscope, when the waveguide of the resonator is heated by the heater, the refractive index of the waveguide changes. When the refractive index changes, the resonance wavelength of the resonator changes. Therefore, according to this spectrometer, by changing the temperature of the resonator, the position of the resonance wavelength can be controlled, that is, spectroscopy can be performed.

  According to a third aspect of the present invention, in the spectrometer according to the first or second aspect, a plurality of the resonators are provided, and the lengths of the waveguides of the resonators are different from each other. Features.

  In this spectrometer, since the lengths of the waveguides of the resonators are different, the resonance wavelengths are different. Therefore, according to such a spectroscope, if the length of each waveguide is changed in accordance with the wavelengths of the plurality of lights to be extracted, the plurality of lights to be extracted can be extracted through the second channel waveguide. .

The invention according to claim 4 is the spectrometer according to any one of claims 1 to 3, wherein the first channel waveguide, the waveguide of the resonator, and the second channel waveguide are The core portion is surrounded by a clad portion, and the core portion includes a gallium arsenide compound, an indium phosphorus compound, a silicon / germanium compound, a zinc semiconductor, LiNbO ₃ , a lithium / titanium compound, nitriding Including at least one of silicon, silicon oxynitride, and silicon carbide, and the cladding includes at least one of a gallium arsenide compound, an indium phosphorus compound, a silicon oxynitride compound, an epoxy polymer, a polyimide polymer, and air. It is characterized by including.

  In this spectroscope, since the material having a high refractive index as described above is used for the core portion, light can be confined in a narrow region below the order of micrometers (μm). Also, in this spectrometer, since a material having a high refractive index is used for the core portion, even if the waveguide formed by the core portion is laid out so as to be sharply bent, the light travels in the waveguide. There is no hindrance. Therefore, in this spectroscope, the degree of freedom of the pattern of the waveguide increases when the waveguide is formed in the core portion.

  Invention of Claim 5 is equipped with the input side channel waveguide for guide | inducing the light irradiated to the said diffraction grating in the spectrometer described in any one of Claim 1 thru | or 4, The light input end of the input side channel waveguide and the light output end of the second channel waveguide are tapered toward the respective ends, and the input end and The output end portion is covered with a material having a smaller refractive index than the material constituting the input end portion and the output end portion.

  In this spectroscope, the input end of light and the output end of light that are tapered are covered with a material having a smaller refractive index than the material constituting the input end and the output end. The sensitivity of the vessel is increased.

  The invention according to claim 6 is a spectroscope comprising a first beam splitting unit that splits incident light, and a plurality of second beam splitting units that further split the light split by the first beam splitting unit. The second spectroscopic unit is the spectroscope according to claim 1.

  In this spectroscope, the light split by the first spectroscopic unit is further spectroscopically split by each second spectroscopic unit which is the spectroscope according to claim 1. Therefore, according to this spectrometer, it is possible to efficiently disperse a wide band of wavelengths.

  According to the spectroscope of the present invention, it is possible to reduce the size while maintaining a high wavelength resolution of light.

  Next, a spectrometer according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. 1 is a perspective view of the spectrometer according to the present embodiment, FIG. 2A is a perspective view showing a state in which the upper cladding layer, the spot size conversion member, and the heat ray of the spectrometer of FIG. 1 are removed, FIG. (B) is a perspective view showing the spot size conversion member attached to the spectrometer of FIG. 1, FIG. 3 is a perspective view for explaining the structure of the spot size conversion member, and FIG. It is sectional drawing in the -A line.

  The spectroscope S1 according to the present embodiment uses a slab structure, and as shown in FIG. 1, a substrate 10, a lower cladding layer 11 formed on the substrate 10, and the lower cladding layer. 11 and a core layer 12 formed on the core layer 12 and an upper cladding layer 13 formed on the core layer 12. The core layer 12 corresponds to a “core part” in the claims, and the lower clad layer 11 and the upper clad layer 13 correspond to “clad parts” in the claims. In the spectroscope S1, near-infrared light having a wavelength of about 1 to 4 μm (hereinafter simply referred to as “light”) is applied to the core layer 12 sandwiched between the lower clad layer 11 and the upper clad layer 13. A so-called slab type waveguide 12a for propagation is formed.

In this embodiment, a silicon wafer is used as the substrate 10.
As the material of the core layer 12, a material having a refractive index of 2 or more can be used. Specifically, for example, a gallium arsenide compound, an indium phosphorus compound, a silicon / germanium compound, a zinc semiconductor, a LiNbO ₃ , lithium / titanium compounds, silicon nitride, silicon oxynitride, silicon carbide and the like.

  As the material of the lower cladding layer 11 and the upper cladding layer 13, a material having a lower refractive index than that of the core layer 12 can be used. Specifically, the refractive index is lower than that of silicon oxide or the core layer. Examples thereof include a silicon oxynitride film, an indium phosphorus compound, a gallium arsenide compound, and the like that have a reduced thickness. Moreover, as a material of the upper clad layer 13, for example, a resin material such as an epoxy material or a polyimide material may be used. Further, the upper clad layer 13 may be air as in the structure in which the upper clad layer 13 is not provided.

  As is apparent from FIG. 2A, the spectroscope S1 is formed by cutting the core layer 12 in a predetermined shape on the lower clad layer 11, and the input-side channel waveguide 14 is formed. A cut-out channel waveguide 15, a ring-shaped waveguide 16 a constituting the resonator 16, and an output-side channel waveguide 18. The cut-out channel waveguide 15 corresponds to a “first channel waveguide” in the claims, and the output-side channel waveguide 18 corresponds to a “second channel waveguide” in the claims. . As shown in FIG. 2B, these waveguides 14, 15, 16 a, 18 are covered with an upper cladding layer 13, and the waveguides 14, 15, 16 a, 18 The periphery is surrounded by the lower cladding layer 11 and the upper cladding layer 13. Further, the spectroscope S1 has a diffraction pattern in which a silicon oxide film constituting the upper clad layer 13 shown in FIG. 1 is fitted into a recess 17a in which the core layer 12 is cut in a predetermined shape on the lower clad layer 11. A grid 17 is provided. Hereinafter, the input side channel waveguide 14, the diffraction grating 17, the cutout channel waveguide 15, the resonator 16, and the output side channel waveguide 18 will be described in this order.

  As shown in FIG. 2A, the input-side channel waveguide 14 is obtained by cutting the core layer 12 into a rod shape on the lower cladding layer 11, and has a rectangular cross-sectional shape. The input-side channel waveguide 14 is formed with an input end 14a through which light is input in the vicinity of the edge of the spectroscope S1. The input end 14a is gradually tapered toward the edge of the spectroscope S1, that is, the end of the input end 14a. The input-side channel waveguide 14 extends linearly from the input end portion 14 a along the lower cladding layer 11, and is bent by changing the extending direction to the direction toward the diffraction grating 17. The tip end portion 14 b extending from the input end portion 14 a of the input-side channel waveguide 14 faces the grating surface 17 b of the diffraction grating 17.

  As described above, the diffraction grating 17 is formed by fitting the material constituting the upper clad layer 13 into the recess 17a obtained by scraping the core layer 12 so as to represent the outer shape of the diffraction grating 17, A large number of fine grooves 17c extending in the thickness direction of the core layer 12 are formed in parallel at equal intervals on the lattice surface 17b facing the tip portion 14b of the channel waveguide 14. When the diffraction grating 17 is input from the input end portion 14 a of the input side channel waveguide 14 and receives light irradiated from the tip end portion 14 b at the grating surface 17 b, the base end portion 15 a of the cut-out channel waveguide 15 receives the light. When reflecting the light received toward, it is comprised so that the received light may be separated (spectroscopic) into a single wavelength component.

  The cut-out channel waveguide 15 cuts and propagates only light in a predetermined band from the light dispersed by the diffraction grating 17 as described later. The cut-out channel waveguide 15 is obtained by cutting the core layer 12 into a rod shape on the lower cladding layer 11 and has a rectangular cross-sectional shape. The cut-out channel waveguide 15 is formed so as to extend linearly along the lower cladding layer 11 from the base end 15a that receives the light reflected by the grating surface 17b of the diffraction grating 17 toward the edge of the spectroscope S1. Has been.

  The resonator 16 includes a ring-shaped waveguide 16 a that is disposed adjacent to the cut-out channel waveguide 15. The ring-shaped waveguide 16a is obtained by cutting the core layer 12 into a ring shape on the lower clad layer 11, and its cross-sectional shape is rectangular. The resonator 16 has many resonance points, and the interval between resonance wavelengths is constant. The resonator 16 can extract light at a constant wavelength interval by a resonance phenomenon as will be described later.

  The output-side channel waveguide 18 is disposed on the lower cladding layer 11 so as to cut out the resonator 16 and sandwich it between the channel waveguide 15. The output side channel waveguide 18 is obtained by cutting the core layer 12 into a rod shape on the lower clad layer 11 and has a rectangular cross-sectional shape. The output-side channel waveguide 18 extends from the edge of the spectroscope S1 so as to be close to the resonator 16, and then turns back and extends again to the vicinity of the edge of the spectroscope S1. As will be described later, the output-side channel waveguide 18 is a band in which a band of light that is split by the diffraction grating 17 and cut out by the cut-out channel waveguide 15 overlaps a band of light that resonates by the resonator 16. Only the light of the light propagates. An output end 18a from which light propagated through the output side channel waveguide 18 is output is formed at the tip of the output side channel waveguide 18 extending to the vicinity of the edge of the spectroscope S1. The output end 18a is gradually tapered toward the edge of the spectrometer S1, that is, the end of the output end 18a.

  In addition to the input-side channel waveguide 14, the diffraction grating 17, the cut-out channel waveguide 15, the resonator 16, and the output-side channel waveguide 18, the spectroscope S1 includes a spot as shown in FIG. Size conversion members 20 a and 20 b and a heat wire 19 are provided. The hot wire 19 corresponds to a “heater” in the claims.

  2A and 2B, the spot size conversion member 20a is disposed at the input end portion 14a of the input-side channel waveguide 14 and is spot size conversion member. 20 b is disposed at the output end 18 a of the output-side channel waveguide 18.

  As shown in FIG. 3, the spot size conversion member 20 a and the spot size conversion member 20 b include a first covering member 21 that covers the input end portion 14 a and the output end portion 18 a on the lower cladding layer 11, and the lower cladding layer 11. And the second covering member 22 that covers the first covering member 21.

  The first covering member 21 is made of a material having a higher refractive index than the lower cladding layer 11 and a lower refractive index than the core layer 12 constituting the input end portion 14a and the output end portion 18a. . The material of the first covering member 21 may be appropriately selected from the materials for the lower cladding layer 11 and the upper cladding layer 13.

  The second covering member 22 is made of a material having a slightly lower refractive index than that of the first covering member 21. The material of the second covering member 22 may be appropriately selected from the materials for the lower cladding layer 11 and the upper cladding layer 13.

  Such a spot size conversion member 20a is connected to an optical fiber (not shown) on the end surface 21a (see FIGS. 1 and 3) of the first covering member 21 exposed on the side surface of the spectroscope S1. The end face 21a of the first covering member 21 of the spot size conversion member 20a has a width and a height that are substantially the same from about half the diameter of the core portion (not shown) of the optical fiber. Should be set.

  The spot size conversion member 20b includes, for example, a PIN photodiode (external to the spectroscope S1) disposed on the end surface 21b (see FIG. 1) of the first covering member 21 exposed at the side of the spectroscope S1. An optical fiber (not shown) for connection to a detector (not shown) such as a PD) is connected. Further, in the spectrometer S1, as shown in FIG. 5A, a detector 24 such as a PIN photodiode (PD) may be connected to the end face 21b instead of the optical fiber. In this spectrometer S1, as shown in FIG. 5A, the detector 24 is connected to the output end 18a via the spot size conversion member 20b. When the detector 24 is directly disposed on 18a, the spot size conversion member 20b may be omitted.

  The hot wire 19 heats the resonator 16, and has a hot wire portion 19a having substantially the same shape as the planar shape of the resonator 16, as shown in FIG. As shown in FIGS. 1 and 4, the hot wire 19 is formed on the surface of the upper cladding layer 13 so that a hot wire portion 19 a having substantially the same shape as the planar shape of the resonator 16 is located above the resonator 16. ing.

  Next, the operation of the spectrometer S1 according to the present embodiment will be described with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 5 (a) is a conceptual diagram for explaining the operation of the spectrometer according to the present embodiment, and FIG. 5 (b) is cut out from the light separated by the diffraction grating by the channel waveguide. FIG. 5C is a graph showing the relationship between the wavelength of the reflected light and the spectral light intensity. FIG. 5C is a graph showing the relationship between the wavelength of the light extracted by the resonator at a constant wavelength interval and the spectral light intensity. d) is a graph showing the relationship between the wavelength of the light propagating through the output channel waveguide through the resonator and the spectral light intensity among the light propagating through the cut-out channel waveguide, and FIG. It is the graph which showed a mode that the resonant wavelength of a resonator changed when it heated.

  First, when light 25 used for spectrum analysis propagates to the optical fiber 23 connected to the spot size conversion member 20a, the light 25 is input to the input side channel waveguide 14 through the spot size conversion member 20a. . At this time, the spot size conversion member 20a is structured such that the first coating member 21 and the second coating member cover the tapered input end portion 14a (see FIG. 3) as described above. Even if the diameter of 23 is as small as several μm to several tens of μm, the spectroscope S1 can couple the optical fiber 23 and the input side channel waveguide 14 with high conversion efficiency. Therefore, the sensitivity of the spectroscope S1 is increased.

  The light input to the input side channel waveguide 14 is irradiated from the front end portion 14 b toward the diffraction grating 17 by propagating through the input side channel waveguide 14. At this time, the input-side channel waveguide 14 is cut out from the core layer 12 and is formed of a material having a large refractive index as described above. Therefore, in the spectroscope S1, since the input side channel waveguide 14 is formed of a material having a high refractive index, light is confined in a narrow region below the micrometer (μm) order, that is, the input side channel waveguide 14. be able to. Further, in this spectroscope S1, since the input side channel waveguide 14 is formed of a material having a high refractive index, the input side channel waveguide 14 is laid out so as to be sharply bent with a radius of, for example, several μm. In addition, the progress of light in the input side channel waveguide 14 is not hindered. Therefore, in the spectroscope S1, the degree of freedom of the pattern of the input side channel waveguide 14 is increased.

  Next, the light irradiated from the tip end portion 14b of the input side channel waveguide 14 is split by the diffraction grating 17, and the split light (spectrum line) is input to the cut channel waveguide 15 and cut out. It propagates through the channel waveguide 15. At this time, by setting the base end portion 15a to a predetermined position, the light 26 propagating through the cut-out channel waveguide 15 has a wavelength among the spectral lines dispersed by the diffraction grating 17, as shown in FIG. Is limited to light belonging to the predetermined band F. When such light 26 propagates, the cut-out channel waveguide 15 is formed of the same high refractive index material as that of the input-side channel waveguide 14 described above, so that the light can be confined in a narrow region.

On the other hand, as shown in FIG. 5C, the resonator 16 extracts light at a constant wavelength interval due to the resonance phenomenon. In this spectrometer S1, the light 26 propagating through the cut-out channel waveguide 15 is extracted. Since it is limited to the light of the band F, the resonator 16 sucks up only the light of the wavelength λ ₀ belonging to the band F as shown in FIG.

  Since such a resonator 16 is formed of the same high refractive index material as that of the input side channel waveguide 14 described above, the light can be confined in a narrow region and laid out so as to be bent sharply. it can. Therefore, the resonator 16 of the spectroscope S1 can be constituted by a ring-shaped waveguide 16a (see FIG. 1) having a radius of about several μm.

  Since such a resonator 16 can realize a Q value of about 1000 to 10000, a narrow resonance peak of about 1 / Q of the resonance wavelength, that is, about 0.1 to 1 nm can be obtained. By setting the radius of the resonator 16 to about several μm, the resonator 16 can expand the interval at which the resonance wavelength occurs to about 100 nm. Therefore, the resonator 16 of the spectroscope S1 can disperse part of the spectrum having a certain band with high accuracy.

The light having the wavelength length λ ₀ sucked up by the resonator 16 propagates as light 27 in the output side channel waveguide 18 and is detected by the detector 24 via the spot conversion member 20b. When the light 27 propagates in the output side channel waveguide 18, the output side channel waveguide 18 is formed of the same high refractive index material as that of the input side channel waveguide 14. It can be confined in a narrow area. Further, since the output side channel waveguide 18 is made of a material having a high refractive index, it can be laid out so as to be bent sharply.

  On the other hand, when the hot wire 19 (see FIGS. 1 and 4) is energized, the hot wire 19 generates heat, and the resonator 16 (see FIG. 1) is caused by the heat transferred from the hot wire 19 through the upper cladding layer 13. Heated. When the ring-shaped waveguide 16a is heated, the refractive index of the ring-shaped waveguide 16a (core layer 12) changes.

  When the refractive index changes in this way, as shown in FIG. 6, the frequency (wavelength) at which the resonator 16 resonates moves in the above-mentioned wavelength band F (see FIGS. 5B and 5D). . Therefore, by changing the temperature of the resonator 16, the position of the resonance wavelength can be controlled, that is, the light can be dispersed.

  More specifically, when, for example, silicon is used for the ring-shaped waveguide 16a (core layer 12), in order to change the wavelength by 1%, it is necessary to instantaneously generate a temperature rise of about 100K to 150K. is there. By using the phenomenon that the wavelength changes in the process of instantaneously raising the temperature of the ring-shaped waveguide 16a and returning to the original temperature, the spectroscope S1 can perform spectroscopy. For example, a change of 1% in wavelength at 1500 nm corresponds to a 15 nm band. For example, the diameter of the ring-shaped waveguide 16a is set to several tens of μm or less, and the thickness of the ring-shaped waveguide 16a (core layer 12) is set to a thickness less than a micrometer (μm), so that at most. The temperature of the ring-shaped waveguide 16a can be adjusted by applying a heat quantity of several tens of micro J for several ms. For this reason, since a large external power and driving circuit are not required, the entire spectroscopic device incorporating the spectroscope S1 can be miniaturized.

  Further, when the resonator 16 is heated with the hot wire 19 in this way, the amount of heat generated by the hot wire 19 is set to several mJ to several tens by setting the thickness of the upper cladding layer 13 (see FIG. 1) to several μm. It can be kept as low as mJ. Further, by reducing the thickness of the lower cladding layer 11 (see FIG. 1), the heat applied to the resonator 16 is quickly diffused toward the substrate 10 (see FIG. 1). As a result, the wavelength sweep at the resonance wavelength interval can be performed in about several ms.

As described above, according to the spectroscope S1 according to the present embodiment, the spectroscope used in the conventional near-infrared spectroscopy has a size that stops at most several cm ² even if it is downsized. it can be miniaturized to the number mm ² in size of hundredths of a. Further, according to the spectroscope S1, the wavelength resolution can be maintained high even when the size is reduced. That is, according to the spectroscope S1, it is possible to cut out only a specific narrow band of light that cannot be realized with a conventional spectroscope, and therefore, high-precision spectroscopy is possible.

  Next, a method for manufacturing the spectrometer S1 according to the present embodiment will be described with reference to the drawings as appropriate. Here, a manufacturing method of the spectroscope S1 including the silicon core layer 12 will be described.

  First, an SOI (Silicon on Insulator) substrate is prepared. As shown in FIG. 2A, the SOI substrate includes a lower clad layer 11 made of a silicon oxynitride film formed on a substrate 10 made of a silicon wafer, and a silicon film formed on the lower clad layer 11. And a core layer 12 made of The silicon film constituting the core layer 12 may be a film made of high-resistance p-type or high-resistance n-type single crystal silicon.

  Alternatively, the silicon film may have a desired thickness by growing a non-doped silicon crystal on a high-resistance p-type or high-resistance n-type single crystal silicon film thinner than the desired thickness. The silicon film constituting the core layer 12 may be either single crystal or polycrystalline as long as it can guide light, and may be polysilicon.

  Next, as shown in FIG. 2A, the input-side channel waveguide 14, the recess 17a for embedding the diffraction grating 17, the cut-out channel waveguide 15, the resonator 16, and the output-side channel waveguide 18 are formed as a core. Formed by scraping layer 12. A known lithographic technique and an etching technique may be employed for the cutting.

  Next, as shown in FIG. 2B, the spot size covers the input end portion 14 a of the input side channel waveguide 14 and the output end portion 18 a (see FIG. 2A) of the output side channel waveguide 18. The conversion member 20a and the spot size conversion member 20b are formed. In addition, as shown in FIG. 3, such a spot size conversion member 20a and a spot size conversion member 20b are formed by using a CVD method to form the first covering member 21 at each of the input end portion 14a and the output end portion 18a. After the first covering member 21 is formed by depositing by sputtering or sputtering, the material constituting the second covering member 22 is deposited on the first covering member 21 by CVD or sputtering to form the second covering member 22. Can be shaped by forming.

  And after forming the spot size conversion member 20a and the spot size conversion member 20b in this way, as shown in FIG.2 (b), the material which comprises the upper clad layer 13 is deposited by CVD method or sputtering method. Thus, the upper clad layer 13 is formed. By forming the upper clad layer 13 in this manner, the material constituting the upper clad layer 13 is fitted into the recess 17a, whereby the diffraction grating 17 is formed, and the input side channel waveguide 14 and the cut-out channel are formed. The waveguide 15, the resonator 16, and the output side channel waveguide 18 are embedded in the upper cladding layer 13 on the lower cladding layer 11. Then, an optical fiber 23 (see FIG. 5A) is attached to the spot size conversion member 20a, and an optical fiber for connecting to the spot size conversion member 20b with an external detector as described above ( By attaching the detector 24 (not shown) or the detector 24 (see FIG. 5A), the spectroscope S1 is completed.

  According to such a method for manufacturing the spectroscope S1, a plurality of spectroscopes S1 can be formed on a large-diameter wafer as in a process for mass-producing LSIs. Therefore, the spectroscope S1 can be easily mass-produced. can do. As a result, the production cost of the spectrometer S1 can be reduced.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, the spectrometer according to the present invention may be a spectrometer as shown in FIGS. 7 to 9 are schematic views showing a spectrometer according to another embodiment. In addition, the same code | symbol is attached | subjected to the element same as spectrometer S1 which concerns on the said embodiment, and the detailed description is abbreviate | omitted.

  In the spectrometer S2 shown in FIG. 7, four resonators 16 are arranged along the direction in which the cut-out channel waveguide 15 extends. Further, four output-side channel waveguides 18 are disposed so that each of the resonators 16 is cut out and sandwiched between the channel waveguides 15.

  And the diameter (circumference length) of the ring-shaped waveguide 16a (refer FIG. 1) which comprises the resonator 16 is different, respectively.

  In such a spectrometer S2, the light input to the input side channel waveguide 14 via the spot size conversion member 20a is split by the diffraction grating 17 and input to the cut-out channel waveguide 15, Similar to the spectroscope S1 according to the embodiment, the light is cut out so that only light in a predetermined band F (see FIG. 5B) is obtained.

  When such light propagates through the cut-out channel waveguide 15, each resonator 16 has a different resonance wavelength (frequency) because the length of the ring-shaped waveguide 16 a is different.

  Therefore, according to such a spectroscope S2, the diameter (circumference length) of each ring-shaped waveguide 16a is set according to the wavelengths of a plurality of lights to be extracted out of the light propagating through the cut-out channel waveguide 15. If changed, a plurality of lights to be extracted are drawn out through the output-side channel waveguide 18, so that these lights can be outputted from the spot size conversion member 20b.

  The spectroscope S3 illustrated in FIG. 8A includes three cut-out channel waveguides 15, resonators 16, output-side channel waveguides 18, and spot size conversion members 20b. A hot wire 19 is disposed in each resonator 16.

  In such a spectroscope S3, the light input to the input-side channel waveguide 14 via the spot size conversion member 20a is split by the diffraction grating 17 and input to each cut-out channel waveguide 15. On the other hand, the refractive index of the ring-shaped waveguide 16a (see FIG. 1) constituting each resonator 16 is changed by heating with the hot wire 19.

  Therefore, according to such a spectroscope S3, if the refractive index of each ring-shaped waveguide 16a is changed by changing the temperature of each ring-shaped waveguide 16a by the hot wire 19, each resonator 16 is changed. The resonance wavelength can be changed. That is, according to the spectroscope S3, a plurality of dispersed light beams can be output from each spot size conversion member 20b according to the temperature setting of the ring-shaped waveguide 16a. Further, according to this spectrometer, by changing the temperature setting of one ring-shaped waveguide 16a stepwise, light having a wavelength depending on the temperature is observed from one spot size conversion member 20b. It becomes possible to do.

  The spectrometer S4 shown in FIG. 8B includes three cut-out channel waveguides 15, and the position of these cut-out channel waveguides 15 is the band F of the wavelength of the cut-out light (see FIG. 5B). Are arranged differently. The resonators 16 disposed in the respective cut-out channel waveguides 15 have resonance wavelength intervals corresponding to the respective bands F cut out by the respective cut-out channel waveguides 15, that is, such resonance wavelength intervals are set. The ring-shaped waveguide 16a is adjusted so that the diameter (peripheral length) is adjusted. Each resonator 16 is provided with a hot wire 19.

  According to such a spectroscope S4, the band F of the wavelength of the light cut out by each of the cut-out channel waveguides 15 can be changed, and the ring-shaped waveguide 16a is heated by the hot wire 19 to thereby make the resonator 16 Therefore, it is possible to detect light that has been dispersed with high resolution for each wavelength region to be detected.

  The spectroscope S5 shown in FIG. 9 includes a first diffraction grating 17a, an input-side channel waveguide 14 through which light dispersed by the first diffraction grating 17a propagates, and light propagated through the input-side channel waveguide 14. The second diffraction grating 17b that receives and splits the light, the cut-out channel waveguide 15 that propagates the light split by the second diffraction grating 17b, and the resonator 16 that is disposed adjacent to the cut-out channel waveguide 15 And an output-side channel waveguide 18 disposed so as to sandwich the resonator 16 between the cut-out channel waveguide 15. The spectroscope S5 includes three input-side channel waveguides 14 and three second diffraction gratings 17b. For each second diffraction grating 17b, the cut-out channel waveguide 15, the resonator 16, and the output-side channel waveguides. Three waveguides 18 are provided. The first diffraction grating 17a corresponds to a “first beam splitting unit” in the claims, and the second diffraction grating 17b, the cut-out channel waveguide 15, the resonator 16, and the output-side channel waveguide 18 are: This corresponds to a “second beam splitting unit” in the claims.

  In the spectroscope S5, the light split by the first diffraction grating 17a is further split by each second diffraction grating 17b. When the light split by the second diffraction grating 17b is drawn out to the output channel waveguide 18 through the cut-out channel waveguide 15 and the resonator 16, the resonator 16 has a constant wavelength due to the resonance phenomenon. While extracting light at intervals, the light is output to the output-side channel waveguide 18. That is, in the spectroscope S5, the incident light is split by the first diffraction grating 17a, the light split by the first diffraction grating 17a is split by the second diffraction grating 17b, and then the second diffraction grating. The resonator 16 splits a part of the light split at 17b with high accuracy. Therefore, such a series of spectroscopy is performed in each second diffraction grating 17b and each resonator 16 including the first diffraction grating 17a. Therefore, according to the spectroscope S5, it is possible to efficiently split a wide band of wavelengths.

  Moreover, in the said embodiment, although the ring-shaped waveguide 16a which comprises the resonator 16 is an annular shape, this invention is not limited to this, For example, as shown to Fig.10 (a) In addition, two halves 16b obtained by dividing a ring into two parts and a so-called racetrack-type resonator 16 (ring-shaped waveguide 16a) in which a straight part 16c is inserted between the halves 16b are used. Also good.

  Such a resonator 16 can change the resonance wavelength by changing the length of the straight portion 16c.

  Further, as shown in FIG. 10B, the resonator 16 may be a wave type in which halves obtained by dividing an annular ring are connected. Such a wave resonator 16 can change the resonance wavelength according to the distance W between the waves.

It is a perspective view of the spectrometer which concerns on embodiment of this invention. (A) is a perspective view showing a state in which the upper clad layer, spot size conversion member, and heat ray of the spectrometer of FIG. 1 are removed, and (b) shows a state in which the spot size conversion member is attached to the spectrometer of FIG. It is a perspective view shown. It is a perspective view for demonstrating the structure of a spot size conversion member. It is sectional drawing in the AA of FIG. (A) is a conceptual diagram explaining operation | movement of the spectrometer which concerns on embodiment of this invention, (b) is the wavelength and spectral light of the light cut out from the light spectrally divided by the diffraction grating, and cut out by the channel waveguide A graph showing the relationship with intensity, (c) is a graph showing the relationship between the wavelength of light extracted by a resonator at a constant wavelength interval and the intensity of spectral light, and (d) is propagating through a cut-out channel waveguide. It is a graph which shows the relationship between the wavelength of the light absorbed by the output side channel waveguide via the resonator among the light, and spectral light intensity. It is the graph which showed a mode that the resonance wavelength of a resonator changes, when a resonator is heated. It is a schematic diagram which shows the spectrometer which concerns on other embodiment. It is a schematic diagram which shows the spectrometer which concerns on other embodiment. It is a schematic diagram which shows the spectrometer which concerns on other embodiment. It is a conceptual diagram which shows the modification of a resonator. It is a schematic diagram of the conventional spectrometer.

Explanation of symbols

12a Slab-type waveguide 14 Input-side channel waveguide 14a Input end 15 Cut-out channel waveguide (first channel waveguide)
16 Resonator 17 Diffraction grating 18 Output-side channel waveguide (second channel waveguide)
18a Output end 19 Heat wire (heater)
S1 spectrometer S2 spectrometer S3 spectrometer S4 spectrometer S5 spectrometer

Claims (6)

In a spectroscope in which input light is split by a diffraction grating formed in a slab waveguide,
A first channel waveguide having a base end portion disposed so as to cut out and propagate only light belonging to a predetermined band out of light dispersed by the diffraction grating;
Is composed of arranged waveguides to be adjacent to the first channel waveguide, a resonator you resonate in a narrow band than the predetermined band belonging to said predetermined band,
A spectroscope comprising: a second channel waveguide disposed so as to sandwich the resonator between the first channel waveguide and light that resonates in the resonator is extracted and propagated. .   The spectroscope according to claim 1, further comprising a heater for heating the waveguide of the resonator.   The spectroscope according to claim 1 or 2, wherein a plurality of the resonators are provided, and the lengths of the waveguides of the resonators are different from each other. The first channel waveguide, the waveguide of the resonator, and the second channel waveguide are configured by a core portion surrounded by a cladding portion, and the core portion includes a gallium arsenide compound and an indium phosphorus compound. , Silicon-germanium compound, zinc-based semiconductor, LiNbO ₃ , lithium-titanium compound, silicon nitride, silicon oxynitride, and silicon carbide. 4. The spectroscope according to claim 1, comprising at least one of a silicon oxynitride compound, an epoxy polymer, a polyimide polymer, and air.   An input-side channel waveguide for guiding the light applied to the diffraction grating; and an input end portion of the input-side channel waveguide and an output end portion of the light of the second channel waveguide, The input end and the output end are covered with a material having a refractive index smaller than that of the material constituting the input end and the output end. The spectroscope according to any one of claims 1 to 4, wherein the spectroscope is provided.   A spectroscope comprising: a first beam splitting unit that splits incident light; and a plurality of second beam splitting units that further split light split by the first beam splitting unit, wherein the second beam splitting unit is claimed in claim 1. A spectrometer as described in 1.

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