Opto-mechanical sensor, opto-mechanical sensor system and method for manufacturing an opto-mechanical sensor

Abstract

An optomechanical sensor (10) according to the present invention comprises a plurality of mechanical vibrators (11) connected together, wherein one mechanical vibrator (13) of the plurality of mechanical vibrators has an optical resonator structure, and the one mechanical vibrator (13) and the other mechanical vibrators (14) resonate with one another. In the optomechanical sensor (10), only the other mechanical vibrators (14) may be placed within an object being measured, and a change in vibration characteristics of the other mechanical vibrators (14) may be detected through resonance between the one mechanical vibrator (13) and the other mechanical vibrators (14) using light incident on the one mechanical vibrator (13).　This allows the optomechanical sensor according to the present invention to provide excellent detection sensitivity.

Description

[Technical Field]

[0001] The present invention relates to an optomechanical sensor having a mechanical oscillator, an optomechanical sensor system, and a method for manufacturing an optomechanical sensor. [Background technology]

[0002] Opto-mechanical sensors use light to detect changes in the vibration characteristics of a mechanical oscillator due to external stimuli or attachments. In particular, optomechanical sensors that detect changes in vibration characteristics using an optical resonator integrated with a mechanical oscillator exhibit high vibration detection sensitivity due to the optical confinement effect (Non-Patent Documents 1 and 2). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] E. Gil-Santos et al., "Optomechanical detection of vibration modes of a single bacterium", Nat. Nanotech. 15, 469 (2020). [Non-patent document 2] E. Gil-Santos et al., "High-frequency nano-optomechanical disk resonators in liquids", Nat. Nanotech. 10, 810 (2015). Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a typical optomechanical sensor, a detection unit that responds to external stimuli or attached objects and a receiving unit that performs optical reading are integrated, so when sensing is performed in a solution, for example, there is a problem that the vibration detection sensitivity decreases due to deterioration of the optical Q value of the optomechanical sensor. In the composite structure disclosed in Non-Patent Document 2, the entire structure is immersed in water, and the optical Q value is 10 6From 10 4 deteriorates to.

[0005] Furthermore, chemical modification to increase the sensor sensitivity to specific chemical species poses the problem of reduced detection sensitivity depending on the optical properties of the modifying material. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the optomechanical sensor according to the present invention comprises: Complex Mechanical oscillator of number and the joint Equipped with the plurality of mechanical vibrators are continuously connected via the coupling portion, Among the plurality of mechanical oscillators, one mechanical oscillator has an optical resonator structure, and the one mechanical oscillator and the other mechanical oscillators , via the coupling portion It is characterized by resonance. In addition, the optical mechanical sensor according to the present invention is characterized in that it comprises a plurality of mechanical oscillators that are connected together, one of the plurality of mechanical oscillators has an optical resonator structure, the one mechanical oscillator resonates with another mechanical oscillator, and the vibration frequency of the one mechanical oscillator is equal to or lower than the vibration frequency of the other mechanical oscillator. In addition, the optical mechanical sensor according to the present invention is characterized in that it comprises a plurality of mechanical oscillators that are connected together, one of the plurality of mechanical oscillators has an optical resonator structure, the one mechanical oscillator resonates with another mechanical oscillator, the optical mechanical sensor comprises a plurality of the other mechanical oscillators, and the plurality of the other mechanical oscillators each have a different shape.

[0007] In addition, the manufacturing method of the optical mechanical sensor according to the present invention includes the steps of: one mechanical oscillator has an optical resonator structure, One mechanical oscillator and Continuously connected via joints Other mechanical oscillators resonate and detecting a change in the vibration characteristics of the other mechanical oscillator by optical resonance in the one mechanical oscillator. A method for manufacturing an optical mechanical sensor, comprising: a first step of heating a predetermined location of a fiber; and a second step of pulling two locations of the fiber in opposite directions in the axial direction of the fiber to form constricted portions in the fiber, wherein the first step and the second step are repeated to form a plurality of constricted portions, and one fiber portion sandwiched between adjacent constricted portions is used as the one mechanical oscillator and the other fiber portion is used as the other mechanical oscillator. The constricted portion is connected to the connecting portion. It is characterized by: [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an optomechanical sensor, an optomechanical sensor system, and a method for manufacturing an optomechanical sensor, all of which have good detection sensitivity. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic diagram showing the configuration of an optomechanical sensor according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of an optomechanical sensor according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a diagram for explaining the operation of the optomechanical sensor according to the second embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing the configuration of an optical mechanical sensor system according to a first embodiment of the present invention. [Figure 5] FIG. 5 is a diagram illustrating the configuration of an optomechanical sensor according to a first embodiment of the present invention. [Figure 6] FIG. 6 is a diagram for explaining a method for manufacturing an optomechanical sensor according to the first embodiment of the present invention. [Figure 7] FIG. 7 is a diagram for explaining the operation of the optomechanical sensor according to the first embodiment of the present invention. [Figure 8] FIG. 8 is a diagram for explaining the effect of the optomechanical sensor according to the first embodiment of the present invention. [Figure 9] FIG. 9 is a diagram for explaining the effect of the optomechanical sensor according to the first embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram showing the configuration of an optical mechanical sensor system according to a second embodiment of the present invention. [Figure 11] FIG. 11 is a diagram for explaining the operation of the optomechanical sensor according to the second embodiment of the present invention. [Figure 12] FIG. 12 is a schematic diagram showing the configuration of an optical mechanical sensor system according to a third embodiment of the present invention. [Figure 13] FIG. 13 is a schematic diagram showing the configuration of an optical mechanical sensor system according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment An optomechanical sensor according to a first embodiment of the present invention will be described with reference to FIGS.

[0011] <Configuration of Opto-Mechanical Sensor> 1, an optical mechanical sensor 10 according to this embodiment includes a receiving unit 13 made up of a mechanical oscillator 11, and a detecting unit 14 made up of a plurality of mechanical oscillators 11 (a group of mechanical oscillators). In the figure, dotted lines indicate coupling between the mechanical oscillators 11. The receiving unit 13 and the detecting unit 14 are connected via a coupling unit 15. Here, the mechanical vibrator 11 of the receiving unit 13 and the mechanical vibrator 11 of the detecting unit 14 are coupled together. Here, the detecting unit 14 may be composed of a single mechanical vibrator 11.

[0012] In the receiving section 13, the mechanical oscillator 11 has a vibration mode and has an optical resonator structure.

[0013] In the detection unit 14, a plurality of mechanical oscillators 11 have vibration modes, and the vibration modes change in response to an external stimulus 2 or an attached object.

[0014] The receiving unit 13 and the detecting unit 14 resonate via the coupling unit 15 and have a coupled vibration mode. As a result, the vibration characteristic changes (changes in vibration frequency and line width) obtained in the detecting unit 14 change the vibration characteristic of the receiving unit 13 via the coupled vibration mode.

[0015] This change in the vibration characteristics of the receiving section 13 causes a change in the optical resonance mode of the optical resonator structure of the receiving section 13 .

[0016] Therefore, this change in the optical resonance mode can be detected (read out) by coupling light incident on the receiving unit 13 from the outside to the optical resonance mode (arrow 3 in the figure).

[0017] In this way, due to the coupling of mechanical vibration modes, changes in the vibration frequency and line width of the detection unit 14 can be detected (read out) by the opto-mechanical conversion of the reception unit 13.

[0018] Furthermore, the mechanical oscillator 11 of the receiving unit 13 has the configuration of an optical resonator, and in the receiving unit 13, mechanical vibrations can be amplified and detected (read out) by optical resonance due to optomechanical coupling with the optical resonator.

[0019] As a result, the optomechanical sensor 10 achieves measurement sensitivity capable of observing thermal fluctuations of the vibration mode through optomechanical conversion in the receiving unit 13, and can obtain information about the external stimulus 2 or attached matter from changes in vibration characteristics excited by thermal fluctuations.

[0020] In addition, conventional optomechanical sensors have a structure in which the detection unit and receiving unit are integrated, so when the object to be measured is a liquid or the like, the entire optomechanical sensor is immersed, reducing the sensing sensitivity.

[0021] According to the optical mechanical sensor of this embodiment, the detection unit and the receiving unit are separated, so when the object to be measured is a liquid or the like, the detection unit only needs to be immersed, and the receiving unit is not immersed, allowing for highly sensitive measurements.

[0022] 2, one example of the configuration of the optical mechanical sensor 10 is a linked bottle structure made on a cylindrical base material, which can be used to link the mechanical oscillator of the receiving unit 13 with the mechanical oscillator of the detecting unit 14. Here, a configuration is shown in which a single bottle structure of the receiving unit 13 and multiple bottle structures of the detecting unit 14 are linked in series.

[0023] In this optomechanical sensor 10, an optical resonant mode 16 in the cylindrical bottle structure of the receiving section 13 is used to enable vibration measurement by resonator-enhanced optomechanical conversion.

[0024] In detail, the bottle structure of the receiving unit 13 and the multiple bottle structures of the detecting unit 14 have a coupled vibration mode, and when the multiple bottle structures of the detecting unit 14 detect changes in vibration frequency and line width, the changes in vibration frequency and line width of the bottle structure of the receiving unit 13 change via the coupled vibration mode.

[0025] The change in the optical resonance mode 16 due to the optical resonator structure caused by the change in the vibration characteristics of the bottle structure of the receiving unit 13 is detected (read out) by coupling light incident on the bottle structure of the receiving unit 13 from the outside to the optical resonance mode 16 (arrow 3 in the figure).

[0026] According to the optomechanical sensor of this embodiment, the optical characteristics of the receiving unit 13 are completely separated from those of the detecting unit 14, and it is therefore possible to prevent a decrease in detection sensitivity due to changes in the optical characteristics of the detecting unit 14. In particular, by making the receiving unit 13 a composite structure of an optical resonator and a mechanical oscillator, it is possible to prevent a decrease in detection sensitivity due to deterioration in the optical Q value of the optical resonator.

[0027] <Second embodiment> An optomechanical sensor according to a second embodiment of the present invention will be described with reference to FIG.

[0028] <Configuration of Opto-Mechanical Sensor> In the optical mechanical sensor according to this embodiment, of the two bottle structures, the bottle structure with the lower vibration frequency is used as the receiving unit 13, and the bottle structure with the higher vibration frequency is used as the detecting unit 14. The other configurations are the same as those in the first embodiment.

[0029] In optical mechanical sensors, exceptional points 17 are used to measure changes in vibration characteristics (W. Chen et al., "Exceptional points enhance sensing in an optical microcavity", Nature 548, 192 (2017)). By appropriately controlling the vibration amplification in the receiving unit 13 and the increase in vibration frequency and damping rate associated with the insertion of the detecting unit 14, the detection sensitivity of external stimuli 2_1, 2_2 or attached objects can be controlled. In particular, the detection sensitivity can be improved by adjusting the coupling state to the exceptional point 17, where both the difference in vibration frequency and the difference in damping rate between the two mechanical oscillators are completely zero.

[0030] The details are explained below. The exceptional point 17 in the two coupled oscillators of the optomechanical sensor is defined as follows: The dynamics of the coupled oscillators is expressed as a matrix equation in the frequency domain obtained by Fourier transforming the equation of motion, as shown in Equation (1).

[0031]

number

[0032] where ω is a frequency domain variable and Ω i and Γ i are the vibration frequency and damping rate (resonance linewidth) of mode i, g0 is the coupling coefficient of the oscillator, and F is the external force vector. This matrix has two complex eigenvalues, the real part of which corresponds to the frequency of the coupled mode, and the imaginary part of which corresponds to the linewidth of the coupled mode.

[0033] The difference δω between the complex eigenvalues ​​is expressed by the formula (2) using the frequency difference δΩ=Ω2-Ω1 and the linewidth difference δΓ=Γ2-Γ1 of the respective oscillators.

[0034]

number

[0035] Exception point 17 is defined as the point where the value of δω becomes zero, i.e., the two coupling modes become degenerate in terms of frequency and linewidth.

[0036] As an example, consider a case where the external stimuli 2_1 and 2_2 affect the frequency reduction and line width increase of the detection unit 14.

[0037] The mode of the receiving unit 13 is set to i=1, and the mode of the detecting unit 14 is set to i=2. In order to make the frequency difference zero after forming the initial state of measurement by the external stimulus 2_1, the initial frequency of the detecting unit 14 is designed to be equal to or higher than the initial frequency of the receiving unit 13, thereby realizing δΩ=0 by the external stimulus 2_1.

[0038] For example, the detection unit is inserted into the target medium 1 (external stimulus 2_1), and the insertion depth is adjusted to set Ω=0.

[0039] Furthermore, the exceptional point 17 can be adjusted by changing the linewidth of the receiving section 13 by the amplification effect due to the parametric optomechanical coupling of the laser light so that δΓ=±2g0 for the increased linewidth.

[0040] As shown in FIG. 3, the vibration frequency adjusted to the exceptional point 17 is again frequency split by a further external stimulus 2_2, for example, a change in the state (viscosity, density, temperature, etc.) of the target medium or the adsorption of chemical species.

[0041] In this frequency splitting, the frequency of the coupled oscillators changes nonlinearly and sharply with respect to changes in the external parameters (arrow 18 in the figure). By utilizing this sharp change in the frequency of the coupled oscillators, it is possible to improve the sensitivity of at least one of the receiving unit 13 and the detecting unit 14 to the external stimulus 2_2.

[0042] According to the optical mechanical sensor of this embodiment, in the mechanical vibration mode, the signal-to-noise ratio can be effectively improved by optical amplification, and the detection sensitivity of changes in the vibration characteristics of the coupling mode can be improved.

[0043] <First Example> An optomechanical sensor and an optomechanical sensor system according to a first embodiment of the present invention will be described with reference to FIGS.

[0044] As shown in FIG. 4, the optomechanical sensor system 20 according to this embodiment includes the optomechanical sensor 10, a laser 21, a tapered fiber 22, and a photodetector .

[0045] As shown in Figure 5, the optical mechanical sensor 10 has a configuration in which two bottle structures are connected together, and each bottle structure is made of a silica optical fiber with a diameter of 125 µm. One of the two bottle structures is the receiving unit 13, and the other is the detecting unit 14. A constricted portion (recess) of the connecting portion 15 is formed between the bottle structure of the receiving unit 13 and the bottle structure of the detecting unit 14. Here, the diameter D1 of the bottle structure of each of the receiving unit 13 and the detecting unit 14 is 125 µm, the diameter D2 of the constricted portion is 115 µm, and the depth d of the constricted portion is 5 µm.

[0046] The optomechanical sensor 10 is fabricated by heating and stretching a silica glass fiber 24, as shown in FIG.

[0047] First, the silica glass fiber 24 is held at two predetermined positions.

[0048] Next, a predetermined portion 24_1 of the silica glass fiber 24 is heated.

[0049] Next, the two positions where the silica glass fiber 24 is held are pulled (pulled) in opposite directions (S1), resulting in the formation of a constricted portion (recess) 25 at the heated position (S2).

[0050] Next, a portion 24_2 different from the portion 24_1 in the silica glass fiber 24 is heated and pulled (pulled), and a constricted portion (recess) 25 is formed at the heated portion (S3 to S4). By repeating this heating and pulling (pulling) process, a plurality of constricted portions (recesses) 25 are formed in the silica glass fiber 24. As a result, a structure in which a plurality of bottle structures are connected by the constricted portions (recesses) 25, i.e., an optical mechanical sensor 10, is produced (S5).

[0051] In this embodiment, after heating the silica glass fiber 24, it was repeatedly pulled (pulled) to form constrictions (recesses) 25 in three places, with one bottle structure serving as the receiving part 13 and the other bottle structure serving as the detecting part 14.

[0052] Here, an example has been given in which silica glass fiber is used as the material for the optical mechanical sensor, but other glass fibers may also be used, as long as they are made of a material that can be stretched by heating or pulling.

[0053] The tapered fiber 22 is a tapered fiber, and is bridged and fixed to the bottle structure of the receiving unit 13. FIG. 7 shows a schematic diagram 201 and a cross-sectional schematic diagram 202 of the portion where the tapered fiber 22 is bridged and fixed. As shown in FIG. 7, the tapered fiber 22 is tightly attached and fixed to the surface of the bottle structure of the receiving unit 13 using a jig or the like (not shown). Here, although there are no limitations on the direction of the tapered fiber (propagation direction of the laser light) and the axial direction of the bottle structure (Z direction in the figure), it is desirable that the direction of the tapered fiber and the axial direction of the bottle structure are perpendicular to each other in order to align the propagation direction of the laser light with the rotation direction of the whispering gallery mode.

[0054] A laser 21 emits laser light for detection. The laser light propagates through a tapered fiber 22, generates a near-field 26 in the region where the tapered fiber 22 and the bottle structure of the receiving unit 13 come into contact, undergoes near-field optical coupling, and is received by a photodetector 23.

[0055] In detail, the laser light is propagated to the area where the tapered fiber 22 and the bottle structure of the receiving unit 13 meet, and near-field light (evanescent light) is emitted from the near-field (evanescent field) 26, and is totally reflected and circulated by the optical resonator structure of the receiving unit 13, resonating in the optical resonance mode 16.

[0056] In this resonant state, if the vibration characteristics of the detector 14 change, the vibration characteristics of the receiver 13 change, causing a change in the optical resonance mode 16. This change in the optical resonance mode 16 is coupled with the laser light in the near-field 26, and the change in the optical resonance mode 16 is detected by the laser light.

[0057] In this way, by bridging and fixing the tapered fiber 22 to the bottle structure of the receiving section 13, optical detection (optical readout) of the coupled vibration mode by near-field optical coupling can be realized.

[0058] An example of measuring the target medium 1 as water using the optomechanical sensor system 20 will now be described.

[0059] First, the two bottle structures of the optomechanical sensor 10 are held in the atmosphere, and laser light is propagated through the tapered fiber 22 and received by the photodetector 23. As a result, the laser light is coupled to the optical resonance mode of the receiving section 13, and the mechanical vibration spectrum is measured via the optomechanical coupling.

[0060] Here, the mechanical vibration spectrum was measured for each of the two bottle structures, and since it is difficult to make the shapes of the two bottles completely identical, differences in the vibration characteristics of each bottle structure arise. Therefore, the bottle structure that exhibits a high-frequency mechanical vibration spectrum is used as the receiving unit 13, and the bottle structure that exhibits a low-frequency mechanical vibration spectrum is used as the detecting unit 14.

[0061] In this way, the measured mechanical vibration spectrum has a peak due to the mechanical vibration of the receiving unit 13 and a peak due to the mechanical vibration of the detecting unit 14.

[0062] Next, the detection unit 14 is inserted into the water by 0.1 mm at a time, and the change in the vibration characteristics of the bottle structure of the detection unit 14 is detected (read) from the mechanical vibration spectrum observed by the photodetector 23.

[0063] 8 and 9 each show the changes in the vibration frequency and resonance linewidth with respect to the insertion depth of the detection unit 14. Here, the solid line with black triangles shows the vibration frequency and resonance linewidth at the peak due to the mechanical vibration of the receiving unit 13, and the solid line with black circles shows the vibration frequency and resonance linewidth at the peak due to the mechanical vibration of the detection unit 14.

[0064] Concerning the vibration frequency, as the insertion depth of the detection unit 14 increases, the vibration frequency of the reception unit 13 remains constant, while the vibration frequency of the detection unit 14 shifts to the lower frequency side.

[0065] Furthermore, as the insertion depth of the detecting section 14 increases, the resonance linewidth of the receiving section 13 remains constant, while the resonance linewidth of the detecting section 14 increases.

[0066] Thus, according to the optomechanical sensor and optomechanical sensor system of this embodiment, in a configuration in which the receiving unit and the detecting unit are separated, by holding the receiving unit in the atmosphere and immersing (inserting) the detecting unit in the target medium, it is possible to detect differences (changes) in vibration characteristics due to thermal fluctuations (Brownian motion) between the atmosphere and the target medium.

[0067] In this embodiment, for the two bottle structures, the bottle structure that exhibits a high-frequency mechanical vibration spectrum may be used as a detector, and the bottle structure that exhibits a low-frequency mechanical vibration spectrum may be used as a receiver.

[0068] According to the optical mechanical sensor and its system of this embodiment, by holding the receiving unit in the atmosphere and inserting the detecting unit into the target medium 1 (gas, liquid, solid), the changes in the vibration frequency and line width of the detecting unit according to the density and viscosity of the target medium 1 can be detected (read) by optical mechanical conversion of the receiving unit.

[0069] <Second Example> An optomechanical sensor and an optomechanical sensor system according to a second embodiment of the present invention will be described with reference to FIGS.

[0070] As shown in FIG. 10, the optomechanical sensor system 30 according to this embodiment includes the optomechanical sensor 10, a laser 21, a tapered fiber 22, a photodetector 23, and a variable optical attenuator 31.

[0071] In the optomechanical sensor system 30 , a variable optical attenuator 31 is provided on the incident side of the tapered fiber 22 , and the laser light emitted from the laser 21 propagates through the tapered fiber 22 via the variable optical attenuator 31 .

[0072] Furthermore, in the optical mechanical sensor 10, since the vibration frequency of the mechanical oscillator decreases in the target medium 1 (for example, water), of the two bottle structures, the bottle structure with the lower vibration frequency is used as the receiving unit 13, and the bottle structure with the higher vibration frequency is used as the detecting unit 14. The other configurations are the same as those in the first embodiment.

[0073] When laser light is incident on the tapered fiber 22 and propagated, by adjusting the laser frequency to be equal to or higher than the resonant frequency of the optical resonator, it is possible to obtain a vibration amplification effect via parametric optomechanical coupling using the laser light as pump light.

[0074] In order to make this amplification effect variable, the intensity of the laser light is adjusted by placing a variable optical attenuator 31 in front of the tapered fiber 22. Here, not only the optical amplification but also the oscillation may be performed.

[0075] FIG. 11 shows a typical change in vibration frequency in the receiving unit 13 (dotted line 32_1) and a typical change in vibration frequency in the detecting unit 14 when the detecting unit 14 is immersed in water (dotted line 32_2).

[0076] In contrast, by adjusting the intensity of the incident laser light and amplifying the vibration, the vibration frequency changes of the receiving unit 13 and the detecting unit 14 are shifted, and a vibration frequency change including the exceptional point 17 is obtained (solid line 33 in the figure).

[0077] Here, by adjusting the insertion depth (Z1 in Figure 11) appropriately, detection becomes possible at the exceptional point 17. In the vicinity of the exceptional point 17, the vibration frequency of the bond mode changes sharply in response to external factors. For example, when adjusted to the exceptional point 17, if a solution other than water is dropped into water, changes in the density and viscosity of the aqueous solution can be detected with high sensitivity.

[0078] In this way, by adjusting the surrounding environment of at least one of the receiving unit 13 and the detecting unit 14, such as the intensity of the laser light or the insertion depth of the detecting unit 14, the frequency and damping coefficient of each mechanical oscillator can be changed, and the state of coupled vibration can be adjusted, thereby improving the detection sensitivity of external stimuli or adhesions.

[0079] According to the optomechanical sensor and system of this embodiment, by using parametric optomechanical coupling through intensity modulation or frequency control of the light incident on the receiving part, it is possible to amplify and oscillate vibrations using light, thereby improving the sensitivity of the detecting part to vibration changes.

[0080] <Third Example> An optomechanical sensor and an optomechanical sensor system according to a third embodiment of the present invention will be described with reference to FIG.

[0081] As shown in FIG. 12, the optomechanical sensor system 40 according to this embodiment includes the optomechanical sensor 10, a laser 21, a tapered fiber 22, a photodetector 23, and a movable stage 41.

[0082] In the optomechanical sensor system 30, a movable stage (three-dimensional positioner) 41 is mounted on the receiving unit 13 of the optomechanical sensor 10. The movable stage (three-dimensional positioner) 41 is driven in three dimensions to sweep the optomechanical sensor 10 in three dimensions. A micro heater 42 may also be provided. The other configurations are the same as those of the first embodiment.

[0083] Measurement using the optomechanical sensor system 30 according to this embodiment will be described using an example in which the target medium 1 is a gelling solution.

[0084] Gelling solutions include, for example, chemically crosslinked gel solutions obtained by chemical crosslinking of various monomers and polymers, and physically crosslinked gel solutions obtained by physical interactions between various polymers.

[0085] First, similarly to the first embodiment, the detection unit 14 is immersed in a gelling solution in a state where the coupled vibration characteristics of the mechanical oscillator of the optomechanical sensor 10 are detected by laser light.

[0086] Next, when a gelation reaction is induced in the gelation solution, the vibration mode changes due to changes in mass and viscoelasticity around the detection unit 14. Here, gelation can be promoted by applying an appropriate initiator 43, heat from the microheater 42, or light stimulation from another light source to the gelation solution.

[0087] As a result, as in the first embodiment, as the detection unit 14 detects this change in vibration mode, a change in vibration characteristics corresponding to gelation can be detected in the optical output signal from the tapered fiber 22 bridged to the receiving unit 13.

[0088] The resonant frequency of the mechanical oscillator of the optical mechanical sensor 10 varies depending on the shape of the bottle, such as its diameter. Therefore, by providing the detection unit 14 with multiple mechanical oscillators of different shapes and resonant frequencies, the resonant frequency can be changed and the frequency dependence can be measured. From this frequency dependence, the dynamic viscoelasticity of the gelling solution can be obtained.

[0089] Finally, the spatial distribution of gelation can be measured by driving the movable stage 41 and sweeping the optomechanical sensor 10 in three dimensions.

[0090] In this example, a gelling solution was measured as the target medium, but a mixed solution with a different viscosity distribution can also be measured as the target medium. Furthermore, the spatial distribution of properties such as density of other target media can also be measured.

[0091] In this embodiment, an example is shown in which a movable stage is installed in the optomechanical sensor system according to the first embodiment, but if a movable stage is installed in the optomechanical sensor system according to the second embodiment, the measurement sensitivity can be further improved and the spatial distribution can be measured.

[0092] The optical mechanical sensor and system according to this embodiment can measure the spatial distribution of gelation, etc. in a mixed solution having a viscosity distribution, such as a gelling solution.

[0093] Naturally, the optical-mechanical sensor system according to the first or second embodiment can be used to obtain the dynamic viscoelasticity of a medium such as a gelling solution.

[0094] <Fourth Example> An optomechanical sensor and an optomechanical sensor system according to a fourth embodiment of the present invention will be described with reference to FIG.

[0095] In the optical mechanical sensor system 50 according to this embodiment, as shown in Fig. 13, the surface of the mechanical oscillator of the detection unit 14 is chemically modified with a protein antibody 51. The other configurations are the same as those in the first example.

[0096] By immersing the detection unit 14 in a target protein solution, a change in vibration characteristics accompanying a change in mass on the surface of the mechanical oscillator of the detection unit 14 due to adsorption of the protein 4_1 and the antibody 51 can be detected.

[0097] Protein 4_1 includes, for example, immune cytokines and growth factors produced by cells, and scaffolding proteins expressed on the cell surface, such as interleukins, nerve growth factors, and laminins, respectively.

[0098] Proteins can be identified because the vibration changes differently depending on the adsorption of different proteins in the mechanical oscillator of the optical mechanical sensor 10. For example, if the relationship between the type of protein and the vibration change is acquired in advance, the type of protein can be identified from the vibration change.

[0099] Furthermore, as shown in FIG. 13, the relationship between the amount of adsorbed protein and the change in vibration can be measured using a fluorescence microscope 52.

[0100] In this measurement, first, the surface of the mechanical oscillator of the detection unit 14 is chemically modified with a predetermined type of protein 4_1 that has been previously labeled with a fluorescent label 4_2.

[0101] The relationship between the amount of protein adsorption and the vibration change can be measured by measuring the change in vibration characteristics with the optical mechanical sensor 10 and evaluating the amount of adsorption based on the brightness of the fluorescent dye of the fluorescent label 4_2 with the fluorescence microscope 52. If this relationship between the amount of protein adsorption and the vibration change is obtained in advance, the amount of protein adsorption can be measured from the vibration change.

[0102] In this example, an example was shown in which the target medium was a protein solution and proteins were measured, but the present invention is not limited to this and chemical species other than proteins can also be measured.

[0103] The optical mechanical sensor and system according to this embodiment can detect specific chemical species (proteins, etc.) and measure the type and adsorption amount of the chemical species.

[0104] If the configuration of the optomechanical sensor system according to the second embodiment is applied to the configuration of the optomechanical sensor system according to this embodiment, the detection sensitivity can be improved.

[0105] Furthermore, if a movable stage is mounted on the optomechanical sensor system according to this embodiment, as in the third embodiment, the spatial distribution of chemical species can be measured.

[0106] <Fifth Example> In the optomechanical sensor and optomechanical sensor system according to this embodiment, the surface of the mechanical oscillator of the detection unit is chemically modified with a magnetostrictive material, and the other configurations are the same as those of the first embodiment.

[0107] Magnetostrictive materials are magnetized by the application of a magnetic field, causing distortion (shape change). Therefore, in the mechanical oscillator of the detection unit chemically modified with magnetostrictive material, the vibration characteristics change due to the external magnetic field. As a result, this change in vibration characteristics is optically detected as in the first embodiment, and the external magnetic field is measured.

[0108] The optical mechanical sensor and system according to this embodiment can measure a magnetic field.

[0109] Furthermore, if the configuration of the optomechanical sensor system according to the second embodiment is applied to the configuration of the optomechanical sensor system according to this embodiment, the detection sensitivity can be improved.

[0110] Furthermore, if a movable stage is mounted on the optomechanical sensor system according to this embodiment, as in the third embodiment, the spatial distribution of the magnetic field can be measured.

[0111] <Sixth Example> In the optomechanical sensor and optomechanical sensor system according to this embodiment, the surface of the mechanical oscillator of the detection unit is chemically modified with a thermostrictive material, and the other configurations are the same as those of the first embodiment.

[0112] In thermostrictive materials, heat (or temperature changes) cause distortion (shape changes). Therefore, in the mechanical oscillator of the detection unit chemically modified with the thermostrictive material, heat (or temperature changes) causes changes in vibration characteristics. As a result, this change in vibration characteristics is optically detected, as in the first embodiment, and the temperature is measured.

[0113] The optical mechanical sensor and system according to this embodiment can measure temperature.

[0114] Furthermore, if the configuration of the optomechanical sensor system according to the second embodiment is applied to the configuration of the optomechanical sensor system according to this embodiment, the detection sensitivity can be improved.

[0115] Furthermore, if a movable stage is mounted on the optomechanical sensor system according to this embodiment, as in the third embodiment, the spatial distribution of temperature can be measured.

[0116] In the optomechanical sensor system according to the embodiment of the present invention, a wavelength band of 1.5 μm is used for the laser light, but the wavelength of the laser light is not limited to this and may be appropriately selected depending on the material of the optical fiber (tapered fiber, etc.).

[0117] In the fourth to sixth embodiments of the present invention, examples have been shown in which the mechanical oscillator of the detection unit of the optical mechanical sensor is chemically modified with a protein antibody, a magnetostrictive material, or a thermostrictive material, but this is not limited to this, and any substance that reacts to an external stimuli may be chemically modified.

[0118] In the optomechanical sensor system according to the embodiment of the present invention, an example has been shown in which the tapered fiber 22 is used to generate a near-field (evanescent field) in the receiving unit 13, but this is not limiting and an optical element such as a prism may also be used, as long as it is an optical element that generates a near-field (evanescent field). In this case, laser light may be incident on an optical element such as a prism in an optical system that uses optical fibers, lenses, mirrors, etc.

[0119] In the embodiments of the present invention, examples of the structure, dimensions, materials, etc. of each component in the configuration and manufacturing method of the optomechanical sensor and optomechanical sensor system are shown, but the present invention is not limited to these. Anything that can demonstrate the functions and effects of the optomechanical sensor and optomechanical sensor system may be used. [Industrial Applicability]

[0120] The present invention relates to a sensor, and can be applied to measurements of media such as water and solutions, chemical species, magnetic fields, temperatures, and other external environments. [Explanation of symbols]

[0121] 10 Opto-mechanical sensors 11 Mechanical oscillator 12 Coupling between mechanical oscillators 13 Receiver (one mechanical oscillator) 14 Detection unit (other mechanical vibrator)

Claims

1. A plurality of mechanical vibrators; a coupling portion; the plurality of mechanical vibrators are continuously connected via the coupling portion, one of the plurality of mechanical oscillators has an optical resonator structure; The one mechanical oscillator and the other mechanical oscillator resonate via the coupling portion.

1. An optomechanical sensor comprising:

2. The plurality of mechanical vibrators are cylindrical. The optomechanical sensor of claim 1 .

3. a part of the other mechanical oscillator is disposed within the measurement object; A change in the vibration characteristics of the other mechanical oscillator changes the vibration characteristics of the one mechanical oscillator via the resonance, and the optical resonance mode of the optical resonator structure of the one mechanical oscillator changes, and light incident on the one mechanical oscillator is coupled to the optical resonance mode and detected.

3. An optomechanical sensor according to claim 1 or claim 2.

4. A device comprising a plurality of mechanical vibrators connected together, one of the plurality of mechanical oscillators has an optical resonator structure; the one mechanical oscillator and the other mechanical oscillator resonate with each other, The vibration frequency of the one mechanical vibrator is equal to or lower than the vibration frequency of the other mechanical vibrator.

1. An optomechanical sensor comprising:

5. A device comprising a plurality of mechanical vibrators connected together, one of the plurality of mechanical oscillators has an optical resonator structure; the one mechanical oscillator and the other mechanical oscillator resonate with each other, a plurality of the other mechanical vibrators; The plurality of other mechanical oscillators each have a different shape.

1. An optomechanical sensor comprising:

6. The other mechanical oscillator is chemically modified with a substance that responds to external stimuli. An optomechanical sensor according to any one of claims 1 to 5.

7. A fiber; a tapered fiber disposed on the surface of the fiber; Equipped with the fiber comprises a waist; the fiber on one side of the constricted portion constitutes the one mechanical oscillator, The fiber on the other side of the constricted portion constitutes the other mechanical oscillator. An optomechanical sensor according to any one of claims 1 to 6.

8. An optomechanical sensor according to any one of claims 1 to 7; Laser and an optical element for generating a near field; Photodetector and An optical-mechanical sensor system comprising:

9. Variable Optical Attenuator The optomechanical sensor system of claim 8 , comprising:

10. a movable stage mounted on the optomechanical sensor; 10. The optomechanical sensor system of claim 8 or claim 9, comprising:

11. A method for manufacturing an optical mechanical sensor in which one of a plurality of connected mechanical oscillators has an optical resonator structure, another mechanical oscillator that is continuously connected to the one mechanical oscillator via a coupling portion resonates, and a change in vibration characteristics of the other mechanical oscillator is detected by optical resonance in the one mechanical oscillator, a first step of heating a predetermined location of the fiber; a second step of pulling the fiber in two opposite directions along its axis to form a neck portion in the fiber; Equipped with The first step and the second step are repeated to form a plurality of the constricted portions, and among the fiber portions sandwiched between the adjacent constricted portions, one fiber portion is used as the one mechanical oscillator, the other fiber portion is used as the other mechanical oscillator, and the constricted portions are used as the coupling portion. A method for manufacturing an optomechanical sensor.

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