JP2003307488A - Measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform an accurate measurement even if a sample is reinstalled in a measuring apparatus for observing a time change in total reflection attenuation for the same measurement unit. <P>SOLUTION: In a sensor for detecting light beams L1 that are totally reflected on an interface 11a while the light beams L1 are made incident at various angles to obtain total reflection conditions on an interface 11a on a thin-film layer 12 on a dielectric block 11, light beams L2 for measuring slope are made incident to the interface 11a, the light beams 12 for measuring inclination being reflected by the interface 11a are received by a light detection means 37, the slope between the first and second measurements for measuring the total reflection attenuation on the interface 11a is obtained, and the second measurement value is corrected by a signal-processing section 20 according to the obtained slope. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a measuring device such as a surface plasmon sensor for quantitatively analyzing a substance in a sample by utilizing the generation of surface plasmons.

[0002]

2. Description of the Related Art In a metal, free electrons oscillate collectively to generate compression waves called plasma waves. And, the quantized compression wave generated on the metal surface is
It is called surface plasmon.

Conventionally, various surface plasmon sensors have been proposed for quantitatively analyzing a substance in a sample by utilizing the phenomenon that the surface plasmon is excited by a light wave.
Among them, one that is particularly well known is one that uses a system called Kretschmann arrangement (see, for example, JP-A-6-167443).

A surface plasmon sensor using the above system basically emits a light beam and a dielectric block formed in a prism shape, a metal film formed on one surface of the dielectric block and brought into contact with a sample. With respect to the light source to be generated and the above-mentioned light beam with respect to the dielectric block, the total reflection condition can be obtained at the interface between the dielectric block and the metal film, and the total reflection attenuation due to the surface plasmon resonance can occur at various angles. And an optical system for measuring the intensity of the light beam totally reflected at the interface to detect the state of surface plasmon resonance, that is, the state of attenuated total reflection.

In order to obtain various incident angles as described above, a relatively thin light beam may be incident on the above interface by changing the incident angle, or a component incident on the light beam at various angles. Therefore, a relatively thick light beam may be incident on the interface in a convergent light state or a divergent light state. In the former case, a light beam whose reflection angle changes according to the change of the incident angle of the incident light beam is detected by a small photodetector that moves in synchronization with the change of the above-mentioned reflection angle, or the direction of change of the reflection angle. It can be detected by an area sensor extending along. On the other hand, in the latter case, all the components of the light beam reflected at various reflection angles can be detected by the area sensor extending in the direction in which the light beam can be received.

In the surface plasmon sensor having the above structure, when a light beam is incident on the metal film at a specific incident angle θ _SP which is equal to or greater than the total reflection angle, an evanescent wave having an electric field distribution in the sample in contact with the metal film. Is generated, and surface plasmons are excited at the interface between the metal film and the sample by this evanescent wave. When the wave vector of the evanescent light is equal to the wave number of the surface plasmon and the wave number matching is established, both are in a resonance state and the energy of the light is transferred to the surface plasmon, so that at the interface between the dielectric block and the metal film. The intensity of the reflected light sharply decreases. This decrease in light intensity is generally detected as a dark line by the light detecting means.

The above resonance occurs only when the incident beam is p-polarized. Therefore, it is necessary to set in advance that the light beam is incident with p-polarized light, or to detect only the p-polarized component.

When the wave number of the surface plasmon is known from the incident angle θ _{SP at which} this attenuated total reflection (ATR) occurs, the dielectric constant of the sample can be obtained. That is, the wave number of the surface plasmon is K
_{Let SP be} the angular frequency of surface plasmons be ω, c be the speed of light in a vacuum, ε _m and ε _S be the metal, and the permittivity of the sample respectively, and the following relationships are established.

[0009]

[Equation 1] If the permittivity ε _S of the sample is known, the concentration of the specific substance in the sample can be known based on a predetermined calibration curve or the like. Therefore, by finally knowing the incident angle θ _{SP at} which the reflected light intensity decreases, the dielectric constant of the sample can be determined. A property related to the index, that is, the refractive index can be obtained.

As a similar sensor utilizing the attenuated total reflection (ATR), for example, "Spectroscopic Research" Vol. 47, No. 1 (1998), pages 21 to 23 and 26 to 27.
Leakage mode sensors described on the page are also known. This leaky mode sensor is basically formed by, for example, a dielectric block formed in a prism shape, a clad layer formed on one surface of the dielectric block, and formed on the clad layer and brought into contact with a sample. An optical waveguide layer, a light source for generating a light beam, and the light beam with respect to the dielectric block, a total reflection condition is obtained at the interface between the dielectric block and the cladding layer, and the light guide layer is used. The optical system that is incident at various angles so that the attenuation of the total reflection due to the excitation of the wave mode may occur, and the intensity of the light beam totally reflected at the interface is measured to determine the excited state of the guided mode, that is, the attenuated total reflection state. And a light detecting means for detecting.

In the leak mode sensor having the above structure,
When a light beam is incident on the cladding layer through the dielectric block at an angle of incidence equal to or more than the total reflection angle, only light with a specific incident angle having a specific wave number is transmitted in the optical waveguide layer after passing through the cladding layer. It propagates in the guided mode. When the guided mode is excited in this manner, most of the incident light is taken into the optical waveguide layer, so that the total reflection attenuation occurs in which the intensity of the light totally reflected at the interface sharply decreases.
Since the wave number of the guided light depends on the refractive index of the sample on the optical waveguide layer, the refractive index of the sample and the related characteristics of the sample are analyzed by knowing the above-mentioned specific incident angle at which attenuation of total reflection occurs. be able to.

As a measuring device utilizing total internal reflection such as a surface plasmon sensor or a leaky mode sensor, light is made incident on the interface at an incident angle at which total reflection conditions are obtained, and the evanescent wave is generated by the light, so that the interface In order to analyze the characteristics of the substance to be measured by measuring the change in the state of the light totally reflected by, the device for measuring the specific incident angle that causes the attenuation of total reflection described above, as well as the light beams of multiple wavelengths A device that detects the degree of attenuation of total reflection for each angular wavelength by making it incident on the interface, or a light beam is made incident on the interface, and a part of this light beam is split before it enters the interface. There are various types such as a device that interferes with a light beam reflected by an interface to measure the state of the interference.

[0013]

In the conventional surface plasmon sensor or leak mode sensor of the type described above, it is necessary to measure one sample (same measurement unit) a plurality of times with time, and to examine the change in the state. In some cases, in order to perform efficient measurement on a plurality of samples, the samples may be exchanged for each dielectric block to perform the measurement. In this case, if one sample is once removed from the measuring device and then set again to perform measurement, a difference (tilt) is generated between the first baseline (the above interface) and the subsequent baseline. There is. If the inclination of the baseline is the inclination in the vertical direction that changes the incident angle of the light beam incident at the various incident angles described above, the angle of the reflected light that is detected is also displaced, and the measurement accuracy is reduced. Will fall.

Further, even if the samples are not replaced, the inclination of the baseline may be slightly changed due to vibration or the like while the plurality of samples are placed on the turntable and rotated. Even in such a case, the inclination of the baseline generated during multiple measurements causes a measurement error.

Further, when the angle of the reflected light is deviated, that is, not only the vertical inclination that changes the incident angle of the light beam but also the inclination of the interface in the horizontal direction intersecting with the vertical direction occurs, the reflected light is reflected. There is a problem in that the reflected light may not be received by the light receiving surface of the light detection means due to the change of the reflection direction, and any inclination in the vertical and horizontal directions of the interface leads to a decrease in measurement accuracy.

In view of the above circumstances, it is an object of the present invention to provide a measuring device having high measurement accuracy even when the same measuring unit is measured a plurality of times.

[0017]

A first measuring device of the present invention comprises a transparent dielectric block, a measuring unit comprising a thin film layer formed on one surface of the dielectric block, and a light beam. Light beam incidence means for making the dielectric block incident at various incident angles so that total reflection conditions can be obtained at the interface between the dielectric block and the thin film layer, and a predetermined value for the light beam totally reflected at the interface. In the measuring device, which comprises a light detecting means for receiving the polarized light component of, performs the measurement a plurality of times on the same measurement unit, and detects a change in the state of attenuation of total reflection during the plurality of measurements,
Vertical tilt measuring means for measuring a vertical tilt that changes the incident angle of the interface between the plurality of measurements, and the tilt according to the vertical tilt measured by the vertical tilt measuring means. And an arithmetic means for obtaining a measured value in which an error due to the above is corrected.

The measuring device may be configured such that the thin film layer is made of a metal film and the measurement is performed by utilizing the effect of the surface plasmon resonance described above.

Further, in the above measuring apparatus, the thin film layer comprises a clad layer formed on the one surface of the dielectric block and an optical waveguide layer formed on the clad layer. The measurement may be performed by utilizing the effect of the excitation of the wave mode.

A second measuring device of the present invention is a measuring unit comprising a transparent dielectric block and a thin film layer formed on one surface of the dielectric block, and a light beam to the dielectric block. And a light detection means for receiving a predetermined polarization component of the light beam totally reflected at the interface, and a light beam incidence means for making the incident angle at which the total reflection condition is obtained at the interface between the dielectric block and the thin film layer. In the measuring device for detecting a change in the state of total reflection during the plurality of measurements, the incident angle of the interface between the plurality of measurements is performed. A vertical inclination measuring unit that measures a vertical inclination to be changed, and the measurement unit that corrects an error caused by the inclination according to the vertical inclination measured by the vertical inclination measuring unit. Tsu bets, is characterized in that a longitudinal adjustment means for adjusting the light beam projecting means and / or the light detecting means.

The measuring device may be configured such that the thin film layer is made of a metal film and the measurement is performed by utilizing the effect of the surface plasmon resonance described above.

Further, in the above measuring apparatus, the thin film layer is composed of a clad layer formed on the upper surface of the dielectric block and an optical waveguide layer formed on the clad layer. The measurement may be performed by utilizing the effect of the excitation of the wave mode.

In the second measuring device, "to detect the change in the state of the total reflection light" means to detect the light beam incident on the interface at various incident angles, as in the first measuring device. It is also possible to detect the change in the state of attenuation of total reflection by detecting the reflected light at the interface of
Noort, K.johansen, C.-F.Mandenius, Porous Gold in Su
rface Plasmon Resonance Measurement, EUROSENSORS X
As described in III, 1999, pp.585-588, a light beam having a plurality of wavelengths is made incident at an incident angle at which total reflection conditions are obtained at the interface, and light totally reflected at the interface for each wavelength. The intensity of the beam may be measured to detect the degree of attenuation of total reflection for each wavelength. In addition, PINikitin, A.
N.Grigorenko, AABeloglazov, MVValeiko, AISavchu
k, OASavchuk, Surface Plasmon Resonance Interfero
metry for Micro-Array Biosensing, EUROSENSORS XII
As described in I, 1999, pp.235-238, the light beam is made incident at an incident angle at which total reflection conditions are obtained at the interface, and a part of this light beam The light beam may be split before it is incident on the laser beam, and the split light beam may be caused to interfere with the light beam totally reflected at the interface to detect a change in the intensity of the light beam after the interference.

In the above description, "to receive a predetermined polarization component of the light beam totally reflected at the interface" means that the light beam is a predetermined linearly polarized light capable of observing the state of totally reflected light, as it is. It only needs to be set to receive light,
Further, if it has a plurality of polarization components, it may be set so as to receive only a predetermined linear polarization component capable of observing the state of totally reflected light using an optical element such as an analyzer.

The "vertical inclination of the interface which changes the incident angle" is an inclination from a reference interface position, and is an inclination from the interface position at a predetermined one time (for example, the first time) measurement. Or the inclination from the average position of the interface during a plurality of measurements.

The "vertical tilt" measured by the vertical tilt measuring means may be the angle of the vertical tilt of the interface itself, or a characteristic value corresponding thereto.

"Adjusting the measuring unit, the light beam incident means and / or the light detecting means" means correcting the inclination of the measuring unit, changing the incident angle of the light beam by the light beam incident means, To move at least one of the detection means,
Any two or all may be combined and implemented.

In the first or second measuring apparatus of the present invention, the light beam incidence means and the light detection means cause the light beam to enter the interface at various incident angles,
It is configured to measure the state of attenuation of total internal reflection that occurs when incident on the interface at a predetermined incident angle,
When the light beam is a single light beam that includes components incident on the interface at various angles and has a predetermined light amount distribution in the direction of change of the incident angle with respect to the interface, the vertical tilt measuring means The tilt in the vertical direction may be measured by utilizing reflection of at least a part of the light beam by a part of the measuring unit.

More specifically, the vertical tilt measuring means may measure the vertical tilt by utilizing a component of the light beam outside the measurement range of the attenuation of total reflection. In this case, the reflected light intensity and the detection position of the portion of the light beam received by the light detection means, which is outside the measurement range of the attenuation of total reflection, in which the light amount largely changes with the change of the incident angle, It is also possible to measure the vertical inclination from the relationship of, the light beam, a part of the component outside the measurement range of the total reflection attenuation is made incident on the interface as a dark line, the photodetection means The tilt in the vertical direction may be measured by detecting the position of a dark line included in the reflected light component of the light beam.

On the other hand, the vertical tilt measuring means receives a light beam converged by the converging lens by converging at least a part of the light beam reflected by a part of the measuring unit, and receives the light beam. Second light detection means for detecting the position of the light beam may be provided. That is, the reflected light of the light beam is converged by the converging lens,
The vertical inclination of the interface may be detected by detecting the change in the convergence position.

If the converging lens is movable between the position on the optical path of the light beam and the position outside the optical path, the light detecting means can also serve as the second light detecting means.
In this case, the tilt measurement may be performed with the converging lens placed on the optical path, and the state of attenuation of total reflection may be measured with the converging lens moved to a position outside the optical path.

When the light beam includes a plurality of polarization components, the second light detecting means receives the components other than the predetermined polarization component of the light beam and detects the light beam. You may do it.

Further, in the measuring device provided with a converging lens, the vertical tilt measuring means further comprises a second lens between the converging lens and the second light detecting means, and the converging lens is provided. The focal lengths of the second lens are f1 and f2, the distance between the reflection position of the light beam and the light detecting means is L, the distance between the reflection position and the converging lens is d0, the converging lens and the converging lens, respectively. The distance from the second lens is d1, the distance between the second lens and the second light detecting means is d2, the shift amount of the reflection position based on the vertical movement amount of the interface is x, and the interface When the vertical tilt is θ, the moving distance A of the attenuation angle of total reflection represented by Ltan θ + x and θ {d1 + d2-d1d2 / f2-d0 (d1 / f1 + d0 /
f1-d1d2 / f1 / f2-1 + d2 / f2} -x (d1 / f1 + d2 / f1-d1d2 / f1 / f2-
1 + d2 / f2), L, d0, d1, so that the relationship with the spot movement amount B of the light beam in the second light detecting means is A = B or A = −B. d2, f1,
You may select f2 and arrange | position the said converging lens, the said 2nd lens, and the said 2nd photon detection means. As described above, by disposing the two lenses at a predetermined interval on the optical path leading to the second light detecting means, it is possible to detect not only the vertical inclination of the interface but also the vertical shift amount of the interface. Become.

For example, the relationship between the distances L, d0, d1, d2 and the focal lengths f1, f2 is d1 = f1, d.
The converging lens, the second lens, and the second light detecting means may be installed so that 2 = f2 and d0 = f1 + L.

Further, in the first or second measuring apparatus of the present invention, the vertical tilt measuring means includes a second light beam which is different from the light beam and is incident on a part of the measuring unit. A light beam incident means and a second light detection means for receiving the second light beam reflected by a part of the measurement unit and detecting the position of the second light beam. Good.

In this case, the second light beam may have a wavelength different from that of the light beam, or when the light beam is linearly polarized light of the predetermined polarization component, The second light beam may be linearly polarized light having a polarization component different from that of the light beam.

In the above description, the part of the measurement unit may be the interface, or a part other than the interface, which is inclined by a predetermined inclination of the interface according to the vertical inclination of the interface. May be a surface. The predetermined surface may be one surface such as a side surface or a bottom surface of the dielectric block, or a reflecting surface provided near the one surface of the dielectric block on which the thin film layer is formed. May be.

A third measuring device of the present invention is a measuring unit comprising a transparent dielectric block and a thin film layer formed on one surface of the dielectric block, and a light beam to the dielectric block. Light beam incidence means for making incident light at various incident angles so that total reflection conditions can be obtained at the interface between the dielectric block and the thin film layer, and a predetermined polarization component of the light beam totally reflected at the interface is received. In a measurement device comprising a light detection means, performing the measurement a plurality of times on the same measurement unit, and detecting a change in the state of attenuation of total internal reflection during the plurality of measurements, the interface between the plurality of measurements. A vertical and horizontal inclination measuring means for measuring a vertical inclination for changing the incident angle and a horizontal inclination intersecting the vertical direction, and the horizontal direction measured by the vertical and horizontal inclination measuring means. Lateral adjustment for adjusting the measuring unit, the light beam incident means and / or the light detecting means so as to correct the deviation of the light receiving position of the light detecting means by the light beam caused by the tilt according to the inclination. Means and means for obtaining a measurement value in which an error due to the inclination is corrected according to the inclination in the vertical direction measured by the vertical and horizontal inclination measuring means.

The measuring device may be configured such that the thin film layer is made of a metal film and the measurement is performed by utilizing the effect of the surface plasmon resonance described above.

In the measuring device, the thin film layer is composed of a clad layer formed on the upper surface of the dielectric block and an optical waveguide layer formed on the clad layer. The measurement may be performed by utilizing the effect of the excitation of the wave mode.

A fourth measuring device of the present invention is a measuring unit comprising a transparent dielectric block and a thin film layer formed on one surface of the dielectric block, and a light beam to the dielectric block. And a light detection means for receiving a predetermined polarization component of the light beam totally reflected at the interface, and a light beam incidence means for making the incident angle at which the total reflection condition is obtained at the interface between the dielectric block and the thin film layer. In the measuring device for detecting the change in the state of the total reflection light during the plurality of measurements, the measurement is performed a plurality of times for the same measurement unit, the incidence of the interface between the plurality of measurements. A vertical / horizontal tilt measuring means for measuring a vertical tilt for changing an angle and a horizontal tilt intersecting the vertical direction, and the horizontal tilt and the vertical tilt measured by the vertical / horizontal tilt measuring means. The measurement unit and the light beam incident so as to correct the deviation of the light receiving position by the light detection unit due to the light beam due to the lateral tilt and the error due to the vertical tilt according to the tilt of the direction. Means and / or vertical and horizontal direction adjusting means for adjusting the light detecting means.

The measuring apparatus may be configured such that the thin film layer is made of a metal film and the measurement is performed by utilizing the effect of the surface plasmon resonance described above.

In the measuring device, the thin film layer is composed of a clad layer formed on the upper surface of the dielectric block and an optical waveguide layer formed on the clad layer. The measurement may be performed by utilizing the effect of the excitation of the wave mode.

In the fourth measuring device, "to detect the change in the state of the total reflected light" is detected as in the third measuring device, the light beam incident on the interface at various incident angles. The reflected light at the interface may be detected to detect the change in the state of attenuation of total reflection, or the incident angle at which the light beams of a plurality of wavelengths are obtained at the interface under the condition of total reflection. It is also possible to detect the degree of attenuation of total reflection for each wavelength by measuring the intensity of the light beam that has been made incident on the above-mentioned optical fiber and totally reflected at the interface for each wavelength. Further, the light beam is made incident at an incident angle at which total reflection conditions are obtained at the interface, and a part of the light beam is divided before the light beam enters the interface, and the divided light beam is The change in the intensity of the light beam after the interference may be detected by causing interference with the light beam totally reflected at the interface.

In the third or fourth measuring apparatus of the present invention, the light beam incident means and the light detection means make the light beam incident on the interface at various incident angles,
It is configured to measure the state of attenuation of total internal reflection that occurs when incident on the interface at a predetermined incident angle,
When the light beam is a single light beam that includes components incident on the interface at various angles and has a predetermined light amount distribution in the direction of change of the incident angle with respect to the interface, A converging lens for converging at least a part of the light beam reflected by a part of the measuring unit;
The two-dimensional light detecting means may be configured to receive the light beam converged by the converging lens and detect the position of the light beam.

In the third or fourth measuring apparatus of the present invention, the vertical / horizontal inclination measuring means causes the second light beam different from the light beam to enter a part of the measuring unit. It may be provided with a beam incidence means and a two-dimensional light detection means for receiving the second light beam reflected by a part of the measurement unit and detecting the position of the second light beam. .

The second light beam may have a wavelength different from that of the light beam, or when the light beam is linearly polarized light of the predetermined polarization component, the second light beam The light beam may be linearly polarized light having a polarization component different from that of the light beam.

As the two-dimensional light detecting means, a four-division photodiode, a resistance type photodetector or the like is suitable.

In the above, the part of the measuring unit may be the interface, or the part other than the interface, the measurement being inclined corresponding to the inclination of the interface in the vertical direction and the horizontal direction. It may be a predetermined surface of the unit. The predetermined surface may be one surface such as a side surface or a bottom surface of the dielectric block, or a reflecting surface provided near the one surface of the dielectric block on which the thin film layer is formed. May be.

The dielectric block may be formed as one block having all of the incident end face and the emitting end face of the light beam and the face on which the thin film layer is formed. The two parts, that is, the part having the incident end face and the exit end face of the light beam and the part having the face on which the thin film layer is formed may be joined via a refractive index matching means.

In each of the above measuring devices, an area sensor, a line sensor or the like can be used as the light detecting means, and more specifically, a two-division photodiode,
A photodiode array or the like can be preferably used.

[0052]

According to the first measuring apparatus of the present invention, the measurement is performed by the vertical inclination measuring means for measuring the vertical inclination that changes the incident angle of the light beam on the interface at each measurement of a plurality of measurements. According to the tilt in the vertical direction, the calculation means for obtaining the measured value in which the error due to the tilt is corrected is provided.
When performing measurement a plurality of times on the same measurement unit and detecting a change in the state of attenuation of total internal reflection during the plurality of measurements, a measurement error caused by the interfaces at the time of each measurement having a vertical inclination with respect to each other is measured. You will be able to compensate and make more accurate measurements.

According to the second measuring apparatus of the present invention, the vertical tilt measured by the vertical tilt measuring means for measuring the vertical tilt that changes the incident angle of the light beam on the interface at each measurement of a plurality of measurements. Since the measurement unit, the light beam incident means and / or the light detection means are adjusted so as to correct the error due to the inclination of the direction, the measurement unit measures the same measurement unit. When a change in the state of the total reflected light is detected during a plurality of measurements, the measurement error caused by the vertical inclination of the interfaces at each measurement is compensated, and more accurate. It becomes possible to perform various measurements.

In the case of a device for measuring the state of attenuation of total reflection by injecting a light beam into an interface at various incident angles, a component outside the measurement range of attenuation of total reflection of the measurement light beam is used as the vertical inclination measuring means. By using the one utilizing the reflected light intensity, it is possible to detect the vertical inclination of the interface without providing a special device, and it is possible to suppress an increase in size and cost of the device.

As the vertical tilt measuring means, a second light beam different from the measuring light beam is used, and in particular, one having a polarization direction different from that of the measuring light beam, or a measuring light beam. If the one having a wavelength different from that of is used, the vertical inclination of the interface can be measured simultaneously with the measurement of the total reflected light without affecting the measurement light beam.

According to the third measuring device of the present invention,
Depending on the vertical and horizontal tilts measured by the vertical and horizontal tilt measuring means for measuring the vertical and horizontal tilts that change the incident angle of the light beam on the interface during each of the plurality of measurements, the horizontal direction A horizontal direction adjusting means for adjusting the measuring unit, the light beam incident means and / or the light detecting means so as to correct the shift of the light receiving position by the light detecting means due to the inclination of the light beam; Since it has a calculation means for obtaining a measurement value in which the error due to the tilt is corrected, the measurement is performed a plurality of times on the same measurement unit, and when detecting a change in the state of attenuation of total reflection during the plurality of measurements, It corrects the deviation of the light receiving position of the measuring light beam caused by the mutual inclination of the interfaces during each measurement, and the light beam is not received by the light detecting means. Thereby preventing the condition, to compensate for measurement errors caused by having a tilt in the longitudinal direction at the time of each measurement, it is possible to perform more accurate measurements.

According to the fourth measuring device of the present invention,
Depending on the vertical and horizontal tilts measured by the vertical and horizontal tilt measuring means for measuring the vertical and horizontal tilts that change the incident angle of the light beam on the interface during each of the plurality of measurements, the horizontal direction The measuring unit, the light beam incident means, and / or the light detection means so as to correct the deviation of the light receiving position by the light detection means by the light beam due to the tilt of the light beam and the error due to the tilt in the vertical direction. Since the vertical and horizontal direction adjusting means is provided, measurement is performed a plurality of times on the same measurement unit, and when detecting a change in the state of total reflected light during the plurality of measurements,
Corrects the deviation of the light receiving position of the measurement light beam caused by the mutual inclination of the interfaces at the time of each measurement, and prevents problems such as the light beam not being received by the light detection means. It becomes possible to compensate for the measurement error caused by having the vertical inclination in and to perform more accurate measurement.

[0058]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The measuring apparatus according to the first embodiment of the present invention is a surface plasmon sensor utilizing surface plasmon resonance, and FIG. 1 shows its side surface shape.

The measuring chip 10 as a measuring unit of this surface plasmon sensor has an inverted truncated quadrangular pyramid shape formed of, for example, a transparent resin.
A sample holding portion 13 in which a sample holding hole 13a having a circular cross section is formed is formed in the upper portion, and the metal film 12 is coated on the bottom surface of the sample holding hole 13a (the surface 11a of the dielectric block 11 described later). The lower part of the sample holding part 13 of the measuring chip 10 on which the sample solution 15 is deposited and on which the sample solution 15 is stored is the dielectric block 11, and two facing surfaces of the four side surfaces are light-receiving. An incident end face 11b and a light emitting end face 11c are formed. That is, the dielectric block 11 includes an incident end face 11b and an emitting end face 11c of the light beam, and a thin film layer (metal film) 12
Is formed as one block having all the surfaces on which is formed. In this example, the sensing medium 30 is fixed on the metal film 12.
Will be described later.

The measuring chip 10 is, for example, a turntable 31.
One by one is fitted and fixed in the chip holding holes 31a provided in the plurality. After the measurement chip 10 is fixed to the turntable 31 in this manner, the turntable 31 is intermittently rotated by a constant angle, and the sample solution 15 is dropped onto the measurement chip 10 stopped at a predetermined position. The liquid 15 is held in the sample holding unit 13. Thereafter, when the turntable 31 is further rotated by a certain angle, the measuring tip 10 is sent to the measuring position shown in FIG. 1 and stopped there.

The surface plasmon sensor of this embodiment is
In addition to the measurement chip 10 which is the above measurement unit,
A light beam incidence means 1 including an optical system which passes the light beam L1 through a dielectric block 11 and makes it incident on an interface 11a between the dielectric block 11 and the metal film 12 so as to obtain various incident angles. A collimator lens 16 for collimating the light beam L1 totally reflected at the interface 11a, a photodetector 17 for detecting the collimated light beam L1, and a differential amplifier connected to the photodetector 17. An array 18, a driver 19, a signal processing section 20 including a computer system and the like, and a display means 21 connected to the signal processing section 20 are provided.

The light beam incident means 1 includes a light source 2 including a semiconductor laser for generating the light beam L1, a collimator lens 3 for collimating the light beam L1 emitted from the light source 2 in a divergent light state, and It is composed of a condenser lens 4 which converges the collimated light beam L1 on the interface 11a.

As shown in FIG. 1, the light beam L1 emitted from the light source 2 in a divergent state is focused on the interface 11a between the dielectric block 11 and the metal film 12 by the action of the lenses 3 and 4. Therefore, the light beam L1 includes components that are incident on the interface 11a at various incident angles θ. This incident angle θ
Is an angle equal to or greater than the total reflection angle. So the light beam L1
Is totally reflected at the interface 11a, and the reflected light beam L1 is
Components that reflect at various reflection angles will be included. The light beam L1 is incident on the interface 11a as p-polarized light. In order to do so, the light source 2 may be arranged in advance so that the polarization direction thereof is the predetermined direction. In addition, the polarization direction of the light beam L1 may be controlled by a wave plate or a polarizing plate. Further, the light beam incidence means 1 applies the light beam L1 to the interface 11
The light may be incident on a in a defocused state. By doing so, the error in the state detection of the surface plasmon resonance (for example, the position measurement of the dark line) is averaged, and the measurement accuracy is improved.

After being totally reflected by the interface 11a, the light beam L1 which is collimated by the collimator lens 16 is a light detecting means.
Detected by 17. The light detecting means 17 in this example is a photodiode array in which a plurality of photodiodes 17a, 17b, 17c ... Are arranged side by side in a row, and a parallel light beam is formed in the plane of the drawing of FIG. The photodiodes are arranged in a direction in which the direction in which the photodiodes are arranged is substantially perpendicular to the traveling direction of L1. Therefore, the different photodiodes 17a, 17b, 17c ... Receive the respective components of the light beam L1 totally reflected at the various reflection angles at the interface 11a.

FIG. 2 is a block diagram showing the electrical construction of this surface plasmon sensor. As shown in the figure, the driver 19 includes the differential amplifiers 18 a, 18 a of the differential amplifier array 18.
The sample-hold circuits 22a, 22b, 22c, ... for sampling and holding the outputs of b, 18c .., the multiplexer 23 to which the outputs of these sample-hold circuits 22a, 22b, 22c. A / D converter 24 that digitizes and inputs to signal processing unit 20, multiplexer 23 and sample hold circuits 22a, 22b, 22
.. and c, and a controller 26 that controls the operation of the drive circuit 25 based on an instruction from the signal processing unit 20.

The photodiodes 17a, 17b, 17c ...
Each output of ... is the difference amplifier 18 of the difference amplifier array 18.
It is input to a, 18b, 18c .... At this time, the outputs of two photodiodes adjacent to each other are input to a common differential amplifier. Therefore, each differential amplifier 18a, 18b,
The output of 18c ... is a plurality of photodiodes 17a, 17
It can be considered that the photodetection signals output by b, 17c ... Are differentiated with respect to their parallel arrangement direction.

The outputs of the differential amplifiers 18a, 18b, 18c, ... Are sample and hold circuits 22a, 22b, 22c ,.
Are sample-held at a predetermined timing by the ... And input to the multiplexer 23. The multiplexer 23 includes the sample-and-hold differential amplifiers 18a, 18b, 18c ...
The outputs of ... Are input to the A / D converter 24 in a predetermined order. The A / D converter 24 digitizes these outputs and inputs them to the signal processing unit 20.

FIG. 3 shows the light beam L1 totally reflected at the interface 11a.
Intensity of each incident angle θ and differential amplifiers 18a, 18b, 18c
It describes the relationship with the output of. Here, the relationship between the incident angle θ of the light beam L1 on the interface 11a and the light intensity I is assumed to be as shown in the graph of FIG.

Light incident on the interface 11a at a specific incident angle θ _SP excites surface plasmons at the interface between the metal film 12 and the sample 15, so that the reflected light intensity I of this light sharply decreases. That is, θ _SP is the attenuated total reflection angle, and the reflected light intensity I takes the minimum value at this angle θ _SP . This decrease in the reflected light intensity I is observed as a dark line in the reflected light, as indicated by D in FIG.

Further, FIG. 3B shows the photodiode 17
a, 17b, 17c ... are shown in a line, and as described above, these photodiodes 17a, 17b, 17c are shown.
The position in the parallel direction of ...... uniquely corresponds to the incident angle θ.

Then, the photodiodes 17a, 17b, 17c
……, the parallel installation position, that is, the incident angle θ and the differential amplifier
The relationship between the outputs 18 ', 18b, 18c ... And the output I' (differential value of the reflected light intensity I) is as shown in FIG.

The signal processing section 20 is based on the value of the differential value I'input from the A / D converter 24, and the differential amplifiers 18a, 18a.
From b, 18c, ..., select the one (the differential amplifier 18d in the example of FIG. 3) that has the output closest to the differential value I '= 0 corresponding to the total reflection attenuation angle θ _SP . , And the differential value I ′ output by it is displayed on the display means 21. In some cases, there is a differential amplifier that outputs a differential value I ′ = 0, and in that case, that differential amplifier is naturally selected.

Thereafter, every time a predetermined time elapses, the differential value I'output from the selected differential amplifier 18d is displayed on the display means 21.
Is displayed in. This differential value I'changes the dielectric constant, that is, the refractive index of the substance in contact with the metal film 12 (see FIG. 1) of the measuring chip 10, and moves the curve shown in FIG. When it changes in shape, it moves up and down accordingly. Therefore, by continuously measuring the differential value I ′ with the passage of time, it is possible to investigate the change in the refractive index of the substance in contact with the metal film 12, that is, the change in the characteristic.

Particularly in this embodiment, the sample solution 15 is applied to the metal film 12.
The sensing medium 30 that binds to the specific substance in the is fixed, and the refractive index of the sensing medium 30 changes according to the binding state thereof, so by continuously measuring the differential value I ′, the binding state You can check the state of change. That is, in this case, both the sample liquid 15 and the sensing medium 30 are the samples to be analyzed. Examples of such a combination of the specific substance and the sensing medium 30 include an antigen and an antibody.

In order to investigate the change in the binding state between the specific substance in the sample solution 15 and the sensing medium 30 with the passage of time, the differential value I'is obtained and displayed every time a predetermined period of time elapses. Alternatively, a difference ΔI ′ between the differential value I ′ (0) measured first and the differential value I ′ (t) measured after a lapse of a predetermined time may be obtained and displayed.

When measuring the time change of the differential value I'as described above, the same measurement chip is measured a plurality of times at every elapse of a fixed time. At this time, in order to efficiently perform measurement on a plurality of samples (a plurality of measurement chips), the measurement chip 10 is once removed from the turntable 31, and the next measurement chip holding another sample is measured, After a certain period of time, the first measurement chip 10 is attached to the turntable 31 again and measurement is performed.

When the measuring chip 10 is reset, there may be a deviation from the state at the time of the previous measurement, and in particular, the vertical inclination of the interface 11a that changes the incident angle of the light beam L1 on the interface 11a may occur. This will greatly affect the measured value.

Therefore, the surface plasmon sensor of the present embodiment uses the second light beam for measuring the vertical inclination of the interface 11a.
A second light beam incident means 32 for making L2 incident on the dielectric block 11 so as to be totally reflected at the interface 11a of the dielectric block 11, and output from the second light beam incident means 32, An inclination measuring means including a second light detecting means 37 for detecting the second light beam L2 reflected by 11a is provided. The second photo-detecting means 37 is specifically a line-like photo-detector such as a photodiode array similar to the photo-detecting means 17, and specifically, the light beam L2 due to the vertical inclination of the interface 11a. Of the light beam L2 in the direction K to detect the deviation of the traveling direction of the light beam L2 due to the change of the incident angle (that is, the reflection angle) of the light beam L2. (Ie change in reflection angle)
Is to detect. The output S _R from the second light detecting means 37 is sent to the signal processing unit 20, the signal processing unit 20, the signal from the light detection means 17 for detecting a plasmon resonance signal, correcting the inclination of the surface 11a By adding the correction signal for the correction, an accurate measurement value in which an error due to the inclination of the interface 11a is corrected is obtained. Specifically, the difference (inclination) in the angle of the interface obtained from the signal from the second light detecting means 37 is added to or subtracted from the angle of the measurement value obtained for the plasmon resonance signal to correct it. That is, the signal processing unit 20 constitutes an arithmetic means. The second light beam L2 for tilt measurement used here is set so as to enter the interface as s-polarized light so as to have a different polarization direction from the light beam L1.

When the first measurement of the sample 15 was performed, the second
The second light beam incident means 32 is incident on the interface 11a.
Is reflected by the interface 11a, and the reflected light is detected by the second light detecting means 37. At the time of the second measurement, the reflected light of the second beam L2 is similarly detected, and the deviation in the arrow K direction from the first detection position is obtained. This shift in the detection position corresponds to the vertical inclination of the interface 11a. As described above, the interface 11 is formed by the second light detecting means 37.
The second light beam L2 reflected by a is received, and the interface 11a
The vertical tilt of the interface 11a is measured by measuring the detection position of the reflected light that changes depending on the vertical tilt of the interface 11a that changes the incident angle on the interface 11a. Based on the vertical inclination of the interface obtained from the change in the detection position of the light beam L2, the signal processing unit 20 obtains a measurement value in which an error due to the inclination is corrected. Also in the third and subsequent measurements, similarly, measured values are obtained by correcting the error due to the vertical inclination of the interface from the time of the first measurement. As a result, it is possible to obtain a measurement value in which the vertical inclination of the interface 11a is compensated, and more precise measurement can be performed.

The reason why the interfaces at the time of each measurement have an inclination with respect to each other when performing the measurement a plurality of times is not only the case where the measurement chip is reset as described above, but also the case where the measurement chip is supported. When the support base is rotated (moved), the support base, the light source for performing the measurement, and the arrangement of the photodetector are moved, and the like. About the vertical inclination of the interface that occurs in these cases Also in the same manner as in the case described above, highly reliable measurement can be performed by measuring the vertical inclination of the interface and obtaining a measured value corrected according to the inclination.

When measuring the state of attenuated total reflection of the sample, the state of attenuated total reflection of the measuring chip 10 is measured before dispensing the sample solution 15 to the measuring chip 10, When the change in the attenuated total reflection angle due to only the sample liquid 15 is measured by subtracting the bulk effect of the measurement tip 10 from the measured value after the dispensing of the sample liquid 15, the inclination of the interface 11a occurs before and after the dispensing of the sample liquid 15. And the reliability of the measured value is impaired. Even in such a case, if the longitudinal inclination of the interface is measured and a measured value corrected according to the inclination is obtained, highly reliable measurement can be performed.

Next, a second embodiment of the present invention will be described with reference to FIG. In addition, in FIG.
Elements that are the same as the elements inside are given the same reference numerals, and descriptions thereof will be omitted unless otherwise necessary.

The measuring apparatus of the second embodiment has substantially the same structure as the plasmon sensor shown in the first embodiment, but the means for compensating the inclination after measuring the inclination of the interface 11a is different. It is a thing. This surface plasmon sensor has an interface 11a obtained from the measurement value of the second light detecting means 37.
In order to compensate for the vertical inclination of the above, the first light detecting means 17 for detecting the attenuated total reflection angle is provided with position adjusting means for moving and adjusting in the direction of the arrow x in the figure. That is, the position adjusting means, which is the vertical direction adjusting means, comprises the light detecting means 17 that is movable in the arrow x direction, and the driving means 35 that moves to adjust the light detecting means 17, and the driving means 35. Adjusts the movement of the light detection means 17 according to an instruction from the signal processing unit 20. That is, in the present embodiment, the measurement value is not corrected by calculation, but the photodetection means 17 is moved so as to correct the error due to the vertical inclination of the interface.

As described above, according to the apparatus of the present embodiment, the vertical direction adjusting means for moving the light detecting means 17 in accordance with the vertical inclination detected by the vertical inclination measuring means is provided,
By physically adjusting the position, it is possible to obtain a measurement result in which the vertical inclination of the interface is compensated.

Further, in the plasmon sensor shown in FIG. 5 as the measuring apparatus of the third embodiment, the light detecting means 17
In addition to the position adjustment described above, an incident angle adjusting means for adjusting the incident angle by the light beam incident means 1 is provided as the vertical direction adjusting means. The incident angle adjusting means has a surface for reflecting the light beam L1 from the light source 2, and the mirror 36 is rotatable in a direction in which the reflecting surface changes the incident angle of the light beam L1, and the mirror 36 is rotated. Drive means for driving 38
The drive means 38 rotates the mirror 36 according to an instruction from the signal processing section 20 to adjust the reflection angle. That is, the light beam L1 to the interface 11a at each measurement
The light beam L1 reflected by the interface 11a is adjusted so as to always be reflected in substantially the same direction by adjusting the incident angle of. The light beam incident means 1 of this embodiment has a configuration in which a small-diameter light beam emitted from the light source 2 is diffused by the concave lens 5.

As described above, since the incident angle to the interface 11a can be made constant by inclining the light beam according to the longitudinal inclination of the interface obtained by the inclination measuring means, the vertical direction of the interface can be kept constant. It is possible to obtain the measurement result in which the inclination is compensated.

As described above, in addition to adjusting the light detecting means 17 or the light beam incident means 1, the measuring chip 10
It may be adjusted so as to correct the vertical inclination of the interface by inclining itself. Furthermore, by adjusting all or arbitrary two positions of the light detecting means 17, the light beam incident means 1, the measuring chip 10 and the like, it is possible to obtain a measured value in which the longitudinal inclination of the interface is compensated as a whole. You may

Next, a fourth embodiment of the present invention will be described with reference to FIG.

The measuring apparatus of the fourth embodiment is the leak mode sensor described above, and in this example also, the measuring chip 10 is used as the measuring unit. However, the cladding layer 40 is formed on the bottom surface of the sample holding hole 13a of the measurement chip 10, and the optical waveguide layer 41 is further formed thereon.

The clad layer 40 is formed into a thin film using a dielectric having a lower refractive index than the dielectric block 11 or a metal such as gold. The optical waveguide layer 41 is also formed in a thin film shape by using a dielectric material having a higher refractive index than the cladding layer 40, for example, PMMA. The clad layer 40 has a film thickness of 36.5 nm, for example, when formed from a gold thin film, and the optical waveguide layer 41 has a film thickness of
For example, when it is formed from PMMA, it is about 700 nm.

In the leaky mode sensor having the above structure,
When the light beam L1 emitted from the light source 2 is incident on the cladding layer 40 through the dielectric block 11 at an angle of incidence equal to or greater than the total reflection angle, the light beam L1 is generated at the interface 11a between the dielectric block 11 and the cladding layer 40. The light having a specific wave number that is totally reflected but is transmitted through the clad layer 40 and incident on the optical waveguide layer 41 at a specific incident angle propagates through the optical waveguide layer 41 in the waveguide mode.
When the guided mode is excited in this way, most of the incident light is taken into the optical waveguide layer 41, so that total reflection attenuation occurs in which the intensity of the light totally reflected at the interface 11a sharply decreases.

Since the wave number of the guided light in the optical waveguide layer 41 depends on the refractive index of the sample 15 on the optical waveguide layer 41, by knowing the specific incident angle at which attenuation of total reflection occurs, the sample
It is possible to analyze the refractive index of 15 and the characteristics of the sample 15 related thereto. Then, the characteristics of the sample 15 can be analyzed based on the reflected light intensity I in the vicinity of the specific incident angle and the differential value I ′ output from each differential amplifier of the differential amplifier array 18.

Further, this leaky mode sensor has an interface 11
The second light beam incidence means 46 for injecting the second light beam L2 for measuring the vertical inclination of a into the dielectric block 11 so as to be totally reflected at the interface 11a of the dielectric block 11; And a light detecting means 47 for detecting the second light beam L2 which is incident on the interface 11a by the two light beam incident means and is reflected by the interface 11a. The output S from this light detecting means 47
_R is sent to the signal processing unit 20, and by adding a correction signal for correcting the vertical inclination of the interface 11a to the signal from the photodetection means 17 that detects the plasmon resonance signal in the signal processing unit 20. Get accurate measurements. That is,
This signal processing unit 20 constitutes a correction means. The second light beam L2 for inclination measurement used here has a wavelength different from that of the light beam L1 for attenuation measurement of total internal reflection.

For the sample 15, the second measurement was performed at the first measurement.
Second light beam incident by the light beam incident means 46 of
L2 is reflected by the interface 11b, and the reflected light is detected by the light detecting means 47. Next, at the time of the second measurement, similarly, the reflected light of the second light beam L2 is detected, and the deviation in the arrow K direction from the first detection position is obtained. This shift in the detection position corresponds to the vertical inclination of the interface 11a. Based on the obtained inclination, the signal processing unit 20 obtains a measurement value in which an error due to the inclination is corrected. As a result, it is possible to obtain a measurement value in which the vertical inclination of the interface 11a is compensated, and more precise measurement can be performed.

Next, a fifth embodiment of the present invention will be described with reference to FIG.

The measuring apparatus of the fifth embodiment is a surface plasmon sensor utilizing surface plasmon resonance as in the first embodiment, and FIG. 7 shows its side surface shape.

The present apparatus is different from that of FIG. 1 in the structure of the measuring unit used. That is, in the present embodiment, the measuring chip used in the apparatus of FIG.
Instead of 10, it is formed from a glass that is a dielectric, and FIG.
A prism 50 having a triangular prism shape extending in a direction perpendicular to the paper surface and a dielectric plate 55 joined to the upper surface of the prism 50 via a refractive index matching oil 52 are used. The prism 50 has an entrance end face 50a and an exit end face 50b of the light beam L1, and a dielectric plate.
A metal thin film 56 is formed on 55, and the light beam L1 is totally reflected at the interface 57 between the dielectric plate 55 and the metal thin film 56. The sample 58 is placed on the dielectric plate 55 on which the metal thin film 56 is formed, and the dielectric plate 55 can be removed together. That is, in the measurement unit according to the present embodiment, the dielectric block is such that the portion 50 having the incident end surface 50a and the emission end surface 50b of the light beam and the portion 55 having the surface on which the thin film layer 56 is formed are matched in refractive index. They are joined by means (refractive index matching oil) 52.

Further, the surface plasmon sensor of this embodiment is provided with a vertical inclination measuring means having a different form from the interface vertical inclination measuring means in the above-mentioned first surface plasmon sensor. The vertical inclination measuring means in this embodiment will be described below.

Generally, in the surface plasmon sensor, a light beam whose light quantity distribution is a Gaussian distribution as shown by a dotted line in FIG. 8 is used. Normally, the total reflection attenuation angle θ _SP is set to be near the peak intensity, and as described above, the time change of the total reflection attenuation angle θ _SP will be observed. Therefore, the portions at both ends of the Gaussian distribution are the portions that hardly contribute to the measurement. Therefore, in the surface plasmon sensor of this embodiment, the component outside the measurement range is used to determine the vertical inclination of the interface 57. Usually, the area outside the measurement range of this Gaussian distribution is the portion where the relationship between the light intensity and the incident angle (reflection angle) does not change, and the change in the relationship between the two is caused only by the difference in the interface angles (tilt). Conceivable. Therefore, in the present embodiment, the light amount at a portion where the light amount distribution is steep, such as the place surrounded by the dotted circle in FIG. 8, is observed, and the vertical inclination of the interface is obtained from the change in this light amount. Specifically, the light intensity of the portion at the incident angle θa is detected by the light detection means 17, that is, the change in the output from a predetermined photodiode of the light detection means 17 is detected to determine the vertical inclination of the interface 57. Ask. Based on the tilt thus obtained, the signal processing unit 20 obtains a measurement value in which an error due to the vertical tilt is corrected, as in the above-described embodiment.

Next, a sixth embodiment of the present invention will be described with reference to FIG.

The measuring apparatus of the sixth embodiment is a surface plasmon sensor utilizing surface plasmon resonance as in the fifth embodiment, and FIG. 9 shows its side surface shape. The structure is almost the same as that of the surface plasmon sensor of the fifth embodiment described above, but a shield 60 is arranged on the optical path of the light beam L1 on the incident optical system side, and a part of the light beam L1 is used as a dark line 61. The difference is that the vertical inclination of the interface 57 is detected by detecting the dark line 61 included in the reflected light of the light beam L1 by making it incident on the interface 57.

As in the fifth embodiment, as the light beam L1, a light amount distribution of which is a Gaussian distribution as shown by a dotted line in FIG. 10 is used, and total reflection attenuation at both ends of the Gaussian distribution is used. The inclination of the interface 57 in the vertical direction is obtained by utilizing the portion that hardly contributes to the measurement of. As described above, a part of the light beam L1 is made to enter the interface 11a as the dark line 61, and the dark line 61 is detected by the light detecting means 17. interface
As long as the vertical inclination of 57 does not change, the position of the dark line 61 detected on the light detecting means 17 does not change, and thus the deviation of the dark line position corresponds to the vertical inclination of the interface 57. For example,
When the dark line 61 is detected by the photodiode corresponding to θb during the first measurement, and then the angle of the interface 57 changes, 2
During the second measurement, the dark line 61 will be detected by a different photodiode. Therefore, the vertical inclination of the interface 57 is obtained depending on which photodiode the dark line 61 is detected, and the signal processing unit 20 corrects the error due to the inclination based on the thus obtained inclination. Get the value.

Embodiments of other measuring devices will be described below with reference to FIGS. 11 to 23. In each sensor, the portions related to the measurement of attenuation of total reflection are substantially the same as those in the above-described embodiments. Since the form of the vertical tilt measuring means is different, the tilt measuring means will be mainly described, and only the changed portion will be described regarding the portion related to the measurement of the attenuated total reflection.

The seventh embodiment of the present invention will be described with reference to FIG.

The vertical inclination measuring means of the measuring apparatus of the seventh embodiment is a converging lens which is movable on the optical path to the light detecting means 17 of the reflected light of the light beam L1 and at a position outside the optical path.
66 and the light detection means 17. In this sensor, the vertical inclination of the interface 11a is measured with the converging lens 66 disposed on the optical path, and the total reflection attenuation state is measured with the converging lens 66 disposed outside the optical path. That is, in the present embodiment, the reflected light of the light beam L1 is converged by the converging lens 66 on the light detecting means 17,
The vertical inclination of the interface 11a is measured by measuring the change in the detection position of the convergent beam on the arrow 17 in the direction of the arrow x.

In the case of the present embodiment, the light beam L1 is made incident on the interface 11a as p-polarized light, and the state of the dark line generated by this surface plasmon resonance is measured. However, light containing a plurality of polarization components is used as the light beam L1. In this case, in order to detect the state of the surface plasmon resonance, p is detected in the light detecting means 17.
It is necessary to be able to detect only the polarized component. Therefore, when the light beam L1 contains a polarization component other than p-polarized light, an analyzer 68 is provided on the light beam incident side of the light detection means 17, as shown in the sensor side view of the eighth embodiment in FIG. It may be arranged so that only the p-polarized component is transmitted. At the time of measuring the inclination, the analyzer 68 may be rotated to detect the position of the converged light of the s-polarized component orthogonal to the p-polarized component.

Next, a ninth embodiment of the present invention will be described with reference to FIG.

The vertical inclination measuring means of the measuring apparatus according to the ninth embodiment is separated by the half mirror 70 and the half mirror 70 arranged on the optical path leading to the light detecting means 17 of the reflected light of the light beam L1. Converging lens 71 that converges part of the light beam
And second light detection means 72 for detecting the light beam converged by the converging lens 71. The reflected light of the light beam L1 is split by the half mirror 70, part of which is used for measuring attenuation of total reflection, and part of which is used for measuring the vertical inclination of the interface 11a. The light beam L1 partially reflected by the half mirror 70 is converged by the converging lens 71 on the second light detecting means 72,
The inclination of the interface 11a in the vertical direction is detected by the change in the detection position of the light beam on the light detecting means 72 in the direction of the arrow Q. In addition, instead of the half mirror 70, a mirror that can be moved between an optical path and a position outside the optical path may be provided. In this case, a mirror is placed on the optical path, the light beam is reflected by the mirror toward the second light detecting means, the tilt is measured, and the mirror is moved to a position outside the optical path to emit the light beam. The total reflection attenuation may be measured by going straight to the detecting means 17.

In the case of the present embodiment, the light beam L1 is made incident on the interface 11a as p-polarized light, and the state of the dark line generated by this surface plasmon resonance is measured. However, light containing a plurality of polarization components is used as the light beam L1. If you do,
As shown in the side view of the sensor of the above embodiment, an analyzer 68 may be arranged on the light beam incident side of the light detecting means 17 so that only the p-polarized component is transmitted.

Next, an eleventh embodiment of the present invention will be described with reference to FIG.

The tilt measuring means of the measuring apparatus of the eleventh embodiment is the second embodiment in the ninth embodiment shown in FIG. 13 and further on the optical path to the second light detecting means 72 for measuring the vertical tilt.
The lens 75 is provided. This sensor can obtain not only the vertical tilt of the interface 11a but also the characteristic value corresponding to the vertical shift amount of the interface 11a by combining two lenses, so that more accurate total reflection attenuation can be achieved. The state of can be measured.

A mechanism for detecting the vertical inclination and shift of the interface will be briefly described with reference to FIG. FIG.
(A) schematically shows the mechanism for detecting the shift amount, and (b) in the figure schematically shows the mechanism for detecting the inclination.

The focal lengths of the converging lens 71 and the second lens 75 are f1 and f2, respectively, the distance between the reflection position of the light beam and the light detecting means 17 is L (see FIG. 15), the light beam reflection position and the converging lens 71. And the distance between the converging lens 71 and the second
, The distance between the second lens 75 and the second light detecting means 72 is d2, the shift amount of the reflection position based on the vertical movement amount y of the interface 11a is x, and the interface 11a is The inclination is θ. Although the optical path is changed by the half mirror 70 in FIG. 15, the optical path is schematically shown as a straight line in FIG.

When the vertical inclination of the interface on which the light beam L1 is incident is θ and the shift amount is x, the moving distance A of the attenuation angle of total reflection due to the variation of the interface is represented by Ltan θ + x.

On the other hand, as shown in FIG. 16A, when the measuring tip 10 shown by the solid line is shifted by the distance y to the measuring tip position shown by the dotted line, the shift amount x of the light beam incident position is x.
Appears as a predetermined shift amount at the light beam detection position on the second light detection means 72 due to the action of the two lenses. Further, as shown in FIG. 16B, when the measuring chip 10 shown by the solid line is inclined by θ like the measuring chip shown by the dotted line, the light beam detection position on the second light detecting means 72 is a predetermined position. The shift amount of changes.

The spot moving amount B of the light beam on the second light detecting means 72 due to the inclination of the interface 11a and the vertical shift is θ {d1 + d2-d1d2 / f2-d0 (d1 / f1 + d0 / f1-d1d2
/ f1 / f2−1 + d2 / f2} −x (d1 / f1 + d2 / f1−d1d2 / f1 / f2−1 + d2
It is represented by / f2).

Therefore, the relationship between the moving distance A of the attenuation angle of total reflection on the light detecting means 17 and the spot moving amount B of the light beam on the second light detecting means 72 is A = B or A = -B.
If L, d0, d1, d2, f1, and f2 are selected so that the converging lens 71, the second lens 75, and the second light detecting means 72 are arranged, all of them due to the fluctuation of the interface can be obtained. The moving distance of the reflection attenuation angle appears as the spot moving amount on the second light detecting means 72. To satisfy the above A = B or A = −B, specifically, the distances L, d0, d1, and d2 and the focal lengths f1 and f2 are d1 = f1 and d2 = f.
2, the converging lens 71, the second lens 75, and the second light detecting means 72 may be installed so that d0 = f1 + L.

As in this embodiment, by using two lenses to obtain the vertical tilt and the vertical shift amount of the interface 11a, the measured value in which the error due to the variation amount of this interface is corrected is obtained. Since it can be obtained, the state of attenuation of total reflection can be measured with higher accuracy.

Next, a twelfth embodiment of the present invention will be described with reference to FIG.

The vertical inclination measuring means of the measuring apparatus according to the twelfth embodiment comprises a lens 80 for condensing the reflected light of the light beam L1 reflected by the light incident surface 11b of the dielectric block 11 of the measuring chip 10 and the lens 80. The second light detecting means 82 detects the light beam converged by the lens 80. That is, the vertical tilt measuring means of the present embodiment uses the reflected light because the light beam L1 is partially reflected by the incident surface 11b. The incident surface 11b is an interface 11a which is a part of the dielectric block 11.
Since the light is tilted in accordance with the vertical tilt of the interface 11a, the position variation of the reflected light on the incident surface 11b on the second photodetector 82 in the direction of the arrow Q depends on the vertical tilt of the interface 11a.

Next, a thirteenth embodiment of the present invention will be described with reference to FIG.

The tilt measuring means of the measuring apparatus according to the thirteenth embodiment comprises a reflecting surface 83 provided on a part of the bottom surface of the sample holding hole 13a of the measuring chip 10 and a light beam reflected by the reflecting surface 83. It is composed of a lens 84 for condensing L1 and a second light detecting means 86 for detecting the light converged by the lens 84. In the present embodiment, the light beam L1 is made to enter the interface 11a in a divergent light state so that a part thereof is made incident on the reflecting surface 83. The light beam incident on the interface 11a is reflected toward the light detecting means 17 for measuring the attenuation of total reflection. On the other hand, a part of the light beam L1 incident on the reflecting surface 83 is the second light detecting means.
The light is reflected to the side of 86, is condensed by the lens 84, and is converged on the light detection means 86. The reflecting surface 83 is provided at a predetermined angle with respect to the interface 11a and tilts in accordance with the vertical tilt of the interface 11a. Therefore, the second light detecting means of the reflected light on the reflecting surface 83 is provided.
The positional fluctuation in the direction of the arrow Q on 86 corresponds to the vertical inclination of the interface 11a.

Next, a fourteenth embodiment of the present invention will be described with reference to FIG.

The inclination measuring means of the measuring apparatus according to the fourteenth embodiment includes a second light beam incident means 90 for making the second light beam incident on the dielectric block 11 so as to be totally reflected at the interface 11a. , A lens 95 for condensing the second light beam reflected by the interface 11a, and a light detecting means 17 for detecting the position of the light beam converged by the lens 95.

The second light beam incident means 90 is arranged to detect the light beam L
In addition to the configuration of the light beam incidence means 1 for making 1 incident on the interface 11a, a λ / 4 plate 91 for making the linearly polarized beam emitted from the light source 2 circularly polarized, and for separating the circularly polarized beam into s polarized light and p polarized light And a Wollaston prism 92 for converting the light beam emitted from the light source 2 into circularly polarized light by the λ / 4 plate 91, and separating the light beam into p-polarized L1 and s-polarized L2 by the Wollaston prism 92. Then, the p-polarized beam L1 and the s-polarized beam L2 are made to emerge in mutually different directions, and are made incident at different positions on the interface 11a.

The reflected light of the s-polarized beam L2 is condensed by the lens 95 and converged on a part of the light detecting means 17, and the vertical inclination of the interface 11a is measured by the position variation of the s-polarized beam L2. On the other hand, by disposing the analyzer 68 on the optical path of the p-polarized beam L1 to the light detecting means 17, the influence of the s-polarized beam L2 is removed and the attenuated total reflection state is detected. Here, as the light detection means 17, a photodiode array that can be detected over a wider area than in the case of detecting only the state of attenuated total reflection is used, and at a location that does not intersect with the portion that detects the state of attenuated total reflection. Although the position of the s-polarized beam L2 is detected, a light detecting means for detecting the s-polarized beam L2 may be separately provided.

Next, a fifteenth embodiment of the present invention will be described with reference to FIG.

The tilt measuring means of the measuring apparatus of the fifteenth embodiment makes the second polarized light beam having a small diameter enter the dielectric block 11 so as to be totally reflected at the interface 11a as the second light beam. The light beam incidence means 100 and the second light beam L2 (s-polarized) reflected at the interface 11a are reflected
It is composed of a PBS 107 that transmits L1 (p-polarized light) and a second light detection means 108 that detects the position of the second light beam reflected by the PBS 107.

In the present embodiment, the light beam incident means 1 includes a light source 2'that emits a small-diameter parallel light L0 as p-polarized light, a beam expansion optical system 3'that expands the diameter of the light beam, and the expansion. The optical system 3'constitutes a lens 4 for converging a p-polarized beam L1 that has passed through the PBS 102, which will be described later, to be incident on the interface 11a.

The second light beam incident means 100 is arranged to
In addition to the configuration of the light beam incidence means 1 for making 1 incident on the interface 11a, a λ / 4 plate 101 for converting the linearly polarized beam L0 emitted from the light source 2 ′ into a circularly polarized beam, and p-polarized light and s-polarized light are transmitted. The linearly polarized beam emitted from the light source 2 ′ is provided with a PBS 102 that reflects light, a mirror 103, 105, 106 that reflects the s-polarized beam L2, and a reduction optical system 104 that reduces the diameter of the s-polarized beam L2. The L0 is circularly polarized by the λ / 4 plate 101, and the light beam expanded by the beam expanding optical system 3'is PB.
In S102, the light beam is transmitted through the p-polarized beam L1 and is separated by reflecting the s-polarized beam L2, and the reduction optical system 104 reduces the diameter of the s-polarized beam L2. Return to the road and p-polarized beam L1
In comparison with the above, the light beam having a smaller diameter is made incident on the interface 11a.

S-polarized beam reflected at the interface 11a
L2 is reflected by the PBS 107 and detected by the second light detecting means 108. That is, the vertical inclination of the interface 11a is measured by the position variation of the s-polarized beam L2 on the second light detecting means 108.

The configuration and the like of the optical element of the second light beam incident means 100 can be variously changed. For example, as shown in FIG. 21, the optical path of the second light beam L2 may be changed by changing the tilts and positions of the reflecting surfaces of the mirrors 103, 105, and 106, which are reflecting optical elements.

Further, as shown in FIG. 22, the mirrors 105, 1
If the inclination of the reflecting surface of 06 is changed so that the second light beam L2 passes through the end of the lens 4, the second light beam L2
Is incident on the interface 11a at a position largely deviated from the incident position of the p-polarized beam L1.
Since the optical paths of the reflected lights of L1 and the second light beam L2 are deviated, it is not necessary to provide the PBS on the photodetector side. Further, a part of the light detecting means 17 can be used for detecting the position of the second light beam L2.

In the measuring apparatus shown in FIGS. 20 to 22, the light beam L0 emitted from the light source 2'is expanded by the light beam expanding optical system 3'and then separated into s-polarized light and p-polarized light. , The λ / 4 plate 101 as shown in FIG.
Before expanding the circularly polarized light beam L0 by PBS
102 separates the p-polarized beam L1 and the s-polarized beam L2,
If only the p-polarized beam L1 is made incident on the magnifying optical system 3 ', the configuration of the second light beam incident means becomes simple.

Incidentally, as shown in FIG. 24, the light beam L0 emitted from the light source 2'is not circularly polarized but is bisected by the half mirror 110 in the state of linearly polarized light (p polarized light),
One may be expanded by the expanding optical system 3'and used as the measurement light beam L1, and the other may be changed in the polarization direction by the λ / 2 plate 111 to be incident on the interface 11a as the s-polarized beam L2. .

Next, a sixteenth embodiment of the present invention will be described with reference to FIG.

The inclination measuring means of the measuring apparatus according to the sixteenth embodiment has a reflecting surface provided on the bottom surface 10d of the measuring chip and an s-polarized beam having a small diameter on the reflecting surface, which is used as the second light beam L2.
Second light beam injection means for making the light incident under the condition of total reflection
It is provided with 120 and a light detecting means 125 for detecting the second light beam L2 reflected by the reflecting surface.

The second light beam incident means 120 is arranged to
In addition to the configuration of the light beam incident means 1 for making 1 incident on the interface 11a, the λ / 4 plate 101 for making the light beam L emitted from the light source 2 ′ circularly polarized, and the circularly polarized beam p-polarized beam L1 Wollaston prism that separates and s-polarized beam L2
It comprises 121 and a mirror 122, and makes the s-polarized beam L2 incident on the bottom surface 10d of the measurement chip 10 at a total reflection angle.

The inclination measuring means is the bottom surface 10 of the measuring chip 10.
d (bottom surface of the dielectric block 11) is used as a reflecting surface, and the second light beam L2 is made incident on the bottom surface 10d of the measuring chip 10 which is inclined corresponding to the inclination of the interface 11a without being made incident on the interface 11a, The vertical inclination of the interface 11a is measured by detecting the positional fluctuation of the reflected light reflected by the bottom surface 10d.

If the second light beam is reflected on the bottom surface in this way, the second light beam is not necessarily s.
It need not be polarized.

In each of the embodiments shown in FIGS. 19 to 25, any of the second light beam incident means for making the s-polarized beam incident on the interface or a predetermined surface inclined corresponding to the interface, is used. Although a part of the light emitted from the light source 2 that generates the light beam L1 for attenuation of total reflection is used, a light source may be separately provided.

In the fourth to sixteenth embodiments, as a method of compensating the error due to the vertical inclination of the interface, the measured value corrected according to the inclination is obtained. The position adjustment of the light beam incident means, the light detection means and / or the measurement unit may be performed as in the second and third embodiments.

Further, in each of the embodiments provided with the calculating means for obtaining the measured value which is corrected according to the inclination, the interface position at the time of the first measurement is used as a reference, and the interface from the interface is fixed at each side thereafter. The form of obtaining the measurement value in which the error due to the tilt is obtained by obtaining the tilt in the vertical direction has been described, but the interface position at the time of a predetermined measurement other than the first measurement among multiple measurements is used as a reference, and each measurement value is The inclination from the reference interface may be obtained and the measured value corrected according to the inclination may be obtained. Alternatively, the average position of the interface during a plurality of measurements may be used as a reference, and the average value may be used for each measured value. The inclination from the position may be obtained and the correction according to the inclination may be performed.

Further, if the detection error in the tilt measurement in the measuring device is held as the machine data for each measuring device and the correction value using the machine data is obtained as the tilt value during the tilt measurement, the measurement accuracy is further improved. You can

Further, in each of the embodiments provided with the calculating means, an alarm is issued when the inclination exceeds a permissible value, and in that case, the light beam incident means, the measuring unit and / or the light detecting means. You may make it adjust such as.

The tilt measurement and the tilt correction in the measuring apparatus described in the first to sixteenth embodiments detect only the tilt of the interface in the vertical direction and correct the error caused by the tilt. The inclination of 11a includes not only the vertical inclination that changes the incident angle of the light beam L1 but also the horizontal inclination that changes the incident position of the light beam L1 in the direction perpendicular to the plane including the changing direction of the incident angle. is there. The inclination in the lateral direction leads to a shift of the light beam L1 totally reflected at the interface in a direction perpendicular to the arrangement direction of the photodiodes, which may cause the light beam L1 to be unable to be received by the light detection means 17. It is sufficient that the deviation is small and the light beam L1 can be received,
In order to prevent the inability to receive light, the embodiments described below are provided with a vertical / horizontal tilt detecting means for detecting a vertical / horizontal tilt, and a correcting means for correcting the vertical / horizontal tilt.

A seventeenth embodiment of the present invention will be described with reference to FIG.

The measuring apparatus according to the seventeenth embodiment is the same as the first embodiment.
The surface plasmon sensor is substantially the same as that of the surface plasmon sensor according to the first embodiment, but is capable of detecting a horizontal tilt in addition to a vertical tilt of the interface.
The second light beam L2 is made incident on the dielectric block 11 so as to be totally reflected at the interface 11a of the dielectric block 11.
Light beam incident means 32 and the second light beam incident means 32
Second light beam L2 emitted from the laser and reflected at the interface 11a
And a means for correcting an error (including a measurement error) due to the inclination, and a vertical / horizontal inclination measuring means including a second light detecting means 130 for detecting

The second light detecting means 130 is a position sensor composed of, for example, a four-division photodiode, and detects a two-dimensional position change of the light beam L2 incident on the light receiving surface. FIG. 27 is a diagram schematically showing the light receiving surface of the second light detecting means 130. As shown, the second photo-detecting means 130 includes four photodiodes PD1, PD2 and PD.
3, PD4, and detects the position from the amount of light received by each photodiode of the incident light beam.
Specifically, the deviation in the x direction (vertical inclination of the interface) is P
It can be obtained from the difference between the addition signal of D1 and PD3 and the addition signal of PD2 and PD4, and the shift in the y direction (the lateral inclination of the interface) is the addition signal of PD1 and PD2 and PD3 and P.
It can be obtained from the difference from the addition signal of D4.

The second light beam L2 for tilt measurement used here is set so as to enter the interface as s-polarized light so that the second light beam L2 has a polarization direction different from that of the light beam L1.

The means for correcting the error due to the inclination is
The light detecting means 17 is moved in the arrow y direction to adjust the position of the light beam L1 on the light detecting means 17 in the arrow y direction due to the inclination in the horizontal direction. It comprises a position adjusting means and a calculating means for obtaining a measured value in which an error due to a tilt in the vertical direction is corrected.

That is, the position adjusting means is composed of the light detecting means 17 which is movable in the y direction and the driving means 135 which is moved to adjust the light detecting means 17, and the driving means 135.
Adjusts the movement of the light detecting means 17 according to an instruction from the signal processing unit 20 which obtains the signal from the second light detecting means 130 for measuring the inclination and obtains the deviation of the light beam L2 in the y direction. Further, the arithmetic means is composed of the signal processing section 20, and the signal processing section 20 obtains the signal from the second photodetecting means 130 and outputs the light beam as in the case of the first embodiment. The error due to the inclination of the interface 11a was corrected by obtaining the deviation of L2 in the x direction and adding the correction signal for correcting the inclination of the interface 11a to the signal from the photodetection means 17 for detecting the plasmon resonance signal. Get accurate measurements. The concrete calculation is the first
The description is omitted because it is the same as that of the first embodiment.

The tilt measurement, position adjustment, and the like are performed as follows. First, in the first measurement of the sample 15, the second light beam L2 incident on the interface 11a by the second light beam incident means 32 is reflected by the interface 11a, and the reflected light is shown by a solid line in FIG. As described above, the setting is made so that the light is received at the center of the second light detecting means 130. At the time of the second measurement, the reflected light of the second light beam L2 is detected, the deviation in the y direction from the first detection position (the lateral inclination of the interface) is detected, and the deviation in the y direction is detected. According to the light detection means 17
Position adjustment in the y direction. The position of only the light detecting means 17 may be adjusted based on the amount of deviation obtained from the signal from the second light detecting means 130 which has received the second light beam L2, or the light detecting means 17 and the second light detecting means 17 may be adjusted. Of the second light detecting means 130, and the light detecting means 130 of FIG.
The position may be adjusted so that the second light beam L2 is received at the center of the direction. After that, the deviation of the second light beam L2 in the x direction (the vertical inclination of the interface) is detected, and the error due to the vertical inclination of the interface 11a is corrected in the signal processing unit 20 based on the deviation amount. Obtain the measured value.

In the third and subsequent measurements as well, after the lateral position adjustment of the photodetector means 17 is performed in accordance with the position of the second light beam L2 received by the second photodetector means 130 in the same manner. The state of return loss is measured, and the measured value is obtained by correcting the error due to the tilt in the vertical direction. As a result, it is possible to obtain a measured value in which the vertical and horizontal inclinations of the interface 11a are compensated, and more precise measurement can be performed.

Next, FIG. 28 shows the eighteenth embodiment of the present invention.
Will be described with reference to.

The measuring apparatus according to the eighteenth embodiment is the same as the first embodiment.
The surface plasmon sensor is substantially the same as the surface plasmon sensor shown in the seventh embodiment, but the means for correcting the error due to the inclination in the vertical and horizontal directions is different. In the present embodiment, the horizontal inclination and the vertical inclination of the interface are eliminated at the same time, and as vertical and horizontal inclination adjusting means for correcting an error (including a measurement error) due to the vertical and horizontal inclination, First light detection means
It is provided with a position adjusting means for two-dimensionally moving 17 in the arrow x direction and the y direction perpendicular to the paper surface to adjust the position. That is, the position adjusting means is composed of the light detecting means 17 that is movable in the xy directions and the driving means 136 that moves to adjust the light detecting means 17.
36 receives the signal from the second light detecting means for inclination measurement, and moves and adjusts the light detecting means 17 according to an instruction from the signal processing section 20 for obtaining the deviation of the light beam L2.

The measurement of the vertical and horizontal inclinations and the position adjustment are performed as follows. First, at the time of the first measurement of the sample 15, the second light beam L2 incident on the interface 11a by the second light beam incident means 32 is reflected by the interface 11a, and the reflected light is shown by a solid line in FIG. As described above, the setting is made so that the light is received at the center of the second light detecting means 130. At the time of the second measurement, the reflected light of the second light beam L2 is detected, the deviation from the first detection position is detected, and the position of the light detecting means 17 in the xy directions is adjusted according to the deviation. The position of only the light detecting means 17 may be adjusted based on the amount of deviation obtained from the signal from the second light detecting means 130 which has received the second light beam L2, or the light detecting means 17 and the second light detecting means 17 may be adjusted. The light detecting means 130 of the second light detecting means 13 is moved in association with each other.
The position may be adjusted so that the second light beam L2 is received at the center of 0.

Also in the third and subsequent measurements, the position of the light detecting means 17 is adjusted in accordance with the position of the second light beam L2 received by the second light detecting means 130, and then the total reflection attenuation is performed. Measure the condition. As a result, it is possible to obtain a measured value in which the vertical and horizontal inclinations of the interface 11a are compensated, and more precise measurement can be performed.

The reason why the interfaces at the time of each measurement have an inclination with respect to each other when the measurement is performed a plurality of times is not only the case where the measurement chip is reset as described above, but also the case where the measurement chip is supported. When the support base is rotated (moved), the support base, the light source for performing the measurement, the arrangement of the photodetector and the like are moved, and the vertical and horizontal inclinations of the interface generated in these cases are also included. Similar to the case described above, highly reliable measurement can be performed by measuring the vertical and horizontal inclinations of the interface and obtaining the measured values corrected according to the inclinations.

When measuring the attenuated total reflection state of the sample, the attenuated total reflection state of the measuring chip 10 is measured before the sample liquid 15 is dispensed to the measuring chip 10. When measuring the change in the attenuated total reflection angle due to the sample liquid 15 only, by subtracting the bulk effect of the measuring tip 10 from the measured value after dispensing, the vertical and horizontal inclinations of the interface 11a before and after the dispensing of the sample liquid 15 are measured. If this occurs, the reliability of the measured value will be impaired. Even in such a case, if the vertical and horizontal inclinations of the interface are measured and the measured values corrected according to the inclination are obtained, highly reliable measurement can be performed.

Next, a nineteenth embodiment of the present invention will be described with reference to FIG.

In the plasmon sensor shown as the measuring apparatus of the nineteenth embodiment shown in FIG. 29, the means for correcting the error due to the vertical and horizontal inclinations of the interface is not the position adjustment of the light detecting means 17, but the light beam incidence. The light beam adjusting means for adjusting the incident angle and the incident position by the means 1 is provided. The light beam adjusting means includes a tilt mirror 138 having a surface for reflecting the light beam L1 from the light source 2, the reflection surface being rotatable in the vertical and horizontal directions, and a driving means 139 for driving the tilt mirror 138. , The driving means 139 is operated by the mirror 1 according to an instruction from the signal processing unit 20.
38 is rotated to adjust the incident angle and incident position of the light beam. The light beam incident means 1 of this embodiment has a configuration in which a small-diameter light beam emitted from the light source 2 is diffused by the concave lens 5.

As described above, the vertical and horizontal tilts of the interface are compensated by adjusting the incident angle and the incident position of the light beam according to the vertical and horizontal tilts of the interface obtained by the vertical and horizontal tilt measuring means. The measurement result can be obtained.

As described above, in addition to adjusting the light detecting means 17 or the light beam incident means 1, the measuring chip 10
You may adjust so that the inclination of the interface in the vertical direction and the horizontal direction may be corrected by inclining itself. Moreover, by adjusting all or any two positions of the light detection means 17, the light beam incidence means 1, the measurement chip 10 and the like, the measured values are compensated for the inclination in the vertical and horizontal directions of the interface as a whole. May be obtained.

Next, a twentieth embodiment of the present invention will be described with reference to FIG.

The measuring apparatus according to the twentieth embodiment is the same leak mode sensor as that of the fourth embodiment described above, but is capable of detecting the horizontal inclination in addition to the vertical inclination of the interface. The second light detecting means 130 has four
Vertical / horizontal tilt measuring means equipped with a position sensor consisting of divided photodiodes and tilt error (including measurement failure)
And a means for correcting

The means for correcting the inclination is the same as in the case of the surface plasmon sensor of the seventeenth embodiment,
Light detecting means 17 movable in the xy directions and the light detecting means 17
The tilt of the interface 11a is compensated by detecting the tilt of the interface for each measurement and adjusting the position of the photodetector 17 according to the tilt. The measured value can be obtained, and more precise measurement can be performed. However, the second light beam L2 for tilt measurement used here is the light beam L1 for attenuation measurement of total reflection.
With a different wavelength from.

Next, a twenty-first embodiment of the present invention will be described with reference to FIG.

The measuring apparatus of the twenty-first embodiment is the same surface plasmon sensor as that of the fifth embodiment described above, and the measuring unit includes a triangular prism 50 extending in the direction perpendicular to the paper surface, and A prism plate 50 and a dielectric plate 55 joined to the upper surface of the prism 50 via a refractive index matching oil 52 are used. In the present embodiment, not only the vertical tilt of the interface but also the horizontal tilt can be detected. As with the seventeenth embodiment, the second light beam L2 for measuring the tilt of the interface 11a is detected. Second light beam incident means 32 for making the light incident on the dielectric block 11 so as to be totally reflected at the interface 11a of the dielectric block 11.
Is output from the second light beam incident means 32, and the interface 11
a vertical / horizontal inclination measuring means having a second light detecting means 130 composed of a four-division photodiode for detecting the second light beam L2 reflected by a, and for correcting an error (including a measurement error) due to the inclination. It is possible to obtain a measured value by compensating for an error due to the vertical and horizontal inclinations of the interface.

In addition, in the measuring apparatus described in each of the seventh to sixteenth embodiments (excluding the eleventh embodiment), as shown in, for example, FIGS. 32 to 34, the second light detecting means 130 is used. In place of the one-dimensional photodiode array, a four-division photodiode or a two-dimensional sensor such as a resistance type photodetector is provided, and the first photodetection means is provided.
If 17 is movable in the xy directions and the driving means 136 for driving the light detecting means 17 to adjust the position is provided, not only the vertical inclination of the interface 11a but also the horizontal inclination can be detected.
It is possible to obtain an accurate measurement value that compensates for an error due to the inclination in the vertical and horizontal directions.

The measuring apparatus of each of the above-described embodiments makes the light beam from the light source incident on the interface at various angles, measures the reflected light from the interface, and attenuates the total reflection from the incident angle that is a dark line. The state of measurement is measured to obtain the binding state between the subject and the sensing medium. The incident angle of the light beam is set to a predetermined angle that satisfies the condition of total reflection at the interface, and light beams having various wavelengths are made incident. Alternatively, the wavelength of the incident light beam may be changed, the reflected light from the interface may be measured, and the binding state between the subject and the sensing medium may be obtained from the attenuated total reflection state for each wavelength.

Further, another measuring device using totally reflected light will be described below as a 22nd embodiment.

As shown in the side view of FIG. 35, the surface plasmon sensor of this embodiment is provided with a measuring chip 10 similar to that of the first embodiment as a measuring unit, and the measuring chip 10 has an inclination correction stage. It is arranged on the combined measurement unit support 300.

A light source 32 is provided on each of the light beam incident surface 11b side and the emission surface 11c side of the dielectric block 11 of the measuring chip 10.
0 and CCD 360 are provided, and these light sources 320 and C
A collimator lens 350, an interference optical system, a condenser lens 355, and an aperture 356 are arranged between the CD 360 and the CD 360.

The interference optical system is composed of a polarization filter 351, a half mirror 352, a half mirror 353, and a mirror 354.

Further, the CCD 360 is connected to the signal processing unit 361, and the signal processing unit 361 is connected to the display unit 362.

In this measuring apparatus, the second light beam L2 for measuring the inclination of the interface 11a, which is similar to the measuring apparatus of the eighteenth embodiment, is totally reflected at the interface 11a of the dielectric block 11. , A second light beam incident means 32 which is incident on the dielectric block 11, and a second light beam L2 which is output from the second light beam incident means 32 and is reflected by the interface 11a. A vertical / horizontal inclination measuring means including the light detecting means 130 and means for correcting an error (including a measurement error) due to the inclination are provided. Measuring tip 10 support 300
However, it also serves as a tilting stage which is a vertical and horizontal tilt adjusting means for correcting an error (including a measurement error) due to tilting in the vertical and horizontal directions, and this tilt correcting stage is instructed by the signal processing unit 361 to measure the chip 10. Adjust the position of.

The measurement of the sample in the surface plasmon sensor of this embodiment will be described below.

The light source 320 is driven and the light beam 330 is emitted in a divergent state. The light beam 330 is collimated by the collimator lens 350 and enters the polarization filter 351. The light beam 330 that has passed through the polarization filter 351 and is incident on the interface 11a as p-polarized light is partially split as a reference light beam 330R by the half mirror 352, and the remaining light that has passed through the half mirror 352. Beam 330
S is incident on the interface 11a. The light beam 330S totally reflected by the interface 11a and the reference light beam 330R reflected by the mirror 354 enter the half mirror 353 and are combined. The combined light beam 330 ′ is condensed by the condenser lens 355,
It passes through aperture 356 and is detected by CCD 360. At this time, the light beam 330 ′ detected by the CCD 360
Generates interference fringes according to the state of interference between the light beam 330S and the reference light beam 330R.

[0180] After dispensing the sample 15 times, measurement is continuously performed a plurality of times,
By detecting the change in the interference fringes detected by the CCD 360, it is possible to detect whether or not the specific substance in the sample is bound to the sensing medium. That is, in this case, when the refractive index of the sensing medium 30 changes according to the binding state between the specific substance and the sensing medium 30, the light beam 330S and the reference light beam 330R totally reflected at the interface 11a.
Since the state of interference changes when the light beams are combined by the half mirror 353, the coupling can be detected according to the change in the interference fringes.

The signal processing unit 361 detects the presence or absence of the above reaction based on the above principle, and the result is displayed on the display unit 362.

The method of detecting the inclination of the interface 11a in this apparatus is the same as in the eighteenth embodiment. The tilt correction stage 300 is driven according to the instruction of the signal processing unit 361 according to the tilt detected by the second light detection means 130 for each measurement time, and the tilt of the chip 10 is adjusted to determine the vertical and horizontal tilts of the interface 11a. Make a correction. Since the position of the interface 11a of the measuring chip 10 is adjusted in this manner, accurate measurement can be performed.

[Brief description of drawings]

FIG. 1 is a side view of a surface plasmon sensor according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of the surface plasmon sensor.

FIG. 3 is a schematic diagram showing the relationship between the light beam incident angle and the detected light intensity in the surface plasmon sensor, and the relationship between the light beam incident angle and the differential value of the light intensity detection signal.

FIG. 4 is a side view of a surface plasmon sensor according to a second embodiment of the present invention.

FIG. 5 is a side view of a surface plasmon sensor according to a third embodiment of the present invention.

FIG. 6 is a side view of a leaky mode sensor according to a fourth embodiment of the present invention.

FIG. 7 is a side view of a surface plasmon sensor according to a fifth embodiment of the present invention.

FIG. 8 is a diagram showing a reflected light intensity distribution in the surface plasmon sensor according to the fifth embodiment.

FIG. 9 is a side view of a surface plasmon sensor according to a sixth embodiment of the present invention.

FIG. 10 is a diagram showing a reflected light intensity distribution in the surface plasmon sensor according to the sixth embodiment.

FIG. 11 is a side view of a surface plasmon sensor according to a seventh embodiment of the present invention.

FIG. 12 is a side view of a surface plasmon sensor according to an eighth embodiment of the present invention.

FIG. 13 is a side view of a surface plasmon sensor according to a ninth embodiment of the present invention.

FIG. 14 is a side view of a surface plasmon sensor according to a tenth embodiment of the present invention.

FIG. 15 is a side view of a surface plasmon sensor according to an eleventh embodiment of the present invention.

FIG. 16 is a view for explaining the inclination measuring means of the surface plasmon sensor according to the eleventh embodiment.

FIG. 17 is a side view of a surface plasmon sensor according to a twelfth embodiment of the present invention.

FIG. 18 is a side view of a surface plasmon sensor according to a thirteenth embodiment of the present invention.

FIG. 19 is a side view of a surface plasmon sensor according to a fourteenth embodiment of the present invention.

FIG. 20 is a side view of a surface plasmon sensor according to a fifteenth embodiment of the present invention.

FIG. 21 is a modification of the surface plasmon sensor according to the fifteenth embodiment.

FIG. 22 is a modification of the surface plasmon sensor according to the fifteenth embodiment.

FIG. 23 is a modification of the surface plasmon sensor according to the fifteenth embodiment.

FIG. 24 is a modification of the surface plasmon sensor according to the fifteenth embodiment.

FIG. 25 is a side view of a surface plasmon sensor according to a sixteenth embodiment of the present invention.

FIG. 26 is a side view of a surface plasmon sensor according to a seventeenth embodiment of the present invention.

FIG. 27 is a view showing the light receiving surface of the second light detecting means.

FIG. 28 is a side view of the surface plasmon sensor according to the eighteenth embodiment of the present invention.

FIG. 29 is a side view of a leaky mode sensor according to a nineteenth embodiment of the present invention.

FIG. 30 is a side view of a surface plasmon sensor according to a twentieth embodiment of the present invention.

FIG. 31 is a side view of a surface plasmon sensor according to a twenty-first embodiment of the present invention.

FIG. 32 is a side view of a surface plasmon sensor according to another embodiment of the present invention.

FIG. 33 is a side view of a surface plasmon sensor according to another embodiment of the present invention.

FIG. 34 is a side view of a surface plasmon sensor according to another embodiment of the present invention.

FIG. 35 is a side view of a surface plasmon sensor according to a twenty-second embodiment of the present invention.

[Explanation of symbols]

1 Light beam incident optical means 2 light sources 10 measuring tip 11 Dielectric block 11a Interface between dielectric block and metal film 12 Metal film 13 Sample holder 15 samples 16 collimator lens 17 Light detection means (photodiode array) 17a, 17b, 17c ... Photodiodes 18 Differential amplifier array 18a, 18b, 18c ... Differential amplifier 19 driver 20 Signal processor 21 Display means 22a, 22b, 22c ... Sample hold circuit 23 Multiplexer 24 A / D converter 25 Drive circuit 26 Controller 30 Sensing medium 31 turntable 32 Second light beam incident means 37 Second light detection means 40 clad layer 41 Optical waveguide layer 50 prism 52 Refractive index matching oil 55 Dielectric plate 56 Metal film 57 Interface between dielectric plate and metal film 58 samples 60 Shield

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Norifumi Mori             798 Miyadai, Kaisei-cho, Ashigarakami-gun, Kanagawa Prefecture             Shishi Film Co., Ltd. (72) Inventor Hitoshi Shimizu             798 Miyadai, Kaisei-cho, Ashigarakami-gun, Kanagawa Prefecture             Shishi Film Co., Ltd. (72) Inventor Shu Sato             798 Miyadai, Kaisei-cho, Ashigarakami-gun, Kanagawa Prefecture             Shishi Film Co., Ltd. F term (reference) 2F065 AA03 AA31 FF52 GG06 HH04                       HH12 HH14 JJ01 JJ18 JJ25                       JJ26 LL00 LL12 LL13 LL34                       LL36 LL37 LL47 MM04 PP12                       QQ03 QQ13 SS01                 2G057 AA02 AB04 AB07 AC01 BA01                       BB01 BB06 BC07 HA04                 2G059 AA01 BB12 CC16 DD12 DD13                       EE02 EE05 EE11 GG01 GG04                       JJ11 JJ12 JJ13 JJ19 JJ20                       JJ22 KK01 KK03 KK04 MM01                       MM09 MM11 PP04

Claims (27)

[Claims] 1. A measuring unit comprising a transparent dielectric block and a thin film layer formed on one surface of the dielectric block, and a light beam for the dielectric block and the thin film. Light beam incidence means for making incident light at various incident angles so that total reflection conditions can be obtained at the interface with the layer, and light detection means for receiving a predetermined polarization component of the light beam totally reflected at the interface, In a measuring device that performs the measurement a plurality of times on a measurement unit and detects a change in the state of attenuation of total reflection during the plurality of measurements, a vertical direction that changes the incident angle of the interface between the plurality of measurements. A vertical inclination measuring means for measuring the inclination of the direction, and an arithmetic means for obtaining a measurement value in which an error due to the inclination is corrected according to the vertical inclination measured by the vertical inclination measuring means. Measuring device characterized by comprising. 2. A measurement unit comprising a transparent dielectric block and a thin film layer formed on one surface of the dielectric block, and a light beam for the dielectric block and the thin film. A light beam incidence means for making incident at an angle of incidence at which the total reflection condition is obtained at the interface with the layer, and a light detection means for receiving a predetermined polarization component of the light beam totally reflected at the interface, and the same measurement unit as described above In a measurement device that performs a plurality of measurements and detects a change in the state of totally reflected light during the plurality of measurements, a vertical inclination that changes the incident angle of the interface during the plurality of measurements is used. Vertical inclination measuring means for measuring, and the measuring unit and the light beam so as to correct an error due to the inclination according to the vertical inclination measured by the vertical inclination measuring means. Measuring device being characterized in that a longitudinal adjustment means for adjusting the means and / or said light detecting means morphism. 3. Total reflection that occurs when the light beam incidence means and the light detection means impinge a light beam on the interface at various incident angles and impinge on the interface at a predetermined incident angle. One that is configured to measure the state of attenuation, wherein the light beam includes components that are incident on the interface at various angles, and that has a predetermined light amount distribution in the direction of change of the incident angle with respect to the interface. The vertical tilt measuring means measures the tilt in the vertical direction by utilizing reflection of at least a part of the light beam by a part of the measuring unit. Item 1. The measuring device according to item 1 or 2. 4. The vertical tilt measuring means measures the vertical tilt using a component of the light beam outside the measurement range of the attenuation of total reflection. The measuring device according to the item. 5. A portion of the light beam received by the light detecting means by the vertical tilt measuring means, of a component outside the measurement range of the attenuation of total reflection, in which a large change in the light quantity occurs with a change in the incident angle. 5. The measuring apparatus according to claim 4, wherein the inclination in the vertical direction is measured from the relationship between the reflected light intensity and the detection position. 6. The vertical tilt measuring means causes a part of a component of the light beam outside the measurement range of the attenuation of total reflection to be incident on the interface as a dark line, and the light detecting means reflects the reflected light of the light beam. 5. The measuring apparatus according to claim 4, wherein the vertical inclination is measured by detecting the position of a dark line included in the component of. 7. The vertical tilt measuring means converges at least a part of the light beam reflected by a part of the measuring unit, and receives the light beam converged by the converging lens to receive the light. 4. The measuring device according to claim 3, further comprising a second light detecting means for detecting the position of the beam. 8. The light beam includes a plurality of polarization components, and the second light detecting means receives a component other than the predetermined polarization component of the light beam to position the light beam. The measuring device according to claim 7, wherein the measuring device detects. 9. The vertical tilt measuring means further includes a second lens between the converging lens and the second light detecting means, and the focal lengths of the converging lens and the second lens are f1 respectively. , F2, the distance between the reflection position of the light beam and the light detecting means is L, the distance between the reflection position and the converging lens is d0, the distance between the converging lens and the second lens is d1, the The distance between the second lens and the second light detecting means is d2, the shift amount of the reflection position based on the vertical movement amount of the interface is x, and the vertical inclination of the interface is θ.
Then, the moving distance A of the total reflection attenuation angle represented by Ltan θ + x
And θ {d1 + d2-d1d2 / f2-d0 (d1 / f1 + d0 / f1-d1d2 / f1 / f2-1 +
d2 / f2} -x (d1 / f1 + d2 / f1-d1d2 / f1 / f2-1 + d2 / f2) represented by the second light detection means in relation to the spot movement amount B of the light beam , L, d0, d1, such that A = B or A = −B.
9. The measuring device according to claim 7, wherein d2, f1 and f2 are selected and the converging lens, the second lens and the second light detecting means are arranged. 10. The convergent lens, the second lens, and the second lens so that the relationship between the distances L, d0, d1, d2 and the focal lengths f1, f2 is d1 = f1, d2 = f2, d0 = f1 + L. The measuring device according to claim 9, wherein the second light detecting means is installed. 11. The vertical inclination measuring means reflects a second light beam incident means for making a second light beam different from the light beam incident on a part of the measuring unit and a part of the measuring unit. 3. The measuring device according to claim 1, further comprising: a second light detecting unit that receives the second light beam that has been generated and detects the position of the second light beam. 12. The measuring device according to claim 11, wherein the second light beam has a wavelength different from that of the light beam. 13. The light beam is linearly polarized light having the predetermined polarization component, and the second light beam is linearly polarized light having a polarization component different from that of the light beam. The measuring device described. 14. The measurement unit according to claim 3, wherein a part of the measurement unit is a predetermined surface of the measurement unit that is inclined corresponding to a vertical inclination of the interface. measuring device. 15. The measuring device according to claim 14, wherein the predetermined surface is a reflecting surface provided in the vicinity of the one surface of the dielectric block on which the thin film layer is formed. 16. A measuring unit comprising a transparent dielectric block and a thin film layer formed on one surface of the dielectric block, and a light beam for the dielectric block and the thin film. Light beam incidence means for making incident light at various incident angles so that total reflection conditions can be obtained at the interface with the layer, and light detection means for receiving a predetermined polarization component of the light beam totally reflected at the interface, In a measuring device that performs the measurement a plurality of times with respect to a measurement unit and detects a change in the state of attenuation of total reflection during the plurality of measurements, changing the incident angle of the interface during the plurality of measurements. A vertical / horizontal tilt measuring means for measuring a vertical tilt and a horizontal tilt intersecting the vertical direction, and the tilt according to the horizontal tilt measured by the vertical / horizontal tilt measuring means. The horizontal direction adjusting means for adjusting the measuring unit, the light beam incident means and / or the light detecting means so as to correct the shift of the light receiving position of the light detecting means due to the light beam, and the vertical and horizontal inclination measurement. A measuring device which obtains a measurement value in which an error due to the inclination is corrected according to the inclination in the vertical direction measured by the measuring device. 17. A measuring unit comprising a transparent dielectric block and a thin film layer formed on one surface of the dielectric block, and a light beam for the dielectric block and the thin film. A light beam incidence means for making incident at an angle of incidence at which the total reflection condition is obtained at the interface with the layer, and a light detection means for receiving a predetermined polarization component of the light beam totally reflected at the interface, and the same measurement unit as described above In a measuring device that performs a plurality of measurements and detects a change in the state of totally reflected light during the plurality of measurements, a vertical inclination that changes the incident angle of the interface during the plurality of measurements. And a vertical / horizontal tilt measuring unit that measures a horizontal tilt that intersects the vertical direction, and according to the horizontal tilt and the vertical tilt measured by the vertical / horizontal tilt measuring unit, The measuring unit, the light beam incident means, and / or the light detection so as to correct the deviation of the light receiving position of the light detection means by the light beam due to the inclination in the horizontal direction and the error due to the inclination in the vertical direction. And a vertical and horizontal adjustment means for adjusting the means. 18. Total reflection that occurs when the light beam incident means and the light detection means make light beams incident on the interface at various incident angles and are incident on the interface at a predetermined incident angle. One that is configured to measure the state of attenuation, wherein the light beam includes components that are incident on the interface at various angles, and that has a predetermined light amount distribution in the direction of change of the incident angle with respect to the interface. And a converging lens for converging at least a part of the light beam reflected by a part of the measuring unit, and a light beam converging by the converging lens for receiving the light beam. The measuring device according to claim 16 or 17, further comprising a two-dimensional light detecting means for detecting the position of the light beam. 19. The vertical / horizontal inclination measuring means reflects a second light beam incident means for causing a second light beam different from the light beam to be incident on a part of the measuring unit, and a part of the measuring unit. 18. A two-dimensional light detecting means for receiving the generated second light beam and detecting the position of the second light beam.
The measuring device described. 20. The measuring device according to claim 19, wherein the second light beam has a wavelength different from that of the light beam. 21. The light beam is linearly polarized light having the predetermined polarization component, and the second light beam is linearly polarized light having a polarization component different from that of the light beam. The measuring device described. 22. The two-dimensional light detecting means is a four-division photodiode, wherein the two-dimensional light detecting means is a four-division photodiode.
1. The measuring device according to any one of 1. 23. The measuring device according to claim 18, wherein the two-dimensional photodetector is a resistance photodetector. 24. A part of the measurement unit is a predetermined surface of the measurement unit which is inclined corresponding to the inclinations of the interface in the vertical direction and the horizontal direction. The measuring device according to the item. 25. The measuring device according to claim 24, wherein the predetermined surface is a reflecting surface provided in the vicinity of the one surface of the dielectric block on which the thin film layer is formed. 26. The dielectric block is formed as one block having all of an incident end surface and an exit end surface of the light beam and a surface on which the thin film layer is formed. Item 25. The measuring device according to any one of items 1 to 25. 27. In the dielectric block, two parts, a part having an incident end face and an exit end face of the light beam and a part having a face on which the thin film layer is formed, are joined via a refractive index matching means. The measuring device according to any one of claims 1 to 25, characterized by comprising: