JP2003194751A - Micro chemical system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized micro chemical system that can improve working efficiency and, at the same time, has high measurement sensitivity. <P>SOLUTION: This micro chemical system is provided with an optical fiber 103 which is fitted with a rod lens 101 having a diffraction lens 102 formed on its end face at its front end and propagates exciting light and detection light in a single mode. This system also has a ferrule 104 for making the outside diameter of the optical fiber 103 equal to that of the rod lens 101. The lens 101 having the diffraction lens 102 on its end face and the fiber 103 are fixed by means of a tube 105. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to microchemical systems, and more particularly to microchemical systems for performing photothermal conversion spectroscopy.

[0002]

2. Description of the Related Art Conventionally, an integrated technique for performing a chemical reaction in a minute space has been attracting attention from the viewpoint of high speed of the chemical reaction, reaction in a minute amount, on-site analysis, etc. , Is being actively promoted worldwide.

As one of the integration techniques of chemical reactions, there is a so-called micro-chemical system which performs mixing, reaction, separation, extraction, detection and the like of a submerged sample in a fine channel formed on a small glass substrate or the like. Examples of reactions performed in this microchemical system include diazotization reaction, nitration reaction, and antigen-antibody reaction, and examples of extraction and separation include solvent extraction, electrophoretic separation, and column separation. The microchemical system may be used only for a single function such as only for separation, or may be used in combination.

Among the above functions, an electrophoresis apparatus for analyzing a very small amount of protein, nucleic acid or the like has been proposed for the purpose of separating only (for example, JP-A-8-178).
897). This comprises a plate-shaped member with a flow path, which is composed of two glass substrates bonded to each other. Since this member is plate-shaped, it is less likely to be damaged and easier to handle than a glass capillary tube having a circular or rectangular cross section.

Since the amount of the sample is very small in these micro chemical systems, a highly sensitive detection method is essential.
As such a method, a photothermal conversion spectroscopic analysis method utilizing a thermal lens effect generated by absorption of light by a submerged sample in a fine channel has been established, and thus a road to practical application of a microchemical system is established. It is open.

When the sample is focused and irradiated with light, the solute in the sample absorbs the light and releases thermal energy. When the temperature of the solvent locally rises due to this thermal energy, the refractive index changes and a thermal lens is formed (photothermal conversion effect). The photothermal conversion spectroscopic analysis method utilizes this photothermal conversion effect.

FIG. 8 is an explanatory view of the principle of the thermal lens.

In FIG. 8, when a very small sample is focused and irradiated with excitation light through an objective lens, a photothermal conversion effect is induced. The temperature of the sample irradiated with the excitation light is increased as it gets closer to the center of light collection, and the temperature of the light collection center becomes the highest, but as the distance from the light collection center increases, the temperature rises due to thermal diffusion. Becomes smaller. Since the refractive index of many substances decreases as the temperature rises, the degree of decrease of the refractive index increases toward the center of light collection, and conversely, the degree of decrease of the refractive index decreases toward the center of light collection. This refractive index distribution has the same optical effect as a concave lens, and this effect is called a thermal lens effect. The magnitude of this thermal lens effect, that is, the power of the concave lens is proportional to the light absorption of the sample. When the refractive index increases in proportion to temperature, the same thermal lens effect as that of the convex lens occurs.

As described above, the photothermal conversion spectroscopic analysis method is suitable for detecting the concentration of a very small sample because it is for observing the diffusion of heat, that is, the change in the refractive index.

In the conventional photothermal conversion spectroscopic analyzer,
The flow path plate-shaped member is disposed below the microscope objective lens, and the excitation light of a predetermined wavelength output from the excitation light source enters the microscope, and the flow path plate-shaped member of the microscope is input by the microscope objective lens. The sample in the channel is focused and irradiated. As a result, a thermal lens is formed on the sample with the focused irradiation position as the center.

On the other hand, a detection light having a wavelength different from that of the excitation light is output from the detection light source and is incident on the microscope. Is focused and illuminated. The detection light focused and irradiated on this sample is transmitted through a thermal lens formed on the sample to be diverged or focused. The light emitted from the sample after diverging or condensing becomes signal light, and the signal light is detected by the detector through both the condenser lens and the filter or only the filter. The intensity of the signal light detected by this detector depends on the thermal lens formed on the sample. The detection light may have the same wavelength as the excitation light, or the excitation light may also serve as the detection light.

As described above, in the above photothermal conversion spectroscopic analysis device, the thermal lens is formed at the focal position of the excitation light, and the refractive index change of the formed thermal lens has the same or different wavelength as the excitation light. (Japanese Patent Laid-Open No. 10-
232210).

[0013]

However, the conventional photothermal conversion spectroscopic analysis device is large in size because the light source, the optical system of the measurement unit and the detection unit (photoelectric conversion unit), and the like are complicatedly upgraded. , Lacks portability. For this reason, when performing analysis using a photothermal conversion spectroscopic analyzer,
When handling a chemical reaction, there is a problem that the place and operation are limited.

Further, in the conventional photothermal conversion spectroscopic analyzer, if the objective lens of the microscope has chromatic aberration, the focal position of the detection light deviates from the focal position of the excitation light on which the thermal lens is formed by a predetermined distance. Can detect changes in the refractive index of the thermal lens as changes in the focal position of the detection light, but the objective lens of the microscope usually does not have chromatic aberration, so the focal position of the detection light is the excitation light that forms the thermal lens. The detection light is not deflected by the thermal lens substantially at the focal point position of 1, and as a result, the change in the refractive index of the thermal lens cannot be detected.

Therefore, as shown in FIGS. 9 (a) and 9 (b), the position of the sample on which the thermal lens 131 is formed is shifted from the focus position 133 of the detection light at each measurement.
As shown in FIG. 10, by slightly diverging or condensing the detection light using a lens (not shown) and making it enter the objective lens 130, the focus position 133 of the detection light is moved to the thermal lens 131.
There is a problem in that work efficiency is poor because it is necessary to shift from the focal position 132 of the excitation light that forms the light.

An object of the present invention is to provide a small-sized microchemical system which can improve working efficiency and has high sensitivity.

[0017]

In order to achieve the above object, a microchemical system according to claim 1 is a light source for excitation light which outputs excitation light, a light source for detection light which outputs detection light, and A guiding optical system that multiplexes and guides the excitation light and the detection light, an irradiation lens that irradiates a sample with the excitation light and the detection light guided by the guiding optical system, and a sample that is irradiated with the excitation light In the microchemical system including a detection unit that detects the detection light that has been transmitted through the thermal lens, the irradiation lens is a diffractive lens.

According to the microchemical system of the first aspect, since the irradiation lens is a diffractive lens, the lens itself is thin and lightweight, and as a result, the microchemical system can be miniaturized. In addition, since the diffractive lens has chromatic aberration due to its structure, it is possible to shift the focal positions of the excitation light and the detection light without using an external optical system in addition to this diffractive lens. Can be made smaller.

The microchemical system according to claim 2 is
The microchemical system according to claim 1, wherein the irradiation lens is a combination of the diffraction lens and a refraction lens.

According to the microchemical system of the second aspect, since the irradiation lens is a combination of the diffractive lens and the refractive lens, the fact that the signs of chromatic aberration of the diffractive lens and the refractive lens are opposite to each other is utilized. As a result of being able to adjust the amount of chromatic aberration of the irradiation lens to an optimum value, it is possible to increase the measurement sensitivity of the microchemical system, reduce the aberration of the irradiation lens, and increase the measurement sensitivity of the microchemical system. Can be higher.

The microchemical system according to claim 3 is
The microchemical system according to claim 2, wherein the diffractive lens is formed on a surface of the refractive lens.

According to the third aspect of the microchemical system, since the diffractive lens is formed on the surface of the refracting lens, the irradiation lens becomes small, and the microchemical system can be further miniaturized.

The microchemical system according to claim 4 is
The microchemical system according to any one of claims 1 to 3, wherein the guiding optical system is an optical fiber.

According to the microchemical system of the fourth aspect, since the guiding optical system is composed of an optical fiber, the excitation light and the detection light combined by the guiding optical system are always coaxial. Therefore, it is not necessary to adjust the optical axes of the excitation light and the detection light, and the work efficiency can be improved. Moreover, since a device for adjusting the optical axis is not required, the microchemical system can be further miniaturized.

The microchemical system according to claim 5 is
The microchemical system according to claim 4, wherein the irradiation lens is fixed to a light emitting side end of the optical fiber.

According to the microchemical system of the fifth aspect, since the irradiation lens is fixed to the light emitting side end of the optical fiber, all the optical axes of the excitation light, the detection light and the irradiation lens are fixed. As a result, it is not necessary to adjust the optical axis, and the working efficiency can be further improved. Further, since a jig for adjusting the optical axis is not necessary, the microchemical system can be further downsized.

The microchemical system according to claim 6 is
The microchemical system according to claim 4 or 5,
It is characterized in that the optical fiber propagates both the excitation light and the detection light in a single mode.

According to the sixth aspect of the microchemical system, since the optical fiber transmits both the excitation light and the detection light in a single mode, the thermal lens generated by the excitation light has a small aberration and a small aberration. As a result of being a lens, accurate measurement can be performed.

The microchemical system according to claim 7 is
The microchemical system according to any one of claims 1 to 3, wherein the guiding optical system comprises an optical waveguide.

According to the microchemical system of the seventh aspect, since the guiding optical system comprises an optical waveguide, the excitation light and the detection light combined by the guiding optical system are always coaxial. Therefore, it is not necessary to adjust the optical axes of the excitation light and the detection light, and the work efficiency can be improved. Moreover, since a device for adjusting the optical axis is not required, the microchemical system can be further miniaturized.

The microchemical system according to claim 8 is
The microchemical system according to claim 7, wherein the irradiation lens is fixed to a light emitting side end of the optical waveguide.

According to the microchemical system of the eighth aspect, since the irradiation lens is fixed to the light emitting side end of the optical waveguide, all the optical axes of the excitation light, the detection light and the irradiation lens are fixed. As a result, there is no need to adjust the optical axis,
Work efficiency can be further improved. Further, since a jig for adjusting the optical axis is not necessary, the microchemical system can be further downsized.

The microchemical system according to claim 9 is
The microchemical system according to claim 7 or 8,
The optical waveguide is characterized by propagating both the excitation light and the detection light in a single mode.

According to the microchemical system of the ninth aspect, since the optical waveguide propagates both the excitation light and the detection light in a single mode, the thermal lens generated by the excitation light is a small lens with small aberration. As a result,
Accurate measurement is possible.

A tenth aspect of the microchemical system according to any one of the second to ninth aspects is that the refractive lens is a gradient index lens.

According to the microchemical system of the tenth aspect, since the refractive lens is a gradient index lens,
As a result of the miniaturization of the irradiation lens, the microchemical system can be further miniaturized.

The microchemical system according to claim 11 is the microchemical system according to claim 10, wherein
The gradient index lens is a rod lens.

According to the microchemical system of the eleventh aspect, since the gradient index lens is a rod lens, the optical axis of the optical fiber or the optical waveguide can be easily aligned with the optical axis of the rod lens. It can be easily held.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventor has found that a light source for excitation light that outputs excitation light, a light source for detection light that outputs detection light, and a guiding optical system that multiplexes and guides the excitation light and the detection light, A micro equipped with an irradiation lens for irradiating the sample with the excitation light and the detection light guided by the guiding optical system, and a detection means for detecting the detection light transmitted through the thermal lens generated by the sample irradiated with the excitation light. In the chemical system, if the irradiation lens is a diffractive lens, the lens itself becomes thin and lightweight,
As a result, the microchemical system can be downsized, and since the diffractive lens has chromatic aberration due to its structure, the excitation light and the detection light can be extracted without using an external optical system in addition to this diffractive lens. It was found that the focal position of the micro chemical system can be shifted, and the micro chemical system can be further miniaturized.

The present invention was made based on the results of the above research.

The microchemical system according to the embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a view showing the schematic arrangement of a microchemical system according to the first embodiment of the present invention.

Referring to FIG. 1, a microchemical system 1 according to the first embodiment of the present invention is configured such that excitation light and excitation light are applied to a submerged sample in a channel 204 formed in a plate member 20 with a channel described later. It is composed of an irradiation unit 1a for irradiating the detection light and a light receiving unit 1b for receiving the excitation light and the detection light that have passed through the plate member 20 with a flow path.

The irradiation unit 1a includes an excitation light source 106 that outputs excitation light and a detection light source 107 that outputs detection light.
A modulator 108 for modulating the excitation light output from the excitation light source 106, the excitation light source 106 and the detection light source 1
07 are connected to each other via optical fibers, and a two-wavelength combining element 109 for combining the excitation light from the excitation light source 106 and the detection light from the detection light source 107, and the combined light are received. At the same time, the optical fiber 10 with a lens that irradiates the combined light to the plate-shaped member 20 with a flow channel in which the flow channel 204 is formed, and the position of the optical fiber 10 with a lens are located in the plate-shaped member 20 with a flow channel. And a jig 30 for adjusting and holding so as to face the flow path 204. By configuring the irradiation unit 1a in this way, it is possible to irradiate the plate-shaped member 20 with a flow path with light obtained by multiplexing the excitation light and the detection light, and the focal point of the excitation light is located in the flow path 204. Can be adjusted to

The excitation light and the detection light are coaxial with each other outside the optical fiber 103 by using a dichroic mirror or the like without using the two-wavelength multiplexing element 109.
May be incident on.

The plate member 20 with a flow path is composed of substrates 201, 202 and 203 bonded in order of three layers, and the flow path formed inside the substrate 202 is for mixing, stirring and synthesizing a submerged sample. , Separation, extraction, detection, etc.

The material of the plate member 20 with a flow path is durable,
Glass is desirable from the viewpoint of chemical resistance and light transmission, and considering the use for biological samples such as cells, for example, for DNA analysis, glass with high acid resistance and alkali resistance, specifically, borosilicate glass, soda. Lime glass, aluminoborosilicate glass, quartz glass and the like are preferable. However, organic substances such as plastics can be used by limiting the use.

Adhesives for adhering the substrates 201, 202 and 203 to each other include, for example, ultraviolet curing type, thermosetting type and
Liquid-curing acrylic and epoxy organic adhesives and inorganic adhesives are available. In addition, the substrate 20 is formed by heat fusion.
You may fuse 1,202,203 comrades.

The light receiving portion 1b receives the excitation light and the detection light that have passed through the plate member 20 with a flow path, and also detects the wavelength filter 402 that selectively filters only the detection light and the filtered detection light. Photoelectric converter 401 and photoelectric converter 40
A lock-in amplifier 403 that synchronizes the signal from 1 with the modulator 108, and a computer 404 that analyzes this signal
It consists of and.

As the wavelength filter 402, for example, an optical interference filter in which a high refractive index and a low refractive index are laminated in multiple layers is used. In addition, a pinhole that selectively transmits only part of the detection light may be arranged on the optical path of the detection light on the upstream side of the photoelectric converter 401.

The optical fiber with a lens 10 is a single mode optical fiber 1 connected to the two-wavelength multiplexing element 109.
03, a ferrule 104, an irradiation lens 40 arranged at the tip of the optical fiber 103, and a tube 105 for fixing the ferrule 104 and the irradiation lens 40. still,
The optical fiber 103 is set to the single mode because when the trace solute in the sample is detected by using the photothermal conversion spectroscopic analysis method, the excitation light is narrowed as small as possible to increase the energy used for the photothermal conversion, This is because it is desirable that the thermal lens generated by the excitation light be a lens with little aberration.

The ferrule 104 makes the outer diameter of the optical fiber 103 equal to the outer diameter of the irradiation lens 40.
It may be in close contact with the irradiation lens 40, or may have a gap.

The tube 105, and by extension, the optical fiber 10 with lens is held by the jig 30 and its position is adjusted so as to be located facing the flow path 204 of the plate member 20 with flow path.

The excitation light used to generate the thermal lens preferably has a Gaussian distribution. Since the light emitted from the single mode optical fiber 103 always has a Gaussian distribution, it is suitable for reducing the focus of the excitation light. Further, when the thermal lens generated by the excitation light is small, it is desirable to narrow down the detection light as much as possible in order to maximize the detection light that passes through this thermal lens. For this reason also, it is preferable that the optical fiber 103 propagates the excitation light and the detection light in a single mode.

Any optical fiber can be used as the optical fiber 103 as long as it transmits excitation light and detection light. However, when a multimode optical fiber is used, the emitted light does not have a Gaussian distribution. Moreover, since the emission pattern changes depending on various conditions such as the degree of bending of the optical fiber, it is not always possible to obtain stable emission light. Therefore, it may be difficult to measure a minute amount of solute and the measured value may not be stable. Therefore, as described above, the optical fiber 1
03 is preferably a single mode.

As shown in FIG. 2, the optical fiber with lens 10 is set so that the focal position 133 of the detection light is slightly deviated from the focal position 132 of the excitation light on which the thermal lens 131 is formed by ΔL. There is.

Ic is calculated as a confocal length (nm) by Ic = π (d / 2) ² / λ ₁ (1) Here, d is d = 1.22 × λ ₁ / NA
Λ ₁ is the wavelength (nm) of the excitation light, and NA is the numerical aperture of the irradiation lens 40. Regarding the value of NA, as in the present embodiment,
When the optical fiber 103 is used, the numerical aperture of the light emitted from the optical fiber is generally small. Therefore, when the irradiation lens 40 having a large numerical aperture is used, it is necessary to use the numerical aperture of the optical fiber 103 for calculation.

The ΔL value changes depending on the thickness of the sample to be measured. When measuring a sample thinner than the confocal length,
The ΔL value is preferably Ic <ΔL <10 · Ic (2), more preferably ΔL = √3 · Ic (3).

For example, NA = 0.46, λ ₁ = 488n
The relationship between the value of the deviation ΔL and the signal intensity at m and λ ₂ = 632.8 nm is represented by a relative ratio coefficient value when the signal intensity at ΔL = 4.67 μm is 100, as shown in FIG. , ΔL = 4.76 μm, the signal intensity becomes maximum. That is, when measuring a sample thinner than the confocal length (Ic), it is preferable to design ΔL so as to satisfy the relationship of the expression (2), preferably the expression (3).
Since the value of ΔL represents the difference between the focal position of the detection light and the focal position of the excitation light, the same result is obtained regardless of whether the focal length of the detection light is longer or shorter than the focal length of the excitation light.

In order to obtain the optimum ΔL for the measurement,
A gradient index rod lens is often used as the irradiation lens 40.

The rod lens is composed of a cylindrical transparent body whose refractive index continuously changes from the center to the periphery, and has a refractive index n at a position of a distance r from the central axis in the radial direction.
(R), on-axis refractive index n ₀ , squared distribution constant g, and distance r
Relationship with is known as converging light transmitting body represented approximately by the following quadratic equation _{n (r) = n 0 {} 1- (g 2/2) · r 2}.

The rod lens has a length z ₀ of 0 <z ₀ <
When selected in the range of π / 2g, its image forming property is the same as that of a normal convex lens even though both end faces are flat, and S ₀ = cot (gz ₀ ) / n ₀ g from the exit end by parallel incident rays. A focus is formed at the position.

The rod lens is manufactured by the following method, for example.

That is, in terms of mole percentage, SiO ₂ : 57 to 63
_{%, B 2 O 3: 17~23} %, Na 2 O: 5~17%, T
1 ₂ O: After forming a rod from glass containing 3 to 15% as a main component, the glass rod is treated in an ion exchange medium such as potassium nitrate, and thallium ions and sodium ions in the glass and potassium in the medium are treated. Ions are exchanged with the ions to provide a continuously decreasing refractive index profile in the glass rod from the center to the periphery.

However, the chromatic aberration of the rod lens is determined mainly by the type of ions used,
As described above, the types of ions capable of providing the refractive index distribution that continuously decreases from the center to the periphery in the glass rod are limited to some such as thallium, lithium, cesium, and silver. With the irradiation lens 40 including only the rod lens, the optimum ΔL cannot be set depending on the measurement conditions. Therefore, in the present embodiment, the one in which the diffraction lens 102 is formed on the end surface of the rod lens 101 (FIGS. 1 and 5) is used as the irradiation lens 40. The reason will be described below.

The diffractive lens 140 is considered to be a phase modulation element, and the phase modulation amount ψ is given by φ (r) = − πr ² / λf, where f is the focal length and r is the distance from the lens center. As a result, in the diffractive lens 102, a section corresponding to an integer multiple of the phase 2π is removed, and the remaining phase is further quantized to have a waveform (FIG. 5A). It becomes the shape of the annular zone (FIG. 5B). The larger the quantization number m, the closer it is to the phase distribution of the refractive lens (Optics vol.30 (4) 270 (2001)).

Since the diffractive lens 102 quantizes the shape based on the phase, the shape differs depending on the wavelength, and the design wavelength always exists.

Any method may be used to form the diffractive lens 102, but since it is necessary to accurately form a depth distribution of about the wavelength, an etching method using a semiconductor exposure apparatus or an electron beam drawing apparatus, A flame hydrolysis deposition method or the like is used. In each case, 2 in one process
Since the step shape is obtained, the 2 ^N step shape is obtained by repeating the process N times. The diffractive optical element having a stepped shape manufactured in this manner is also called a binary optical element. Therefore, as shown in FIG.
When viewed from above, the diffractive lens 102 has a plurality of annular zones 2 ^N formed concentrically.

Next, when the combination of the rod lens 101 and the diffractive lens 102 is used as the irradiation lens 40, the value of ΔL that maximizes the signal intensity can be adjusted regardless of the value. Explain why you can.

As described above, the chromatic aberration of the diffractive lens 102 is caused by the shape of the diffractive lens, whereas the rod lens 101 is chromatic aberration because the chromatic aberration is caused by the dispersion of the material. Has the opposite sign,
By combining the chromatic aberration amount of the rod lens 101 and the chromatic aberration of the diffractive lens 102 formed on the end surface of the rod lens 101, the chromatic aberration amount of the optical fiber with lens 10 can be adjusted.

When the rod lens 101 having the diffractive lens 102 formed on the end face is used as the irradiation lens 40, the aberration of the irradiation lens 40 is smaller than that when the single diffractive lens 140 is used. The focus of light can be reduced.

Since the rod lens 101 has a cylindrical shape and the bottom surface is a flat surface, the optical fiber 103
The optical axis of the lens can be easily attached to the optical axis of the optical fiber 103 while being easily attached to the end face. Further, since the shape is cylindrical, it is easy to hold the lens when the jig 30 is used when attaching the lens to the optical fiber 103.

According to the microchemical system according to the first embodiment of the present invention, the rod lens 101 having the diffractive lens 102 formed on the end face is attached to the tip of the optical fiber 103 for propagating the excitation light and the detection light. Therefore, the optical axis of the excitation light and the detection light and the diffractive lens 1 for each measurement are
It is not necessary to adjust the optical axis of the rod lens 101 in which 02 is formed on the end face, and a jig for adjusting the optical axis and a solid surface plate are not necessary, so that the microchemical system can be miniaturized. Further, by combining the chromatic aberrations of the diffractive lens 102 and the rod lens 101, the chromatic aberration amount suitable for the dimension of the groove used for the measurement can be obtained, so that the measurement with high sensitivity becomes possible.

The rod lens 101 having the diffractive lens 102 formed on the end face does not have to be in contact with the plate member 20 with flow passages. The focal length of the rod lens 101 having the diffractive lens 102 formed on the end face can be adjusted by the thickness.
If the substrate 201 is not thick enough, the diffractive lens 102
A spacer for adjusting the focal length may be inserted between the rod lens 101 formed on the end face and the substrate 201. In these cases, it is not necessary to adjust the focal length of the excitation light, and the device can be further downsized.

Further, as described above, since the chromatic aberration can be adjusted by adjusting the shape of the diffractive lens according to the design wavelength, the irradiation lens 40 may be configured by only the diffractive lens (FIG. 4). .

If the tip of the optical fiber 103 is processed into a spherical shape to form a lens, the excitation light and the detection light can be narrowed down without attaching a lens to the tip of the optical fiber 103. In this case, Since there is almost no chromatic aberration, the focus positions of the excitation light and the detection light are almost the same. For this reason,
There is a problem that the signal of the thermal lens is hardly detected. Further, since the lens produced by processing the tip of the optical fiber 103 has large aberration, there is a problem that the focus of the excitation light and the detection light is large. Therefore, in the present embodiment, the irradiation lens 40 described above is attached to the tip of the optical fiber 103.

FIG. 6 is a diagram showing a schematic structure of the microchemical system according to the second embodiment of the present invention.

In FIG. 6, the microchemical system 2 according to the second embodiment of the present invention has basically the same structure as the microchemical system 1 (FIG. 1) according to the first embodiment of the present invention. Therefore, the same components are denoted by the same reference numerals and the description thereof will be omitted. Only different points will be described below.

In FIG. 6, the irradiation unit 2a in the microchemical system 2 is disposed on the substrate 205, and the substrate 205
Is a gradient index rod lens 101, a diffractive lens 102 formed on the upper end surface of the rod lens 101,
A prism 121 disposed on the diffractive lens 102. Further, on the upper surface of the substrate 205, an optical waveguide 120 is formed, one end of which is directed to the prism 121 and the other end of which is bifurcated. An excitation light source is formed at each of the two ends of the optical waveguide 120. 106 and a light source 107 for detection light are arranged, and a two-wavelength multiplexing element 109 is provided near the branch portion.
Are arranged.

The optical waveguide 120 propagates the excitation light from the excitation light source 106 and the detection light from the detection light source 107 in a single mode, and the direction is changed by the prism 121 to change the direction of the diffraction lens 102 and the refractive index distribution type. Rod lens 10
1 to irradiate the flow path 204 of the plate-shaped member 20 with flow path.

The optical waveguide 120 may be formed by any method, for example, flame hydrolysis method.
This flame hydrolysis method is, for example, flame hydrolysis of silicon tetrachloride and germanium tetrachloride to deposit two glass fine particle layers for the lower clad and the core on the surface of the substrate 205, and the fine particle layer is transparent by heating at a high temperature. Reform into a glass layer. Then, a core portion having a circuit pattern is formed by photolithography and reactive etching. After that, the upper clad is formed by flame hydrolysis of silicon tetrachloride (J. Lightwave Tech. Vol. 17 (5) 771 (1999).
etc). In the above, when the refractive index of the substrate 205 and the core portion have appropriate values, the lower clad may not be formed.

The tip of the optical waveguide 120 has a prism 121.
May be contacted with. Further, in order to adjust the focal length of the excitation light, the prism 121 and the rod lens 101 may be installed separately. The end surface of the rod lens 101 may be the same surface as the surface of the plate member 20 with a flow path.

According to the microchemical system according to the second embodiment of the present invention, the rod lens 101 having the diffractive lens 102 formed on the end face is attached to the tip of the optical waveguide 120 for propagating the excitation light and the detection light. Since it has been
Optical axis of excitation light and detection light and diffractive lens 102 for each measurement
It is not necessary to adjust the optical axis of the rod lens 101 formed on the end face, and a jig for adjusting the optical axis and a solid surface plate are not required, so that the microchemical system can be miniaturized.

Further, the diffractive lens 102 and the rod lens 1
By combining the chromatic aberration of 01, the chromatic aberration amount suitable for the dimension of the groove used for the measurement can be obtained, and thus the measurement with high sensitivity becomes possible.

FIG. 7 is a diagram showing a schematic configuration of the microchemical system according to the third embodiment of the present invention.

In FIG. 7, the microchemical system 3 according to the third embodiment of the present invention has basically the same structure as the microchemical system 1 (FIG. 1) according to the first embodiment, and the same structure. The same reference numerals are given to the constituent members, the description thereof will be omitted, and only different points will be described below.

In FIG. 7, the irradiation section 4a in the microchemical system 3 is the substrate 20 of the plate member 20 with a flow path.
1, the excitation light source 106 for irradiating the diffraction lens 150 on the plate member 20 with the flow path with the excitation light through the dichroic mirror 152, and the detection light. A detection light source 106 for irradiating the diffractive lens 150 on the plate-like member 20 with a flow path through the excitation light from the excitation light source 106 for improving the S / N ratio of the thermal lens signal. Is modulated by the acousto-optic modulator 151.

A chopper may be used instead of the acousto-optic modulator 151. The modulated excitation light is reflected by the dichroic mirror 152. Detection light from the detection light source 107 is incident on the dichroic mirror 152. The excitation light and the detection light are made coaxial by the dichroic mirror 152 and guided to the diffractive lens 150 formed on the surface of the plate member 20 with a flow path.

According to the microchemical system 3 according to the third embodiment of the present invention, as the irradiation lens 40, the plate-like member 2 having a flow path through which the sample detected by the diffraction lens 150 flows.
Since it is formed on the surface of 0, the thickness of the irradiation lens 40 portion is eliminated, and as a result, the microchemical system can be made extremely small.

[0090]

As described in detail above, according to the microchemical system of the first aspect, since the irradiation lens is a diffractive lens, the lens itself is thin and lightweight, and as a result, the microchemical system is miniaturized. can do. In addition, since the diffractive lens has chromatic aberration due to its structure, it is possible to shift the focal positions of the excitation light and the detection light without using an external optical system in addition to this diffractive lens. Can be made smaller.

According to the microchemical system of the second aspect, since the irradiation lens and the diffractive lens are further combined with the refractive lens, the fact that the signs of chromatic aberration of the diffractive lens and the refractive lens are opposite to each other is utilized, As a result of being able to adjust the amount of chromatic aberration of the irradiation lens to an optimum value, it is possible to increase the measurement sensitivity of the microchemical system, reduce the aberration of the irradiation lens, and increase the measurement sensitivity of the microchemical system. Can be higher.

According to the third aspect of the microchemical system, since the diffractive lens is formed on the surface of the refracting lens, the irradiation lens becomes small, and the microchemical system can be further miniaturized.

According to the microchemical system of the fourth aspect, since the guiding optical system comprises an optical fiber, the excitation light and the detection light combined by the guiding optical system are always coaxial. Therefore, it is not necessary to adjust the optical axes of the excitation light and the detection light,
Work efficiency can be improved. Moreover, since a device for adjusting the optical axis is not required, the microchemical system can be further miniaturized.

According to the microchemical system of the fifth aspect, since the irradiation lens is fixed to the end of the optical fiber on the light emitting side, all the optical axes of the excitation light, the detection light and the irradiation lens are fixed. As a result, it is not necessary to adjust the optical axis, and the working efficiency can be further improved. Further, since a jig for adjusting the optical axis is not necessary, the microchemical system can be further downsized.

According to the microchemical system of the sixth aspect, since the optical fiber propagates both the excitation light and the detection light in a single mode, the thermal lens generated by the excitation light is a small lens with small aberration. As a result, accurate measurement can be performed.

According to the microchemical system of the seventh aspect, since the guiding optical system comprises an optical waveguide, the excitation light and the detection light combined by the guiding optical system are always coaxial. Therefore, it is not necessary to adjust the optical axes of the excitation light and the detection light, and the work efficiency can be improved. Moreover, since a device for adjusting the optical axis is not required, the microchemical system can be further miniaturized.

According to the eighth aspect of the microchemical system, since the irradiation lens is fixed to the light emitting side end of the optical waveguide, all the optical axes of the excitation light, the detection light and the irradiation lens are fixed. As a result, there is no need to adjust the optical axis,
Work efficiency can be further improved. Further, since a jig for adjusting the optical axis is not necessary, the microchemical system can be further downsized.

According to the microchemical system of the ninth aspect, since the optical waveguide propagates both the excitation light and the detection light in a single mode, the thermal lens generated by the excitation light is a small lens with small aberration. As a result,
Accurate measurement is possible.

According to the microchemical system of the tenth aspect, since the refractive lens is a gradient index lens,
As a result of the miniaturization of the irradiation lens, the microchemical system can be further miniaturized.

According to the microchemical system of the eleventh aspect, since the gradient index lens is a rod lens, the optical axis of the optical fiber or optical waveguide and the optical axis of the rod lens can be easily aligned and held. Can be easy.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a microchemical system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a formation position of a thermal lens and a focus position of detection light with respect to an optical axis (Z-axis direction) of excitation light.

FIG. 3 is an explanatory diagram of a change in signal intensity with respect to a shift ΔL in the optimum focus position.

FIG. 4 is a diagram showing a schematic configuration of a modified example of the microchemical system according to the first embodiment of the present invention.

FIG. 5 is an irradiation lens 4 according to the first embodiment of the present invention.
0 is a schematic diagram of 0, (a) is a cross-sectional view of the irradiation lens 40, (b) is a plan view of the irradiation lens 40.

FIG. 6 is a diagram showing a schematic configuration of a microchemical system according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a schematic configuration of a microchemical system according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram of a principle of a thermal lens.

FIG. 9 is an explanatory diagram of a method of detecting a change in the refractive index of a thermal lens in a conventional photothermal conversion spectroscopic analyzer, (a)
Shows the case where the focal position of the detection light is made longer than the position of the thermal lens, and (b) shows the case where the focal position of the detection light is made shorter than the position of the thermal lens.

FIG. 10 is an explanatory diagram of a method for detecting a change in the refractive index of a thermal lens in a conventional photothermal conversion spectroscopic analyzer, in which a lens is inserted in the optical path to slightly diverge or condense the detected light and The case where the focal length is made longer than the focal length of the excitation light is shown.

[Explanation of sign]

10 optical fiber with lens 20 plate-like member with flow path 101 rod lens 102 diffractive lens 103 optical fiber 104 ferrule 105 tube 106 light source for excitation light 107 light source for detection light 108 modulator 109 two wavelength multiplexing element 120 optical waveguide 121 prism 130 Objective lens 131 Thermal lens 132 Focus position of excitation light 133 Focus position of detection light by objective lens having chromatic aberration 134 Focus position of detection light by objective lens having no chromatic aberration 140, 150 Diffraction lens 151 Acousto-optic modulator 152 Dichroic mirrors 201, 202, 203 Substrate 204 Flow path 205 Substrate 401 Photoelectric converter 402 Wavelength filter 403 Lock-in amplifier 404 Computer

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2G040 AA02 AB07 BA02 BA24 CA12                       CA23 CB02 EA06 EB02 EC04                       GA05 GA07                 2G059 AA05 BB04 BB12 CC16 EE01                       GG03 GG06 JJ02 JJ03 JJ07                       JJ11 JJ12 JJ17 JJ18 JJ22                       JJ24 KK01 MM01                 2H049 AA04 AA18 AA33 AA37 AA55

Claims (11)

[Claims] 1. A pumping light source that outputs pumping light, a detection light source that outputs detection light, a guiding optical system that multiplexes and guides the pumping light and the detecting light, and the guiding optical system. Micro chemistry comprising an irradiation lens for irradiating a sample with the guided excitation light and the detection light, and detection means for detecting the detection light transmitted through a thermal lens generated by the sample irradiated with the excitation light In the system, the micro-chemical system is characterized in that the illumination lens is a diffractive lens. 2. The microchemical system according to claim 1, wherein the irradiation lens is a combination of the diffraction lens and a refraction lens. 3. The microchemical system according to claim 2, wherein the diffractive lens is formed on a surface of the refractive lens. 4. The microchemical system according to claim 1, wherein the guiding optical system comprises an optical fiber. 5. The microchemical system according to claim 4, wherein the irradiation lens is fixed to an end of the optical fiber on the light emission side. 6. The microchemical system according to claim 4, wherein the optical fiber propagates both the excitation light and the detection light in a single mode. 7. The microchemical system according to claim 1, wherein the guiding optical system comprises an optical waveguide. 8. The microchemical system according to claim 7, wherein the irradiation lens is fixed to a light emitting side end of the optical waveguide. 9. The microchemical system according to claim 7, wherein the optical waveguide propagates both the excitation light and the detection light in a single mode. 10. The microchemical system according to claim 2, wherein the refractive lens is a gradient index lens. 11. The microchemical system according to claim 10, wherein the gradient index lens is a rod lens.