JPS62144032A - Spectrophotometer - Google Patents

Abstract

PURPOSE:To realize the automation, simplification and miniaturization of light absorption analysis, by providing a diffraction lattice polarizing light with a specific wavelength at the predetermined position corresponding to the incident light path of a wave guide layer and further providing a specimen solution flow passage so as to traverse the diffracted light path on the way thereof. CONSTITUTION:A specimen solution is made to flow through a specimen solution flow passage 6 and incident light 7 is allowed to irradiate each diffraction lattice 4 through a wave guide layer 3 at an incident angle theta. The diffraction lattices 4 are provided so as to mutually hold a predetermined interval therebetween and plural rows of membranes are formed to the surface of the wave guide layer of each diffraction lattice 4 and diffracted light with a specific wavelength is guided to the specimen solution flow passage 6 through a diffracted light path 8 and again emitted through the diffracted light path 8. This diffracted light is passed above a photodiode 5 before and after absorbed by the specimen solution, accurate absorption by the specimen solution can be obtained on the basis of the ratio of light intensity detection signals from the photodiodes 5 in the upstream and downstream sides of the specimen solution flow passage 6 and automation can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a spectrophotometer, and more particularly, to a spectrophotometer that can be particularly suitably used for performing spectrophotometric analysis of a sample solution.

<Prior art> Conventionally, when measuring a sample solution, the sample solution is stored inside an absorption cell, the absorption cell is irradiated with light of a predetermined intensity, and the intensity of the transmitted light is measured. is commonly practiced. When performing such measurements, the ratio of the intensity of transmitted light to the intensity of irradiated light on the absorption hill has a predetermined relationship with the product of the concentration of the sample solution and the cell length (Lambert- (See Beer's law), the concentration of the sample solution can be determined based on the preset irradiation light intensity, cell length, and the measured transmitted light intensity.

FIG. 5 is a diagram showing the configuration of a spectrophotometer conventionally used when performing such measurements, in which output light from a light source (21) consisting of a tungsten lamp or the like is passed through a cut filter (22), a slit, etc. (23), mirror (24),
Diffraction grating (25), mirror (26) (27), slit (28), mirror (29) (3ON31N32H33)
, and a quartz window (34) so that the light is guided to an absorption cell (35) containing a sample solution, and the light transmitted through the absorption hill (35) is guided to a light intensity detector (37) through a quartz window (36). I have to. Further, the mirror (32) is formed to be rotatable, and in addition to the above-mentioned path, the mirror (32) is
33') and an absorption cell (35') containing a reference solution through a quartz window (34').
A path is formed in which the light transmitted through the quartz window (3B') is guided to the light intensity detection 'F &(37'), and the intensity of the transmitted light that has been absorbed by the sample solution and the reference solution can be measured. That's what I do.

<Problems to be solved by the invention> The spectrophotometer shown in FIG. 5 above has a complex optical system as a whole.
There is also the problem that a mechanism for driving the diffraction grating (25) and mirror (32) is required, and that proper TM absorbance analysis cannot be performed unless the relative positions of each part are set accurately. Therefore, the accuracy of spectrophotometric analysis is reduced due to the influence of disturbances such as vibrations.

In addition, there is the problem that the overall size of the device increases, and because the sample solution must be contained in an absorption cell and set in the optical path, there is the problem that it is difficult to automate spectrophotometric analysis. be.

<Object of the invention> This invention was made in view of the above problems,
It is an object of the present invention to provide a spectrophotometer that does not reduce measurement accuracy due to vibrations, etc., can easily automate spectrophotometric analysis, and can easily achieve simplification and miniaturization of the configuration. The purpose is

Means for Solving the Problems> In order to achieve the above object, the spectrophotometer of the present invention includes an optical waveguide layer formed on the root, and a predetermined optical path of the optical waveguide layer corresponding to the optical path of the incident light. at least one diffraction grating formed at a position and deflecting only light of a specific wavelength; a light intensity detection means formed corresponding to the optical path of the diffracted light deflected by the diffraction grating; and a light intensity detection means upstream of the light intensity detection means. A sample solution channel is provided on the side of the sample solution channel, which is formed so as to cross the middle of the diffracted light optical path.

However, the optical waveguide layer is preferably formed of a material having a higher refractive index than the adjacent material.

The diffraction grating preferably has periodic protrusions or four stripes formed on the surface of the optical waveguide layer at a predetermined position corresponding to the optical path of the incident light.

Furthermore, a light intensity detection means may also be formed on the terminal side of the incident light optical path, and a light intensity detection means may also be formed on the upstream side of the sample solution flow path in the diffracted light optical path. may have been done.

The light intensity detection means is preferably formed directly below the optical waveguide layer.

Effect> With the spectrophotometer with the above configuration, when light of a predetermined intensity is introduced into the optical waveguide layer while the sample solution is flowing through the sample solution flow path, a predetermined specific signal can be detected. Only the wavelength of light is deflected by the diffraction grating and guided into the sample solution flow path.

Then, the light is absorbed by the sample solution inside the sample solution flow path, and then the transmitted light intensity is detected by the light intensity detection means.

If the optical waveguide layer is formed of a material having a higher refractive index than an adjacent material, efficient propagation of light can be achieved.

Further, if the above-mentioned diffraction grating has periodic protrusions or grooves formed on the surface of the optical waveguide layer at a predetermined position corresponding to the optical path of the incident light, the diffraction grating can be easily formed. I can do it.

Furthermore, if a light intensity detection means is formed on the terminal side of the incident light optical path or on the upstream side of the sample solution flow path in the diffracted light optical path, measurement errors caused by fluctuations in the incident light intensity can be compensated for. can be done.

If the light intensity detection means is formed directly under the optical waveguide layer, the light intensity can be indirectly detected by the evanescent wave component of the light propagating through the optical waveguide layer.

<Example> Hereinafter, the present invention will be described in detail with reference to the accompanying drawings without showing examples.

FIG. 1 is a perspective view showing an embodiment of the spectrophotometer of the present invention, in which a 3iQ2 layer (2) is formed on the surface of a 3i substrate (1), and a 3iQ2 layer (2) is formed on the 3iQ2 layer (2) by a CVO method or the like. , S
An optical waveguide layer (3) made of i3N4 is formed, and a plurality of diffraction gratings (4) are formed at predetermined positions on the upper surface of the optical waveguide layer (3) at predetermined intervals. Then, at a predetermined position on the surface of the 3i substrate (1), 3
A region having a conductivity type different from that of the i-substrate (1) is formed to form a photodiode (5) as a light intensity detection section, and a sample solution flow path (6) for passing the sample solution. has been done.

As shown in FIG. 2, each of the above-mentioned diffraction gratings (4) is formed by forming a plurality of thin films (4a) on the surface of the optical waveguide layer (3) with a predetermined distance of 11 JAd between each other. wave layer (
The incident angle of the incident light (71) propagating through 3) is set to θ.

Therefore, the wavelength λ of the light diffracted by each diffraction grating (4) is expressed by λ=2ndSinθ (where n is a positive integer), and by changing the interval d,
The wavelength of the light diffracted by each diffraction grating (4) can be selected as appropriate.

Each of the above-mentioned diffraction gratings (4) is arranged so as to have a constant angle of incidence with respect to the incident light (sword).

The formation position of the photodiode (S) is a position corresponding to the optical path (8) of the diffracted light by each diffraction grating, and is located on the upstream side and downstream side of the sample solution flow path (6), respectively. Although the signal lead-out line from the photodiode (5) is not shown at all, it is assumed that it is taken out by normal electrode wiring.

Note that the upper gi1 port of the sample solution flow path (6) is an anode.
A glass plate ( 9 ) is covered by

If the spectrophotometer has the above configuration, the sample solution flow path (6)
While passing the sample solution through the optical waveguide layer (3
) through each diffraction grating (4) so that the incident angle to each diffraction grating (4) is θ.
4) The light of a specific wavelength is diffracted by the diffracted light optical path (
8) and is guided to the sample solution flow path (6), then passes through the diffracted light optical path (8) again and is emitted. The diffracted light passing through the diffracted light optical path (8) passes over the photodiode (5) before and after being absorbed by the sample solution, so that the light propagating through the optical waveguide layer (3) is directly irradiated. Although it is not necessarily the case, the evanescent wave 1
In response to iHt, it is possible to indirectly output a light intensity detection signal corresponding to the light intensity before and after absorption by the sample solution.

Therefore, based on the ratio of the light intensity detection signal from the photodiode (5) located on the downstream side of the sample solution flow path (6) and the light intensity detection signal from the photodiode (5) located on the upstream side, , accurate absorbance by sample solution can be obtained.

Moreover, since the above-mentioned absorbance is obtained corresponding to the diffracted light of the wavelength determined by each diffraction grating (4), the wavelength dependence of the absorbance can be obtained by combining the wavelengths.

In the sixth embodiment, as is clear from the above description, each element such as the diffraction grating (4) and the sample solution channel (6) is integrally constructed, so the optical system can be simplified and , can be miniaturized, and automation of spectrophotometric analysis can be easily achieved.

FIG. 3 is a diagram showing the configuration of the diffraction grating (4), and the difference from the configuration shown in FIG. 2 above is that multiple thin films (4a) are formed on the surface of the optical waveguide layer (3) instead. The only difference is that a plurality of grooves (4b) are formed on the surface of the optical waveguide layer (3).

Therefore, when forming the thin film (4a), it is necessary to form a thin film of a predetermined thickness by a conventionally known film forming method, and then perform etching to remove unnecessary portions. When forming the grooves (4b), it is sufficient to simply perform etching directly on the surface of the optical waveguide layer (3). In any of the above image configurations, the wavelength of the diffracted light can be appropriately selected by changing the distance d between the thin films (4a) and the distance d between the grooves (4b).

Furthermore, if the light intensity is detected by the photodiode (5) while the sample solution is continuously flowing,
Measurements can be made over time, and furthermore,
Measurements of many types of sample solutions can be easily automated.

FIG. 4 is a perspective view showing another embodiment. The difference from the embodiment shown in FIG. 1 is that the photodiode (5) on the upstream side of the sample solution flow path (6) is completely omitted, Photodiodes (5) downstream of all diffraction gratings (4)
It is only the points that formed the .

Therefore, in the case of this example, it is not possible to detect the light intensity before and after absorption by the sample solution for each diffracted light, but the light intensity on the downstream side of all diffraction gratings (4) cannot be detected. The incident light (
7), that is, a signal corresponding to the fluctuation of the light source (not shown), and the output signal from the photodiode (5) located downstream of the sample solution flow path (6). By correcting based on the above signal, it is possible to remove changes caused by fluctuations in the light source and obtain accurate absorbance due to the sample solution.

However, in this embodiment, the ratio of each wavelength component in the output light from the light source is determined, and the intensity of light of each wavelength can be calculated based on the output signal from the photodiode (5). There is.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and for example, a Qa As substrate may be used instead of the Si substrate (1), or a photodiode may be used instead of the photodiode (5).
- In addition to being able to form a transistor, it is also possible to use a glass substrate instead of the Si substrate (1) and to form a photoconductive thin film made of amorphous silicon or the like on the optical waveguide layer (3). Various other design changes can be made without changing the gist of the invention.

<Effects of the Invention> As described above, the present invention has an optical system for spectrophotometry that is
Since it is formed on a single substrate, the relative positional relationship between each part will not shift due to external imaging etc. and the measurement accuracy will not deteriorate, and the automation of absorbance analysis can be achieved in the cylinder. This has the unique effect of simplifying the configuration and reducing the size.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the spectrophotometer of the present invention, FIGS. 2 and 3 are longitudinal sectional views showing the configuration of a diffraction grating, and FIG. 4 is a perspective view showing another embodiment. FIG. 5 is a schematic diagram showing a conventional example. (1)...3i substrate, (3)...optical waveguide layer, (4)
...Diffraction grating, (4a)...Thin film, (4b)...
Concave groove, (5)...photodiode, (6)...sample solution flow path, (7)...incident light, (8)...diffracted light optical path

Claims (1)

[Claims] 1. Optical waveguide layer formed on the substrate and optical waveguide layer A predetermined position in the wave layer corresponding to the incident light path is formed to deflect only light of a specific wavelength at least one diffraction grating for diffraction; Compatible with diffracted light optical path deflected by grating A light intensity detection means formed by The diffracted light optical path is located upstream of the degree detection means. Sample solution flow formed to cross the middle Spectroscopic light characterized by comprising: meter. 2. The optical waveguide layer has a refractive index higher than that of the adjacent material. It is made of high quality material Spectrophotometry according to claim 1 Total. 3. The diffraction grating is the optical path of the incident light in the optical waveguide layer. periodic protrusions on the surface at a predetermined position corresponding to It is formed with stripes or grooves. The portion stated in claim 1 above Photometer. 4. Light intensity detection also on the terminal side of the incident light optical path The above claims in which means are formed The spectrophotometer according to item 1 below. 5. Upstream of the sample solution flow path in the diffracted light optical path A light intensity detection means is also formed on the side. Spectral light according to claim 1 above meter. 6. The light intensity detection means is located directly below the optical waveguide layer. Claim 1 as formed above Section 4, Section 5, or Section 5. Spectrophotometer.