JPWO2019234842A1 - Spectral measuring device and spectroscopic measuring method - Google Patents

Abstract

It suppresses the influence of scattering by the object, specifically, the fluctuation of the spectroscopic measurement value due to scattering. The spectroscopic measuring device is arranged between a light source unit that outputs an electromagnetic wave for irradiating an object and the light source unit and the object, and a beam that adjusts the beam diameter of the electromagnetic wave output from the light source unit. The diameter adjusting unit, the light receiving unit that receives the electromagnetic wave after the beam diameter adjustment incident through the object and generates a light receiving signal indicating the light receiving result, and the beam diameter adjusting unit based on the light receiving signal. The signal processing unit includes a signal processing unit that determines the beam diameter to be adjusted, and the signal processing unit has a maximum integrated intensity of the electromagnetic waves received by the light receiving unit or a predetermined range from the maximum. The maximum beam diameter is determined to be the optimum beam diameter, and the beam diameter adjusting unit adjusts the beam diameter of the electromagnetic wave output from the light source unit to the optimum beam diameter according to the control from the signal processing unit. It is characterized by doing.

Description

The present invention relates to a spectroscopic measuring device and a spectroscopic measuring method.

Conventionally, as a method for measuring a substance constituting an object to be measured (hereinafter, simply referred to as an object), spectroscopic measurement is known in which the object is irradiated with an electromagnetic wave having a predetermined wavelength and the scattered wave or transmitted wave is analyzed. There is. For example, when a drug such as a tablet is an object, spectroscopic measurement using an electromagnetic wave typified by an electromagnetic wave in the terahertz band (hereinafter referred to as a terahertz wave), which is less affected by irradiation of the object, is drawing attention.

For example, in the frequency band of 100 GHz (gigahertz) or more and 30 THz (terahertz) or less, there are many absorption peaks due to intermolecular vibration or intramolecular vibration. Therefore, by analyzing these absorption peaks, it is possible to discriminate the type of substance, distinguish the difference in binding state, and quantitatively measure the content concentration of each molecule constituting the drug of each molecule. It turns out to be possible.

For example, Patent Document 1 has "a terahertz wave generating portion that generates a terahertz wave and a transport surface on which a sample as an object to be inspected is placed, and the sample can be transported in the in-plane direction of the transport surface. A transport unit configured in the above, an irradiation direction changing portion for changing the irradiation direction of the terahertz wave emitted from the terahertz wave generating portion and irradiating the sample placed on the transport surface, and a transport portion mounted on the transport surface. A terahertz wave detection unit for detecting a terahertz wave transmitted or reflected by being irradiated on the placed sample is provided, and the irradiation direction changing unit changes the position of the terahertz wave generating unit to change the irradiation direction. It is stated that a sample inspection device that "changes" can suppress a decrease in detection accuracy due to scattering of terahertz waves.

Japanese Unexamined Patent Publication No. 2014-1793967

The sample inspection apparatus described in Patent Document 1 deals only with the scattering of electromagnetic waves due to the surface shape and arrangement state of the object, and does not consider the removal of the scattering by the particles constituting the object.

The present invention has been made in view of such a situation, and makes it possible to suppress the influence of scattering due to the shape of the particles or the object constituting the object, specifically, the fluctuation of the spectroscopic measurement value due to the scattering. The purpose is.

The present application includes a plurality of means for solving at least a part of the above problems, and examples thereof are as follows. In order to solve the above problems, the spectroscopic measuring device according to one aspect of the present invention is arranged between a light source unit that outputs an electromagnetic wave for irradiating an object and the light source unit and the object, and the light source. A beam diameter adjusting unit that adjusts the beam diameter of the electromagnetic wave output from the unit, and a light receiving unit that receives the electromagnetic wave after adjusting the beam diameter incident through the object and generates a light receiving signal indicating the light receiving result. And a signal processing unit that determines the beam diameter to be adjusted by the beam diameter adjusting unit based on the received light signal, and the signal processing unit receives light received by the light receiving unit based on the received signal. The optimum beam diameter is determined by the maximum integrated intensity of the electromagnetic wave or the maximum beam diameter within a predetermined range from the maximum, and the beam diameter adjusting unit is output from the light source unit under control from the signal processing unit. The beam diameter of the electromagnetic wave is adjusted to the optimum beam diameter.

According to the present invention, it is possible to suppress the influence of scattering due to the particles constituting the object or the shape of the object, specifically, the fluctuation of the spectroscopic measurement value due to the scattering.

Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.

It is a block diagram which shows the structural example of the spectroscopic measuring apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the example of the detected light intensity distribution. FIG. 2A is a diagram when the beam diameter is 1 mm. FIG. 2B is a diagram when the beam diameter is 10 mm. It is a figure which shows the correspondence relationship between a beam diameter and an integral intensity. It is a figure which shows the 1st structural example of the beam diameter adjustment part. It is a figure which shows the 2nd structural example of the beam diameter adjustment part. It is a figure for demonstrating the relationship between the parameter of a beam diameter adjustment part, and a beam diameter. It is a flowchart explaining an example of the beam diameter adjustment processing by the spectroscopic measuring apparatus which concerns on 1st Embodiment of this invention. It is a flowchart explaining an example of the measurement process for adjustment. It is a block diagram which shows the structural example of the spectroscopic measuring apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the 1st structural example of a wavelength conversion part. It is a block diagram which shows the 2nd structural example of the wavelength conversion part. It is a block diagram which shows the 3rd structural example of the wavelength conversion part. It is a block diagram which shows the structural example of the spectroscopic measuring apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows an example of the table which shows the correspondence relation between the object and the optimum beam diameter. It is a block diagram which shows the structural example of the spectroscopic measuring apparatus which concerns on 4th Embodiment of this invention. It is a figure which shows the specific example of the object measurement part. FIG. 16A is a diagram showing an imaging device as a specific example. FIG. 16B is a diagram showing a measuring instrument as a specific example. It is a block diagram which shows the structural example of the spectroscopic measuring apparatus which concerns on 5th Embodiment of this invention. It is a block diagram which shows the structural example of the imaging part. It is a flowchart explaining an example of the beam diameter adjustment processing by the spectroscopic measuring apparatus which concerns on 5th Embodiment of this invention. It is a block diagram which shows the structural example of the spectroscopic measuring apparatus which concerns on 6th Embodiment of this invention. It is a figure for demonstrating the coping method when an object is small.

Hereinafter, a plurality of embodiments according to the present invention will be described with reference to the drawings. In addition, in all the drawings for explaining each embodiment, in principle, the same members are designated by the same reference numerals, and the repeated description thereof will be omitted. Further, in the following embodiments, it goes without saying that the components (including element steps and the like) are not necessarily essential unless otherwise specified or clearly considered to be essential in principle. No. In addition, when saying "consisting of A", "consisting of A", "having A", and "including A", other elements are excluded unless it is clearly stated that it is only that element. It goes without saying that it is not something to do. Similarly, in the following embodiments, when the shape, positional relationship, etc. of a component or the like is referred to, the shape, etc. It shall include those similar to or similar to.

<Structure example of the spectroscopic measuring apparatus according to the embodiment of the present invention>
The spectroscopic measuring apparatus according to the embodiment of the present invention targets a drug such as a tablet, irradiates the object with a terahertz wave, receives and analyzes the terahertz wave that has passed through the object, and analyzes a substance constituting the object. It is a judgment. The object is not limited to pharmaceutical products and is arbitrary.

Further, the spectroscopic measuring device may irradiate the object with an electromagnetic wave other than the terahertz wave. Specifically, for example, the object may be irradiated with infrared light, an electromagnetic wave having a wavelength shorter than the infrared light, a millimeter wave, or an electromagnetic wave having a wavelength longer than the millimeter wave.

<Structure example of the spectroscopic measuring apparatus according to the first embodiment of the present invention>
FIG. 1 shows a configuration example of the spectroscopic measuring apparatus according to the first embodiment of the present invention. The spectroscopic measurement device 100 includes a light source unit 11, a beam diameter adjusting unit 12, a light receiving unit 13, and a signal processing unit 14.

The light source unit 11 outputs the terahertz wave L1 to the beam diameter adjusting unit 12. The beam diameter adjusting unit 12 adjusts the beam diameter (full width at half maximum) of the terahertz wave L1 output from the light source unit 11 in the range of the minimum value M1 to the maximum value M2 according to the control from the signal processing unit 14, and the beam diameter D The object 1 is irradiated with the terahertz wave L2 of (M1 ≦ D ≦ M2).

The light receiving unit 13 receives the terahertz wave L3 that has passed through the object 1, that is, the terahertz wave L2 is absorbed or scattered by the object 1 (a substance constituting the object 1). Further, the light receiving unit 13 acquires a two-dimensional image of the electric field amplitude distribution or the intensity distribution of the terahertz wave L3 on the light receiving surface. Further, the light receiving unit 13 outputs a two-dimensional image of the electric field amplitude distribution or the intensity distribution, or the integrated intensity obtained by adding the intensity distribution to the signal processing unit 14 as a light receiving signal. The light receiving unit 13 includes, for example, a THz camera, a Schottky diode, a pyrometer, a bolometer, an antenna array, and the like.

When a two-dimensional image of the electric field amplitude distribution of the terahertz wave L3 is input from the light receiving unit 13 as a light receiving signal, the signal processing unit 14 converts the value into an intensity distribution by squaring and then adds and integrates. Gain strength. When a two-dimensional image of the intensity distribution of the terahertz wave L3 is input from the light receiving unit 13 as a light receiving signal, the signal processing unit 14 adds the values to obtain the integrated intensity.

The signal processing unit 14 determines the optimum beam diameter, which is the optimum value of the beam diameter D of the terahertz wave L2 output from the beam diameter adjusting unit 12, based on the integrated intensity of the terahertz wave L3 in the light receiving unit 13.

Further, the signal processing unit 14 determines the type of the substance constituting the object 1 based on the integrated intensity of the terahertz wave L3 in the light receiving unit 13, distinguishes the difference in the binding state, and constitutes a drug for each molecule. Quantitatively measure the content concentration of each molecule.

Here, the relationship between the beam diameter D of the terahertz wave L2 irradiating the object 1 and the influence of scattering will be described.

FIG. 2 shows an example of the intensity distribution of the terahertz wave L3 received by the light receiving unit 13. FIG. 2A shows a beam diameter D of 1 mm, and FIG. 2B shows a beam diameter D of 10 mm. Is the case. In both FIGS. (A) and (B), the distance between the object 1 and the light receiving portion 13 was set to 100 mm.

As shown in FIGS. (A) and (B), large spots due to scattering in the object 1 occur in the intensity distribution of the terahertz wave L3 received by the light receiving unit 13.

In the case of FIG. 3B, the size of the spots of the intensity distribution due to scattering is smaller than that in the case of FIG. Therefore, when the light receiving unit 13 averages the intensity of the entire terahertz wave within the range shown in FIGS. (A) and (B) to calculate the light receiving intensity value of the terahertz wave L3, the case of FIG. That is, the larger the beam diameter D, the more uniform the value can be obtained by averaging the entire intensity distribution of the terahertz wave L3 including a plurality of spots. Therefore, it can be said that the larger the beam diameter D, the smaller the variation in the measured value caused by the variation in the size and number of spots caused by scattering. However, when the beam diameter D of the terahertz wave L2 is larger than the light receiving range of the light receiving unit 13, the ratio of the amount of light that can be received by the light receiving unit 13 to the total light amount of the terahertz wave L3 decreases, so that the SN ratio decreases. .. Therefore, it is important to appropriately adjust the beam diameter D of the terahertz wave L2 to irradiate the object 1. If the beam diameter D is appropriately adjusted, it is possible to reduce the influence of scattering and suppress the decrease in the SN ratio.

FIG. 3 shows an example of the correspondence between the beam diameter D and the integrated intensity. As shown in the figure, when the beam diameter D is changed from the minimum value M1 to the maximum value M2, the integrated intensity becomes maximum when the beam diameter D is from M1 to M3. Further, as the beam diameter D changes from M3 to M2, the integrated intensity gradually decreases. Therefore, in the signal processing unit 14, M3, which can obtain the maximum integrated intensity and has the maximum beam diameter D, is determined as the optimum beam diameter.

Next, a method of adjusting the beam diameter D in the beam diameter adjusting unit 12 will be specifically described.

FIG. 4 shows a first configuration example of the beam diameter adjusting unit 12. The first configuration example includes a lens 121 and a lens driving unit 122 that drives the lens 121.

In the first configuration example, the lens driving unit 122 adjusts the beam diameter D by moving the lens 121 closer to or further away from the object 1 according to the control from the signal processing unit 14. can do.

FIG. 5 shows a second configuration example of the beam diameter adjusting unit 12. The second configuration example includes a lens 121 and an object driving unit 123.

In the second configuration example, the object driving unit 123 moves the object 1 closer to or further from the lens 121 according to the control from the signal processing unit 14, thereby causing the beam diameter D to be changed. Can be adjusted.

It should be noted that the first and second configuration examples described above may be combined so that both the lens 121 and the object 1 can be brought closer to or further away from each other. Further, the position of the light receiving unit 13 and the light receiving sensitivity may be adjusted according to the change of the beam diameter D.

Further, the method of adjusting the beam diameter D is not limited to the above-mentioned example, and for example, a beam expander using two or more lenses, a diffuser plate, or the like may be used.

Next, FIG. 6 is a diagram for explaining the relationship between the beam diameter D and the lens 121. The focal length f1 of the lens 121 and the beam diameter d1 of the terahertz wave L1 incident on the lens 121 can be obtained in advance. Further, the initial value t0 of the distance between the lens 121 and the object 1 can also be obtained. Further, if the amount of change in the distance between the lens 121 and the object 1 by the lens driving unit 122 or the object driving unit 123 is acquired as dt, the actual distance t between the lens 121 and the object 1 is t = t0 + dt. You can ask. Using f1, d1, t obtained as described above, the beam diameter D can be calculated according to the following equation (1).
D = d1 (t-f1) / f1 ... (1)

Next, FIG. 7 is a flowchart illustrating an example of the beam diameter adjusting process by the spectroscopic measuring device 100.

The beam diameter adjusting process is executed, for example, when the spectroscopic measuring device 100 is started up, when the object 1 is changed, or the like.

First, the spectroscopic measurement device 100 executes an adjustment measurement process for determining the optimum value (optimum beam diameter) of the beam diameter D of the terahertz wave L2 to irradiate the object 1 (step S1).

FIG. 8 is a flowchart detailing an example of the adjustment measurement process. First, the signal processing unit 14 sets the measurement range [M1, M2] of the beam diameter D and the measurement interval dM (change amount of the beam diameter D) with respect to the beam diameter adjusting unit 12. Further, the signal processing unit 14 calculates the number of measurements N by adding 1 to the result of dividing the measurement range [M1, M2] by the measurement interval dM (step S11).

Next, the signal processing unit 14 sets the beam diameter D of the terahertz wave L2 emitted from the beam diameter adjusting unit 12 to the minimum value M1 and notifies the beam diameter adjusting unit 12 (step S12).

In response to this notification, the beam diameter adjusting unit 12 adjusts the beam diameter of the terahertz wave L1 from the light source unit 11 to the minimum value M1, and irradiates the object 1 as the terahertz wave L2. Then, the light receiving unit 13 receives the terahertz wave L3 that has passed through the object 1, calculates the integrated intensity thereof, and outputs the terahertz wave L3 to the signal processing unit 14. The signal processing unit 14 stores the integrated intensity input from the light receiving unit 13 in association with the current beam diameter (step S13).

Next, the signal processing unit 14 determines whether or not the current number of measurements is the Nth (step S14). When it is determined that the current number of measurements is not the Nth (NO in step S14), the signal processing unit 14 increases the current beam diameter D by the measurement interval dM and notifies the beam diameter adjusting unit 12 (step S15). ). After that, the process returns to step S13, and the processes of steps S13 to S15 are repeated.

Then, when the signal processing unit 14 determines that the current number of measurements is the Nth time (YES in step S14), the maximum integrated intensity is maximized based on the integrated intensity and the beam diameter stored in association with each other. The beam diameter M3 of is determined to be the optimum beam diameter (step S16).

In step S16, the control accuracy of the lens driving unit 122 (FIG. 4) and the object driving unit 123 (FIG. 5) is taken into consideration, and the integrated intensity is optimized by allowing a variation of ± 20% with respect to the maximum value. The beam diameter M3 may be determined.

After determining the optimum beam diameter M3 in this way, the process proceeds to step S2 in FIG. Next, the signal processing unit 14 notifies the beam diameter adjusting unit 12 of the optimum beam diameter M3 (step S2).

In response to this notification, the beam diameter adjusting unit 12 adjusts the beam diameter of the terahertz wave L1 from the light source unit 11 to the optimum beam diameter M3, and irradiates the object 1 as the terahertz wave L2 (step S3). This completes the beam diameter adjustment process. After that, the terahertz wave L2 having the optimum beam diameter M3 is applied to the object 1, and the signal processing unit 14 determines the type of the substance constituting the object 1 and distinguishes the difference in the bonding state. , The content concentration of each molecule constituting the drug of each molecule is quantitatively measured.

In the adjustment measurement process of step S1 described above, the beam diameter D of the terahertz wave L2 was gradually increased from the minimum value M1 to the maximum value M2, but the beam diameter D of the terahertz wave L2 was increased from the maximum value M2 to the minimum value. It may be gradually reduced to M1. Further, in the signal processing unit 14, the integrated intensity for N times and the beam diameter D are stored in association with each other, but the difference from the previous integrated intensity and the beam diameter D are stored in association with each other. May be good.

Further, when the same object 1 is continuously measured, the adjustment measurement process in step S1 may be omitted.

As described above, according to the spectroscopic measuring device 100, since the terahertz wave L2 having the optimum beam diameter M3 is irradiated to the object 1, it is possible to reduce or eliminate the influence of scattering caused by the substance constituting the object 1. it can. Further, since most of the light rays of the terahertz wave L2 can be applied to the object 1, the SN ratio can be kept large and the spectroscopic measurement sensitivity can be improved.

<Structure example of the spectroscopic measuring apparatus according to the second embodiment of the present invention>
Next, FIG. 9 shows a configuration example of the spectroscopic measuring apparatus according to the second embodiment of the present invention. The spectroscopic measurement device 200 replaces the light receiving unit 13 in the spectroscopic measurement device 100 (FIG. 1) with the light receiving unit 20. Among the components of the spectroscopic measurement device 200, those common to the components of the spectroscopic measurement device 100 are designated by the same reference numerals, and thus the description thereof will be omitted as appropriate.

The light receiving unit 20 includes a wavelength conversion unit 201 and a converted wave light receiving unit 202. The wavelength conversion unit 201 converts the wavelength of the terahertz wave L3 that has passed through the object 1, and irradiates the conversion wave light receiving unit 202 with the conversion wave LC3 obtained as a result. The conversion wave light receiving unit 202 receives the conversion wave LC3 and outputs a value (integrated intensity) obtained by adding the electric field amplitude distribution, the intensity distribution, or the intensity distribution in the beam plane of the received conversion wave LC3 to the signal processing unit 14. .. The integrated intensity and the like output by the converted wave receiving unit 202 reflect the integrated intensity and the like in the beam plane of the terahertz wave L3.

For example, the wavelength conversion unit 201 converts the wavelength of the terahertz wave L3 into the conversion wave LC3 in the IR (infrared) optical band. In this case, the converted wave receiving unit 202 may have light receiving sensitivity with respect to the converted wave LC3 which is IR light. In general, devices that are sensitive to IR light are
It is cheaper and has higher light-receiving sensitivity than a device having light-receiving sensitivity to electromagnetic waves in the terahertz band. The device conversion wave light receiving unit 202 having a light receiving sensitivity to IR light can be realized by, for example, a PD (Photo Diode), a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary MOS) image sensor, or the like.

Next, FIG. 10 shows a first configuration example of the wavelength conversion unit 201. The first configuration example includes a probe light source unit 31, a beam diameter adjusting unit 32, a polarizer 33, a beam splitter 34, a nonlinear optical crystal 35, a compensator 36, and a polarizer 37. The first configuration example utilizes the Pockels effect of the nonlinear optical crystal 35.

The probe light source unit 31 irradiates the beam diameter adjusting unit 32 with, for example, IR light as the probe light LC1. The beam diameter adjusting unit 32 adjusts (enlarges or reduces) the beam diameter of the probe light LC1 and emits the probe light LC2 having the beam diameter DP to the polarizer 33. The polarizer 33 polarizes the probe light LC2 and emits it to the beam splitter 34. The beam splitter 34 reflects the polarized probe light LC2 in the direction of the nonlinear optical crystal 35. Further, the beam splitter 34 transmits the conversion wave LC3 from the nonlinear optical crystal 35.

The nonlinear optical crystal 35 includes, for example, an electro-optical crystal, and is composed of, for example, ZnTe, GaAs, LiNbO3, GaP, DAST, and the like. The nonlinear optical crystal 35 produces a nonlinear optical effect when the terahertz wave L3 and the probe light LC2 are incident on each other. Examples of the nonlinear optical effect include the Pockels effect and parametric generation. In the first configuration example, the Pockels effect is utilized.

The nonlinear optical crystal 35 can convert the terahertz wave L3 into a conversion wave (IR light) LC3 having the same wavelength as the probe light LC2 by the Pockels effect. The converted wave LC3 converted by the nonlinear optical crystal 35 passes through the beam splitter 34 and is incident on the compensator 36 and the polarizer 37.

The compensator 36 and the polarizer 37 detect a change in the polarization state of the converted wave LC3. The conversion wave light receiving unit 202 receives the converted wave LC3 incident through the compensator 36 and the polarizer 37, detects the intensity distribution or the integrated intensity in the beam plane, and outputs the signal processing unit 14.

In the first configuration example, the beam diameter of the probe light LC1 from the probe light source unit 31 is adjusted by the beam diameter adjusting unit 32, and is output to the beam splitter 34 as the probe light LC2 of the beam diameter DP via the splitter 33. Then, it is reflected by the beam splitter 34 and incident on the nonlinear optical crystal 35.

A terahertz wave L3 is also incident on the nonlinear optical crystal 35, and the terahertz wave L3 is converted into a conversion wave (IR light) LC3 by the Pockels effect. The converted wave LC3 converted by the nonlinear optical crystal 35 is incident on the converted wave receiving unit 202 via the beam splitter 34, the compensator 36, and the polarizer 37.

When the converted wave receiving unit 202 detects the intensity distribution or the integrated intensity of the converted wave LC3, the transmission axes of the polarizer 33 and the polarizer 37 are orthogonal to each other, and the fast axis or the slow axis of the compensator 36 is polarized. A method of matching with the transmission axis of the child 33 can be used.

When the intensity distribution of the converted wave LC3 is detected by the converted wave receiving unit 202, the signal processing unit 14 converts the value of the intensity of the converted wave LC3 of each pixel into the intensity of the terahertz wave L3 and adds them. The integrated intensity of the terahertz wave L3 is calculated.

Alternatively, the electric field amplitude distribution of the terahertz wave L3 is obtained by making the transmission axes of the polarizer 33 and the polarizer 37 orthogonal to each other and making the speed axis or the slow axis of the compensator 36 an angle larger than 0 degrees from the transmission axis of the polarizer 33. It may be measured, squared by the signal processing unit 14, and then added to obtain the integrated intensity of the terahertz wave L3.

Further, a Wollaston prism or a polarization-dependent beam splitter is arranged instead of the polarizer 37 to divide the converted wave LC3 into two optical paths, the converted wave receiving unit 202 is used as a balance detector, and the intensity difference of the converted wave LC3 of each optical path. The detection efficiency may be improved by detecting the above.

Next, FIG. 11 shows a second configuration example of the wavelength conversion unit 201. The components common to the second configuration example and the first configuration example are designated by the same reference numerals, and thus the description thereof will be omitted as appropriate.

The second configuration example includes a probe light source unit 31, a beam diameter adjusting unit 32, a polarizer 33, a wavelength selection mirror 39, a nonlinear optical crystal 35, a compensator 36, and a polarizer 37. The second configuration example utilizes the Pockels effect of the nonlinear optical crystal 35 as in the first configuration example.

The wavelength selection mirror 39 has a property of transmitting terahertz waves and reflecting IR light. Therefore, the wavelength selection mirror 39 reflects the probe light LC2 incident through the polarizer 33 in the direction of the nonlinear optical crystal 35, and transmits the terahertz wave L3 incident through the object 1. The wavelength selection mirror 39 is composed of an optical element such as a pellicle or a silicon plate.

The nonlinear optical crystal 35 converts the terahertz wave L3 into a conversion wave (IR light) LC3 having the same wavelength as the probe light LC2 by the Pockels effect. The converted wave LC3 converted by the nonlinear optical crystal 35 is incident on the converted wave receiving unit 202 via the compensator 36 and the polarizer 37.

In the second configuration example, the beam diameter of the probe light LC1 from the probe light source unit 31 is adjusted by the beam diameter adjusting unit 32, and the wavelength selection mirror 39 is used as the probe light LC2 having the beam diameter DP via the polarizer 33. It is incident, reflected by the wavelength selection mirror 39, and incident on the non-linear optical crystal 35.

A terahertz wave L3 transmitted through the wavelength selection mirror 39 is also incident on the nonlinear optical crystal 35, and the terahertz wave L3 is converted into a conversion wave (IR light) LC3 by the Pockels effect. The converted wave LC3 converted by the nonlinear optical crystal 35 is incident on the converted wave receiving unit 202 via the compensator 36 and the polarizer 37.

Next, FIG. 12 shows a third configuration example of the wavelength conversion unit 201. The components common to the third configuration example and the first configuration example are designated by the same reference numerals, and thus the description thereof will be omitted as appropriate.

The third configuration example includes a probe light source unit 31, a beam diameter adjusting unit 32, and a nonlinear optical crystal 35. The third configuration example utilizes the parametric generation by the nonlinear optical crystal 35. It is assumed that the frequency ω1 of the probe light LC1 irradiated by the probe light source unit 31 in the third configuration example has the relationship of the frequency ω2 of the terahertz wave L3 and the frequency ω3 of the converted wave LC3 with the following equation (2). ..
ω3 = ω1-ω2 ・ ・ ・ (2)

In the third configuration example, the beam diameter of the probe light LC1 from the probe light source unit 31 is adjusted by the beam diameter adjusting unit 32, and is incident on the nonlinear optical crystal 35 as the probe light LC2 having the beam diameter DP.

A terahertz wave L3 that has passed through the object 1 is also incident on the nonlinear optical crystal 35, and is converted into a converted wave LC3 by parametric generation. The converted wave LC3 converted by the nonlinear optical crystal 35 is incident on the converted wave receiving unit 202.

According to the spectroscopic measurement device 200 provided with the wavelength conversion unit 201 that employs any of the first to third configuration examples described above, the light receiving unit 13 corresponding to the terahertz band is cheaper and has higher light receiving sensitivity or higher conversion wave light receiving. Part 202 can be used. Therefore, it is possible to reduce the cost and improve the detection sensitivity as compared with the spectroscopic measuring device 100. In addition, it is possible to reduce or eliminate the influence of scattering from the measurement results.

<Structure example of the spectroscopic measuring apparatus according to the third embodiment of the present invention>
Next, FIG. 13 shows a configuration example of the spectroscopic measuring device according to the third embodiment of the present invention. The spectroscopic measurement device 300 is obtained by adding an input unit 15 and a storage unit 16 to the spectroscopic measurement device 100 (FIG. 1). Among the components of the spectroscopic measurement device 300, those common to the components of the spectroscopic measurement device 100 are designated by the same reference numerals, and thus the description thereof will be omitted as appropriate.

The input unit 15 receives identification information (name, identification number, etc.) for identifying the object 1 from the user and notifies the signal processing unit 14. Further, the input unit 15 receives the table 161 (FIG. 14) stored in the storage unit 16 from the user and outputs it to the signal processing unit 14. The input table 161 is recorded in the storage unit 16 by the signal processing unit 14. Further, the input unit 15 receives the update information for the table 161 stored in the storage unit 16 from the user and notifies the signal processing unit 14. The signal processing unit 14 updates the table 161 stored in the storage unit 16 based on the input update information. The storage unit 16 stores the table 161.

FIG. 14 shows an example of the table 161. In the table 161, the identification information (name in the case of the figure), the size (diameter in the case of the figure), and the optimum beam diameter of the object 1 are recorded in association with each other.

The signal processing unit 14 in the spectroscopic measurement device 300 corresponds to the identification information of the object 1 input from the user to the input unit 15 by referring to the table 161 stored in the storage unit 16 at the time of startup. The optimum beam diameter to be used is specified and notified to the beam diameter adjusting unit 12.

Therefore, if the spectroscopic measurement device 300 has a record corresponding to the identification information of the object 1 input by the user in the table 161, the adjustment measurement process (FIG. 8) for determining the optimum beam diameter is unnecessary. , The spectroscopic measurement can be started more quickly than the spectroscopic measurement device 100.

When there is no record in the table 161 corresponding to the identification information of the object 1 input by the user, the spectroscopic measurement device 300 executes the adjustment measurement process (FIG. 8) in the same manner as the spectroscopic measurement device 100. Can be done.

Further, the spectroscopic measurement apparatus 300 executes the adjustment measurement process to determine the optimum beam diameter for the current object 1, and then adds the identification information of the object 1 and the optimum beam diameter to the table 161. It may be updated automatically.

Further, on the table 161, instead of the optimum beam diameter or in addition to the optimum beam diameter, the adjustment value in the beam diameter adjusting unit 12 for adjusting to the optimum beam diameter (lens by the lens driving unit 122 (FIG. 4)). The moving position of 121, the moving position of the object 1 by the object driving unit 123 (FIG. 5), and the like may be recorded. In this case, the signal processing unit 14 is optimally corresponding to the identification information of the object 1 input by the user to the input unit 15 by referring to the table 161 stored in the storage unit 16 at the time of startup. The beam diameter may be specified, the adjustment value in the beam diameter adjusting unit 12 for adjusting to the optimum beam diameter may be acquired, and the beam diameter adjusting unit 12 may be notified.

<Structure example of the spectroscopic measuring apparatus according to the fourth embodiment of the present invention>
Next, FIG. 15 shows a configuration example of the spectroscopic measuring device according to the fourth embodiment of the present invention. The spectroscopic measurement device 400 is an object measurement unit 17 added to the spectroscopic measurement device 100 (FIG. 1). Among the components of the spectroscopic measurement device 400, those common to the components of the spectroscopic measurement device 100 are designated by the same reference numerals, and thus the description thereof will be omitted as appropriate.

The object measuring unit 17 measures the size and shape of the object 1, or acquires information capable of measuring the size and shape of the object 1 and outputs the information to the signal processing unit 14. The signal processing unit 14 in the fourth configuration example determines the optimum beam diameter based on the notification from the object measuring unit 17 and controls the beam diameter adjusting unit 12.

FIG. 16 shows a specific example of the object measuring unit 17.

FIG. (A) shows a case where the object measuring unit 17 is realized by the image pickup apparatus 171. The image pickup apparatus 171 takes an image of the object 1 and outputs an image obtained as a result to the signal processing unit 14. The signal processing unit 14 calculates the size of the object 1 based on the distance between the image pickup device 171 and the object 1 acquired in advance and the image of the object 1, determines the optimum beam diameter, and determines the beam diameter. Controls the adjusting unit 12.

FIG. (B) shows a case where the object measuring unit 17 is realized by the measuring instrument 172. The measuring instrument 172 is, for example, an automatically driven digital caliper, a digital micrometer, a distance measuring sensor using a laser, or the like.

The measuring instrument 172 measures the size of the object 1 and notifies the signal processing unit 14 of the measurement result. The signal processing unit 14 determines the optimum beam diameter and controls the beam diameter adjusting unit 12 based on the distance between the image pickup device 171 and the object 1 acquired in advance and the measurement result of the object 1.

According to the spectroscopic measurement device 400 described above, since the optimum beam diameter is determined based on the measurement results of the size and shape of the object 1, improvement in spectroscopic measurement sensitivity can be expected.

<Structure example of the spectroscopic measuring apparatus according to the fifth embodiment of the present invention>
Next, FIG. 17 shows a configuration example of the spectroscopic measuring device according to the fifth embodiment of the present invention. The spectroscopic measurement device 500 is obtained by adding an imaging unit 18 between the object 1 and the light receiving unit 13 with respect to the spectroscopic measurement device 100 (FIG. 1). Among the components of the spectroscopic measurement device 500, those that are common to the components of the spectroscopic measurement device 100 are designated by the same reference numerals, and thus the description thereof will be omitted as appropriate.

The imaging unit 18 adjusts the beam diameter of the terahertz wave L3 according to the size of the light receiving surface of the light receiving unit 13. Specifically, the beam diameter of the terahertz wave L3 is adjusted so that the entire terahertz wave L3 transmitted through the object 1 occupies the maximum size without protruding from the light receiving surface of the light receiving unit 13.

FIG. 18 shows a configuration example of the imaging unit 18. The imaging unit 18 has a biconvex lens 181 (FIG. 18) that moves between the object 1 and the light receiving unit 13 under the control of the signal processing unit 14. The biconvex lens 181 may be fixed and the light receiving surface of the light receiving unit 13 may be moved.

The relationship between the biconvex lens 181 forming the image forming portion 18 and the beam diameter of the terahertz wave L3 will be described with reference to FIG.

As shown in the figure, the distance from the object 1 to the biconvex lens 181 is f2, the distance from the biconvex lens 181 to the light receiving surface of the light receiving unit 13 is f3, and the focal length of the biconvex lens 181 is fd (not shown). If so, the object 1, the biconvex lens 181 and the light receiving portion 13 are arranged so as to satisfy the following equation (3).
f2 + f3> fd ・ ・ ・ (3)

In this case, the beam diameter Dd on the light receiving surface of the light receiving unit 13 is as shown in the following equation (4).
Dd = Df3 / f2 ... (4)

The imaging unit 18 may be configured by a lens other than the biconvex lens 181. For example, two or more lenses may be used to reduce aberrations. Alternatively, a cylindrical lens may be adopted so that the beam diameter of the terahertz wave L3 is changed to a vertically and horizontally asymmetrical shape.

Next, FIG. 19 is a flowchart illustrating a beam diameter adjusting process by the spectroscopic measuring device 500 provided with the imaging unit 18. The beam diameter adjusting process is obtained by adding the process of step S4 to the beam diameter adjusting process (FIG. 7) by the spectroscopic measuring device 100 (FIG. 1).

That is, in the beam diameter adjustment process by the spectroscopic measurement device 500, the signal processing unit 14 determines the optimum beam diameter M3 in the adjustment measurement process in step S1 as in the spectroscopic measurement device 100. Next, in step S2, the signal processing unit 14 notifies the beam diameter adjusting unit 12 of the optimum beam diameter M3. In response to this notification, in step S3, the beam diameter adjusting unit 12 adjusts the beam diameter of the terahertz wave L1 from the light source unit 11 to the optimum beam diameter M3, and irradiates the object 1 as the terahertz wave L2.

Next, in step S4, the signal processing unit 14 determines the position of the biconvex lens 181 based on the optimum beam diameter M3 and the size of the light receiving surface of the light receiving unit 13. Then, the imaging unit 18 adjusts the beam diameter Dd by moving the biconvex lens 181 according to the control from the signal processing unit 14. This completes the beam diameter adjustment process by the spectroscopic measuring device 500.

According to the spectroscopic measurement device 500 described above, since the imaging unit 18 adjusts the beam diameter Dd of the terahertz wave L3 on the light receiving surface of the light receiving unit 13, the light receiving unit 13 can efficiently receive the terahertz wave L3. Therefore, it is possible to further improve the spectral measurement sensitivity while reducing or eliminating the influence of scattering.

<Structure example of the spectroscopic measuring apparatus according to the sixth embodiment of the present invention>
Next, FIG. 20 shows a configuration example of the spectroscopic measuring device according to the sixth embodiment of the present invention. The spectroscopic measurement device 600 is obtained by adding a beam shape changing section 19 between the beam diameter adjusting section 12 and the object 1 with respect to the spectroscopic measuring device 100 (FIG. 1). Among the components of the spectroscopic measurement device 600, those common to the components of the spectroscopic measurement device 100 are designated by the same reference numerals, and thus the description thereof will be omitted as appropriate.

The signal processing unit 14 in the spectroscopic measurement device 600 determines the size and shape of the object 1 based on the received signal from the light receiving unit 13, and controls the beam shape changing unit 19 based on the determination result.

The beam shape changing unit 19 matches the beam shape of the terahertz wave L2 having the beam diameter D output from the beam diameter adjusting unit 12 with the shape of the object 1 according to the control from the signal processing unit 14, for example, an elliptical shape. , Triangle, quadrangle, etc. The beam shape changing unit 19 can be realized by, for example, a MEMS (Micro Electro Mechanical Systems), an SLM (Spatial Light Modulator), a mask obtained by cutting out a metal plate into an arbitrary shape, or the like.

According to the spectroscopic measuring device 600, since the terahertz wave L2 whose shape is changed according to the object 1 is irradiated to the object 1, the cross-sectional shape of the object 1 is not circular but oval, square, or other shape. Even if there is, the light beam of the terahertz wave L2 can be efficiently irradiated to the object 1, and the spectroscopic measurement sensitivity can be further improved while reducing or eliminating the influence of scattering.

An object measuring unit 17 (FIG. 15) is added to the spectroscopic measuring device 600, and the signal processing unit 14 identifies the shape of the object 1 based on the measurement result by the object measuring unit 17, and the identification result is obtained. The beam shape changing unit 19 may be controlled based on the above.

<What to do when the size of object 1 is small>
By the way, when the size of the object 1 is smaller than the minimum value M1 of the beam diameter that can be adjusted by the beam diameter adjusting unit 12, the spectroscopic measuring devices 100 to 600 described above suppress the influence of scattering by the object 1. Can't. In such a case, a cluster (aggregate) composed of a plurality of objects 1 may be formed, and the cluster may be used as the object 1 for spectroscopic measurement.

FIG. 21 shows an example of a cluster of the object 1. FIG. 3A is an example in which a circular object 1 is spread in a plane to form a cluster 101. FIG. 3B is an example in which a rectangular object 1 is laid out in a plane to form a cluster 102. FIG. 3C is an example in which a circular object 1 is three-dimensionally spread to form a cluster 103.

The shape of the object 1, the shape of the clusters 101 to 103, the laying method, and the density are not limited to the illustrated examples. However, from the viewpoint of improving sensitivity, it is desirable that the distance between the objects constituting the clusters 101 to 103 is as small as possible.

As described above, if the object 1 having a smaller size than the minimum value M1 of the beam diameter is clustered and spectroscopically measured, the influence of scattering by the object 1 can be reduced or eliminated.

<Application example>
The present invention can also be applied to measurements other than spectroscopic measurements. For example, it can be applied to CT scans using terahertz waves, imaging scanning using the absorption rate / reflectance of terahertz waves, and other measurements that are affected by fluctuations in measured values and deterioration of measurement accuracy due to scattered light.

It should be noted that the effects described in the present specification are merely examples and are not limited, and other effects may be obtained.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, each of the above-described embodiments has been described in detail in order to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to those including all the components described above. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

11 ... Light source unit, 12 ... Beam diameter adjustment unit, 13 ... Light receiving unit, 14 ... Signal processing unit, 15 ... Input unit, 16 ... Storage unit, 17 ... Target Object measurement unit, 18 ... imaging unit, 19 ... beam shape change unit, 20 ... light receiving unit, 31 ... probe light source unit, 32 ... beam diameter adjustment unit, 33 ... polarization Child, 34 ... Beam splitter, 35 ... Non-linear optical crystal, 36 ... Compensator, 37 ... Polarizer, 39 ... Wavelength selection mirror, 100 ... Spectroscopic measuring device, 101-103 ... Cluster, 121 ... Lens, 122 ... Lens drive unit, 123 ... Object drive unit, 161 ... Table, 171 ... Imaging device, 172 ... Measuring instrument, 181 ... Biconvex lens, 200 ... spectroscopic measuring device, 201 ... wavelength converter, 202 ... converted wave receiver, 300 ... spectroscopic measuring device, 400 ... spectroscopic measuring device, 500 ... Spectral measuring device, 600 ... Spectral measuring device

Claims (14)

A light source unit that outputs electromagnetic waves to irradiate an object,
A beam diameter adjusting unit arranged between the light source unit and the object and adjusting the beam diameter of the electromagnetic wave output from the light source unit, and a beam diameter adjusting unit.
A light receiving unit that receives the electromagnetic wave incident through the object and generates a light receiving signal indicating the light receiving result.
A signal processing unit that determines the beam diameter to be adjusted by the beam diameter adjusting unit based on the received signal, and a signal processing unit that determines the beam diameter.
With
Based on the received signal, the signal processing unit determines the maximum beam diameter at which the integrated intensity of the electromagnetic wave received by the light receiving unit is the maximum or within a predetermined range from the maximum as the optimum beam diameter.
The beam diameter adjusting unit is a spectroscopic measuring apparatus characterized in that the beam diameter of the electromagnetic wave output from the light source unit is adjusted to the optimum beam diameter in accordance with control from the signal processing unit. The spectroscopic measuring apparatus according to claim 1.
The light receiving unit receives the electromagnetic wave incident through the object and generates the integrated intensity of the electromagnetic wave as a light receiving signal indicating the light receiving result.
The signal processing unit is a spectroscopic measuring apparatus characterized in that the optimum beam diameter is determined by the maximum beam diameter at which the integrated intensity of the electromagnetic wave as a received signal is the maximum or within a predetermined range from the maximum. The spectroscopic measuring apparatus according to claim 1.
The light receiving unit receives the electromagnetic wave incident through the object, and generates a two-dimensional image of the electric field amplitude distribution or the intensity distribution of the electromagnetic wave as a light receiving signal representing the light receiving result.
The signal processing unit calculates the integrated intensity based on the two-dimensional image of the electric field amplitude distribution or the intensity distribution of the electromagnetic wave as the received signal, and the calculated integrated intensity is the maximum or the maximum to a predetermined range. A spectroscopic measuring device characterized in that the maximum beam diameter is determined to be the optimum beam diameter. The spectroscopic measuring apparatus according to claim 1.
The light receiving part is
A wavelength conversion unit that generates a converted wave by converting the wavelength of the electromagnetic wave incident through the object, and
A conversion wave light receiving unit that receives the conversion wave and generates a light receiving signal that represents the light receiving result.
Have,
The signal processing unit calculates the integrated intensity based on the received signal generated by the converted wave receiving unit, and optimizes the beam diameter at which the calculated integrated intensity is the maximum or the maximum beam diameter within a predetermined range from the maximum. Determining the diameter A spectroscopic measuring device characterized in that the optimum beam diameter is determined. The spectroscopic measuring apparatus according to claim 4.
The wavelength conversion unit is a spectroscopic measurement device that converts the wavelength of the electromagnetic wave incident through the object by utilizing the Pockels effect or parametric generation of a nonlinear optical crystal. The spectroscopic measuring apparatus according to claim 1.
A storage unit that stores the identification information of the object and the optimum beam diameter in association with each other.
A spectroscopic measuring device characterized by being provided. The spectroscopic measuring apparatus according to claim 6.
When the input identification information of the object is stored in the storage unit, the signal processing unit reads out the optimum beam diameter corresponding to the identification information, and based on the read-out optimum beam diameter, the signal processing unit reads out the optimum beam diameter. A spectroscopic measuring device characterized by controlling the beam diameter adjusting unit. The spectroscopic measuring apparatus according to claim 6.
The signal processing unit is a spectroscopic measurement device that stores the input identification information of the object in the storage unit in association with the optimum beam diameter determined for the object. The spectroscopic measuring apparatus according to claim 1.
An imaging unit that is arranged between the object and the light receiving portion and that changes the beam diameter of the electromagnetic wave incident on the light receiving surface of the light receiving portion via the object is provided.
The signal processing unit is a spectroscopic measuring device characterized in that the position of the imaging unit is controlled based on the optimum beam diameter and the size of the light receiving surface. The spectroscopic measuring apparatus according to claim 1.
A beam shape changing part, which is arranged between the beam diameter adjusting part and the object and changes the beam shape of the electromagnetic wave,
A spectroscopic measuring device characterized by being provided. The spectroscopic measuring apparatus according to claim 1.
The object is a spectroscopic measuring apparatus characterized in that the beam diameter adjusting unit is an aggregate of substances smaller than the minimum value of the adjustable beam diameter. A light source unit that outputs electromagnetic waves to irradiate an object,
A light receiving unit that receives the electromagnetic wave incident through the object and generates a light receiving signal indicating the light receiving result.
It is a spectroscopic measurement method of a spectroscopic measuring device provided with
Based on the received signal, a determination step of determining the maximum beam diameter at which the integrated intensity of the electromagnetic wave received by the light receiving unit is the maximum or within a predetermined range from the maximum is determined as the optimum beam diameter.
An adjustment step for adjusting the beam diameter of the electromagnetic wave output from the light source unit to the optimum beam diameter, and
A spectroscopic measurement method comprising. An object measuring unit that measures the size of an object,
A light source unit that outputs electromagnetic waves for irradiating the object, and
A beam diameter adjusting unit arranged between the light source unit and the object and adjusting the beam diameter of the electromagnetic wave output from the light source unit, and a beam diameter adjusting unit.
A light receiving unit that receives the electromagnetic wave incident through the object and generates a light receiving signal indicating the light receiving result.
A signal processing unit that analyzes the object based on the received signal,
With
The signal processing unit determines the optimum beam diameter based on the measurement result by the object measuring unit.
The beam diameter adjusting unit is a spectroscopic measuring apparatus characterized in that the beam diameter of the electromagnetic wave output from the light source unit is adjusted to the optimum beam diameter in accordance with control from the signal processing unit. A light source unit that outputs electromagnetic waves to irradiate an object,
A light receiving unit that receives the electromagnetic wave incident through the object and generates a light receiving signal indicating the light receiving result.
It is a spectroscopic measurement method of a spectroscopic measuring device provided with
A measurement step for measuring the size of the object, and
A determination step for determining the optimum beam diameter based on the measurement result of the size of the object, and
An adjustment step for adjusting the beam diameter of the electromagnetic wave output from the light source unit to the optimum beam diameter, and
A spectroscopic measurement method comprising.

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