Spectroscopic measurement method, spectroscopic measurement device, product inspection method, product inspection device, and product sorting device

Abstract

To provide spectroscopic measurement technology with which both high speed and high S / N ratio suitably applicable for product inspection are achieved.SOLUTION: Pulse light, of which an elapsed time in pulse and the wavelength of light correspond 1 for 1, is emitted from a plus light source 1, with which a product P is irradiated multiple times, and a plurality of pulse light having passed through the product P enter a photodetector 2. The output of the photodetector 2 is digitized by an AD converter 21, and after the value of time assumed to be of the same wavelength in each pulse light is integrated by an FPGA 61 as integration means 6, The output of the photodetector 2 is also input to caluculation means 7 and an absorption spectrum is calculated by a measurement program 33, and a specific component is quantized to determine whether or not the product P is good by a quality determinataion program 34.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The invention of this application relates to spectroscopic measurement technology. [Background technology]

[0002] The technique of irradiating an object with light and measuring the spectrum of the light (transmitted light, reflected light, scattered light, etc.) from that object is a typical technique for analyzing the composition and properties of the object. A typical spectroscopic measurement method uses a diffraction grating. The light to be measured that enters through an entrance slit is converted into parallel light by a concave mirror and irradiated onto a diffraction grating. The dispersed light from the diffraction grating is similarly focused by a concave mirror and detected by a photodetector placed at the focusing position. By changing (scanning) the position of the diffraction grating, light of different wavelengths is sequentially incident on the photodetector, and the output of the photodetector becomes a spectrum.

[0003] Another method that does not use diffraction gratings is the so-called Fourier transform spectroscopy. In this method, light is made to interfere with other light using an interference optical system such as a Michelson interferometer, and the optical path length is changed by scanning a movable mirror when the interfering light is incident on a photodetector. The output of the photodetector is an interferogram, and a spectrum is obtained by Fourier transforming this. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-205390 [Non-patent literature]

[0005] [Non-Patent Document 1] Edited by Yukihiro Ozaki, published by Kodansha Co., Ltd., "Near Infrared Spectroscopy," pp. 59-75 Summary of the Invention [Problem to be solved by the invention]

[0006] Among the conventional spectroscopic measurement techniques mentioned above, spectroscopic measurement using a diffraction grating requires scanning of the diffraction grating, which makes high-speed measurement impossible.Fourier transform spectroscopy also requires scanning of a movable mirror, which limits high-speed measurement. The demand for high-speed spectroscopic measurement is particularly pronounced when the measurement is performed for the purpose of product inspection. When the product is a certain type of material (for example, a pharmaceutical), the material is dissolved into a liquid phase and spectroscopically measured using chromatography such as HPLC to quantify characteristic components. This makes it possible to determine whether the product is good or bad. However, this method is extremely time-consuming, and it is impossible to perform real-time inspection of manufactured products on-site. From a quality control perspective, 100% product inspection is desirable, but this method is simply not possible. When considering the need to analyze products in real time at the manufacturing site, high-speed spectroscopic measurement technology is absolutely necessary.

[0007] On the other hand, in addition to high speed, a high signal-to-noise ratio is also an important factor. Even if spectroscopic measurements can be performed at high speed, if the signal-to-noise ratio of the measurement results is low, the reliability of the measurement results will also be low. Therefore, it will be difficult to apply such methods to product inspection. The present invention has been made in consideration of these problems, and aims to provide a spectroscopic measurement technology that combines high speed and a high signal-to-noise ratio, making it suitable for application to product inspection. [Means for solving the problem]

[0008] In order to solve the above problems, this specification first discloses an invention of a spectroscopic measurement method and an invention of a spectroscopic measurement device. The spectroscopic measurement method according to the disclosed invention includes an irradiation step of irradiating the same object multiple times with pulsed light, in which the elapsed time in the pulse corresponds one-to-one to the wavelength of the light; a light receiving step of receiving, with a light receiver, each pulsed light from the object irradiated multiple times with the pulsed light in the irradiation step; and an arithmetic processing step of converting the output from the light receiver that received each pulsed light in the light receiving step into a spectrum. This spectroscopic measurement method includes an integration step of integrating the values ​​at the times when light of the same wavelength is deemed to be received for the output of each pulse of light from the photodetector, and a calculation step of performing calculations in which each value after integration in the integration step is regarded as the intensity of light at each corresponding wavelength. The spectroscopic measurement method further includes a reference time assigning step of assigning a reference time to the integration in the integration step when specifying a time at which light of the same wavelength is considered to have been received. The integration step is a step of integrating the values ​​of each pulse of light by regarding the time at which the same elapsed time from the reference time assigned in the reference time assigning step as the time at which light of the same wavelength was received. Furthermore, this spectroscopic measurement method may have a configuration in which the reference time assigning step is a step of generating a trigger signal in association with the emission of each pulsed light, and the integrating step is a step of integrating the value of the output from the photodetector that received each pulsed light at a time when the elapsed time from the trigger signal is the same. Furthermore, this spectroscopic measurement method may have a configuration in which the irradiation step is a step of broadening the bandwidth by making ultrashort pulse laser light from an ultrashort pulse laser source incident on a nonlinear element to generate a nonlinear effect, and making the broadband pulse light emitted from the nonlinear element incident on an expansion element to expand the pulse width, and then irradiating the broadband pulse light onto the object multiple times, and the reference time assignment step is a step of detecting the ultrashort pulse laser light before it is incident on the nonlinear element and generating a trigger signal. Furthermore, this spectroscopic measurement method may have a configuration in which the irradiation step is a step of broadening the bandwidth by making ultrashort pulse laser light from an ultrashort pulse laser source incident on a nonlinear element to generate a nonlinear effect, wavelength-dividing the broadband pulse light output from the nonlinear element using an arrayed-waveguide grating, and then transmitting and delaying the divided pulse light, which is the wavelength-divided broadband pulse light, through delay fibers, and collecting the divided pulse light output from each delay fiber to irradiate the target as a composite pulse light, wherein the material and length of each delay fiber are selected so that there is a one-to-one correspondence between the elapsed time of the composite pulse light and the wavelength of the light, and the integration step is a step of integrating, for each value corresponding to each channel in the arrayed-waveguide grating, an output from a photodetector that receives light from the target irradiated with the composite pulse light. Furthermore, this spectroscopic measurement method can have a configuration in which each delay fiber has normal dispersion characteristics or anomalous dispersion characteristics in the wavelength range of each divided pulse light incident thereon, and the integration step is a step of integrating the pulse output from the photodetector corresponding to each divided pulse light over a narrow width excluding the tail portions on both sides of the pulse.

[0009] In addition, the spectroscopic measurement device according to the disclosed invention includes a pulsed light source that emits pulsed light in which the elapsed time in the pulse corresponds one-to-one to the wavelength of the light, a light receiver that is positioned to receive light from an object irradiated with the pulsed light from the pulsed light source, and a calculation means that performs calculation processing to convert the output from the light receiver into a spectrum. An integrating means is provided for integrating the output from the photodetector for each pulse when pulsed light is irradiated multiple times from the pulsed light source onto the same object, for each value of the time at which light of the same wavelength is deemed to be received, and the calculating means is a means for performing arithmetic processing in which each value integrated by the integrating means is the intensity of light at each corresponding wavelength. In addition, in this spectroscopic measurement device, the integrating means is provided with a reference time setting unit that sets a reference time when specifying the time at which light of the same wavelength is considered to have been received. The integrating means is a means for integrating the value by regarding the time when the same elapsed time has elapsed from the reference time given by the reference time giving unit for each pulse of light as the time when light of the same wavelength was received. Furthermore, this spectroscopic measurement device may have a configuration in which the reference time providing unit is a trigger signal generating unit that generates a trigger signal in response to the emission of each pulsed light from the pulsed light source, the trigger signal generating unit is connected to an integrating means so that the trigger signal is input to the integrating means, and the integrating means is means for integrating each value of the output from the photodetector that received each pulsed light at a time when the same elapsed time has elapsed since the trigger signal. In addition, this spectroscopic measurement device can have a configuration in which the pulse light source includes an ultrashort pulse laser source, a nonlinear element that generates a nonlinear effect in the ultrashort pulse laser light from the ultrashort pulse laser source to broaden the bandwidth, and an expansion element that expands the pulse width of the broadband pulse light emitted from the nonlinear element, and the trigger signal generating unit includes a detector that detects the ultrashort pulse laser light before it enters the nonlinear element to generate a trigger signal. Furthermore, this spectroscopic measurement device can have a configuration in which the pulse light source includes an ultrashort pulse laser source, a nonlinear element that generates a nonlinear effect in the ultrashort pulse laser light from the ultrashort pulse laser source to broaden the bandwidth, an arrayed waveguide grating that wavelength-divides the broadband pulse light emitted from the nonlinear element, and delay fibers that transmit and delay each of the divided pulse light that is the pulse light wavelength-divided by the arrayed waveguide grating, the material and length of each delay fiber being selected so that when the divided pulse light emitted from each delay fiber is collected and irradiated onto an object as a composite pulse light, there is a one-to-one correspondence between the elapsed time and the wavelength of the light in the composite pulse light, and the integrating means is means for integrating an output from a photodetector that receives light from the object irradiated with the composite pulse light, for each value corresponding to each channel in the arrayed waveguide grating. Furthermore, this spectroscopic measurement device can have a configuration in which each delay fiber has normal dispersion characteristics or anomalous dispersion characteristics in the wavelength range of each divided pulse light incident thereon, and the integrating means is a means for integrating the pulse output from the photodetector corresponding to each divided pulse light over a narrow width excluding the tail portions on both sides of the pulse.

[0010] Furthermore, in order to solve the above problems, this specification discloses inventions of a product inspection method, a product inspection device, and a product sorting device. The product inspection method of the disclosed invention is a spectroscopic measurement method of the disclosed invention, which includes a spectroscopic measurement step in which a manufactured product is used as an object, and a pass / fail judgment step in which the pass / fail of the product is judged based on the results of spectroscopic measurement in the spectroscopic measurement step. Furthermore, this product inspection method may be configured such that the spectroscopic measurement step is a step of measuring the absorption spectrum of the product, and includes a quantification step of quantifying a specific component of the product from the measured absorption spectrum, and the pass / fail judgment step is a step of judging the pass / fail of the product from the amount of the specific component determined in the quantification step. In this product inspection method, the quantifying step may be a step of quantifying a specific component by chemometrics. Furthermore, this product inspection method may have a configuration in which the spectroscopic measurement step is a step of measuring the absorption spectrum of the product, the product has an average wavelength transmittance of pulsed light of less than 10%, the irradiation step is a step of irradiating pulsed light onto the same product 100 times or more, and the integration step is a step of integrating each value of the time at which light of the same wavelength is deemed to have been received for the pulsed light irradiated 100 times or more. In this product inspection method, the irradiating step may be a step of irradiating the same moving product with pulsed light multiple times. The product inspection device according to the disclosed invention is a spectroscopic measurement device that performs spectroscopic measurement on manufactured products as objects, and includes the spectroscopic measurement device according to the disclosed invention, and includes a pass / fail judgment means that judges the pass / fail of the product according to the results of the spectroscopic measurement obtained by the calculation means. Furthermore, this product inspection device may be configured such that the photoreceiver is positioned to receive light that has passed through the product, the calculation means is a means for obtaining the absorption spectrum of the product as a measurement result, and is equipped with a quantification means for quantifying a specific component of the product from the measured absorption spectrum, and the pass / fail judgment means is a means for judging the pass / fail of the product from the amount of the specific component obtained by the quantification means. In this product inspection device, the quantifying means may be a means for quantifying a specific component by chemometrics. Furthermore, this product inspection device may have a configuration in which the pulsed light source is a light source that irradiates pulsed light onto the same product 100 or more times, and the integrating means is a means for integrating each value of the time at which light of the same wavelength is deemed to have been received for the pulsed light that has been irradiated 100 or more times. In addition, the product sorting device of the disclosed invention is equipped with the product inspection device of the disclosed invention, and further includes an exclusion mechanism that excludes products determined to be defective by the pass / fail judgment means from the production line. [Effects of the Invention]

[0011] As explained below, the spectroscopic measurement method or spectroscopic measurement device according to the disclosed invention performs spectroscopic measurement by irradiating an object with pulsed light, in which the wavelength of light corresponds one-to-one to the elapsed time, thereby enabling extremely high-speed spectroscopic measurement. Furthermore, the measurement results are calculated by integrating the values ​​at each time point when light of the same wavelength is received, thereby simultaneously achieving a high signal-to-noise ratio. While multiple irradiations of pulsed light are required to achieve a high signal-to-noise ratio, the effect on the high-speed measurement can be substantially eliminated by sufficiently increasing the repetition frequency of the pulsed light. Furthermore, if a reference time is assigned during integration and the reference time is a trigger signal generated in response to the emission of each pulse of light from the pulsed light source, then when integrating the output of the photodetector due to each pulse of light, there is no need to determine the reference time within the output data, and integration can be performed at high speed. Furthermore, in a configuration in which a trigger signal is generated by detecting ultrashort pulse laser light before it enters the nonlinear element, the trigger signal can be obtained stably, preventing wavelength confusion during integration, thereby improving measurement accuracy. Furthermore, in a configuration in which the broadband pulsed light emitted from the nonlinear element is wavelength-divided by an arrayed-waveguide grating and each wavelength is transmitted through an appropriate delay fiber, and integration is performed in units of channels of the arrayed-waveguide grating, it is possible to make the wavelength resolution more uniform over the entire measurement wavelength range and further improve the signal-to-noise ratio. In this case, if each delay fiber has normal dispersion characteristics or anomalous dispersion characteristics in the wavelength range of each incident divided pulse light, and the pulse output from the photodetector corresponding to each divided pulse light is integrated over a narrow width excluding the foot portions on both sides of the pulse, crosstalk can be eliminated, and the purity of the measurement value, i.e., the reliability of the measurement value, can be further improved. Furthermore, with a product inspection method or product inspection device that performs such spectroscopic measurement on a product and judges the quality of the product based on the results, the high speed and high S / N ratio spectroscopic measurement makes it possible to judge the quality of products flowing through the production line in real time, and even to inspect all products, which can be applied to products that require particularly high quality, such as pharmaceutical tablets. Furthermore, in a configuration in which the absorption spectrum of a product is measured to quantify specific components and then judge whether the product is good or bad, it is possible to select components that are easy to judge whether they are good or bad, or components that are particularly important in the product, and thereby to judge whether the product is good or bad, thereby improving the accuracy and significance of the judgment. Furthermore, by irradiating products with an average transmittance of less than 10% with pulsed light 100 or more times and integrating the light, it becomes possible to make a real-time pass / fail judgment on products that were previously thought to be impossible to inspect using real-time spectroscopic measurement. Furthermore, the invention of a product sorting mechanism equipped with an exclusion mechanism that excludes products determined to be defective from the production line makes use of the real-time nature of inspection to effectively prevent defective products from being shipped, thereby greatly contributing to improving product reliability. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of a spectroscopic measurement device according to a first embodiment. [Figure 2] FIG. 1 is a schematic diagram illustrating pulse stretching by a stretching element. [Figure 3] FIG. 2 is a diagram illustrating a main part of an example of a measurement program included in the spectroscopic measurement device. [Figure 4] FIG. 10 is a schematic diagram illustrating integration by an integrating means. [Figure 5] FIG. 1 is a schematic diagram showing sampling periods and channels in an AD converter. [Figure 6] FIG. 10 is a schematic diagram showing the improvement of the signal-to-noise ratio by an integrating means. [Figure 7] FIG. 10 is a schematic diagram of a spectroscopic measurement device according to a second embodiment. [Figure 8] FIG. 10 is a schematic diagram of an arrayed waveguide grating employed as a dividing element in the second embodiment. [Figure 9] FIG. 10 is a schematic diagram showing light entering an output waveguide of an arrayed waveguide grating. [Figure 10] FIG. 10 is a schematic diagram illustrating crosstalk reduction by selecting an integration range. [Figure 11] FIG. 10 is a schematic diagram for explaining another configuration of the reference time setting unit. [Figure 12] FIG. 10 is a schematic diagram showing an example of an integrating means for performing integration in the state of analog data. [Figure 13] 1 is a schematic diagram of a product inspection device according to an embodiment. [Figure 14] FIG. 2 is a diagram showing an outline of a quality determination program constituting the determination means. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, modes (embodiments) for carrying out the invention of this application will be described. First, a spectroscopic measurement device according to an embodiment of the present invention will be described. Fig. 1 is a schematic diagram of a spectroscopic measurement device according to a first embodiment. In order to achieve high-speed measurement, the spectroscopic measurement device of the embodiment is a device that irradiates pulsed light onto an object P and performs spectroscopic measurement of light (e.g., transmitted light) from the object P. More specifically, one of the features of the spectroscopic measurement device of the embodiment is that it is a device that irradiates pulsed light onto the object P, in which the elapsed time in the pulse corresponds one-to-one to the wavelength of the light.

[0014] In recent years, there has been active research into broadening the wavelength of pulsed lasers, and a typical example is the generation of supercontinuum light (hereinafter referred to as SC light) using nonlinear optical effects. SC light is obtained by passing light from a pulsed laser through a nonlinear element such as a fiber and broadening the wavelength by nonlinear optical effects such as self-phase modulation and stimulated Raman scattering. Although the wavelength range of broadband pulsed light is significantly expanded, the pulse width (time width) remains close to that of the input pulse used to generate the SC light. However, the pulse width can also be expanded by utilizing the group delay in a transmission element such as a fiber. In this case, by selecting an element with appropriate chromatic dispersion characteristics, the pulse can be expanded with a one-to-one correspondence between the time (elapsed time) within the pulse and the wavelength.

[0015] The spectroscopic measurement device of the embodiment is a device that irradiates the object P with wideband pulsed light (wideband stretched pulsed light) that has been stretched in this way. More specifically, the spectroscopic measurement device of the embodiment includes a pulsed light source 1 that emits wideband stretched pulsed light, a photoreceiver 2 that is disposed at a position where it receives light from the object P that has been irradiated with the wideband stretched pulsed light from the pulsed light source 1, and a calculation means 3 that performs processing to convert the output from the photoreceiver 2 into a spectrum.

[0016] The pulse light source 1 includes an ultrashort pulse laser source 11, a nonlinear element 12, and an expansion element 13. In this embodiment, the ultrashort pulse laser 11 is fiber In addition, a gain switch laser, a microchip laser, etc. can also be used as the ultrashort pulse laser 11.

[0017] Fiber is often used as the nonlinear element 12. For example, photonic crystal fiber or other nonlinear fibers can be used as the nonlinear element 12. Although the fiber is often single-mode, multi-mode fibers can also be used as the nonlinear element 12 as long as they exhibit sufficient nonlinearity.

[0018] Such a pulsed light source 1 preferably emits pulsed light having a continuous spectrum over a wide wavelength range, including the measurement wavelength range. For example, it is desirable for the light source to emit light having a continuous spectrum over a wavelength width of at least 10 nm in the range of 900 nm to 1300 nm. The term "a continuous spectrum over a wavelength width of at least 10 nm in the range of 900 nm to 1300 nm" refers to any continuous wavelength width of at least 10 nm in the range of 900 to 1300 nm. For example, the spectrum may be continuous over a wavelength width of 900 to 910 nm or 990 to 1000 nm. A continuous spectrum over a wavelength width of at least 50 nm is more preferable, and a continuous spectrum over a wavelength width of at least 100 nm is even more preferable. Furthermore, "a continuous spectrum" means that the spectrum is continuous over a certain wavelength width. This does not necessarily mean that the spectrum is continuous over the entire spectrum of the pulsed light, but may also be partially continuous.

[0019] As described above, the stretching element 13 is an element that stretches the pulse so that the relationship between the time and the wavelength of the light after stretching is one to one. This point will be explained using Fig. 2. Fig. 2 is a schematic diagram showing pulse stretching by a stretching element. When SC light L1, which has a continuous spectrum in a certain wavelength range, is passed through a delay fiber (group delay fiber) 130 having positive dispersion characteristics in that wavelength range, the pulse width is effectively extended. As shown in Figure 2, in the SC light L1, although it is an ultrashort pulse, the longest wavelength λ1 exists at the beginning of one pulse, and as time passes, light with gradually shorter wavelengths appears, and at the end of the pulse, the shortest wavelength λ n When this light is passed through the normal dispersion delay fiber 130, the shorter the wavelength of the light, the more delayed it propagates through the normal dispersion delay fiber 130, so the time difference within one pulse is increased, and when it is output from the delay fiber 130, the light with the shorter wavelength is delayed further than the light with the longer wavelength. As a result, the output SC light L2 becomes light whose pulse width is extended while the uniqueness of time versus wavelength is ensured. That is, as shown in the lower part of FIG. 2, nis the wavelength λ1 to λ n The pulse is stretched in a one-to-one correspondence with each of the wavelengths. Pulsed light whose wavelength changes continuously over time in this way is sometimes called chirped pulse light.

[0020] It is also possible to use an anomalous dispersion fiber as the stretcher element 13. In this case, the SC light is dispersed in such a way that the long-wavelength light present at the beginning of the pulse is delayed and the short-wavelength light present at a later time is advanced, so the temporal relationship within one pulse is reversed, and the pulse is stretched in such a way that the short-wavelength light is present at the beginning of the pulse and the long-wavelength light is present as time passes. However, compared to the case of normal dispersion, it is often necessary to make the propagation distance longer for pulse stretching, which tends to result in larger losses. Therefore, in this respect, normal dispersion is preferable.

[0021] 1, the pulsed light stretched by the stretching element 13 is irradiated onto the object P by the irradiation optical system 3. A holding member for holding the object P is provided at the irradiation position. In this embodiment, the pulsed light is irradiated from above, so the holding member is a receiver 4. Furthermore, since the device in this embodiment is a device for measuring the spectral transmittance characteristics of the object P, the receiver 4 is translucent, and a light receiver 2 is provided at a position for receiving the transmitted light. Alternatively, a slit narrower than the width of the object P may be provided in the receiver 4, and the transmitted light may be received by the light receiver 2 through the slit.

[0022] Furthermore, this embodiment employs a configuration in which reference measurement values ​​are acquired in real time. That is, as shown in FIG. 1, a beam splitter 51 is provided to split the optical path extending from the expander element 13. One of the split optical paths is for measurement and reaches the optical receiver 2 via the object P. The other optical path 50 is a reference optical path, and a reference optical receiver 52 is disposed on this optical path. The light that has traveled through the reference optical path 50 (reference light) reaches the reference optical receiver 52 without passing through the object P.

[0023] In this embodiment, a general-purpose PC is used as the calculation means 3. Furthermore, an AD converter 21 is provided between the photoreceiver 2 and the calculation means 3, and the output of the photoreceiver 2 is input to the calculation means 3 via the AD converter 21. In addition, an AD converter 53 is provided between the reference photoreceiver 52 and the calculation means 3, and the output of the reference photoreceiver 52 is also digitized and input to the calculation means 3. The calculation means 3 includes a processor 31 and a storage unit (hard disk, memory, etc.) 32. A measurement program 33 that processes output data from the photodetector 2 to calculate a spectrum and other necessary programs are installed in the storage unit 32. Fig. 3 is a diagram that schematically shows the main parts of an example of a measurement program included in the spectroscopic measurement device.

[0024] The example in FIG. 3 is an example of a program in which the measurement program 33 measures an absorption spectrum (spectral absorptance). A reference spectral intensity is used to calculate the absorption spectrum. The reference spectral intensity is a value for each wavelength that serves as a reference for calculating the absorption spectrum. In this embodiment, the reference spectral intensity is an output from the reference photodetector 52 input via the AD converter 53 (real-time reference spectral intensity). The reference spectral intensity is a value for each time resolution Δt, and is stored as the reference intensity (V1, V2, V3, . . .) for each Δt (t1, t2, t3, . . .).

[0025] The reference intensities V1, V2, V3, at each time t1, t2, t3, are the intensities (spectrum) of the corresponding wavelengths λ1, λ2, λ3,. The relationship between the times t1, t2, t3, and wavelengths within one pulse is examined in advance, and the values ​​V1, V2, V3, at each time are treated as the values ​​of λ1, λ2, λ3,. The output from the photodetector 2 that receives the light that has passed through the object P is similarly stored in memory as values ​​(measured values) for each time t1, t2, t3, ... via the AD converter 21 (v1, v2, v3, ...). Each measured value is compared with the reference spectral intensity (v1 / V1, v2 / V2, v3 / V3, ...), and the result is the absorption spectrum (taking the logarithm of the reciprocal if necessary). The measurement program 33 is programmed to perform the above-mentioned calculation processing. Although not shown in the figure, the measurement AD converter 21 and the reference AD ​​converter 53 need to perform sampling in synchronization, so a synchronization circuit is provided to share a clock signal.

[0026] The spectroscopic measurement device of this embodiment is provided with an integrating means 6 to achieve measurement with a high S / N ratio. The integrating means 6 is means for integrating the values ​​at each time that are considered to be of the same wavelength for the output from the photodetector 2 due to each pulse of light. In this embodiment, the integrating means 6 is means for performing integration using hardware, and an FPGA (Field Programmable Gate Array) 61 is used as the integrating means 6.

[0027] Furthermore, in order to optimize the integration in the integrating means 6, the spectroscopic measurement device of this embodiment is provided with a reference time providing unit. The reference time providing unit is an element that provides the integrating means 6 with a reference time for identifying each time at which the output from the photodetector 2 due to each pulsed light is considered to be of the same wavelength. In this embodiment, a trigger signal generating unit 62 that generates a trigger signal having a certain temporal relationship with each pulsed light that reaches the photodetector 2 is employed as the reference time providing unit. More specifically, the trigger signal generating unit 62 that generates a trigger signal as the pulsed light source 1 emits each pulsed light is employed. 1, the trigger signal generating unit 62 generates a trigger signal by extracting and detecting a portion of the output of the ultrashort pulse laser source 11. That is, the trigger signal generating unit 62 is composed of a beam splitter 621 that extracts a portion of the output from the ultrashort pulse laser 11, and a detector 622 that detects the extracted light. Alternatively, a portion of the output from the nonlinear element 12 may be extracted by the beam splitter 621 and used as a trigger signal.

[0028] Fig. 4 is a schematic diagram showing integration by the integrating means 6. Fig. 4(1) shows the ultrashort pulse laser light emitted from the ultrashort pulse laser source 11, and Fig. 4(2) shows the trigger signal generated by the trigger signal generating unit 62. Fig. 4(3) shows the pulse light (broadband stretched pulse light) that has been band-broadened by the nonlinear element 12 and further stretched by the stretching element 13. Fig. 4(4) shows integration for a certain channel, showing how the value increases as integration proceeds. Note that each horizontal axis in Fig. 4 represents time, and the elapsed time (each time) corresponds to the wavelength as described above.

[0029] As shown in Fig. 4(2), the trigger signal generating unit 62 generates a trigger signal in response to the emission of the ultrashort pulse laser beam. The trigger signal is generated at a stable timing when the light intensity signal detected by the detector 622 exceeds a certain threshold. Alternatively, a simpler configuration would be to adjust the voltage of the light intensity signal detected by the detector 622 and use it as the trigger signal. In Figure 4(4), v m is a channel C m The term "channel" is used for convenience of explanation and means a time that can be considered to have the same elapsed time from the reference time. In Figure 4(4), for the sake of understanding, one channel C m However, in reality, there is a channel for each sampling period in the AD converter 21, and integration is performed on each channel.

[0030] FIG. 5 is a schematic diagram showing the sampling period and channels in the AD converter 21. As shown in FIG. In FIG. 5(1), the dashed line shows an example of the waveform of one pulse output PO1 output from the photodetector 2. This output is analog and is digitized by the AD converter 21. The digitization is carried out by sampling the value of the analog output at a sampling period T s For convenience of illustration, the sampling period is T s is depicted as being wider than it actually is. In the analog pulse output PO1, if the rising edge of the pulse, that is, the time when the value that can be considered to have effectively exceeded 0 for the first time, is sampled is t1, then t1 is the first channel (C1). The next sampling time, t2, is the next channel C2. In other words, the sampling period T s The time for each channel C1~C n In Figure 4(4), a certain channel C m Integral at time t m The value v at m The integral of

[0031] As described above, each trigger signal is input to the FPGA 61 used as the integrating means 6. When the output from the photodetector 2 in response to the first pulse of light is digitized by the AD converter 21 and sent, the FPGA 61 digitizes the time t1 to t2 based on the time t0 of the trigger signal. n The elapsed time T1 to T n That is, time T1 from t0 to t1, time T2 from t0 to t2, ... t0 to t n Time T n Remember.

[0032] 5(2)(3), the FPGA 61 adds and integrates the stored values ​​(values ​​sampled by the AD converter 21) corresponding to each elapsed time for each pulse output PO2, PO3, ... from the photodetector 2 due to the next and subsequent pulsed light. That is, it adds the value of channel C1 for the next pulsed light (value for the same elapsed time T1) to the value of channel C1 for the first pulsed light, adds the value of channel C2 for the next pulsed light (value for the same elapsed time T2) to the value of channel C2 for the first pulsed light, ... Channel C for the first pulsed light n For the value of channel C in the next pulse light n The value of (the same elapsed time T n (value of

[0033] The FPGA 61 controls the channels C1 to C2 for each pulse output PO1, PO2, PO3, . . . n Addition is performed sequentially for each channel C1 to C n The FPGA 61 is pre-programmed to perform this process. As can be seen from the above explanation, each channel C1 to C n corresponds to the "order" of the values ​​when the AD converter 21 digitizes the output from the photodetector 2 in response to each pulse of light. Therefore, the FPGA 61 may be programmed to simply add values ​​in the same order (same number). In other words, the times at a predetermined number of sampling points away from the time t0 of the trigger signal are added to the channels C1 to C2. n and each channel C1 to C n The digital value at is subjected to integration processing between pulses.

[0034] As can be seen from the above explanation, this embodiment is based on the premise that values ​​at the same elapsed time from the time of the trigger signal can be considered to be values ​​of the same wavelength (light intensity). In this case, if the expansion state by the expander element 13 differs between pulsed lights, the timing at which the light reaches the photodetector 2 will differ even if the wavelength is the same, and this premise will be violated. However, the repetition frequency of pulsed light is at least on the order of kHz, and even if it is repeated 100 times, it will take less than 0.1 seconds. It is unlikely that any significant changes will occur in the expansion characteristics of the expander element 13 in such a short time, and therefore the above premise will not be violated in practice. It is expected that, over a longer time span, the elongation characteristics of the elongation element 13 will change, and the main factor behind this is temperature. Therefore, it is possible to store the elongation element 13 in a thermostatic chamber or the like to maintain a constant temperature.

[0035] In any case, this integration process significantly improves the S / N ratio of spectroscopic measurement. This will be explained below with reference to Fig. 6. Fig. 6 is a schematic diagram showing the improvement of the S / N ratio by the integration means 6. In FIG. 6, a certain channel C in the output of the photodetector 2 due to each pulse of light m The value of v m1 ~v m4 As mentioned above, the output from photodetector 2 also contains noise components, and channel C m The value of is the original light intensity signal E S In addition to the noise component E N Includes: Channel C m The noise component E in N If the magnitude of is exactly the same for each pulse, the noise component E N However, the incidence state of stray light and background light and the magnitude of electrical noise are not exactly the same for each pulse, and generally, the noise component E N The magnitude of is different for each pulse.

[0036] If there is such a fluctuation in the noise component between pulses, the calculated absorptance will differ even after dividing by the reference spectral intensity, i.e., even if the actual absorptance is the same, the calculated absorptance will be different due to the difference in the noise component. On the other hand, when integration is performed by the integration means 6, the noise component E N Fluctuation range ΔE N That is, a certain channel C m By integrating the value, the noise component E N Fluctuation range ΔE N decreases inversely proportional to the square root of the number of integrations, which reduces the amount of noise in the final measurement result.

[0037] An important aspect of such integration processing is that the spectroscopic measurement device of this embodiment assumes that the light transmittance of the object P is very low and the signal intensity is extremely small. By "very low," we mean a light transmittance of less than 10%, more specifically, 5% or less (e.g., 1% to 5%, 0.5% to 5%, etc.) or 3% or less (e.g., 0.5% to 3%, 0.1% to 3%, etc.). Therefore, the measured light (light that has passed through the object P) that enters the light receiver 2 is weak, and the amount of noise components is relatively large. The greater the amount of noise components, the greater the fluctuations, so improving the S / N ratio through the integration described above is particularly effective.

[0038] According to the inventor's research, when measuring the absorption spectrum of an object P with such low light transmittance, integrating 100 times or more is found to be particularly effective, as it increases the signal-to-noise ratio by more than 10 times. Therefore, it is preferable to irradiate the same object P with at least 100 pulses of light, integrate the values ​​for each channel, and then compare them with the reference spectral intensity. More than 1000 times is even more preferable, as it increases the signal-to-noise ratio by more than 30 times. 1, an FPGA 54 as an integrating means 60 is also provided for the output from the reference photoreceiver 52, and integrates the values ​​digitized by the reference AD ​​converter 53 for each channel. In one measurement, the number of pulsed lights (number of pulses) incident on the reference photoreceiver 52 is the same as that of the measurement photoreceiver 2, and therefore the number of integrations in the integrating means 60 is also the same.

[0039] The FPGAs 61 and 54 as the integration means 6 and 60 respectively integrate the data (channel C1 to channel C2) of each channel. n The data set is output to the calculation means 3. n , V1~V n is equivalent to For the FPGAs 61 and 54, the channels C1 to C n In this embodiment, the calculation means 3 is configured to generate gate signals for the FPGAs 61 and 54.

[0040] Next, the operation of the spectroscopic measurement device of this embodiment will be described. The following description also describes the spectroscopic measurement method. When performing spectroscopic measurement using the spectroscopic measurement device of the embodiment, the object P is placed on the holder 4, and the pulse light source 1 is operated. In the pulse light source 1, the ultrashort pulse light emitted from the ultrashort pulse laser source 11 is band-broadened by the nonlinear element 12 and pulse-stretched by the stretching element 13. The emitted pulse light is split by the beam splitter 51, one of which is irradiated onto the object P, and the pulse light that has transmitted through the object P reaches the photodetector 2. The other split pulse light reaches the reference photodetector 52 as is.

[0041] Such irradiation of pulsed light and incidence on each photodetector 2, 52 are repeated multiple times, and an output due to each pulsed light is generated from each photodetector 2. Each output is sampled and digitized by AD converters 21, 53, respectively, and integrated by FPGAs 61, 54, which serve as integrating means 6, 60. Then, data sets v1 to v2 of the measurement signals are generated. n and the reference signal data sets V1 to V n are input to the calculation means 3. The calculation means 3 calculates the data sets v1 to v2 of the measurement signals. n Each value contained in the reference signal data set V1 to V n The measured intensity is divided by the reference intensity obtained at the same time and used as the absorption spectrum measurement result.

[0042] According to the spectroscopic measurement device or spectroscopic measurement method of this embodiment, the object P is irradiated with pulsed light, in which the elapsed time and the wavelength of the light correspond one-to-one, for spectroscopic measurement, thereby enabling extremely high-speed spectroscopic measurement. Furthermore, the measurement results are obtained by integrating the time values ​​that can be considered to be the same wavelength, thereby simultaneously achieving a high S / N ratio. Although multiple irradiations of pulsed light are required to achieve a high S / N ratio, the repetition frequency of the pulsed light can be sufficiently high, with virtually no effect on the high-speed measurement. For example, when an ultrashort pulse laser source with a repetition frequency of 10 kHz is used, the time required to irradiate the object P with pulsed light 100 times is only 10 milliseconds.

[0043] Next, a spectroscopic measurement device and a spectroscopic measurement method according to a second embodiment will be described. Fig. 7 is a schematic diagram of the spectroscopic measurement device according to the second embodiment. The second embodiment differs from the first embodiment in the configuration for realizing a one-to-one correspondence between the elapsed time within a pulse and the wavelength of light. In the second embodiment, the pulse light output from the nonlinear element 12 is split into individual wavelengths by a splitter element, and an appropriate delay amount is ensured when transmitting each wavelength through a fiber, thereby realizing the one-to-one correspondence.

[0044] In this embodiment, the dividing element for dividing the light into each wavelength is an arrayed waveguide grating (AWG) 14. Fig. 8 is a schematic diagram of the arrayed waveguide grating used as the dividing element in the second embodiment. The arrayed waveguide grating is an element developed for optical communications and is not generally used for spectroscopic measurement. As shown in Figure 8, the arrayed waveguide grating 14 is configured by forming functional waveguides 142 to 146 on a substrate 141. Each functional waveguide includes a number of grating waveguides 142 with slightly different optical path lengths, slab waveguides 143 and 144 connected to both ends (the entrance side and the exit side) of the grating waveguide 142, an entrance side waveguide 145 that inputs light to the entrance side slab waveguide 143, and exit side waveguides 146 that extract light of each wavelength from the exit side slab waveguide 144.

[0045] The slab waveguides 143 and 144 are free space, and light incident through the input waveguide 145 spreads in the input slab waveguide 143 and enters each grating waveguide 142. Because each grating waveguide 142 has a slightly different length, the light reaching the end of each grating waveguide 142 is shifted in phase by this difference. Light is diffracted and emitted from each grating waveguide 142, and the diffracted light interferes with each other as it passes through the output slab waveguide 144 and reaches the input end of the output waveguide 146. Due to the phase shift, the interference light has its highest intensity at a position corresponding to its wavelength. In other words, light of successively different wavelengths enters each output waveguide 146, and the light is spatially dispersed. In other words, each output waveguide 146 is formed so that its input end is positioned at the split position. (See below.) The incident pulsed light is split and each light emitted from each output-side waveguide 146 is called a split pulsed light.

[0046] As shown in FIG. 8 , a delay fiber 15 is connected to each output-side waveguide 146. The delay fibers 15 are ultimately bundled together to form a fiber bundle. An output end unit 16 is provided at the output end of the fiber bundle, and the output light is irradiated onto the object P. The output end unit 16 includes elements such as a collimator lens, and is a unit that causes the pulsed light transmitted through each delay fiber 15 to overlap and be irradiated onto the object P. Therefore, in this embodiment, the pulsed light is split by the arrayed waveguide grating into divided pulsed light beams, which are then collected and combined on the object P. Note that the term "combined" includes cases where the pulsed light beams are irradiated with a time lag but spatially overlap on the object P. Furthermore, as will be described later, the object P may be irradiated while moving, and in this case, there may be cases where the pulsed light beams do not overlap spatially. However, this expression remains true because what was originally a single pulsed light beam is irradiated onto the same object P. Hereinafter, the combined pulsed light will be referred to as a combined pulsed light beam.

[0047] Light of different wavelengths is sequentially incident on each delay fiber 15, and each delay fiber 15 has an appropriate length depending on the wavelength of the incident light. An appropriate length is a length that achieves a one-to-one correspondence between time and wavelength in the composite pulse light. Length optimization often refers to a configuration in which each delay fiber has a different length depending on the wavelength of the incident light. In addition to length, the material of each delay fiber 15 may also be optimized. That is, different materials may be used depending on the wavelength of the incident light. In either case, this configuration optimizes the delay amount depending on the wavelength, thereby making the Δλ / Δt shown in Figure 2 more uniform. In other words, the wavelength resolution can be made uniform across the entire range of measurement wavelengths. This effect is particularly noticeable when uniforming the wavelength resolution over a wide wavelength range, such as in a configuration using SC light. In addition to making Δλ / Δt uniform as described above, an arbitrary Δλ / Δt can be achieved by appropriately selecting the length and material of each delay fiber 15.

[0048] In the second embodiment as well, the outputs from the photodetectors 2 and 52 are input to the calculation means 3 via the AD converters 21 and 53 and the FPGAs 61 and 54 serving as the integrating means 6 and 60, and the values ​​at times that can be considered to be of the same wavelength are integrated and then converted to a spectrum. In this case, in the second embodiment, the integration in the FPGAs 61 and 54 is optimized in relation to the division of the pulsed light by the arrayed waveguide grating 14. This point will be explained below.

[0049] FIG. 9 is a schematic diagram showing the light when it enters the output waveguide of the arrayed waveguide grating. Figure 9(1) shows a schematic representation of light reaching each output waveguide 146 through the output slab waveguide 144. Figure 9(2) shows a schematic representation of the light intensity of each wavelength at the incident surface of each output waveguide 146. Therefore, the horizontal axis in Figure 9(2) represents the position at the incident surface of each output waveguide 146. As shown in FIG. 9(2), on the incident surface of the output side waveguide 146, the light of λ1 is focused in a limited range, peaking at the center position, and the intensity outside the range is zero. The light of λ2 peaks at the adjacent position, and the intensity outside the range is zero. In this way, λ n The peak positions of the light up to 1 / 4 are shifted sequentially on the end face of the output-side slab waveguide 144. Although the end face of the output-side slab waveguide 144 is depicted as flat in Fig. 9, it has an arc-shaped cross section, similar to the end face of the input-side slab waveguide 143.

[0050] In a configuration using the arrayed-waveguide grating 14, the time group at which pulses emitted from one output waveguide 146 are detected constitutes one channel, and all signal intensities within that channel correspond to the intensity of one wavelength. In other words, when the arrayed-waveguide grating 14 is used, the wavelength resolution is determined by the interval (shown as I in FIG. 9(2)) between the input ends of the output waveguide 146, and the output of light transmitted through one channel can be integrated over time. As shown enlarged in FIG. 9(3), if multiple samples are taken for the output from one channel and there are multiple digitized data, they are added together to determine the optical intensity of that channel.

[0051] In this case, between the light of λ1 and the light of λ2, light of wavelengths between them exists with successive peaks. Therefore, light of wavelengths before and after λ1 also enters the output waveguide 146 to which the light of λ1 enters. In other words, each output waveguide 146 does not completely separate the wavelengths, but rather the wavelengths before and after λ1 are mixed together (λ1±Δλ1). In this case, although the amount is small, ±Δλ1 includes wavelengths that are common to adjacent channels, resulting in a state of so-called crosstalk. Crosstalk reduces the wavelength purity of a channel, but by selecting an appropriate integration range, the crosstalk-induced degradation of wavelength purity can be reduced. Figure 10 illustrates this point, showing a schematic diagram of crosstalk reduction by selecting an integration range.

[0052] Crosstalk occurs in an arrayed waveguide grating because the entrance end of each exit waveguide has a certain width and each entrance end has a certain interval I. Hereinafter, the wavelength at which the intensity peaks at the center of the entrance end of the exit waveguide 146 corresponding to a certain channel is referred to as the channel wavelength for that channel. For example, as shown in Figure 10(A1), when I is narrow, in addition to the channel wavelength λ2, a small amount of light of the channel wavelengths λ1 and λ3 of the adjacent channels is incident on the incident end of the output side waveguide 146 corresponding to channel C2. If I is set large, as shown in Figure 10(B1), light of the channel wavelengths of the adjacent channels will not be incident, but it is still possible for light of a wavelength common to the adjacent channels to be incident. For example, if the wavelength midway between λ1 and λ2 is set to λ 1.5 Then, the wavelength λ 1.5 The light can be incident little by little on the output waveguide 146 corresponding to channel C1 and little by little on the output waveguide 146 corresponding to channel C2.

[0053] In Figures 10(A1) and 10(B1), the horizontal axis represents the position on the end face of the output slab waveguide 144, and thus represents space. Although the individual beams of light are spatially offset, they all overlap in time. Due to differences in the amount of delay experienced when propagating through the delay fibers 15 connected to each output waveguide 146, these beams also have a time offset when they exit each delay fiber 15. This is shown in Figures 10(A2-1), (A2-2), (B2-1), and (B2-2). Figures 10(A2-1) and 10(B2-1) show the case where the difference in the amount of delay is small, while Figures 10(A2-2) and 10(B2-2) show the case where the difference in the amount of delay is large. In Figures 10(A2-1), (A2-2), (B2-1), and 10(B2-2), the horizontal axis (axis omitted) represents time.

[0054] 10(A2-1), (A2-2), (B2-1), and (B2-2), when the difference in the delay amount is small, the divided pulse light beams overlap in time at the base, but when the difference in the delay amount is increased, the divided pulse light beams become completely separated in time. In either case, the wavelength components of each divided pulse light beam include not only the channel wavelength but also the wavelengths before and after it at the base. These divided pulsed beams are collected and irradiated as a composite pulsed beam onto the same object P, generating an output from the photodetector 2, whose temporal changes also have a pattern corresponding to Figure 10 (A2-1) (A2-2) (B2-1) (B2-2). Therefore, as shown in Figure 10 (A2-1) (A2-2) (B2-1) (B2-2), by performing integration over a narrow time width δt excluding the tail portion, crosstalk can be eliminated and wavelength purity can be increased.

[0055] The above configuration is based on the premise that each divided pulse light emitted from each delay fiber 15 is chirped pulse light. Since it is chirped pulse light, crosstalk wavelengths exist in the tail portion of the pulse (time waveform), and crosstalk can be reduced by excluding this portion. To obtain chirped pulse light, each delay fiber 15 needs to have normal dispersion characteristics over the entire range of wavelengths of the divided pulse light to be transmitted, or anomalous dispersion characteristics over the entire range.

[0056] In the second embodiment, the optimum range is set as described above, and the values ​​are integrated in each channel, and then further integrated between pulses. That is, the values ​​of the same channel are added together to determine the light intensity in that channel. In other words, in the second embodiment, the value of each channel is the integration of multiple sampling data, which is then further integrated between pulses to obtain a data set (v1 to v n ,V1~V n ) is obtained, and each FPGA 61, 54 is programmed to perform such processing. In the above explanation, integration processing between pulses is performed after integration processing within a channel, but integration processing within a channel may be performed after integration processing between pulses, and in that case, the function to perform integration processing within a channel may be implemented in the measurement program 33.

[0057] As can be seen from the above explanation, the spectroscopic measurement device of the second embodiment not only achieves the effects of faster measurement and a higher S / N ratio, but also has the effect of making wavelength resolution more uniform over the entire range of measurement wavelengths because it uses the arrayed-waveguide grating 14 to divide wavelengths, generate delays according to the wavelengths, and then combines the signals. Furthermore, the device is configured to eliminate the problem of crosstalk that occurs when using the arrayed-waveguide grating 14 during integration, which increases the purity of the measurement values, i.e., the reliability of the measurement values.

[0058] When using the arrayed waveguide grating 14, a configuration in which only one piece of sampling data is available in one channel is also possible. For example, if it is sufficient to measure over a wavelength range of 500 nm and the required wavelength resolution is 5 nm, the number of channels will be 100. Therefore, the arrayed waveguide grating 14 will also have 100 channels, and it is possible to manufacture a device with such a number of channels. In this case, if the length of the delay fiber 15 is designed so that the wavelength resolution in the sampling period is 5 nm, then there will be only one piece of sampling data in one channel, and time integration within the channel will not be necessary. In addition, when there are multiple sampling data in one channel, in addition to a configuration that integrates data within the channel and data between pulses, a configuration that identifies the peak value (maximum value sampling data) in the channel and integrates it between pulses may also be adopted.

[0059] Next, another configuration of the reference time setting unit will be described with reference to Fig. 11. Fig. 11 is a schematic diagram for explaining another configuration of the reference time setting unit. In the above embodiments, the reference time setting unit is the trigger signal generating unit 62 that generates a trigger signal in response to the emission of each pulse of light, but other configurations are also possible. For example, the reference time setting unit may be configured to be internally provided in the integrating means 6. An example of this is shown in Figure 11(1). The solid line indicates a pulse output PO from the photodetector 2. The FPGA 61 as the integrating means 6 can determine whether a value exceeding 0 is acquired for the first time for the digital data output from the AD converter 21 for each sampling period. The time when it is determined that the data is acquired for the first time is set as t1, and the value of "the time when the wavelengths can be considered to be the same" can be acquired based on this. The sampling period T s is constant for each pulsed light, so the time that elapses from t1 to t2 for the first pulsed light is equal to the time that elapses from t1 to t2 for the next pulsed light, and the time that elapses from t1 to t3 for the first pulsed light is equal to the time that elapses from t1 to t3 for the next pulsed light. The same is true for t4 and onwards, and for the following pulsed light.

[0060] Therefore, the FPGA 61 can achieve the same effect by simply determining t1 for the data from each pulsed light and integrating values ​​with the same number of sampling periods (same-th values). This concept is based on the premise that Δλ / Δt shown in FIG. 2 is the same for each pulsed light. This premise also breaks down if the nonlinear optical effect of the nonlinear element 12 or the pulse stretching action of the stretching element 13 varies between pulsed lights, causing Δλ / Δt to change. However, since no changes that affect measurement accuracy actually occur, Δλ / Δt can be considered to be the same for each pulsed light. Note that the term "the same Δλ / Δt" means that Δλ / Δt at a certain wavelength is the same for each pulsed light, and it may differ between wavelengths within a single pulsed light. However, in the case of the method in Figure 11(1), as shown by the dashed line, if there is a change in the way the pulse rises between the first and second pulsed lights, the measurement accuracy may decrease. For example, if the wavelength t1 of the first pulse is λ1 and the pulse rises from here, but the pulse rises from λ2 of the second pulsed light, then λ2 of the second pulsed light will be t1, and the intensity of λ2 will be added to the intensity of λ1 and integrated (a mix-up).

[0061] This example is an extreme one, but in any case, the time when a value exceeding 0 is first obtained is easily unstable because it is a small value. In comparison, a configuration in which a trigger signal is generated upon emission of an ultrashort pulse laser beam and used as the reference time is preferable because it avoids instability of the reference time. However, although the deformation of the pulse rise as shown in Figure 11(1) indicates that the bandwidth widening achieved by the nonlinear element 13 has become unstable, such instability rarely occurs within a measurement time on the order of milliseconds or tens of milliseconds, and in most cases does not need to be taken into consideration.

[0062] FIG. 11(2) shows an example in which the reference time of the pulsed light is created by an external element, and the external element serves as a reference time assigner. In this example, although not shown, a marker element is placed on the optical path on the output side of the expander element 13. For example, a notch filter that selectively attenuates only a known wavelength can be used as the marker element. A volume Bragg grating can also be used as the marker element. A volume Bragg grating is an optical element that refracts or reflects only light of a specific wavelength in a different direction. Hereinafter, the wavelength selected by these marker elements is referred to as the marking wavelength. In a notch filter, the wavelength that is selectively attenuated is the marking wavelength, while in a volume Bragg grating, the wavelength of light that is selectively refracted or reflected is the marking wavelength.

[0063] When a marker element is placed, the light of the marking wavelength is significantly reduced in the pulsed light incident on the photodetectors 2 and 52, making it possible to identify the time when the light of the marking wavelength was incident. In other words, as shown in Figure 11(2), if only a specific data value is zero or close to zero during a pulse of a certain pulse output PO, the time when that data was acquired can be considered the time when the light of the marking wavelength reached the photodetector 2. Then, integration is performed by adding the same data based on that time. That is, the marking wavelength data is identified for each pulsed light, and then each data is identified as 1st, -1st, 2nd, -2nd, 3rd, -3rd, etc. Then, for each pulsed light, integration is performed by adding the same values ​​before and after, such as the 1st value, the -1st value, the 2nd value, the -2nd value, etc. Because the sampling period is constant here as well, the values ​​of the times at which the elapsed time (positive or negative) in the pulse can be considered the same are added. This method is also based on the premise that Δλ / Δt is constant for each pulsed light.

[0064] When a marker element is used, even if the rising edge of the pulse is deformed as shown in FIG. 11(1), this does not affect the time-to-wavelength correspondence and does not reduce the reliability of the measurement. For example, suppose the earliest time t1 present in the first pulse output PO is the kth wavelength from the sampling wavelength time. In this case, the kth wavelength may not exist in the second pulse due to a change in the rising edge. In this case, the FPGA 61, 54 can be programmed to either integrate the value from the first pulse output as is, or to invalidate and exclude the kth channel itself. Note that when a marker element is used, measurement results cannot be obtained at the marking wavelength (a missing portion of the spectrum occurs). In this respect, the method of FIG. 11(1) or the method using the trigger signal generator 62 is preferable. The marker element can also be used to assign absolute wavelength values ​​in the time-to-wavelength correspondence, i.e., by determining Δλ / Δt shown in Figure 2 in advance, the absolute wavelength value at each time is determined in relation to the time at which light of the marking wavelength is received.

[0065] In addition to using a marker element, if the spectrum of broadband pulsed light has an inherently characteristic point, it can also be used as a marker (marker wavelength). For example, in the case of pulsed light obtained by broadening the spectrum of ultrashort pulsed laser light using a nonlinear element, the wavelength of the ultrashort pulsed laser light may remain at a high intensity, and the intensity of this wavelength may protrude in a ripple-like manner. This can be used as the marker wavelength. In this case, in the data set obtained by each pulsed light, data with a particularly high value is taken as data of the marker wavelength, and data at the same position before and after that data are respectively integrated.

[0066] Next, other examples of the integrating means 6, 60 will be described. In the above embodiments, the integrating means 6, 60 are FPGAs 61, 54, which are implemented by hardware, but they can also be implemented by software. For example, the integrating means 6, 60 can be implemented as one module of the measurement program 33. In this case, each data set v1 to v2 sampled for each pulsed light is n , V1~V n are temporarily stored in memory. Then, the same data are added together to obtain an integral value, and each integrated measurement value is compared with each integrated reference intensity to calculate the absorption spectrum.

[0067] When implemented by software as described above, hardware such as FPGAs 61 and 54 is not required, but the writing, reading, and calculation (addition) of large volumes of data is required, which has the drawback of taking a long time to process. Hardware such as FPGAs 61 and 54 is preferable because it enables high-speed processing. It is also possible to use ASICs as the integrating means 6 and 60. Furthermore, the integrating means 6, 60 may be configured to perform integration in the form of analog data. An example of this is shown in Figure 12. Figure 12 is a schematic diagram showing an example of integrating means 6 that performs integration in the form of analog data.

[0068] 12 is a circuit unit disposed between the photoreceiver 2 and the AD converter 21. This circuit unit includes a time division switch 631 that divides the output from the photoreceiver 2 by time, an integrator 632 that integrates the analog output (voltage) for each time period divided by the time division switch 631, and a readout switch 633 that sequentially selects and outputs each integration circuit in the integrator 632. The integrator 632 has integrating circuits arranged in parallel, the number of which corresponds to the number of data (channels) in one pulsed light. The time-division switch 631 is a circuit element that switches the analog output from the photodetector 2 for each sampling period and sequentially connects it to each integrating circuit. The readout switch 633 is a circuit element that sequentially connects each integrating circuit to the AD converter 21 and reads out the integrated value when a readout command is input after a predetermined number of pulsed light irradiations have been completed. The AD converter 21 digitizes the integrated value of each integrating circuit and inputs it to the calculation means 3. The processing in the calculation means 3 is the same as above. For the output from the reference photoreceiver 52, the integrating means 60 can also be configured to perform analog integration in a similar manner.

[0069] Next, embodiments of the product inspection device, the product inspection method, and the product selection device will be described. Fig. 13 is a schematic diagram of a product inspection device according to an embodiment. The product inspection device shown in Fig. 13 has the configuration of the spectroscopic measurement device described above, and is a device that determines whether a product P is good or bad based on the results of spectroscopic measurement. This product inspection device also has an exclusion mechanism 7 that excludes products P that are determined to be defective from the production line. Therefore, the following description of the product inspection device also describes an embodiment of the product sorting device according to the invention.

[0070] 13 is an apparatus that employs the configuration of the spectroscopic measurement apparatus of the first embodiment. This product inspection apparatus includes a pass / fail judgment program 34 in the calculation means 3. A sequence control program 35 that controls the product inspection sequence is implemented in the calculation means 3. In other words, the calculation means 3 also serves as a controller that controls the entire device. The sequence control program 35 is programmed to execute the measurement program 33, and then execute the pass / fail judgment program 34 using the resulting absorption spectrum as an argument.

[0071] FIG. 14 is a diagram showing an outline of the pass / fail judgment program 34 constituting the judgment means. As shown in FIG. 14, the pass / fail judgment program 34 includes a spectrum quantification module 341 and a judgment module 342. As described above, the measurement program 33 compares the measurement spectrum S1, which is integrated output data, with the reference spectrum intensity S0, which is similarly integrated output data, to calculate the absorption spectrum S2. The pass / fail judgment program 34 is then executed using the calculated absorption spectrum S2 as an argument. In the pass / fail judgment program, the spectrum quantification module 341 is a module that calculates a quantity Q (hereinafter referred to as a quantitative value) that can be compared with a reference value based on the absorption spectrum S2. The judgment module 342 is a module that compares the calculated quantitative value Q with the reference value, makes a pass / fail judgment, and outputs the result as the execution result of the program.

[0072] The absorption spectrum S2 passed as an argument is the sum of the absorption spectra of each component contained in product P. It is possible to judge the quality of product P based on the amount of all of these components contained, but this would be too complicated, so the quality is judged based on the amount of a specific component. A specific component may be the component that has the greatest impact on the quality of product P, or the component that is most abundant in product P. In the case of pharmaceuticals, the quality may also be judged based on the amount of the active ingredient. In this way, it is preferable to judge the quality of a product by focusing on the significant components in the product.

[0073] In any case, in this embodiment, the quality is judged based on the absorption spectrum S2 in the near-infrared region. As is well known, the absorption bands of many materials overlap in the near-infrared region, making it difficult to directly determine the amount of the target component from the calculation results of the absorption spectrum. For this reason, the spectrum quantification module 341 employs a chemometrics method.

[0074] Known chemometrics techniques include PCA (principal component analysis), PCR (principal component regression analysis), and PLSR (partial least squares regression, PLS regression) analysis. Any of these techniques can be used, but we will explain the case of using PLSR as an example. When performing PLSR, similar measurements are performed on a large number of samples (product P) with known amounts of the target component to obtain a data set. Regression analysis is then performed based on the large number of data sets obtained to determine the regression coefficients. During actual quantification, the determined regression coefficients are used to predict the amount of the target component, and the predicted value is used as the quantified value.

[0075] PLSR is an advanced method of PCA and PCR, and first performs principal component analysis. That is, as shown in Equation 1 below, multivariate data X (here, absorption spectra measured for samples with known amounts of target components) is decomposed into principal component scores T, loading vectors R, and residuals E.

number

[0076] In PLSR, principal component analysis is performed on multivariate data X, and regression analysis is performed using the principal component scores T obtained therein to avoid collinearity. In this case, only the portion of the spectral data set X related to the amount of principal components is extracted, and regression coefficients are found using the least squares method. A calibration curve is then created based on the regression coefficients thus found. PLSR and other chemometrics are explained in Non-Patent Document 1 and other literature, so further explanation will be omitted.

[0077] 14, the pass / fail judgment program 34 executes a judgment module 342 after executing a spectrum quantification module 341. The judgment module 342 is a module that compares the quantitative value Q obtained by the spectrum quantification module 341 with a reference value to judge pass / fail. The reference value and the tolerance for deviation from the reference value are given as constants to the judgment module 342. The judgment module 342 judges pass / fail in accordance with these and outputs the result as the execution result of the pass / fail judgment program 34.

[0078] The amount Q of the target component may be a ratio to the whole (content ratio) or an absolute value (content amount). When calculating an absolute value, a calibration curve must be prepared so that the absolute value can be calculated, or in the case of a weight ratio, the weight of the product P must be measured separately and then calculated. In practice, the output data D is preprocessed by smoothing and second-order differentiation, and then the regression coefficients obtained by PLSR are applied to obtain the quantitative value Q. At this time, wavenumber range selection is performed to extract only the portion related to the target component, and then the quantitative value Q is obtained.

[0079] The product inspection device of the embodiment is a device that judges the quality of a product P in real time on the manufacturing line of the product P. "In real time" means that the quality is judged on the spot where the product P is manufactured, and does not mean that the product P is taken to another location, dissolved in a solution, and analyzed by an analyzer such as HPLC to determine the quality later.

[0080] As shown in Figure 13, this product inspection device similarly irradiates pulsed light while holding a product P in a receiving device 4, but is equipped with a moving mechanism 400 that moves the receiving device 4 in order to sequentially determine the quality of a large number of products P. Each receiver 4 is plate-shaped, lined up horizontally, and connected to one another. The movement mechanism 400 is a mechanism that moves each receiver 4 in the direction in which it is lined up. For example, if the horizontal direction perpendicular to the movement direction is defined as left and right, a configuration can be adopted in which a linear guide is provided on one of the left and right sides, and a linear drive source such as a linear motor is provided on the other side. Each receiver 4 is connected to one another, and moves linearly while being guided by the linear guide by the linear drive source.

[0081] When moved by the moving mechanism 400, each receiver 4 is sequentially positioned at the pulsed light irradiation position, and the pulsed light is irradiated onto the product P, and the quality is judged as described above. A placement mechanism 8 is provided on the moving path upstream of the irradiation position, which places the products P one by one onto each receiver 4. The placement mechanism 8 can be, for example, a robot equipped with an arm at the tip that picks up and transfers the product P.

[0082] The exclusion mechanism 7 is provided downstream of the irradiation position. The exclusion mechanism 7 is a mechanism that excludes products P that have been determined to be defective from the production line to prevent them from being shipped. The exclusion mechanism 7 is provided with an exclusion control unit 71, to which an output signal from the calculation means 3 is input.

[0083] An exclusion signal output program 36 is implemented in the calculation means 3. The sequence control program 35 is programmed to execute the exclusion signal output program 36 when a result indicating a defective product is returned as the execution result of the pass / fail judgment program 34. The exclusion signal output program 36 is a program that outputs a signal to the exclusion control unit 71 and operates the exclusion mechanism 7. The exclusion mechanism 7 may be a robot that similarly sucks the product P onto its tip, picks it up from the receiver 4, and places it in a disposal box (not shown). The exclusion control unit 71 is configured so that the exclusion mechanism 7 operates when the receiver 4, which was at the irradiation position (the position for determining whether the product is good or bad), reaches the exclusion position in the exclusion mechanism 7.

[0084] The operation of the product inspection device will be described below, along with an explanation of an embodiment of a product inspection method. The manufactured products P are placed one by one on the receivers 4 by the placement mechanism 8. Each receiver 4 with the product P placed thereon is moved by the movement mechanism 400 and reaches the irradiation position. At the irradiation position, pulsed light is irradiated onto the product P multiple times. The light that passes through the product P during these irradiations reaches the photodetector 2 and generates an output from the photodetector 2. The output of the photodetector 2 is converted into digital data by the AD converter 21, integrated by the FPGA 61 serving as the integrating means 6, and input to the calculating means 3. The output of the reference photodetector 52 is also digitized and integrated in the same way and input to the calculating means 3.

[0085] In the calculation means 3, the measurement program 33 calculates the absorption spectrum S2, and the pass / fail judgment program 34 receives the calculated spectrum and judges whether the product P is pass / fail. When the execution result indicates that the product is defective, the sequence control program 35 executes the exclusion signal output program 36, and the exclusion mechanism 7 removes the product P from the production line. In this way, the pass / fail judgment is made sequentially for each product P on the receiver 4, and any product P determined to be defective is removed.

[0086] In the above-described product inspection, when the pulsed light is irradiated multiple times, the receiver 4 may be stationary or may be moving. As mentioned above, even if pulsed light with a repetition frequency of 10 kHz is irradiated 100 times, the time required for this is 10 milliseconds, and it is easy to irradiate the pulsed light 100 times while the product P is moving, unless the product P is very small and is moved at high speed.

[0087] However, when irradiating the product P with pulsed light multiple times while moving it, strictly speaking, the spectral characteristics of different locations on the product P are being measured. Therefore, if it is desired to precisely measure the spectral characteristics of only a specific location, the product P must be stopped. On the other hand, when irradiating the product P with pulsed light multiple times while moving it, the spectral characteristics of the product P are measured at multiple different locations and then integrated. This is equivalent to measuring the average spectral characteristics of the product P, and is advantageous in that it means that the average spectral characteristics of the entire product P, which has variations in spectral characteristics depending on the location, can be instantly measured. It is possible to perform spectroscopic measurement by irradiating the same location with multiple pulses while moving the product P. Specifically, a scanning mechanism using a galvanometer mirror or the like can be provided in the optical system that irradiates the pulsed light, and the irradiation position of the pulsed light can be scanned in synchronization with the movement of the product P.

[0088] In the above embodiment, it is not necessary to quantify a specific component to determine whether product P is good or bad. For example, there may be a characteristic wavelength in the spectral absorption characteristics of product P, and the quality can be determined based on that value alone. In this case, the value of that wavelength from the absorption spectrum is compared with a reference value to determine whether product P is good or bad. Since only a specific wavelength is required, there is no need to obtain a spectrum (values ​​at each wavelength across a certain wavelength range). The quality can be determined simply by dividing the measured value at that wavelength by a reference intensity and comparing the result with the reference value.

[0089] In the devices and methods of the above-described embodiments, the light from the object P when irradiated with multiple pulsed light is transmitted light, but it may also be reflected light or scattered light. When performing spectroscopic measurement of reflected light or scattered light, the light receiver 2 is placed at a position where the reflected light or scattered light is received. Furthermore, the reference spectral intensity is obtained by performing measurements using a standard plate with known spectral reflection characteristics and spectral scattering characteristics placed in place of the holder 4. When it is desired to obtain the reference spectral intensity in real time, such a standard plate is placed on the reference optical path, and the reflected light and scattered light are received by the reference light receiver 52.

[0090] Although the description of the types of product P has been omitted, various products other than the tablets mentioned above can be inspected. For example, oral products such as various health foods other than tablets can be inspected. In addition, industrial products manufactured using various molding techniques can also be inspected. It is not necessary for the product to be solid-phase; liquid-phase products can also be inspected. For example, in the case of pharmaceuticals, the manufactured liquid-phase pharmaceutical is placed in a transparent container and pulsed light is irradiated through the container to inspect whether it is good or bad.

[0091] Furthermore, the pulse light source 1 may include an ultrashort pulse laser source 11 that emits SC light using a nonlinear element 12, or may include an ASE (Amplified Spontaneous Emission) light source, an SLD (Superluminescent Diode) light source, or the like, and may extend light from any of these light sources using a stretcher element 13. Since an ASE light source generates light within a fiber, when a fiber is used as the stretcher element 13, broadband pulse light can be made incident on the stretcher element 13 with high affinity and low loss, enabling the broadband pulse light to be stretched with high efficiency. Furthermore, an SLD light source also extracts light emitted from a narrow active layer, allowing it to be made incident on the stretcher element 13 with low loss, enabling the broadband pulse light to be stretched with high efficiency. [Explanation of symbols]

[0092] 1. Pulsed light source 11 Ultrashort pulse laser source 12 Nonlinear elements 13 Extension element 14 Arrayed Waveguide Grating 15 Delay Fiber 2 Receiver 3 Calculation means 33 Measurement Program 34 Good / bad judgement program 35 Sequence control program 36 Exclusion signal output program 4 Receptacle 400 Moving mechanism 52 Reference receiver 53 AD converter 54 FPGA 6 Integral means 60 Integral means 61 FPGA 62 Trigger generation section 7 Exclusion mechanism P Object (product)

Claims

1. an irradiation step of irradiating the same object multiple times with pulsed light, the elapsed time of the pulse corresponding to the wavelength of the light being one-to-one; a light receiving step of receiving, with a light receiver, each pulse of light from the object irradiated with the pulsed light multiple times in the irradiating step; a calculation processing step of converting an output from a light receiver that has received each pulse of light in the light receiving step into a spectrum, an integration step is provided for integrating the values ​​of the times at which light of the same wavelength is regarded as being received for the outputs of the light pulses from the light receiver; The calculation processing step is a step of performing processing to determine each integrated value in the integration step as the light intensity at each corresponding wavelength, a reference time assigning step of assigning a reference time to the integration in the integration step when specifying a time at which light of the same wavelength is regarded as having been received in each pulse light, A spectroscopic measurement method characterized in that the integration step is a step of integrating values ​​for each pulse of pulsed light by regarding the time at which the same elapsed time from the reference time assigned in the reference time assignment step is the time at which light of the same wavelength was received.

2. the reference time assigning step is a step of generating a trigger signal in response to emission of each of the pulsed lights; 2. The spectroscopic measurement method according to claim 1, wherein the integrating step is a step of integrating the output from the photodetector that received each pulse of light at a time when the same time has elapsed since the trigger signal.

3. the irradiation step is a step of broadening the bandwidth of ultrashort pulsed laser light from an ultrashort pulsed laser source by making the ultrashort pulsed laser light incident on a nonlinear element to generate a nonlinear effect, making the broadband pulsed light output from the nonlinear element incident on an elongation element to elongate the pulse width, and then irradiating the broadband pulsed light onto the object multiple times; 3. The spectroscopic measurement method according to claim 2, wherein the reference time providing step is a step of detecting the ultrashort pulse laser light before it is incident on a nonlinear element and generating a trigger signal.

4. the irradiation step is a step of broadening the bandwidth by making ultrashort pulse laser light from an ultrashort pulse laser source incident on a nonlinear element to generate a nonlinear effect, wavelength-dividing the broadband pulse light output from the nonlinear element using an arrayed waveguide diffraction grating, and then transmitting and delaying the divided pulse light, which is the wavelength-divided broadband pulse light, through delay fibers, and collecting the divided pulse light output from each delay fiber to irradiate an object as a composite pulse light, wherein the material and length of each delay fiber are selected so that there is a one-to-one correspondence between the elapsed time of the composite pulse light and the wavelength of the light, 2. The spectroscopic measurement method according to claim 1, wherein the integrating step is a step of integrating an output from a photodetector that receives light from an object irradiated with the composite pulsed light for each value corresponding to each channel in an arrayed waveguide grating.

5. each delay fiber has normal dispersion characteristics or anomalous dispersion characteristics in a wavelength range of each of the divided pulse lights incident thereon; 5. The spectroscopic measurement method according to claim 4, wherein the integration step is a step of integrating the pulse output from the photodetector corresponding to each divided pulse light over a narrow width excluding the tail portions on both sides of the pulse.

6. a pulsed light source that emits pulsed light in which the elapsed time of the pulse corresponds one-to-one to the wavelength of the light; a light receiver disposed at a position to receive light from an object irradiated with pulsed light from a pulsed light source; and a calculation means for converting the output from the photodetector into a spectrum, an integrating means for integrating outputs from the photodetector due to each pulse of light when the same object is irradiated with pulsed light from the pulsed light source for each time value at which light of the same wavelength is considered to be received; the calculation means is means for performing a calculation process in which each value integrated by the integration means is the light intensity at each corresponding wavelength, the integrating means is provided with a reference time unit that provides a reference time for specifying a time at which light of the same wavelength is regarded as having been received in each pulse of light; The integrating means is a means for integrating values ​​by regarding, for each pulse of light, the time at which the same elapsed time from the reference time assigned by the reference time assigning unit is the time at which light of the same wavelength was received.

7. the reference time setting unit is a trigger signal generating unit that generates a trigger signal in response to emission of each pulsed light from the pulsed light source, the trigger signal generating unit is connected to the integrating means so that the trigger signal is input to the integrating means; 7. The spectrometer according to claim 6, wherein the integrating means integrates the output from the photodetector that has received each pulse of light at a time when the same time has elapsed since the trigger signal was received.

8. the pulse light source includes an ultrashort pulse laser source, a nonlinear element that generates a nonlinear effect in the ultrashort pulse laser light from the ultrashort pulse laser source to broaden the bandwidth, and an elongation element that elongates the pulse width of the broadband pulse light emitted from the nonlinear element; 8. The spectroscopic measurement device according to claim 7, wherein the trigger signal generating section includes a detector for detecting the ultrashort pulse laser light before it is incident on the nonlinear element in order to generate the trigger signal.

9. the pulse light source comprises an ultrashort pulse laser source, a nonlinear element that generates a nonlinear effect in the ultrashort pulse laser light from the ultrashort pulse laser source to broaden the bandwidth, an arrayed waveguide grating that wavelength-divides the broadband pulse light emitted from the nonlinear element, and delay fibers that transmit and delay each divided pulse light, which is the pulse light wavelength-divided by the arrayed waveguide grating, and the material and length of each delay fiber are selected so that when the divided pulse light emitted from each delay fiber is collected and irradiated onto an object as a composite pulse light, there is a one-to-one correspondence between the elapsed time and the wavelength of the light in the composite pulse light, 7. The spectroscopic measurement device according to claim 6, wherein the integrating means is means for integrating an output from a photodetector that receives light from an object irradiated with the composite pulsed light for each value corresponding to each channel in an arrayed waveguide grating.

10. each delay fiber has normal dispersion characteristics or anomalous dispersion characteristics in a wavelength range of each of the divided pulse lights incident thereon; 10. The spectroscopic measurement device according to claim 9, wherein the integrating means integrates the pulse output from the photodetector corresponding to each divided pulse light over a narrow width excluding both tail portions of the pulse.

11. a spectroscopic measurement step of performing the spectroscopic measurement method according to any one of claims 1 to 5 on a manufactured product as the object; a quality determination step for determining whether the product is good or bad according to the results of the spectroscopic measurement in the spectroscopic measurement step; A product inspection method comprising:

12. the spectroscopic measurement step is a step of measuring an absorption spectrum of a product as the target object, The method includes a quantification step of quantifying a specific component of the product from the measured absorption spectrum, 12. The product inspection method according to claim 11, wherein the quality determining step determines the quality of the product based on the amount of the specific component determined in the quantifying step.

13. 13. The product inspection method according to claim 12, wherein the quantitative determination step is a step of quantifying the specific component by chemometrics.

14. the spectroscopic measurement step is a step of measuring an absorption spectrum of a product as the target object, the target product has a wavelength-averaged transmittance of the pulsed light of less than 10%, the irradiation step is a step of irradiating the pulsed light onto the same product as the target object 100 times or more, 14. A product inspection method according to claim 11, 12 or 13, wherein the integration step is a step of integrating the values ​​at each time when light of the same wavelength is considered to be received for pulsed light irradiated 100 or more times.

15. 15. The product inspection method according to claim 11, wherein the irradiating step is a step of irradiating the same product as the moving object with the pulsed light a plurality of times.

16. A product inspection device including the spectroscopic measurement device according to any one of claims 6 to 10, which performs spectroscopic measurement of a manufactured product as the object, A product inspection device comprising a quality determining means for determining whether a product is good or bad in accordance with the results of spectroscopic measurement obtained by the calculation means.

17. the light receiver is provided at a position where it receives light transmitted through a product as the target object, and the calculation means is means for obtaining an absorption spectrum of the product as a measurement result, The apparatus is provided with a quantitative determination means for determining the amount of a specific component of a product from the measured absorption spectrum, 17. A product inspection apparatus according to claim 16, wherein the quality determining means determines the quality of the product based on the amount of the specific component determined by the quantifying means.

18. 18. The product inspection device according to claim 17, wherein the quantifying means is a means for quantifying the specific component by chemometrics.

19. the pulsed light source is a light source that irradiates the pulsed light onto the same product as the target object 100 times or more, 19. A product inspection device according to claim 16, 17 or 18, wherein the integrating means is means for integrating each value at each time when light of the same wavelength is considered to have been received for pulsed light irradiated 100 times or more.

20. a moving mechanism for moving a product through a position where light is irradiated from the pulsed light source; 20. The product inspection device according to claim 16, wherein the pulsed light source is a light source capable of irradiating the same product with the pulsed light a plurality of times while the irradiation position is moving.

21. A product sorting device comprising the product inspection device according to any one of claims 16 to 20, The product selection device further comprises an exclusion mechanism for excluding from the manufacturing line products that have been determined to be defective by the quality determining means.

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