JP7238541B2 - Spectroscopic measurement device and spectroscopic measurement method - Google Patents

Description

The invention of this application relates to a spectroscopic measurement technique.

Spectroscopic measurement technology, which irradiates an object with light and measures the spectrum of the light (transmitted light, reflected light, scattered light, etc.) from the object, is a typical technique for analyzing the composition and properties of the object. It is. A typical spectroscopic measurement technique is a technique using a diffraction grating. The light to be measured that is incident through the entrance slit is collimated by a concave mirror and radiated onto the diffraction grating, and the dispersed light from the diffraction grating is similarly collected by the concave mirror and detected by placing a light receiver at the collection position. By changing (scanning) the posture of the diffraction grating, light with different wavelengths is sequentially incident on the photodetector, and the output of the photodetector becomes a spectrum.

Spectroscopic measurement using such a diffraction grating requires scanning of the diffraction grating, so high-speed measurement is not possible. Also, since the light is confined at the entrance slit, the SN ratio of the measurement cannot be increased. For this reason, it is necessary to repeat scanning several times to increase the total amount of light (light amount) incident on the light receiver, which is also a factor preventing high-speed measurement.

2. Description of the Related Art In recent years, multichannel spectrometers using an area sensor in which a large number of photoelectric conversion elements are arranged in a row have been developed. In the case of the multi-channel type, scanning of the diffraction grating is unnecessary, so high speed can be expected. However, since the basic structure of limiting the light with the entrance slit and irradiating it on the diffraction grating with the concave mirror remains as it is, the problem of a small SN ratio is not solved, and the disadvantage that the measurement time is long to obtain the amount of light is solved. not

JP 2013-205390 A

On the other hand, in the field of light source technology, extensive research is being conducted to broaden the wavelength band of pulsed light emitted from a pulsed light source. A typical pulse light source is a pulse oscillation laser (pulse laser). In particular, when an ultrashort pulse laser beam is passed through a nonlinear element such as a fiber, the band is broadened by a nonlinear optical effect such as self-phase modulation. This light is called supercontinuum light (hereinafter referred to as SC light).

Broadband pulsed light, such as SC light, is extended in terms of wavelength range, but remains narrow in terms of pulse width (time width). However, the pulse width can also be extended by creating an appropriate transmission delay difference between wavelengths. For example, when broadband pulsed light is passed through a fiber with suitable group delay characteristics, such as dispersion compensating fiber (DCF), the pulse width is stretched due to transmission delay differences between wavelengths. When the pulse is stretched, if an element having appropriate wavelength dispersion characteristics is selected, the pulse can be stretched with one-to-one correspondence between the elapsed time (time) in the pulse and the wavelength.

The correspondence relationship between the elapsed time and the wavelength in the broadband pulsed light thus pulse-stretched (hereinafter referred to as broadband stretched pulsed light) can be effectively used for spectroscopic measurement. That is, when a broadband stretched pulsed light is received by a certain photodetector, the temporal change in the light intensity detected by the photodetector corresponds to the light intensity of each wavelength, that is, the spectrum. Therefore, temporal changes in the output data of the photodetector can be converted into a spectrum, enabling spectroscopic measurement without using a special dispersive element such as a diffraction grating. In other words, by irradiating a sample with a broadband stretched pulsed light, receiving the light from the sample with a photodetector, and measuring the change over time, it is possible to know the spectral characteristics (for example, spectral transmittance) of the sample. become.

However, according to the inventor's research, there are actually problems with the characteristics of the element that performs pulse stretching and the characteristics of the light receiver that detects broadband stretched pulsed light, and when considering the spectroscopic measurement system as a whole, there are practical problems. exists.
The invention of this application was made to solve the above-mentioned problems when using broadband stretched pulsed light for spectroscopic measurement, and is a practical method that can perform spectroscopic measurement at high speed with sufficient accuracy over a wide wavelength band. Aims to provide technology.

In order to solve the above problems, the invention of the spectrometer of the present application includes a pulsed light source that emits broadband pulsed light having a continuous broadband spectrum ;
an expansion element for expanding the pulse width of the broadband pulsed light from the pulsed light source so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a splitting element for splitting the broadband pulsed light whose pulse width has been stretched by the stretching element into two;
a first light receiver that receives light from an object irradiated with one of the light beams split by the splitting element;
a second light receiver for receiving light from an object irradiated with the other light divided by the splitting element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum,
The first and second photoreceivers have different spectral sensitivity characteristics, the first photoreceiver being sensitive over a first wavelength range and the second photoreceiver being sensitive to the first wavelength. having sensitivity over a second unmatched range of wavelengths;
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector Among them, it has a configuration that it is a means for performing arithmetic processing for converting the temporal change of the output in the time zone corresponding to the second wavelength range into the spectrum of the second wavelength range.
Further, in this spectrometer, the first photoreceiver has a higher spectral sensitivity than the second photoreceiver in the first wavelength range, and the second photoreceiver has a higher spectral sensitivity in the second wavelength range. It can have a configuration in which the light receiver has higher spectral sensitivity than the first light receiver.
Further, in order to solve the above problems, the invention of the spectrometer of the present application provides a pulsed light source for emitting broadband pulsed light having a continuous broadband spectrum ,
an expansion element for expanding the pulse width of the broadband pulsed light from the pulsed light source so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
The broadband pulsed light whose pulse width is stretched by the stretching element is divided into light whose spectrum is continuous in the first wavelength range on the long wavelength side and in the second wavelength range on the short wavelength side with respect to the division wavelength. a splitting element for splitting into spectrally continuous light ;
a first photoreceiver for receiving light from an object irradiated with light in a first wavelength range among those split by the splitting element;
a second photoreceiver for receiving light from an object irradiated with light in a second wavelength range among those split by the splitting element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum ,
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector Among them, it has a configuration that it is a means for performing arithmetic processing for converting the temporal change of the output in the time zone corresponding to the second wavelength range into the spectrum of the second wavelength range.
Further, in order to solve the above problems, the invention of the spectrometer of the present application provides a pulsed light source for emitting broadband pulsed light having a continuous broadband spectrum ,
Broadband pulsed light emitted from a pulsed light source is divided into light whose spectrum is continuous in a first wavelength range on the long wavelength side and spectrum is continuous in a second wavelength range on the short wavelength side with respect to the split wavelength. a splitting element for splitting into light and
a first stretching element for stretching the pulse width of the light in the first wavelength range split by the splitting element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a second stretching element for stretching the pulse width of the light in the second wavelength range split by the splitting element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a first light receiver for receiving light from an object irradiated with light whose pulse width is stretched by the first stretching element;
a second light receiver that receives light from an object irradiated with light whose pulse width is stretched by the second stretching element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum ,
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector Among them, it has a configuration that it is a means for performing arithmetic processing for converting the temporal change of the output in the time zone corresponding to the second wavelength range into the spectrum of the second wavelength range.
Further, in order to solve the above problems, the spectroscopic measurement apparatus of the present application includes a pulsed light source that emits broadband pulsed light having a continuous broadband spectrum ,
an expansion element for expanding the pulse width of the broadband pulsed light from the pulsed light source so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a splitting element that splits light from an object irradiated with broadband pulsed light that has been stretched by the stretching element into two;
a first light receiver that receives one of the lights split by the splitting element;
a second photoreceiver for receiving the other light split by the splitting element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum,
The first and second photoreceivers have different spectral sensitivity characteristics, the first photoreceiver being sensitive over a first wavelength range and the second photoreceiver being sensitive to the first wavelength. having sensitivity over a second unmatched range of wavelengths;
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector Among them, it has a configuration that it is a means for performing arithmetic processing for converting the temporal change of the output in the time zone corresponding to the second wavelength range into the spectrum of the second wavelength range.
Further, in this spectrometer, the first photoreceiver has a higher spectral sensitivity than the second photoreceiver in the first wavelength range, and the second photoreceiver has a higher spectral sensitivity in the second wavelength range. It can have a configuration in which the light receiver has higher spectral sensitivity than the first light receiver.
Further, in order to solve the above problems, the spectroscopic measurement apparatus of the present application includes a pulsed light source that emits broadband pulsed light having a continuous broadband spectrum ,
an expansion element for expanding the pulse width of the broadband pulsed light from the pulsed light source so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
The light from the object irradiated with the broadband pulsed light expanded by the expansion element is divided into light in the first wavelength range on the long wavelength side and light in the second wavelength range on the short wavelength side with respect to the division wavelength. a splitting element that splits into light and
a first light receiver for receiving light in a first wavelength range among those split by the splitting element;
a second photoreceiver for receiving light in a second wavelength range among those split by the splitting element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum ,
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector Among them, it has a configuration that it is a means for performing arithmetic processing for converting the temporal change of the output in the time zone corresponding to the second wavelength range into the spectrum of the second wavelength range.
In order to solve the above problems, the spectroscopic measurement method of the present application includes an emission step of emitting broadband pulsed light having a continuous broadband spectrum from a pulsed light source;
a pulse extension step of extending the pulse width of the broadband pulsed light emitted in the emission step with an extension element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a splitting step of splitting the broadband pulsed light whose pulse width has been stretched in the pulse stretching step into two by a splitting element;
a first light receiving step of receiving, with a first light receiver, light from an object irradiated with one of the light beams divided in the dividing step;
a second light receiving step of receiving, with a second light receiver, the light from the object irradiated with the light of the other wavelength of the light split in the splitting step;
Calculation for converting the temporal change in the output from the first photodetector received in the first light receiving process and the temporal change in the output from the second photodetector received in the second light receiving process into a spectrum by the calculation means and
The first and second photoreceivers have different spectral sensitivity characteristics, the first photoreceiver having sensitivity over the first wavelength range and the second photoreceiver having sensitivity over the first wavelength range. having sensitivity over a second range of wavelengths inconsistent with
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector Among them, the step of converting the temporal change in the output in the time period corresponding to the second wavelength range that does not match the first wavelength range into the spectrum of the second wavelength range.
Further, in this spectroscopic measurement method, the first photoreceiver has a higher spectral sensitivity than the second photoreceiver in the first wavelength range, and the second photoreceiver has a higher spectral sensitivity in the second wavelength range. It can have a configuration in which the light receiver has higher spectral sensitivity than the first light receiver.
In order to solve the above problems, the spectroscopic measurement method of the present application includes an emission step of emitting broadband pulsed light having a continuous broadband spectrum from a pulsed light source;
a pulse extension step of extending the pulse width of the broadband pulsed light emitted in the emission step with an extension element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
Broadband pulsed light whose pulse width has been stretched in the pulse stretching step is divided into light whose spectrum is continuous in a first wavelength range on the long wavelength side and a second wavelength range on the short wavelength side with respect to the division wavelength. A splitting step of splitting the light into light with a continuous spectrum in the splitting element,
a first light-receiving step of receiving, with a first light receiver, the light from the object irradiated with the light in the first wavelength range among those divided in the dividing step;
a second light-receiving step of receiving, with a second light receiver, the light from the object irradiated with the light in the second wavelength range among the light split in the splitting step;
Calculation for converting the temporal change in the output from the first photodetector received in the first light receiving process and the temporal change in the output from the second photodetector received in the second light receiving process into a spectrum by the calculation means and _
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector Among them, the step of converting the temporal change in the output in the time period corresponding to the second wavelength range that does not match the first wavelength range into the spectrum of the second wavelength range.
In order to solve the above problems, the spectroscopic measurement method of the present application includes an emission step of emitting broadband pulsed light having a continuous broadband spectrum from a pulsed light source;
The broadband pulsed light emitted in the emission step is divided into light whose spectrum is continuous in a first wavelength range on the long wavelength side and spectrum is continuous in a second wavelength range on the short wavelength side with respect to the division wavelength. a splitting element for splitting into light and
a first pulse stretching step of pulse stretching with a first stretching element so that the relationship between the elapsed time in the pulse and the wavelength is one to one for the light in the first wavelength range among the light split in the splitting step; ,
a second pulse stretching step of pulse stretching with a second stretching element so that the light in the second wavelength range split in the splitting step has a one-to-one relationship between the elapsed time in the pulse and the wavelength; ,
a first light receiving step of receiving, with a first light receiver, light from an object irradiated with the light pulse-stretched in the first pulse stretching step;
a second light receiving step of receiving, with a second light receiver, light from an object irradiated with the light pulse-stretched in the second pulse stretching step;
calculating means for converting into a spectrum the temporal change in the output from the first photodetector received in the first light receiving step and the temporal change in the output from the second photodetector received in the second light receiving step; equipped with
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector Among them, the step of converting the temporal change in the output in the time period corresponding to the second wavelength range that does not match the first wavelength range into the spectrum of the second wavelength range.
Further, in order to solve the above-mentioned problems, the invention of the spectroscopic measurement method of the present application includes an emission step of emitting broadband pulsed light having a broadband and continuous spectrum from a pulsed light source,
a pulse extension step of extending the pulse width of the broadband pulsed light emitted in the emission step with an extension element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a splitting step of splitting the light from the object irradiated with the broadband pulsed light whose pulse width is stretched in the pulse stretching step into two by a splitting element;
a first light receiving step of receiving one of the light beams split in the splitting step with a first light receiver;
a second light receiving step of receiving the other of the light split in the splitting step with a second light receiver;
Calculation for converting the temporal change in the output from the first photodetector received in the first light receiving process and the temporal change in the output from the second photodetector received in the second light receiving process into a spectrum by the calculation means and
The first and second photoreceivers have different spectral sensitivity characteristics, the first photoreceiver being sensitive over a first wavelength range and the second photoreceiver being sensitive to the first wavelength. having sensitivity over a second unmatched range of wavelengths;
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector Among them, the step of converting the output temporal change in the time zone corresponding to the second wavelength range into the spectrum of the second wavelength range.
Further, in this spectroscopic measurement method, the first photoreceiver has a higher spectral sensitivity than the second photoreceiver in the first wavelength range, and the second photoreceiver has a higher spectral sensitivity in the second wavelength range. It can have a configuration in which the light receiver has higher spectral sensitivity than the first light receiver.
Further, in order to solve the above-mentioned problems, the invention of the spectroscopic measurement method of the present application includes an emission step of emitting broadband pulsed light having a broadband and continuous spectrum from a pulsed light source,
an elongation step of pulse-expanding the pulse width of the broadband pulsed light emitted in the emission step with an elongation element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
The light from the object irradiated with the broadband pulsed light extended in the extension step is divided into the light and the short wavelength side of the spectrum in the first wavelength range on the long wavelength side with respect to the division wavelength. a splitting step of splitting the light into light having a continuous spectrum in a second wavelength range with a splitting element;
a first light receiving step of receiving the light in the first wavelength range among the light split in the splitting step with a first light receiver;
a second light receiving step of receiving the light in the second wavelength range, which is split in the splitting step, with a second light receiver;
a calculation step of converting into a spectrum the temporal change in the output from the first photodetector received in the first light receiving step and the temporal change in the output from the second photodetector received in the second light receiving step; equipped with
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector Among them, the step of converting the output temporal change in the time zone corresponding to the second wavelength range into the spectrum of the second wavelength range.
Further, in order to solve the above problems, the spectroscopic measurement method of the present application includes a first emitting step of emitting broadband pulsed light having a continuous spectrum in a first wavelength range from a pulsed light source;
a first pulse stretching step of stretching the pulse width of the broadband pulsed light emitted in the first emitting step with an stretching element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a first irradiation step of irradiating an object with the broadband pulsed light pulse-stretched in the first pulse-stretching step;
a first light receiving step of receiving light from the object irradiated in the first irradiation step with a first light receiver;
a second emitting step of emitting from the pulsed light source another broadband pulsed light whose spectrum is continuous in a second wavelength range that does not match the first wavelength range;
a second pulse stretching step of stretching the pulse width of the broadband pulsed light emitted in the second emitting step with an stretching element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a second irradiation step of irradiating the object with the broadband pulsed light pulse-stretched in the second pulse-stretching step;
a second light receiving step of receiving light from the object irradiated in the second irradiation step with a second light receiver having spectral sensitivity characteristics different from those of the first light receiver;
Calculation for converting the temporal change in the output from the first photodetector received in the first light receiving process and the temporal change in the output from the second photodetector received in the second light receiving process into a spectrum by the calculation means and
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector Among them, the step of converting the output temporal change in the time zone corresponding to the second wavelength range into the spectrum of the second wavelength range.
In each of the above configurations, the stretching element can be a single mode fiber, a single mode multicore fiber, a single mode fiber bundle fiber, a multimode fiber, a diffraction grating, a chirped fiber Bragg grating, or a prism.
In each of the above configurations, the first elongated element and the second elongated element can be elements with different elongation properties.
In each of the above configurations, the splitting element can be any one of a dichroic mirror, a wavelength division multiplex coupler, a diffraction grating, and an arrayed waveguide grating.
In each of the configurations above, the pulsed light source may be a supercontinuum light source.
In each of the above configurations, the pulse light source may be a supercontinuum light source that outputs light whose spectrum is continuous over a wavelength width of at least 10 nm in the wavelength range of 900 nm or more and 1300 nm or less.
In each of the configurations above, the first photodetector may be an InGaAs photodiode photodetector.
In each of the above configurations, the second photoreceiver can be a Si photodiode photoreceiver.
In each of the above configurations, the spectroscopic measurement apparatus includes a position irradiated with one of the light beams split by the splitting element or the long-wavelength light and a position irradiated with the other light split by the splitting element or the short-wavelength light. A moving mechanism may be provided for moving between positions where the light of the wavelength is irradiated.
In each of the above configurations, the spectroscopic measurement apparatus includes a position where the object is irradiated with light whose pulse width is stretched by the first stretching element, and a position where the light whose pulse width is stretched by the second stretching element is irradiated. A moving mechanism may be provided to move between the position where the
In the arithmetic processing performed by the arithmetic means included in the spectroscopic measurement apparatus having each of the configurations described above, the first wavelength range and the second wavelength range can be continuous with a wavelength resolution therebetween.
In the calculation process included in the spectroscopic measurement method having each of the configurations described above, the first wavelength range and the second wavelength range can be continuous with a wavelength resolution therebetween.

As described below, according to the spectroscopic measurement device or the spectroscopic measurement method of the present application, in the spectroscopic measurement using the time-wavelength uniqueness of pulse-stretched broadband pulsed light, measurement is performed by dividing the measurement into two detection systems. The detection of light in each wavelength band can be optimized according to the characteristics of the stretcher and the characteristics of the receiver. Therefore, spectroscopic measurement can be performed at high speed with sufficient accuracy over a wide wavelength band.
In addition, according to the spectroscopic measurement device or the spectroscopic measurement method of the present application, in the spectroscopic measurement using the time-wavelength uniqueness of the pulse-stretched broadband pulsed light, the measurement is performed by dividing the two detection systems according to the wavelength region. , the detection of light in each wavelength band can be optimized according to the characteristics of the stretching element and the characteristics of the receiver. Therefore, spectroscopic measurement can be performed at high speed with sufficient accuracy over a wide wavelength band.
Further, in the configuration in which the broadband pulsed light is wavelength-divided by the splitting element and then pulse stretched, if the first and second stretching elements have different stretching characteristics, the pulse stretching can be optimized according to the wavelength range. can.
In addition, if the light from the object is divided into two and measured by two detection systems, the structure becomes simpler, and even if the reproducibility of the broadband pulsed light deteriorates, the measurement accuracy can be improved. An effect of not lowering is obtained.
Further, when the pulse light source is a supercontinuum light source that outputs light whose spectrum is continuous over a wavelength width of at least 10 nm in the wavelength range of 900 nm or more and 1300 nm or less, spectroscopic analysis of solid-phase or liquid-phase objects is particularly meaningful for

1 is a schematic diagram of a spectrometer of a first embodiment; FIG. FIG. 2 is a schematic diagram showing the principle of pulse extension of broadband pulsed light; It is the schematic which showed an example of the spectral sensitivity characteristic of each light receiver. FIG. 4 shows the transmission properties of a fiber used as a stretching element; FIG. 4 is a schematic diagram showing data handled by a measurement program; It is the flowchart which showed the schematic of a measurement program. FIG. 2 is a schematic diagram of a spectroscopic measurement device of a second embodiment; FIG. 3 is a schematic diagram of a spectroscopic measurement device according to a third embodiment; FIG. 11 is a schematic diagram of a spectroscopic measurement device according to a fourth embodiment; FIG. 11 is a schematic diagram of a spectroscopic measurement device according to a fifth embodiment; FIG. 4 is a schematic diagram showing another example of splitting elements; FIG. 11 is a schematic diagram of a spectroscopic measurement device according to a sixth embodiment; FIG. 11 is a schematic diagram of a spectroscopic measurement device according to a seventh embodiment; FIG. 11 is a schematic diagram of a spectroscopic measurement device of an eighth embodiment; FIG. 11 is a schematic diagram showing another example of an elongated element;

Hereinafter, modes (embodiments) for carrying out the invention of this application will be described.
FIG. 1 is a schematic diagram of the spectroscopic measurement device of the first embodiment. The spectroscopic measurement apparatus shown in FIG. 1 is an apparatus for spectroscopically measuring an object S by irradiating it with pulsed light. It is a device for spectroscopic measurement.
Specifically, the spectroscopic apparatus shown in FIG. Irradiation optical system 3 for irradiating the object S with light, light receivers 41 and 42 for receiving the light from the object S irradiated with the pulsed light, and calculation for calculating the spectrum according to the output from the light receivers 41 and 42 means 5;

The pulse light source 1 emits SC light in this embodiment. A pulse light source 1 which is an SC light source includes an ultrashort pulse laser source 11 and a nonlinear element 12 .
A gain switch laser, a microchip laser, a fiber laser, or the like can be used as the ultrashort pulse laser source 11 . As the nonlinear element 12, a fiber is often used. For example, photonic crystal fibers or other nonlinear fibers can be used as nonlinear element 12 . The mode of the fiber is often a single mode, but even a multimode fiber can be used as the nonlinear element 12 as long as it exhibits sufficient nonlinearity.

The wavelength range of the broadband pulsed light is not particularly limited. The SC light can have a continuous spectrum over a very wide wavelength range of, for example, about 500 to 2000 nm, and may be pulsed light with a wide band to this extent. In some cases, the pulse light source 1 is used as the pulse light source 1, which is not so wide and emits pulsed light having a wide band within a necessary range. For example, for spectrometry in the near-infrared region, a light source that emits pulsed light that is a continuous spectrum over at least 10 nm, 50 nm, or 100 nm in the range of about 900 to 1300 nm can be used as the pulsed light source 1 .
As elongation element 2 a single-mode fiber 20 is used in this embodiment. For example, fibers with a given group delay characteristic, such as those used as dispersion compensating fibers (DCF) in the field of optical communications, can be used as stretching elements 2 .

FIG. 2 is a schematic diagram showing the principle of pulse extension of broadband pulsed light. As means for extending the pulse width of broadband pulsed light such as SC light, for example, when SC light L1, which is a continuous spectrum in a certain wavelength range, is passed through a fiber 20 having a positive dispersion characteristic in that wavelength range, the pulse width is is effectively stretched. That is, as shown in FIG. 2, although the SC light L1 is an ultrashort pulse, light with the longest wavelength _λ1 exists at the beginning of one pulse, and light with shorter wavelengths gradually exists as time elapses. However, at the end of the pulse there is light with the shortest wavelength _λn . When this light is passed through the fiber 20 with normal dispersion, light with a shorter wavelength propagates later in the fiber 20 with normal dispersion. Light with longer wavelengths lags behind light with longer wavelengths. As a result, the emitted SC light L2 becomes light whose pulse width is elongated while the uniqueness of time versus wavelength is ensured. That is, as shown in the lower part of FIG. 2, the pulses are extended in a one-to-one correspondence with the wavelengths λ ₁ to _λn at times t ₁ to t _n .

An anomalous dispersion fiber can also be used as the fiber 20 for pulse stretching. In this case, in the SC light, the light on the longer wavelength side that existed at the beginning of the pulse is delayed, and the light on the shorter wavelength side that existed later is dispersed in the advanced state. The relationship is reversed, and the pulse is stretched in a state in which short-wavelength light exists at the beginning of one pulse and longer-wavelength light exists as time elapses. However, compared with the case of normal dispersion, it is often necessary to lengthen the propagation distance for pulse extension, which tends to increase the loss. Therefore, normal variance is preferred in this respect.

The illumination optics 3 includes a beam expander 30 in this embodiment. Although the light from the fiber 20 as the stretching element 2 is time-stretched broadband pulsed light, it is the light from the ultrashort pulse laser source 11, taking into account the small beam diameter. In addition, a scanning mechanism such as a galvanomirror may be provided to cover a wide irradiation area by beam scanning.

In this embodiment, it is assumed that the absorption spectrum of the object S is to be measured. Receiving plates 61 and 62 are provided at the irradiation position of the broadband pulsed light by the irradiation optical system 3 . The receiving plates 61, 62 are transparent in the measurement wavelength range. The object S is placed on the receiving plates 61 and 62 . The irradiation optical system 3 is designed to irradiate light from above, and the light receivers 41 and 42 are positioned on the output side (in this example, below) of the receiving plates 61 and 62 .

A general-purpose PC is used as the computing means 5 in this embodiment. An AD converter 7 is provided between the photodetectors 41 and 42 and the computing means 5, and the outputs of the photodetectors 41 and 42 are digitized by the AD converter 7 and input to the computing means.
The computing means 5 includes a processor 51 and a storage section (hard disk, memory, etc.) 52 . A measurement program 53 for processing output data from the photodetectors 41 and 42 to calculate a spectrum and other necessary programs are installed in the storage unit 52 .

In the spectroscopic measurement apparatus of such an embodiment, the entire spectroscopic measurement system is optimized in consideration of the characteristics of the expansion element 2 and the characteristics of the light receivers 41 and 42 . Specifically, the spectrometry system in the device of the embodiment divides the broadband pulsed light into two and detects each separately, and two different detection systems, the first and the second, are provided. .

More specifically, as shown in FIG. 1, the irradiation optical system 3 includes a splitting element. A beam splitter 31 is used in this embodiment as a splitting element. The beam splitter 31 is a 1/2 splitting mirror, and is an element that splits the beam into halves of the beam.
Since the beam splitter 31 is arranged as a splitting element, the optical path from the expansion element 2 branches into a first optical path P1 and a second optical path P2, as shown in FIG. Receiving plates 61 and 62 are provided on the optical paths P1 and P2, respectively, and light receivers 41 and 42 are arranged on the output sides of the receiving plates 61 and 62, respectively.

In this embodiment, photodetectors 41 and 42 having different spectral sensitivity characteristics are employed as components of different detection systems. That is, the light receivers 41 and 42 having different spectral sensitivity characteristics depending on the measurement wavelength range are used. Assuming that the light receivers 41 and 42 are a first light receiver 41 and a second light receiver 42, the first light receiver 41 has higher spectral sensitivity than the second light receiver 42 in the first wavelength range, The second photodetector 42 has higher spectral sensitivity than the first photodetector 41 in a second wavelength range different from the first wavelength range. As an example, an InGaAs diode photodetector using an InGaAs diode as a photodetector can be used as the first photodetector 41, and a Si diode photodetector using an Si diode as a photodetector cell can be used as the second photodetector 42. can be used.

FIG. 3 is a schematic diagram showing an example of spectral sensitivity characteristics of each light receiver. Similarly, the example of FIG. 3 shows the spectral sensitivity characteristics of an InGaAs diode photodetector as the first photodetector 41 and the spectral sensitivity characteristics of a Si diode photodetector as the second photodetector 42 . As shown in FIG. 3, the InGaAs diode photodetector has good sensitivity in the range of about 1000-1700 nm, and the Si diode photodetector has good sensitivity in the range of about 500-1000 nm.

The reason why the spectroscopic measurement apparatus of the embodiment has two different detection systems is that the transmission characteristics of the fiber used as the extension element 2 and the sensitivity characteristics of the light receiver itself are taken into consideration. This point will be described below.
FIG. 4 shows the transmission characteristics of a fiber used as stretching element 2. In FIG. The fiber whose transmission characteristics are shown in FIG. 4 is a silica-based single-mode fiber having positive dispersion characteristics. In FIG. 4, the horizontal axis indicates the wavelength, and the vertical axis indicates the attenuation rate (dB) per 1 km. As shown in FIG. 4, this fiber has transmission characteristics in which the attenuation rate increases as the wavelength becomes shorter.

On the other hand, when a fiber is used as the elongated element 2 as in the embodiment, a certain length is required. This is because the slope in the time-wavelength uniqueness (Δλ/Δt shown in FIG. 2) needs to be moderated to some extent. This is because if the gradient is steep, the wavelength resolution will be low due to the relationship with the response speed (signal output cycle) of the photodetector. A gentler slope Δλ/Δt requires a larger amount of elongation, which requires a longer fiber.

However, as can be seen from FIG. 4, the longer the fiber, the greater the attenuation of light, especially on the short wavelength side. In other words, if the fiber length is increased in order to increase the wavelength resolution, the attenuation will increase especially on the short wavelength side. As a result, even if the pulse light source 1 emits broadband pulsed light with flat intensity characteristics between wavelengths, the intensity balance between wavelengths is lowered due to the decrease in intensity in the short wavelength region after the pulse extension. can be.

Another problem is that it is difficult for the photodetector to have uniform sensitivity characteristics with respect to broadband light. For example, when performing spectrometry in the near-infrared region, an InGaAs diode photodetector employing InGaAs as a photodetector cell can be suitably used. However, when attempting to perform spectroscopic measurements over a wide band from the visible region to the near-infrared region, the InGaAs diode photodetector does not have sufficient sensitivity in the short wavelength region of less than 900 nm, as shown in FIG.

In consideration of these, the spectroscopic measurement apparatus of the embodiment divides the detection system into two wavelength bands and uses an optimum light receiver for each. That is, as described above, the InGaAs diode photodetector is used as the first photodetector 41 in the first wavelength range (long wavelength range), and the second photodetector 42 is used in the second wavelength range (short wavelength range). A Si diode photodetector is used as the As shown in FIG. 3, the Si diode photoreceiver has good sensitivity in the short wavelength range up to about 1050 nm, and the attenuation in the fiber as the stretching element 2 causes the intensity to drop in the short wavelength range. Also, a sufficient photoelectric conversion output can be obtained, and spectrometry in this wavelength range can be performed without any trouble.

Next, the measurement program 53 installed in the computing means will be described. FIG. 5 is a schematic diagram showing data handled by the measurement program 53, and FIG. 6 is a flowchart showing a schematic diagram of the measurement program 53. As shown in FIG.
The examples of FIGS. 5 and 6 are examples of programs in which the measurement program 53 measures an absorption spectrum (spectral absorptance) as a spectral characteristic. As described above, the outputs from the photodetectors 41 and 42 are input to the computing means 5 through the AD converters 7, respectively. This is a data set, which is a collection of data (photoelectric conversion values) for each signal output period in each of the light receivers 41 and 42 . Hereinafter, the data set input from the first photodetector 41 via the AD converter 7 will be referred to as the first data set, and the data set input from the second photodetector 42 via the AD converter 7 will be referred to as the first data set. Let it be the second data set.
As described above, the first photoreceiver 41 is for measurements over a first wavelength range and the second photoreceiver 42 is for measurements over a second wavelength range. Hereinafter, for convenience of explanation, the first wavelength range is λ ₁ to λ _m . Also, the second wavelength range is λ _m+1 to λ _n .

Reference spectrum data is used in calculating the absorption spectrum. The reference spectrum data is a value for each wavelength that serves as a reference for calculating the absorption spectrum. The reference spectrum data is obtained in advance by causing broadband pulse-stretched light to enter each of the light receivers 41 and 42 without passing through the object S. FIG. That is, the light is directly incident on the light receivers 41 and 42 without passing through the object S, and the outputs of the light receivers 41 and 42 are similarly input via the AD converters 7 . Data sets input in this way are hereinafter referred to as a first reference data set and a second reference data set. Each reference data set is recorded in a file, and each file is stored in the storage unit 52 .

Each reference data set is reference intensity (V ₁ , V ₂ , V ₃ , . . . ) at each time t ₁ , t ₂ , t ₃ , . The time resolution Δt is the response speed (signal output period) of the detector 5 and the time interval for outputting the signal. Hereinafter, a first reference data set is a reference data set for the first wavelength range, and is reference intensities V ₁ , V ₂ , V ₃ , . . . , V _m at times t ₁ to t _m . The second reference data set is a reference data set for the second wavelength range, and is reference intensities V _m+1 , V _m+2 , V _m+3 , . . . , V _n at times t _m+ 1 to t _n .

For _the first reference data set, the relationships between the times _{t 1} , t ₂ , _{t 3} , . _{3 ,} . . . , V _m are taken to be the light intensities at each λ ₁ , λ ₂ , λ ₃ , . The same _is true for the second reference data set, and values Vm _{+1 ,} Vm _{+ 2} , Vm _{;3 ,} . , λ _n is taken to be the light intensity.

As shown in FIG. 6, the measurement program 53 first acquires the first data set and the first reference data set from the files. Each measured value in the first data set is then compared to each reference value in the first reference data set ( _v1 / _V1 , _v2 / _V2 , _v3 / _V3 , . . . , v _m /V _m ), and temporarily store the result in a variable (array variable).
Next, the measurement program 53 obtains a second data set and a second reference data set respectively from the files. Each measurement in the second data set is then compared to each reference value in the second reference data set (v _m+1 /V _m+1 , v _m+2 /V _m+2 , v _m+3 /V _m+3 , . v _n /V _n ) and temporarily store the result in another variable (array variable).

Next, the measurement program 53 acquires the calculation results from each variable, and treats them as continuous calculation results as the calculation results of the absorption spectrum _SA . That is, let _{v 1} /V ₁ be the absorptance at λ _{1 ,} v ₂ /V ₂ be the absorptance at _{λ 2} , . Let v _m+1 /V _m+1 be the absorptance at λ _m+1 , v _m+2 /V _m+2 be the absorptance at λ _m+2 , and v _n /V _n be the absorptance at λ _n . If necessary, the logarithm of each reciprocal is taken as the absorptivity. As a result, each absorption rate of λ ₁ to λ _n , that is, the absorption spectrum S _A is obtained. The measurement program 53 terminates the obtained absorption spectrum _SA as the program execution result.

The operation of the spectrometer of such an embodiment will be described below. The following explanation is also an explanation of the spectroscopic measurement method of the embodiment.
First, the object S is placed on the first receiving plate 61 and the pulse light source 1 is operated. In the pulse light source 1, ultrashort pulse light from an ultrashort pulse laser source 11 is incident on a nonlinear element 12, broadband by a nonlinear optical effect, and emitted as broadband pulse light. The broadband pulsed light is incident on the stretching element 2 and the pulse width is stretched by the stretching element 2 .

The pulsed light whose pulse width has been extended is split by a beam splitter 31 as a splitting element, one of which travels along the first optical path P1, and the other of which travels along the second optical path P2. The object S is irradiated with the light that has traveled along the first optical path P1. The light transmitted through the object S enters the first light receiver 41 . The output from the first photodetector 41 is input to the computing means 5 via the AD converter 7 and is temporarily recorded in a file and stored in the storage section 52 .

Next, the operation of the pulse light source 1 is temporarily stopped, and the (same) object S (the object S measured with the light traveling along the first optical path P1) is transferred to the second receiving plate 62. (For example, the measurer transfers it by hand). In this state, the pulse light source 1 is operated again. Similarly, broadband pulsed light is expanded by expansion element 2 and split by beam splitter 31 as a splitting element. This time, the object S is irradiated with the other light that has traveled the second optical path P2, and the light that has passed through the object S is received by the second light receiver . The output of the second photodetector 42 is input to the computing means 5 via the AD converter 7 . Then, similarly, it is temporarily recorded in a file and stored in the storage section 52 .
When the detection of the transmitted light by the two detection systems is completed in this way, the measurement program 53 operates and the absorption spectrum is calculated as described above. The calculated absorption spectrum is appropriately displayed on a display or the like.

In the above operation, the output from the first light receiver 41 includes values v m ₊₁ to v _n from t m ₊₁ to t _n , and the output from the second light receiver 42 includes values t ₁ to t _{m are included} , but they are not included in the final measurement result. However, regarding the output data from the second photodetector 42, it is necessary to specify the time _t1 (rising edge of the pulse) in order to specify the time tm ₊₁ . In that part, the data of the time before tm ₊₁ is also used for the measurement. That is, the spectrum is obtained by taking the time _t1 as a reference and the time tm ₊₁ with respect to it as the intensity of the wavelength λm ₊₁ . The same is true for λ _m+2 and beyond.

According to the spectroscopic measurement apparatus and the spectroscopic measurement method of such an embodiment, in the spectroscopic measurement using the time-wavelength uniqueness of the pulse-stretched broadband pulsed light, the two detection systems are divided. Detection of light in each wavelength band can be optimized according to the characteristics and the characteristics of the light receivers 41 and 42 . Therefore, a spectroscopic measurement apparatus and a spectroscopic measurement method are provided that are capable of high-speed spectroscopic measurement with sufficient accuracy over a wide wavelength band.
In the above-described embodiment, the structure is divided into two detection systems, but it is of course possible to divide into three or more detection systems.

Since the above operation and method are configured to selectively use one of the detection systems for measurement, it is preferable to employ a configuration that cancels the measurement in the detection system that is not selected. For example, each of the receiving plates 61 and 62 is provided with a sensor for detecting whether or not the object S is placed. There may be a configuration in which no input is made to the computing means 5 (or even if it is input, it is canceled). Alternatively, each detection system may be appropriately provided with a shutter so that the light does not enter the light receivers 41 and 42 in the detection system that is not in use.

In the above embodiment, the wavelength band of the broadband pulsed light from the pulse light source 1 and the total sensitive wavelength band of the two light receivers 41 and 42 cover the near-infrared region of 900 to 1300 nm. This point has significance that the object S is in a solid phase or a liquid phase and is suitable for analyzing the object S by absorption. Many materials have absorption wavelengths in the band of 900 to 1300 nm, and wide coverage of this band by two detection systems is particularly significant for spectroscopic analysis of the solid-phase or liquid-phase object S. . For example, the spectroscopic measuring device and spectroscopic measuring method of the embodiments can be used for analysis of drugs (tablets, etc.).

In the above description, the spectroscopic measurement is performed with one pulse of broadband pulsed light emitted from the pulse light source 1, but in reality, the spectroscopic measurement is often performed with a plurality of pulses of broadband pulsed light. In this case, each data set is a plurality of data sets, and the spectrum is calculated by averaging the measured values of each data set.
Also, in the above example, the absorption spectrum was measured as the spectral characteristic, but other spectra such as reflection spectrum and scattering spectrum may be used. When measuring the reflection spectrum, the light receivers 41 and 42 are arranged at positions for receiving the reflected light from the object S, and when measuring the scattering spectrum, the light receivers 41 and 42 are arranged at positions for receiving the scattered light. is placed.

Next, a spectroscopic measurement apparatus and spectroscopic measurement method according to a second embodiment will be described. FIG. 7 is a schematic diagram of the spectroscopic measurement device of the second embodiment.
The first and second detection systems are also provided in the second embodiment. The second embodiment differs from the first embodiment in that the splitting element is provided on the optical path in front of the stretching element, and as a result, two first and second stretching elements 21 and 22 are provided. The point is that In this embodiment, too, a beam splitter 31 is used as splitting element.

An incident end of a fiber (hereinafter referred to as a first fiber) 210 as a first extension element 21 is arranged on an optical path P1 of one light beam transmitted through the beam splitter 31, and the other light beam reflected by the beam splitter 31 is An incident end of a fiber (hereinafter referred to as a second fiber) 220 as the second elongation element 22 is arranged on the optical path P2. A first receiving plate 61 is arranged at the irradiation position of the light emitted from the first fiber 210 , and a second receiving plate 62 is arranged at the irradiation position of the light emitted from the second fiber 220 . Further, as in the first embodiment, the first photoreceiver 41 is arranged on the emission side of the first receiving plate 61, and the second photoreceiver 42 is arranged on the emission side of the second receiving plate 62. It is

The difference between the first embodiment and the second embodiment is whether the light is wavelength-divided after pulse extension or pulse extension is performed before pulse extension, and other parts are basically the same. be. One of the lights transmitted through the beam splitter 31 as a splitting element is transmitted through the first fiber 210 to have its pulse width expanded, and then the object S is irradiated with the light. Then, the light transmitted through the object S is detected by the first light receiver 41 . The other light reflected by the beam splitter 31 is transmitted through the second fiber 220 to have its pulse width extended, and then the object S is irradiated with the light. Then, the light transmitted through the object S is detected by the second light receiver 42 . Outputs from the photodetectors 41 and 42 are input to the computing means 5 via the AD converter 7, and the spectrum is calculated by the measurement program 53. FIG.

The configuration of the second embodiment can be said to be a configuration in which a pulse stretching element is incorporated in each detection system. This configuration has the advantage that it is possible to employ the optimum expansion element according to the characteristics of the detection system. That is, the pulse stretching can be optimized as a whole by using stretching elements 21 and 22 with different dispersion characteristics to obtain the desired dispersion. For example, different group dispersion characteristics can be used for the first fiber 210 and the second fiber 220 . Also, different lengths of the first fiber 210 and the second fiber 220 can be used.

In a more preferred configuration, in the pulse extension shown in FIG. 2, it is desirable that the slope of time versus wavelength (Δλ/Δt) after extension be constant over the entire wavelength range. This is because it becomes easier to associate time and wavelength, and the accuracy of spectrum calculation increases. In this case, the fibers 210 and 220 used as the stretching elements 21 and 22 often have different magnitudes of delay depending on the wavelength even if they have the same positive dispersion. For this reason, a first detection system including the first photodetector 41 for the purpose of measuring the first wavelength range and a second detection system including the second photodetector 42 for the purpose of measuring the second wavelength range are provided. In the detection system of , the pulses are stretched by separate fibers, and the respective delay amounts are optimized. As a result, Δλ/Δt after pulse extension can be uniformed as a whole. The configuration of the second embodiment is superior to the first embodiment in that such a thing becomes possible.
However, since two expansion elements 2 are required, the cost is high in that respect. Conversely, the first embodiment, in which the pulse is stretched and then wavelength-divided, is more advantageous in terms of cost.

Next, a third embodiment will be described. FIG. 8 is a schematic diagram of the spectroscopic measurement device of the third embodiment.
The third embodiment has a configuration in which a dichroic mirror 32 is used instead of the beam splitter 31 as a splitting element in the configuration of the first embodiment. Other configurations are the same as in the first embodiment.
The dichroic mirror 32 is an element that splits light into two lights according to wavelength. For example, as shown in FIG. 9, one that transmits light with a longer wavelength than the split wavelength λc and transmits light with a shorter wavelength than λc is used. A first light receiver 41 is arranged on the first optical path P1 for long wavelengths, and a second light receiver 42 is arranged on the second optical path P2 for short wavelengths.

In this embodiment, the light is split by the splitting element according to the wavelength, and the detection system is different for each wavelength range. In this respect, the spectrometer is more suitable. This point will be described below.
In the first embodiment, the light is split into two by the beam splitter 31 without splitting according to the wavelength, and the light is received by the first and second light receivers 41 and 42 via the object S. FIG. Then, among the outputs from the first and second light receivers 41 and 42, wavelength ranges with higher spectral sensitivities are selected and converted into wavelengths to obtain measurement results. In this configuration, the wavelength range where the spectral sensitivity is low is not used for measurement, resulting in loss in a certain sense.

On the other hand, in the third embodiment, since the dichroic mirror 32 that splits the light according to the wavelength is used as the splitting element, the split wavelength λc is appropriately selected, loss is eliminated when a wavelength range having a higher spectral sensitivity is selected and converted into a wavelength. Therefore, a spectroscopic measurement apparatus and a spectroscopic measurement method are provided that are capable of performing spectroscopic measurement with sufficient accuracy, at high speed, and efficiently over a wide wavelength band.

The division wavelength can be the boundary wavelength between the first wavelength range and the second wavelength range in the first embodiment. That is, when the InGaAs diode photodetector and the Si diode photodetector are used as described above, both have sensitivity in the range of about 900 to 1100 nm (the sensitive wavelength ranges overlap). Therefore, the division wavelength is selected within this range, and can be, for example, about 1050 nm. That is, the dichroic mirror 32 as a splitting element can be a mirror that transmits light of 1050 nm or more and reflects light of less than 1050 nm.

The configuration of the computing means is basically the same as that of the first and second embodiments, but the processing of the output data from the second photodetector 42 is slightly different. In the first and second embodiments, in processing the output data from the second photodetector 42, to specify the time tm ₊₁ of the first wavelength λm ₊₁ , t ₁ (rising edge of pulse) is used as a reference. In a third embodiment, no light of wavelength λ ₁ corresponding to t ₁ enters the second receiver 42 . The light of the first wavelength incident on the second photodetector 42 is the wavelength closest to λc among the lights that are shorter than λc and have an effective intensity (e.g., an intensity of 5% or more with respect to the peak of the pulse). (hereinafter referred to as division reference wavelength). The time of the split reference wavelength becomes the reference time for processing the output data from the second photodetector 42, and the intensity of light of each wavelength is obtained from the elapsed time for each Δt. The division reference wavelength is checked in advance, and the time when the effective intensity of the output data from the second photodetector 42 is first observed is set as the division reference wavelength. Then, hereinafter, the intensity of each wavelength is determined according to the corresponding relationship for each Δt.

Next, a fourth embodiment will be described. FIG. 9 is a schematic diagram of the spectrometer of the fourth embodiment.
The spectroscopic measurement apparatus of the fourth embodiment has a configuration in which a dichroic mirror 32 is used as a splitting element instead of the beam splitter 31 in the configuration of the second embodiment. Other configurations are the same as those of the second embodiment.

Similarly, the dichroic mirror 32 is an element that splits the broadband pulsed light into two light beams depending on the wavelength. of light is used . An incident end of a first fiber 210 as a first stretching element 21 is arranged on the first optical path P1 for long wavelengths, and a second stretching fiber 210 is arranged on the second optical path P2 for short wavelengths. The input end of a second fiber 220 as element 22 is arranged. Similarly, the first light receiver 41 is arranged at a position where the light emitted from the first fiber 210 is received through the object S, and the light emitted from the second fiber 220 is received through the object S. A second photodetector 42 is arranged at a position for receiving light.
Also in the fourth embodiment, since the light of λ1 does not enter the second light receiver 42, the division reference wavelength is checked in advance as in the third embodiment, and the effective Assume that the time at which the intensity is observed is the division reference wavelength. Thereafter, the intensity of light of each wavelength is obtained from the corresponding relationship for each Δt.

The fourth embodiment also has the advantage that it is possible to adopt the optimum elongation element according to the characteristics of the detection system. That is, the appropriate use of stretching elements 21 and 22 with different dispersion characteristics can provide the desired dispersion and optimize the pulse stretching as a whole. At this time, since the dichroic mirror 32 that splits the light according to the wavelength is used as a splitting element, each characteristic of the expansion elements 21 and 22 can be utilized more effectively. Then, as in the third embodiment, there is no light that is not used for measurement, resulting in a highly efficient spectroscopic measurement apparatus and spectroscopic measurement method.

Next, a fifth embodiment will be described. FIG. 10 is a schematic diagram of the spectroscopic measurement device of the fifth embodiment.
A fifth embodiment, shown in FIG. 10, uses a WDM (Wavelength Division Multiplexing) coupler 33 as a splitting element. Other configurations are the same as those of the third embodiment shown in FIG.
In this embodiment, the WDM coupler 33 is of the fiber type, and is made by splicing and drawing two single-mode or multi-mode fibers. As shown in FIG. 10, one end on the incident side is terminated and the light from the elongated element 2 enters from the other incident end 331 . Light having a wavelength longer than the split wavelength is emitted from one of the two output ends 332 , and light having a wavelength shorter than the split wavelength is output from the other output end 333 .

In the fifth embodiment, since the fiber-type WDM coupler 33 is used, when the fiber 20 is used as the expansion element 2, it is preferable because of their high mutual affinity. In other words, since the fibers are connected to each other, a connector or the like can be appropriately used to enable connection and transmission with low loss, and a highly efficient spectroscopic measurement apparatus can be obtained.
Similarly, when irradiating the object S, it is preferable to provide a beam expander 30. As shown in FIG. be done.

The fiber-type WDM coupler 33 can also be used as a splitting element in the fourth embodiment shown in FIG. In this case, the input end 331 of the WDM coupler 33 is connected to the output end of the fiber as the nonlinear element 12 . One of the branched output ends 332 is connected to the first fiber 210 and the other 333 is connected to the second fiber 220 . Also in this case, since the fibers are connected to each other, the connection and transmission can be performed with low loss, and a highly efficient spectroscopic measurement apparatus can be obtained.

FIG. 11 is a schematic diagram showing another example of splitting elements.
As shown in FIG. 11, a diffraction grating, an AWG (arrayed waveguide grating), or the like can be used as the splitting element in addition to the above.
For example, as shown in FIG. 11(1), the light from the expansion element 2 is wavelength-dispersed by the diffraction grating 35, condensed by the lens 363 according to the divided wavelengths, and made incident on the auxiliary fibers 361 and 362. FIG. The output end of the first auxiliary fiber 361 is arranged so as to irradiate the object S on the first receiving plate 61 , and the second auxiliary fiber 362 is arranged to irradiate the object S on the second receiving plate 62 . An exit end is arranged to irradiate S with light. In this case, each auxiliary fiber 361, 362 can be used as a fiber for pulse extension (first and second fibers 210, 220).

Also, as shown in FIG. 11(2), an AWG 37 can be used as the dividing element. The AWG 37 is constructed by forming functional waveguides 372 to 376 on a substrate 371 . Each functional waveguide includes a large number of arrayed waveguides 372 with slightly different optical path lengths, slab waveguides 373 and 374 connected to both ends (incidence side and output side) of the arrayed waveguides 372, and an incident side slab waveguide. An incident side waveguide 375 for making light incident on 373 and each emitting side waveguide 376 for extracting light of each wavelength from the emitting side slab waveguide 374 .

The slab waveguides 373 and 374 are free spaces, and the light incident through the incident-side waveguide 375 spreads in the incident-side slab waveguide 373 and enters each arrayed waveguide 372 . Since each arrayed waveguide 372 has a slightly different length, the light reaching the end of each arrayed waveguide 372 is shifted in phase by this difference. Light is diffracted and emitted from each arrayed waveguide 372 , and the diffracted lights interfere with each other to pass through the emission-side slab waveguide 374 and reach the incident end of the emission-side waveguide 376 . At this time, due to the phase shift, the intensity of the interfering light becomes highest at the position corresponding to the wavelength. That is, light having different wavelengths is incident on each output end waveguide 376, and the light is spatially dispersed. Strictly speaking, each output side waveguide 376 is formed so that each incident end is positioned at such a position where light is dispersed.

Two auxiliary fibers 377 and 378 are connected to the exit-side waveguide 376 according to the split wavelengths. That is, the first auxiliary fiber 377 is connected to the output side waveguide 376 that outputs the wavelength longer than the split wavelength, and the second auxiliary fiber 378 is connected to the output side waveguide 376 that outputs the wavelength shorter than the split wavelength. is connected. A lens (not shown) is interposed or a fan-in-fan-out device is used to connect the auxiliary fibers 377 and 378 . In this case also, each of the auxiliary fibers 377, 378 illuminates the object S on the receiving plates 61, 62, respectively, and can similarly be a fiber for pulse stretching.
11(1) and 11(2) also have a high affinity with the fiber, so that they can be easily connected to the fiber as the nonlinear element 12 with low loss, resulting in a highly efficient spectroscopic measurement apparatus. can be

Next, a sixth embodiment will be described. FIG. 12 is a schematic diagram of a spectrometer of the sixth embodiment.
In the above-described first embodiment, the transfer of the object S from the first receiving plate 61 to the second receiving plate 62 was described as if the measurement person performed the transfer. may be provided separately and performed automatically. The sixth embodiment is a modification of the third embodiment from this point of view.

In this embodiment, a moving mechanism 8 for moving the object S is provided in order to continuously perform the measurement by the first detection system and the measurement by the second detection system at high speed. Specifically, in this embodiment, a large number of receiving plates 63 are arranged in a row in the horizontal direction. The moving mechanism 8 is a mechanism for linearly moving the receiving plates 63 in the direction in which the receiving plates 63 are arranged (hereinafter referred to as the moving direction). For example, if the horizontal direction perpendicular to the movement direction is defined as left and right, a configuration 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 can be employed. Each receiving plate 63 is connected to each other and linearly moved while being guided by a linear guide by a linear drive source.
In this embodiment, the receiving plate 63 is provided with a concave portion (not shown) so that the object S does not shift. Each target object S is placed on each receiving plate 63 in a state of being dropped into the concave portion.

A control unit 81 is provided in the moving mechanism 8 . The control unit 81 is configured to sequentially position the receiving plates 63 at irradiation positions set above the light receivers 41 and 42 . The control unit 81 controls the linear drive source so that the receiving plates 63 move integrally with a predetermined stroke. In the apparatus, a position irradiated with light traveling along the first optical path P1 (hereinafter referred to as the first irradiation position) and a position irradiated with light traveling along the second optical path P2 (hereinafter referred to as the second irradiation position ) are set, and the predetermined stroke is the interval between the first and second irradiation positions. The controller 81 is designed to receive a signal from the computing means 5 . A sequence program 54 for operating each part of the device including the control part 81 in a predetermined sequence is installed in the calculation means 5 .

Such a spectroscopic measurement apparatus according to the sixth embodiment is suitable for applications in which a large number of objects S are spectroscopically measured sequentially at high speed. For example, spectroscopic measurements can be made during product inspection on a manufacturing line. A reference absorption spectrum for a non-defective product is checked in advance, and the absorption spectrum of each product is determined by spectroscopic measurement and compared with the reference absorption spectrum to determine whether the product is acceptable. The device of the sixth embodiment is preferably used for such applications. In this application, as shown in FIG. 12, a pass/fail determination program 55 is installed in the computing means 5, and a file (not shown) in which the reference absorption spectrum is recorded is stored in the storage unit 52. FIG.

Specifically, each object S is dropped into a concave portion of each receiving plate 63 and held. Then, the object S on each receiving plate 63 is sequentially moved to the first irradiation position and the second irradiation position by the moving mechanism 8 . Then, when positioned at the first irradiation position, the pulse light source 1 operates to irradiate the object S with light on the longer wavelength side, and the transmitted light is received by the first light receiver 41 . Then, a data set (first data set) on the longer wavelength side of the object S is temporarily recorded in a file.

The receiving plate 63 is then moved to the second irradiation position, and in this state the pulse light source 1 operates to irradiate the object S with light on the short wavelength side. Then, a data set on the short wavelength side (second data set) for the object S is temporarily recorded in a file.
After that, the measurement program 53 operates, and the absorption spectrum of the object S is calculated. Next, the acceptance/rejection determination program 55 operates to perform acceptance/rejection determination. That is, the calculated absorption spectrum is compared with the reference absorption spectrum, and it is determined whether the divergence is within a predetermined range. If it is within the specified range, it is accepted, and if it is outside the range, it is rejected.

The moving mechanism 8 sequentially positions the object S on each receiving plate 63 at the first and second irradiation positions, and the first and second data sets are obtained by irradiating light at the respective positions. Then, the measurement program 53 sequentially calculates the absorption spectrum, and the pass/fail judgment program judges pass/fail. The pass/fail determination result is stored in the storage unit 52 as product inspection information. It is more preferable to provide an exclusion mechanism for excluding rejected products from the production line and not shipping them.
Further, in the sixth embodiment, when the object S is placed at the second irradiation position and the measurement is performed, the next object S is placed at the first irradiation position and the measurement is performed at the same time. will be That is, the first data set and the second data set are acquired simultaneously in one irradiation. In this case, the measurement program 53 in the computing means 5 combines the first data set in one irradiation and the second data set in the next irradiation to calculate the overall absorption spectrum of the object S. programmed to result. For each data set, the absorption spectrum may be calculated by comparing with the reference absorption spectrum and then combining them, or each data set may be combined into a whole data set and then compared with the reference absorption spectrum to measure the absorption spectrum. Good as a result.

In the spectroscopic measurement apparatus and the spectroscopic measurement method of the sixth embodiment, since each target S is moved by the moving mechanism 8 and sequentially positioned at the first and second irradiation positions, a large number of targets S can be moved at high speed. can be spectroscopically measured, and can be suitably used for applications that require such a requirement.
In FIG. 12, the moving mechanism 8 is provided for the configuration of the third embodiment, but the moving mechanism 8 may be provided for the configuration of other embodiments such as the first embodiment. Good things, of course.

Acquisition of the reference spectrum data will now be supplementarily described.
As described above, when calculating the spectral characteristics of the object S, reference spectral data is obtained in advance. In this case, the acquisition of reference spectrum data (measurement without placing the object S) is periodically performed as calibration work in consideration of temporal characteristic changes of the pulse light source 1 and the light receivers 41 and 42 .

For more reliable spectroscopic measurements, it is preferable to frequently acquire reference spectral data. A preferred way to do this without compromising the efficiency of the measurement is to use one receiver to acquire a data set while the other receiver is used to acquire a reference data set. That is, in each of the first to fifth embodiments, when the object S is placed on the first receiving plate 61 and the first data set is obtained, the object S is not placed on the second receiving plate 62. Since it is not mounted, the reference spectrum data for the second photodetector 42 is acquired from the data output from the second photodetector 42 at this time. Further, when the object S is placed on the second receiving plate 62 and the second data set is acquired from the output from the second light receiver 42, the object S is placed on the first receiving plate 61. At this time, the data output from the first photodetector 41 is used to acquire the reference data set for the second photodetector 42 . In this way, the acquisition of each reference data set can be performed frequently in close temporal proximity to the actual measurements. Therefore, the spectroscopic measurement device and the spectroscopic measurement method are more reliable.

Next, a spectroscopic measurement device according to a seventh embodiment will be described. FIG. 13 is a schematic diagram of the spectroscopic measurement device of the seventh embodiment.
In order to further improve the reliability of spectroscopic measurement, a configuration is conceivable in which acquisition of each data set and acquisition of each reference data set are performed simultaneously (in real time). The seventh embodiment shown in FIG. 13 has this configuration.
The seventh embodiment shown in FIG. 13 is an embodiment that performs real-time calibration in the configuration of the third embodiment shown in FIG. Specifically, first and second beam splitters 341 and 342 are provided on the first and second optical paths P1 and P2 extending from the dichroic mirror 32 as a splitting element.

The first beam splitter 33 further splits the first optical path P1 into two. These two optical paths P11 and P12 are hereinafter referred to as a first measuring optical path and a first reference optical path. A first receiving plate 61 is arranged in the first measurement optical path P11, as in the first embodiment, and a first light receiver 41 is arranged on the exit side thereof. A first reference light receiver 43 is arranged in the first reference optical path P12. No receiving plate is arranged in the first reference optical path P12, and the light enters the first reference light receiver 43 without passing through the object S. As shown in FIG.

The second beam splitter 34 also splits the second optical path P2 into two optical paths P21 and P22. These two optical paths P21 and P22 are hereinafter referred to as a second measurement optical path and a second reference optical path. A second receiving plate 62 is similarly arranged in the second measurement optical path P21, and a second light receiver 42 is arranged on the exit side thereof. A second reference light receiver 44 is arranged in the second reference optical path P22. No receiving plate is arranged in the second reference optical path P22, and the light enters the second reference light receiver 44 without passing through the object S. As shown in FIG.

Outputs from the photodetectors 41 to 44 are input to the computing means 5 via the AD converter 7 . Outputs from the photodetectors 41 to 44 are recorded in separate files as a first data set, a first reference data set, a second data set, and a second reference data set, respectively, and stored in the storage unit 52. stored temporarily. Then, it is read by the measurement program 53 and the spectrum is acquired. The measurement program 53 itself is the same as described above, so the description is omitted.
In the seventh embodiment, one light split by each beam splitter 33, 34 is used for measurement and the other light is used for reference, and each reference data set is acquired in real time. Therefore, more reliable spectroscopic measurement can be performed.

Next, an eighth embodiment will be described. FIG. 14 is a schematic diagram of the spectroscopic measurement device of the eighth embodiment.
The spectrometer of the eighth embodiment has a configuration obtained by modifying the third embodiment shown in FIG. Specifically, in this spectrometer, a splitting element is arranged at a position where the light from the object S is split. It is configured to receive light. In this embodiment, the splitting element is the dichroic mirror 32, but it may be the beam splitter 31 as well.

The light from the expansion element 2 is directly applied to the object S, and the light from the object S is split by the dichroic mirror 32 . The split long-wavelength light is received by the first light receiver 41 and the short-wavelength light is received by the second light receiver 42 . The configuration of the computing means for processing the output data from each of the light receivers 41 and 42 to acquire the spectrum is the same as in the third embodiment.

In the eighth embodiment, the entire spectrum can be obtained by irradiating only one pulse for one object 2, so spectroscopic measurement can be performed with higher precision in this respect. As in each of the above embodiments, when spectroscopic measurement is performed by irradiating different pulses for the measurement of the first wavelength range and the measurement of the second wavelength range for one target S, the reproducibility of the broadband pulsed light should decrease, it will cause a decrease in measurement accuracy. However, the eighth embodiment does not have such a problem. Embodiments other than the third embodiment can also be modified in this way.

In FIG. 14, the object S is assumed to be in a liquid phase or a gas phase, and is placed in a transparent cell for measurement. Such a configuration may also be adopted in the first to seventh embodiments. Further, in the eighth embodiment, it is of course possible to employ a configuration in which a receiving plate in a horizontal posture is provided and the light from the object on the receiving plate is split. Since the light from the object S irradiated with the broadband pulsed light is split by the splitting element, one receiving plate is sufficient. Therefore, it becomes structurally simpler.

Another example of the expansion element 2 will now be described with reference to FIG. FIG. 15 is a schematic diagram showing another example of the expansion element 2. FIG. As the stretching element 2, a single mode fiber, a single mode multi-core fiber, a single mode bundle fiber, a multimode fiber, or the like can be used. Additionally, the elongated element 2 can be constructed using a diffraction grating, a chirped fiber Bragg grating (CFBG), a prism, or the like.
For example, as shown in FIG. 15(1), two diffraction gratings 23 are used for wavelength dispersion. At this time, an optical path difference is formed according to the wavelength, and the pulse is extended in a state in which time-wavelength uniqueness is achieved. In this example, the longer the wavelength of the light, the shorter the optical path. As described above, since it is possible to use a diffraction grating as a splitting element, it is also possible to employ a configuration in which both pulse extension and wavelength division are performed by the diffraction grating.

In addition, as shown in FIG. 15(2), it is also possible to use the CFBG 24 to extend the pulse. An FBG is a fiber in which a diffraction grating is constructed by periodically providing regions where the refractive index changes in the longitudinal direction of the core. It can be said that the reflection position is different depending on the wavelength. When used as the stretching element 2, in the CFBG 24, of the incident light, for example, light on the long wavelength side is reflected back on the front side in the direction of travel in the fiber, and as it becomes on the short wavelength side, it is reflected on the back side and returned. forming a refractive index changing layer in the core; This is a configuration equivalent to a normal dispersion fiber. Since the short wavelength side returns later, the time wavelength uniqueness is similarly ensured.

Furthermore, as shown in FIG. 15(3), a prism 25 can be used to extend the pulse. In this example, four prisms 25 are used, and the extension element 2 is configured by arranging them so that the shorter the wavelength, the longer the optical path. In this example as well, the shorter the wavelength, the later the light is emitted, so the time-wavelength uniqueness is ensured.
Incidentally, in the examples of FIGS. 15(1) to 15(3), an optical path difference is formed when the light is returned. As a configuration for extracting light on the return path, a configuration in which a combination of a polarizing beam splitter and a quarter-wave plate is arranged on the optical path in front of the expansion element 2 can be adopted. On the forward path, the light travels through the polarizing beam splitter and the 1/4 wavelength plate in that order and enters the expansion element 2. On the return path, the light returning from the expansion element 2 travels through the 1/4 wavelength plate and the polarizing beam splitter in that order. Configure.

In each of the above embodiments, the InGaAs diode photodetector is used in one of the detection systems for detecting light on the long wavelength side, and the Si diode photodetector is used in the other detection system for detecting light on the short wavelength side. , this is an example and other types of receivers can be used. For example, a CdS photodetector or the like can be used for the visible region, and a PbS photodetector or an InSb photodetector or the like can be used for the near-infrared region.
The wavelength range for spectroscopic measurement may be the visible range or the infrared range longer than the near-infrared range.
Further, although an SC light source is used as the pulse light source 1, other broadband pulse light sources such as an ASE (Amplified Spontaneous Emission) light source and an SLD (Superluminescent Diode) light source may also be used. .

In addition, in the present invention, provision of the dividing element is not necessarily essential. If there is no splitting element, the first and second optical paths P1 and P2 are not split, so the first and second detection systems are configured by temporally splitting. That is, the first and second irradiation steps are performed on the object on the receiving plate. In each irradiation step, the receiving plate and the object are held at the same position, but in the first irradiation step the first light receiver 41 is placed at the light receiving position and the measurement is performed, and in the second irradiation step the second A light receiver 42 is placed at the light receiving position and measurements are taken. The measurement program 53 similarly calculates the spectrum based on the data sets from each photodetector 41,42. A mechanism (for example, a revolver-like mechanism) for exchanging the light receivers 41 and 42 may be provided.
Further, in each embodiment, the receiving plates 61 to 63 are in a horizontal posture, and the object S is irradiated with light from above, but this is an example, and the object S is irradiated with light from the side. , the light may be irradiated obliquely.

1 pulse light source 11 ultrashort pulse laser source 12 nonlinear element 2 expansion element 21 fiber 210 first fiber 220 second fiber 3 irradiation optical system 31 beam splitter 32 dichroic mirror 33 wavelength division multiplex couplers 41 to 44 light receiver 5 computing means 51 processor 52 storage unit 53 measurement programs 61 to 63 receiving plate 7 AD converter 8 moving mechanism 81 control unit

Claims (36)

a pulsed light source that emits broadband pulsed light having a continuous broadband spectrum ;
an expansion element for expanding the pulse width of the broadband pulsed light from the pulsed light source so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a splitting element for splitting the broadband pulsed light whose pulse width has been stretched by the stretching element into two;
a first light receiver that receives light from an object irradiated with one of the light beams split by the splitting element;
a second light receiver for receiving light from an object irradiated with the other light divided by the splitting element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum,
The first and second photoreceivers have different spectral sensitivity characteristics, the first photoreceiver being sensitive over a first wavelength range and the second photoreceiver being sensitive to the first wavelength. having sensitivity over a second unmatched range of wavelengths;
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector A spectroscopic measurement apparatus characterized by performing arithmetic processing for converting a temporal change in output in a time zone corresponding to the second wavelength range into a spectrum of the second wavelength range. The first photoreceiver is a photoreceiver having higher spectral sensitivity than the second photoreceiver in the first wavelength range, and the second photoreceiver is the first photoreceiver in the second wavelength range. 2. A spectroscopic measurement apparatus according to claim 1, wherein said photodetector has a higher spectral sensitivity than said photodetector. a pulsed light source that emits broadband pulsed light having a continuous broadband spectrum ;
an expansion element for expanding the pulse width of the broadband pulsed light from the pulsed light source so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
The broadband pulsed light whose pulse width is stretched by the stretching element is divided into light whose spectrum is continuous in the first wavelength range on the long wavelength side and in the second wavelength range on the short wavelength side with respect to the division wavelength. a splitting element for splitting into spectrally continuous light ;
a first photoreceiver for receiving light from an object irradiated with light in a first wavelength range among those split by the splitting element;
a second photoreceiver for receiving light from an object irradiated with light in a second wavelength range among those split by the splitting element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum,
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector A spectroscopic measurement apparatus characterized by performing arithmetic processing for converting a temporal change in output in a time zone corresponding to the second wavelength range into a spectrum of the second wavelength range. a pulsed light source that emits broadband pulsed light having a continuous broadband spectrum ;
Broadband pulsed light emitted from a pulsed light source is divided into light whose spectrum is continuous in a first wavelength range on the long wavelength side and spectrum is continuous in a second wavelength range on the short wavelength side with respect to the split wavelength. a splitting element for splitting into light and
a first stretching element for stretching the pulse width of the light in the first wavelength range split by the splitting element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a second stretching element for stretching the pulse width of the light in the second wavelength range split by the splitting element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a first light receiver for receiving light from an object irradiated with light whose pulse width is stretched by the first stretching element;
a second light receiver that receives light from an object irradiated with light whose pulse width is stretched by the second stretching element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum ,
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector A spectroscopic measurement apparatus characterized by performing arithmetic processing for converting a temporal change in output in a time zone corresponding to the second wavelength range into a spectrum of the second wavelength range. a pulsed light source that emits broadband pulsed light having a continuous broadband spectrum ;
an expansion element for expanding the pulse width of the broadband pulsed light from the pulsed light source so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a splitting element that splits light from an object irradiated with broadband pulsed light that has been stretched by the stretching element into two;
a first light receiver that receives one of the lights split by the splitting element;
a second photoreceiver for receiving the other light split by the splitting element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum,
The first and second photoreceivers have different spectral sensitivity characteristics, the first photoreceiver being sensitive over a first wavelength range and the second photoreceiver being sensitive to the first wavelength. having sensitivity over a second unmatched range of wavelengths;
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector A spectroscopic measurement apparatus characterized by performing arithmetic processing for converting a temporal change in output in a time zone corresponding to the second wavelength range into a spectrum of the second wavelength range. The first photoreceiver is a photoreceiver having higher spectral sensitivity than the second photoreceiver in the first wavelength range, and the second photoreceiver is the first photoreceiver in the second wavelength range. 6. The spectroscopic measurement apparatus according to claim 5, wherein the photodetector has a spectral sensitivity higher than that of the photodetector. a pulsed light source that emits broadband pulsed light having a continuous broadband spectrum ;
an expansion element for expanding the pulse width of the broadband pulsed light from the pulsed light source so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
The light from the object irradiated with the broadband pulsed light expanded by the expansion element is divided into light in the first wavelength range on the long wavelength side and light in the second wavelength range on the short wavelength side with respect to the division wavelength. a splitting element that splits into light and
a first light receiver for receiving light in a first wavelength range among those split by the splitting element;
a second photoreceiver for receiving light in a second wavelength range among those split by the splitting element;
computing means for converting the temporal change in the output from the first photodetector and the temporal change in the output from the second photodetector into a spectrum ,
The calculation means converts the temporal change in the output from the first photodetector in the time zone corresponding to the first wavelength range into a spectrum of the first wavelength range, and outputs from the second photodetector A spectroscopic measurement apparatus characterized by performing arithmetic processing for converting a temporal change in output in a time zone corresponding to the second wavelength range into a spectrum of the second wavelength range. 4. The stretching element is a single mode fiber, a single mode multicore fiber, a bundle fiber of single mode fibers, a multimode fiber, a diffraction grating, a chirped fiber Bragg grating or a prism. , 5, 6 or 7. wherein said first stretching element and said second stretching element are a single mode fiber, a single mode multicore fiber, a single mode fiber bundle fiber, a multimode fiber, a diffraction grating, a chirped fiber Bragg grating or a prism. 5. The spectroscopic measurement device according to claim 4. 10. The spectroscopic measurement apparatus according to claim 4, wherein the first elongation element and the second elongation element are elements having elongation characteristics different from each other. 8. A spectroscopic measurement apparatus according to claim 3, wherein said splitting element is one of a dichroic mirror, a wavelength division multiplex coupler, a diffraction grating, and an arrayed waveguide grating. 12. The spectrometry apparatus according to claim 1, wherein said pulse light source is a supercontinuum light source. 13. The spectroscopic measurement according to claim 12, wherein the pulse light source is a supercontinuum light source that outputs light whose spectrum is continuous over a wavelength width of at least 10 nm in a wavelength range of 900 nm or more and 1300 nm or less. Device. 14. The spectroscopic measurement apparatus according to any one of claims 1 to 13, wherein said first photodetector is an InGaAs photodiode photodetector. 15. The spectroscopic measurement apparatus according to claim 1, wherein said second photodetector is a Si photodiode photodetector. a moving mechanism for moving the object between a position where one of the lights split by the splitting element is irradiated and a position where the other light split by the splitting element is irradiated; 3. The spectrometer according to claim 1, further comprising: A position where the object is irradiated with light in a first wavelength range among those divided by the dividing element, and a position where light within a second wavelength range among those divided by the dividing element is irradiated. 4. The spectrometer according to claim 3 , further comprising a moving mechanism for moving between. The object is moved between a position irradiated with light having a pulse width stretched by the first stretching element and a position irradiated with light having a pulse width stretched by the second stretching element. 5. The spectroscopic measurement apparatus according to claim 4, further comprising a moving mechanism for moving. an emission step of emitting broadband pulsed light having a broadband and continuous spectrum from a pulsed light source;
a pulse extension step of extending the pulse width of the broadband pulsed light emitted in the emission step with an extension element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a splitting step of splitting the broadband pulsed light whose pulse width has been stretched in the pulse stretching step into two by a splitting element;
a first light receiving step of receiving, with a first light receiver, light from an object irradiated with one of the light beams divided in the dividing step;
a second light receiving step of receiving, with a second light receiver, the light from the object irradiated with the light of the other wavelength of the light split in the splitting step;
Calculation for converting the temporal change in the output from the first photodetector received in the first light receiving process and the temporal change in the output from the second photodetector received in the second light receiving process into a spectrum by the calculation means and
The first and second photoreceivers have different spectral sensitivity characteristics, the first photoreceiver having sensitivity over the first wavelength range and the second photoreceiver having sensitivity over the first wavelength range. having sensitivity over a second range of wavelengths inconsistent with
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector A spectroscopic measurement method characterized by a step of converting a temporal change in output in a time zone corresponding to a second wavelength range that does not match the first wavelength range into a spectrum of the second wavelength range. The first photoreceiver is a photoreceiver having higher spectral sensitivity than the second photoreceiver in the first wavelength range, and the second photoreceiver is the first photoreceiver in the second wavelength range. 20. The spectroscopic measurement method according to claim 19, wherein the photodetector has higher spectral sensitivity than the photodetector of . an emission step of emitting broadband pulsed light having a broadband and continuous spectrum from a pulsed light source;
a pulse extension step of extending the pulse width of the broadband pulsed light emitted in the emission step with an extension element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
Broadband pulsed light whose pulse width has been stretched in the pulse stretching step is divided into light whose spectrum is continuous in a first wavelength range on the long wavelength side and a second wavelength range on the short wavelength side with respect to the division wavelength. A splitting step of splitting the light into light with a continuous spectrum in the splitting element,
a first light-receiving step of receiving, with a first light receiver, the light from the object irradiated with the light in the first wavelength range among those divided in the dividing step;
a second light-receiving step of receiving, with a second light receiver, the light from the object irradiated with the light in the second wavelength range among the light split in the splitting step;
Calculation for converting the temporal change in the output from the first photodetector received in the first light receiving process and the temporal change in the output from the second photodetector received in the second light receiving process into a spectrum by the calculation means and
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector A spectroscopic measurement method characterized by a step of converting a temporal change in output in a time zone corresponding to the second wavelength range into a spectrum of the second wavelength range. an emission step of emitting broadband pulsed light having a broadband and continuous spectrum from a pulsed light source;
The broadband pulsed light emitted in the emission step is divided into light whose spectrum is continuous in a first wavelength range on the long wavelength side and spectrum is continuous in a second wavelength range on the short wavelength side with respect to the division wavelength. A splitting step of splitting the light into the splitting element,
a first pulse stretching step of pulse stretching with a first stretching element so that the relationship between the elapsed time in the pulse and the wavelength is one to one for the light in the first wavelength range among the light split in the splitting step; ,
a second pulse stretching step of pulse stretching with a second stretching element so that the light in the second wavelength range split in the splitting step has a one-to-one relationship between the elapsed time in the pulse and the wavelength; ,
a first light receiving step of receiving, with a first light receiver, light from an object irradiated with the light pulse-stretched in the first pulse stretching step;
a second light receiving step of receiving, with a second light receiver, light from an object irradiated with the light pulse-stretched in the second pulse stretching step;
a calculation step of converting into a spectrum the temporal change in the output from the first photodetector received in the first light receiving step and the temporal change in the output from the second photodetector received in the second light receiving step; equipped with
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector A spectroscopic measurement method characterized by a step of converting a temporal change in output in a time zone corresponding to the second wavelength range into a spectrum of the second wavelength range. an emission step of emitting broadband pulsed light having a broadband and continuous spectrum from a pulsed light source;
a pulse extension step of extending the pulse width of the broadband pulsed light emitted in the emission step with an extension element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a splitting step of splitting the light from the object irradiated with the broadband pulsed light whose pulse width is stretched in the pulse stretching step into two by a splitting element;
a first light receiving step of receiving one of the light beams split in the splitting step with a first light receiver;
a second light receiving step of receiving the other of the light split in the splitting step with a second light receiver;
Calculation for converting the temporal change in the output from the first photodetector received in the first light receiving process and the temporal change in the output from the second photodetector received in the second light receiving process into a spectrum by the calculation means and
The first and second photoreceivers have different spectral sensitivity characteristics, the first photoreceiver having sensitivity over the first wavelength range and the second photoreceiver having sensitivity over the first wavelength range. having sensitivity over a second range of wavelengths inconsistent with
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector A spectroscopic measurement method characterized by a step of converting a temporal change in output in a time zone corresponding to a second wavelength range that does not match the first wavelength range into a spectrum of the second wavelength range. The first photoreceiver is a photoreceiver having higher spectral sensitivity than the second photoreceiver in the first wavelength range, and the second photoreceiver is the first photoreceiver in the second wavelength range. 24. The spectroscopic measurement method according to claim 23, wherein the photodetector has a spectral sensitivity higher than that of the photodetector. an emission step of emitting broadband pulsed light having a broadband and continuous spectrum from a pulsed light source;
an elongation step of pulse-expanding the pulse width of the broadband pulsed light emitted in the emission step with an elongation element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
The light from the object irradiated with the broadband pulsed light extended in the extension step is divided into the light and the short wavelength side of the spectrum in the first wavelength range on the long wavelength side with respect to the division wavelength. a splitting step of splitting the light into light having a continuous spectrum in a second wavelength range with a splitting element;
a first light receiving step of receiving the light in the first wavelength range among the light split in the splitting step with a first light receiver;
a second light receiving step of receiving the light in the second wavelength range, which is split in the splitting step, with a second light receiver;
a calculation step of converting into a spectrum the temporal change in the output from the first photodetector received in the first light receiving step and the temporal change in the output from the second photodetector received in the second light receiving step; equipped with
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector A spectroscopic measurement method characterized by a step of converting a temporal change in output in a time zone corresponding to the second wavelength range into a spectrum of the second wavelength range. 19, 20, 21, characterized in that said stretching element is a single mode fiber, a single mode multicore fiber, a single mode fiber bundle fiber, a multimode fiber, a diffraction grating, a chirped fiber Bragg grating or a prism. , 23, 24 or 25. wherein said first stretching element and said second stretching element are a single mode fiber, a single mode multicore fiber, a single mode fiber bundle fiber, a multimode fiber, a diffraction grating, a chirped fiber Bragg grating or a prism. 23. The spectroscopic measurement method according to claim 22. 28. The spectroscopic measurement method according to claim 22 or 27, wherein said first elongation element and said second elongation element are elements with elongation characteristics different from each other. 26. The spectroscopic measurement method according to any one of claims 21, 22 and 25, wherein said splitting element is one of a dichroic mirror, a wavelength division multiplex coupler, a diffraction grating, and an arrayed waveguide grating. 30. The spectroscopic measurement method according to claim 19, wherein said broadband pulsed light is supercontinuum light. 31. The spectroscopic measurement method according to claim 30, wherein said broadband pulsed light is supercontinuum light whose spectrum is continuous over a wavelength width of at least 10 nm in a wavelength range of 900 nm or more and 1300 nm or less. 32. The spectroscopic measurement method according to claim 19, wherein said first photodetector is an InGaAs photodiode photodetector. 33. The spectroscopic measurement method according to claim 19, wherein said second photodetector is a Si photodiode photodetector. a first emitting step of emitting broadband pulsed light having a continuous spectrum in a first wavelength range from a pulsed light source;
a first pulse stretching step of stretching the pulse width of the broadband pulsed light emitted in the first emitting step with an stretching element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a first irradiation step of irradiating an object with the broadband pulsed light pulse-stretched in the first pulse-stretching step;
a first light receiving step of receiving light from the object irradiated in the first irradiation step with a first light receiver;
a second emitting step of emitting from the pulsed light source another broadband pulsed light whose spectrum is continuous in a second wavelength range that does not match the first wavelength range;
a second pulse stretching step of stretching the pulse width of the broadband pulsed light emitted in the second emitting step with an stretching element so that the relationship between the elapsed time in the pulse and the wavelength is one to one;
a second irradiation step of irradiating the object with the broadband pulsed light pulse-stretched in the second pulse-stretching step;
a second light receiving step of receiving light from the object irradiated in the second irradiation step with a second light receiver having spectral sensitivity characteristics different from those of the first light receiver;
Calculation for converting the temporal change in the output from the first photodetector received in the first light receiving process and the temporal change in the output from the second photodetector received in the second light receiving process into a spectrum by the calculation means and
The calculating step converts the temporal change of the output in the time zone corresponding to the first wavelength range out of the output from the first photodetector into the spectrum of the first wavelength range, and the output from the second photodetector A spectroscopic measurement method characterized by a step of converting a temporal change in output in a time zone corresponding to the second wavelength range into a spectrum of the second wavelength range. 19. The spectroscopic measurement according to any one of claims 1 to 18, wherein the first wavelength range and the second wavelength range are continuous with a wavelength resolution in the arithmetic processing performed by the arithmetic means. Device. 35. The spectroscopic measurement method according to claim 19, wherein in said calculating step, said first wavelength range and said second wavelength range are continuous across a wavelength resolution.

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