WO2021172290A1 - Analysis method, light emission analysis device, diffuse optical tomography, imaging device, reflectivity measurement device, analysis device, and program - Google Patents

Abstract

According to the present invention, the characteristics of an object that includes temporal characteristics are analyzed while reducing damage to the object. An analysis method including a generation step for generating a plurality of photons, a first detection step for detecting a first photon among the plurality of photons, a second detection step for detecting a second photon among the plurality of photons, and an analysis step for analyzing characteristics pertaining to an object with reference to the difference in timing of detection performed in the first detection step and the second detection step.

Description

Analytical method, luminescence analyzer, diffused light tomography device, imaging device, reflectance measuring device, analyzer, and program

The present invention relates to an analysis method, a light emission analyzer, a diffuse tomography apparatus, an imaging apparatus, a reflectance measuring apparatus, an analyzer, and a program.

Conventionally, a method of analyzing the characteristics of an object such as a molecule or a crystal using light has been known. For example, there is known a method of analyzing the characteristics of an object by irradiating the object with one of two pulsed lights and using the other as a reference.

Although the fields and application targets are different, research on the generation and utilization of quantum entangled photons is also progressing (for example, Patent Documents 1 and 2).

Japanese Patent Publication "Japanese Patent Laid-Open No. 2008-216369 (published on September 18, 2008)" Japanese Patent Publication "Special Table 2012-522883 (published on September 27, 2012)"

As described above, in the method of analyzing the characteristics of an object using pulsed light, the scale of the analyzer tends to be large, and the object may be damaged by irradiating the pulsed light. There is a problem. Further, in order to reduce damage to the object, it is conceivable to irradiate the object with continuous light, but such a method has a problem that it is difficult to specify the temporal characteristics of the object.

One aspect of the present invention has been made to solve the above-mentioned problems, and realizes a technique capable of analyzing the characteristics of an object including temporal characteristics while reducing damage to the object. The purpose is to do.

In order to solve the above problems, the analysis method according to one aspect of the present invention includes a generation step of generating a plurality of photons in a quantum entangled state with each other and a first detection of a first photon among the plurality of photons. A detection step of 1, a second detection step of detecting a third photon obtained by irradiating or incident a second photon of the plurality of photons on an object, and a detection in the first detection step. It includes an analysis step of analyzing the characteristics of the object with reference to the difference between the timing and the detection timing in the second detection step.

The analyzer according to one aspect of the present invention includes a generation unit that generates a plurality of photons in a quantum entangled state with each other, a first detection unit that detects a first photon among the plurality of photons, and the plurality of photons. A second detection unit that detects a third photon obtained by irradiating or incident a second photon on an object, a detection timing by the first detection unit, and the second detection unit. It is provided with an analysis unit that analyzes the characteristics of the object with reference to the difference from the detection timing according to the above.

According to one aspect of the present invention, it is possible to realize a technique capable of analyzing the characteristics of an object including temporal characteristics while reducing damage to the object.

It is a schematic diagram which shows the structure of the analyzer which concerns on Embodiment 1 of this invention. FIG. 5 is a block diagram showing an analysis unit included in the analyzer according to the first embodiment of the present invention together with a first detection unit and a second detection unit. It is a figure which shows the photon pair generated by the analyzer which concerns on Embodiment 1 of this invention, and is generated by spontaneous parametric downward transformation. It is a figure which shows the photon pair generated by the analyzer which concerns on Embodiment 1 of this invention, and is generated by spontaneous parametric downward transformation. It is a flowchart which shows the flow of processing by the analyzer which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the light emission analyzer which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the arithmetic part of the light emission analyzer which concerns on Embodiment 2 of this invention. It is a graph which shows the detection result example by the detection part of the issuing analyzer which concerns on Embodiment 2 of this invention. It is a graph which shows the detection result example by the luminescence analyzer which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the diffused light tomography apparatus which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the arithmetic part of the diffused light tomography apparatus which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the image pickup apparatus which concerns on Embodiment 4 of this invention. It is a block diagram which shows the structure of the arithmetic part of the image pickup apparatus which concerns on Embodiment 4 of this invention. It is a block diagram which shows the structure of the reflectance measuring apparatus which concerns on Embodiment 5 of this invention. It is a block diagram which shows the structure of the calculation part of the reflectance measuring apparatus which concerns on Embodiment 5 of this invention.

[Embodiment 1]
<Overview>
Hereinafter, the analyzer according to the embodiment of the present invention will be described. The analyzer according to the present embodiment uses one photon as a reference (reference) and another photon for irradiating or incident on an object (sometimes referred to as measurement) among a plurality of photons. It is a device that analyzes the characteristics of an object. The analyzer 1 can be regarded as an example of a device generally called a TCSPC (Time-Correlated Single Photon Counting) device.

Here, the plurality of photons according to the present embodiment are a plurality of single photons in a quantum entangled state with each other. Here, a plurality of single photons in a quantum entangled state are temporally synchronized with each other. More specifically, the plurality of photons according to the present embodiment are two single photons in a quantum entangled state with each other.

Conventionally, a technique for analyzing the characteristics of an object using a pulse wave that is synchronized in time has been known, but there is a problem that the use of a pulse wave causes great damage to the object. It is also conceivable to use continuous light in order to reduce damage to the object, but when continuous light is used in this way, there is a problem that it is difficult to measure the temporal characteristics of the object. rice field.

Further, in the conventional method, since a device for generating a pulse wave is required, there is a problem that the configuration of the device becomes complicated. Further, when a plurality of components are present with respect to the temporal characteristics of the object (for example, when a plurality of fluorescence lifetime components are present), it is necessary to perform measurement at various modulation frequencies, and measurement for determining the fluorescence lifetime. And there was a problem that the analysis was complicated.

In the analyzer according to the present embodiment, among a plurality of photons, one photon is used as a reference and another photon is used for irradiating or incident on the object to analyze the characteristics of the object. In the analyzer according to the present embodiment, as will be described later, a plurality of photons in a quantum entangled state are generated at random timings. Therefore, unlike the case of using a pulse wave, a large number of photons are not irradiated to the object at the same time, and as a result, the characteristics of the object are analyzed while minimizing the damage to the object. be able to.

Further, according to one configuration example of the analyzer according to the present embodiment, there is no need for an apparatus for generating a pulse wave as compared with the case where a pulse wave is used, so that there is an advantage that the configuration of the entire apparatus can be simplified. There is also. On the other hand, by using the property that two paired photons are temporally synchronized, it is possible to directly measure the temporal characteristics of an object as in the case of using a pulse wave. Even when a plurality of components are present with respect to the temporal characteristics of the object (for example, when a plurality of fluorescence lifetime components are present), the measurement can be performed with only one continuous light source. Therefore, there is an advantage that it is not necessary to modulate the intensity of the light source each time.

<Configuration example>
Hereinafter, a configuration example of the analyzer according to the present embodiment will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of the analyzer 1 according to the present embodiment. As shown in FIG. 1, as an example, the analyzer 1 includes a light source 10, a first mirror 21, a first lens 22, a first bandpass filter 23-1, and a second bandpass filter 23-2. 2nd mirror 24, 3rd mirror 25, 2nd lens 26, 3rd lens 27, long pass filter 28, 4th lens 29, 5th lens 30, 1st detection unit 50, 2nd It is configured to include a detection unit 60 and an analysis unit 70.

The light source 10 generates a plurality of photons in a quantum entangled state with each other in time synchronization. As an example, the light source 10 includes a continuous light source 11, a light source lens 12, and a crystalline substance 13. The continuous light source 11 is, for example, a laser light source that produces a laser that is continuous light having a specific wavelength, but this is not limited to this embodiment. The continuous light generated by the continuous light source 11 may be referred to as pump light. Further, the light source 10 may be referred to as a generation unit.

The crystalline substance 13 generates a plurality of photons in a quantum entangled state with each other in response to the incident of continuous light from the continuous light source 11. As an example, the crystalline substance 13 produces two photons (photon pairs) that are in a quantum entangled state with each other. In addition, the crystalline substance 13 generates photon pairs at random timings. Non-linear optical crystals can be mentioned as an example of the crystalline substance 13, but this does not limit the present embodiment. Specific examples of the crystalline substance 13 will be described later.

The first mirror 21 directs the first photon of the plurality of photons supplied from the light source 10 along the first path, and secondly directs a second photon different from the first photon. Orient along the path of. The specific configuration of the first mirror 21 is not limited to this embodiment, but it is preferably a configuration that preferably reflects the first photon and the second photon.

The first lens 22 refracts the first photon and the second photon, and as an example, as shown in FIG. 1, the first photon and the second photon propagate in parallel with each other. Orient the 1st photon and the 2nd photon.

The first bandpass filter 23-1 transmits photons having a first angular frequency among the first photons and blocks photons other than those having the first angular frequency. Further, the second bandpass filter 23-2 transmits photons having a second angular frequency among the second photons, and blocks photons other than those having the second angular frequency.

The first and second angular frequencies are the light source 10, the object 40, and the first detection under the condition that the sum of the two matches the angular frequency of the continuous light source 11. Appropriate values may be appropriately selected according to the characteristics of the unit 50, the second detection unit 60, and the like.

The first photon travels along the first path, passes through the fourth lens 29, is detected by the first detection unit 50, and the detection signal is supplied to the analysis unit 70.

On the other hand, the second photon is reflected by the second mirror 24 and the third mirror 25, and then passes through the second lens 26 arranged on the second path. Then, the second photon transmitted through the second lens 26 is irradiated or incident on the object 40.

Here, the object 40 emits a third photon in response to being irradiated or incident with the second photon. The third photon may be the same photon as the second photon, or may be a photon different from the second photon, and the matter does not limit the present embodiment. Further, the third photon may be a plurality of single photons.

The emitted third photon passes through the fifth lens 30 after passing through the third lens 27 and the long pass filter 28. The long-pass filter 28 transmits photons having an angular frequency equal to or lower than a specific third angular frequency among the third photons, and blocks other photons. The third photon that has passed through the fifth lens 30 is detected by the second detection unit 60, and the detection signal is supplied to the analysis unit 70.

As the first detection unit 50 and the second detection unit 60, a single photon detector can be used as an example. More specifically, a one-photon application type avalanche photodiode can be used, but this does not limit the present embodiment.

In the analyzer 1 configured as described above, the first photon reaches the first detection unit 50 and is detected without being irradiated or incident on the object 40. On the other hand, the second photon is irradiated or incident on the object 40, and the third photon obtained accordingly reaches the second detection unit 60 and is detected.

Generally, after the second photon is irradiated or incident on the object 40, it takes a non-zero response time until the third photon is obtained. Therefore, as shown in FIG. 1, the timing at which the third photon is detected by the second detection unit 60 is delayed from the timing at which the first photon is detected by the first detection unit 50. The analysis unit 70 analyzes the characteristics of the object 40 by identifying and referring to this delay time. In other words, the analyzer 1 uses the detection timing of the first photon as a reference for analyzing the characteristics of the object 40.

(Analysis Department)
Subsequently, a configuration example of the analysis unit 70 will be described with reference to FIG. As described above, the analysis unit 70 refers to the difference between the detection timing of the first photon by the first detection unit 50 and the detection timing of the third photon by the second detection unit 60, and refers to the object. It is a configuration for analyzing the characteristics related to 40.

As shown in FIG. 2, the analysis unit 70 includes a first acquisition unit 71, a second acquisition unit 72, a first conversion unit 73, a second conversion unit 74, and a calculation unit 75. ..

The first acquisition unit 71 acquires the detection signal by the first detection unit 50, performs signal processing, and then supplies the detection signal to the first conversion unit 73. As an example, the first conversion unit 73 amplifies the detection signal by the first detection unit 50, and supplies the amplified signal to the first conversion unit 73.

The second acquisition unit 72 has the same configuration as the first conversion unit 73, except that the detection signal to be acquired is the detection signal by the first detection unit 50.

The first conversion unit 73 converts the signal supplied from the first acquisition unit 71, and supplies the converted signal to the calculation unit 75. As an example, the first conversion unit 73 converts the analog signal supplied from the first acquisition unit 71 into a digital signal, and supplies the converted digital signal to the calculation unit 75.

The second conversion unit 74 has the same configuration as the first conversion unit 73, except that the signal to be acquired is a signal supplied from the second acquisition unit 72.

The calculation unit 75 analyzes the characteristics of the object 40 with reference to the difference between the detection timing of the first photon by the first detection unit 50 and the detection timing of the third photon by the second detection unit 60. do. As shown in FIG. 1, the calculation unit 75 specifies a time difference that specifies a time difference between the detection timing of the first photon by the first detection unit 50 and the detection timing of the third photon by the second detection unit 60. The part 751 is provided.

According to the analyzer 1 configured as described above, among a plurality of photons in a quantum entangled state with each other, the first photon is detected without passing through the object 40, and the second photon is the object 40. The third photon obtained by irradiating or incident on the object is detected with a delay time depending on the object as an example. Then, the analyzer 1 analyzes the characteristics of the object 40 with reference to the difference between the detection timing of the first photon and the detection timing of the third photon, so that the damage to the object is minimized. At the same time, the characteristics of the object can be suitably analyzed.

<About the generation of photons that are in a quantum entangled state with each other>
Hereinafter, "a plurality of photons in a quantum entangled state with each other" in the present embodiment will be described in more detail. It should be noted that the following description exemplifies a plurality of photons generated by spontaneous parametric downward conversion in the crystalline substance 13 which is a nonlinear optical crystal as an example, but this is for illustration purposes only. .. The “plurality of photons in a quantum entangled state with each other” in the present embodiment is not limited to those generated by using the crystalline substance 13 which is a nonlinear optical crystal, and is not limited to those produced by various production methods as described later. It may be generated.

FIG. 3 is a schematic diagram for explaining an example of generation of photon pairs by the crystalline substance 13. As described above, pump light is supplied from the continuous light source 11 to the crystalline substance 13, and a part of the pump light is spontaneously parametric down-conversion (SPDC: Spontaneous Parametric Down-Conversion) in the crystalline substance 13. Is converted into two temporally synchronized single photons (one is also called signal light and the other is sometimes called idler light). FIG. 3 illustrates a Type II SPDC in which the two photons have different polarizations.

Here, the (angular frequency, wave vector) of the pump light _{is expressed as (ω P} , k _p ), and the (angular frequency, wave vector) of the two generated photons are (ω ₁ , k _{1), respectively.} ) (Ω ₂ , k ₂ )
ω _P = ω ₁ + ω ₂・ ・ ・ (Equation 1)
k _p = k ₁ + k ₂・ ・ ・ (Equation 2)
Is satisfied. Equation 1 expresses the law of conservation of energy, and Equation 2 expresses the law of conservation of momentum. In this specification, the angular frequency may be simply referred to as a frequency.

As shown in FIG. 3, the two photons generated by the SPDC are paths on two cones that are symmetrically located with respect to the pump light and propagate along the path symmetrical with respect to the pump light. do.

FIG. 3 shows a photon pair A as an example of a plurality of photons in a quantum entangled state with each other, and a photon pair B as another example. In the case of the type II SPDC shown in FIG. 3, the state of photon pair A containing photon A1 and photon A2 having paths on different cones is an example.
| Ψ> = | V> ₁ | H> ₂・ ・ ・ (Equation 3)
Or
| Ψ> = | H> ₁ | V> ₂・ ・ ・ (Equation 4)
It is expressed as. Here, V and H represent vertically polarized light and horizontally polarized light, respectively, and the subscripts 1 and 2 of Kett |> are indexes for distinguishing two photons. As shown in Equations 3 and 4, the photons A1 and A2 contained in the photon pair A are not entangled with each other in terms of polarization state.

On the other hand, in the case of type II SPDC, the state of photon vs. B containing photon B1 and photon B2 with the line of intersection of two cones as an example is an example.
| Ψ> = (1 / √2) | V> ₁ | H> ₂ + (1 / √2) | H> ₁ | V> ₂・ ・ ・ (Equation 5)
It is expressed as. As described above, the photon B1 and the photon B2 contained in the photon pair B are in an entangled state with respect to the polarization state.

As a plurality of photons in a quantum entangled state with each other used in the present embodiment, the photon A1 and the photon A2 contained in the above-mentioned photon pair A may be used, or the photon B1 and the photon B2 contained in the photon pair B may be used. You may use it. In other words, the "plurality of photons in a quantum entangled state with each other" in the present embodiment may or may not have a polarization entangled relationship with each other as long as they are temporally synchronized.
FIG. 4 is a schematic diagram for explaining another example of generation of a photon pair by the crystalline substance 13. FIG. 4 illustrates a Type I SPDC in which the polarizations of the two photons are equal to each other. In this example as well, the (angular frequency, wave vector) of the pump light _{is expressed as (ω P} , k _p ), and the (angular frequency, wave vector) of the two generated photons are (ω ₁ , k p, respectively). ₁ ) When _{expressed as (ω 2} , k ₂ ), the above-mentioned equations 1 and 2 are satisfied as in the case of FIG.
As shown in FIG. 4, the two photons generated by the SPDC are paths on one cone about the pump light and propagate along a path symmetrical to the pump light.
FIG. 4 shows a photon pair C as an example of a plurality of photons in a quantum entangled state with each other. In the case of the type I SPDC shown in FIG. 4, the state of photon vs. C containing photon C1 and photon C2 with the path on the cone is an example.
| Ψ> = | V> ₁ | V> ₂・ ・ ・ (Equation 3')
Or
| Ψ> = | H> ₁ | H> ₂・ ・ ・ (Equation 4')
It is expressed as. Here, as shown in the formulas 3'and 4', the photon C1 and the photon C2 contained in the photon pair C are not entangled with each other in terms of the polarization state.
Photon C1 and photon C2 contained in the above-mentioned photon pair C may be used as a plurality of photons in a quantum entangled state with each other used in the present embodiment.

In the following, we will explain in more detail the situation in which a two-photon state | Ψ> containing two photons with _{frequencies ω 1} and ω ₂ is generated by SPDC using light with _{frequency ω p as pump light.} , "A plurality of photons in a quantum entangled state with each other" in the present specification will be described in more detail.

First, the creation operators that generate two photons, respectively.

When the vacuum state without photons is written as | 0>, the two-photon state | Ψ> is expressed as follows.

Here, in Equation 8

Is a Dirac delta function, and it can be seen that due to the existence of this delta function, as shown in Equation 9, only the case where the energy conservation law shown in Equation 1 is satisfied needs to be considered.

As can be seen from Equation 9, the two-photon state | Ψ> cannot be expressed by the product of the one-photon state with _{frequency ω 1} and the one-photon state with frequency ω _2. Such a state is expressed in the present specification as "entangled with each other in terms of frequency (angular frequency)".

The above description is in the frequency domain, but in the following, it will be rewritten in the time domain in order to investigate the temporal correlation between two photons. First, the Fourier transform

Is assigned to Equation 9 and the relational expression of the delta function

By calculating the integral of _{ω 1 first using}

To get. As can be seen from Equation 14, the two photons are temporally synchronized.

To express it more concretely, it is assumed that one photon exists in the path a and the other photon exists in the path b. If the state in which one photon exists in the path a at time t is expressed as | 1> _a (t), Equation 14 can be rewritten as follows.

Furthermore, if the time integral is expressed in sum,

... (Equation 16)
To get. As can be seen from Equations 15 and 16, the two-photon state | Ψ> cannot be expressed as the product of the two photon states. Such a state is referred to herein as "tangled with each other in terms of time."

As described above, the "plurality of photons in a quantum entangled state" used in the present embodiment is, for example, a plurality of photons that are entangled with each other in terms of frequency (angular frequency) or time.

<About crystalline substances>
A more specific description of the crystalline substance 13 according to the present embodiment is as follows. As described above, the light source 10 is not limited to the configuration including the crystalline substance 13, but the configuration of the analyzer 1 can be made simpler by configuring the light source 10 to include the crystalline substance 13. There is a merit that it can be done.

As an example, the crystalline substance 13 is a non-linear optical crystal in which the crystal responds non-linearly to incident light and birefringence exists. However, this does not limit this embodiment.

Specific examples of the crystalline substance 13 include BBO (β-BaB ₂ O ₄ ), KDP (KH ₂ PO ₄ ), ppKTP (Periodically Polled KTIOPO ₄ ), ppLN (Periodically Collected LiNbo ₃ ) and the like. However, these specific examples do not limit the present embodiment.

Further, in the SPDC using the nonlinear optical crystal, as described above, there are a type I that generates two photons having the same polarization direction and a type II that generates two photons having different polarization directions. In this embodiment, type I and type II SPDCs may be used. For example, a BBO may be used to generate a photon pair with a type II SPDC, or a BBO may be used to generate a photon pair with a type I SPDC.

The frequency of photon pairs generated by the crystalline substance 13 is not limited to this embodiment, but it may be set to several to several million times per second as an example by adjusting the intensity of the pump light. Can be done.

Further, as another example of the crystalline substance 13, a _{substance obtained by reversing the spontaneous polarization in the lithium niobate (LiNbO 3} ) crystal in two different cycles may be used. In the material constructed in this way, by controlling two different phase matching conditions, a quantum entangled state in which the polarization and frequency of the photon pair that can be generated in each region are alternately correlated is directly generated. be able to.

The photon pair generated in this way can also be used as "a plurality of photons in a quantum entangled state with each other" according to the present embodiment.

<Other light source configuration examples>
The configuration example of the light source 10 is not limited to the above example. For example, the light source 10 includes one of a Mach-Zehnder interferometer, a Michaelson-type interferometer, and a Sanyak-type interferometer instead of the crystalline material 13, and is quantum to each other by any of these interferometers. It may be configured to generate a plurality of entangled photons.

<About the second photon and the third photon>
As described above, the third photon according to the present embodiment is obtained by irradiating or incident on the object 40 with the second photon. Depending on how the object 40 and the analyzer 1 are applied, it may be more preferable to interpret the second photon and the third photon as the same photon, or they may be interpreted as different photons. It may be more preferable.

For example, when a luminescent (fluorescent, phosphorescent) substance is used as an example of the object 40, the object 40 transitions to an excited state by absorbing a second photon in the object 40. Then, a third photon is emitted with the transition from the excited state to the lower energy state. In such an example, it is preferable to interpret that the third photon is a photon different from the second photon.

As another example, consider the case where the second photon is reflected by the mirror or propagates through the fiber as the object 40, because in these processes the second photon is only reflected or transmitted. , The interpretation that the second photon and the third photon are the same photon is preferably valid.

On the other hand, the third photon travels in a different direction from the second photon, and the time width of the photon wave packet may become wider while propagating in the fiber. Thus, the physical properties of the second and third photons are generally not exactly the same. Therefore, in that sense, the interpretation that the second photon and the third photon are different photons is also valid.

In specifying the invention described in the present embodiment, whether the second photon and the third photon are the same or different depends on how the object 40 and the analyzer 1 are applied. It is a matter that includes an interpretation theory as to whether or not to interpret it, and is not essential.

<Processing flow by analyzer 1>
Subsequently, the flow of processing by the analyzer 1 according to the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing the flow of processing by the analyzer 1.

(Step S11)
First, in step S11, the light source 10 generates a plurality of photons in a quantum entangled state with each other. Here, for the generation of photons by the light source 10, the method already described may be used.

(Step S12)
Subsequently, in step S12, the first detection unit 50 detects the first photon propagating in the first path among the plurality of photons in the quantum entangled state with each other generated in step S11.

(Step S13)
Subsequently, in step S13, the second detection unit 60 is obtained by irradiating or incident the second photon on the object 40 among the plurality of photons in the quantum entangled state with each other generated in step S11. Detects a third photon.

(Step S14)
In step S14, the analysis unit 70 analyzes the characteristics of the object 40 with reference to the difference between the detection timing by the first detection unit 50 in step S12 and the detection timing by the second detection unit 60 in step S13. do.

According to the analysis method including the above steps, among a plurality of photons in a quantum entangled state with each other, the first photon is detected without passing through the object 40, and the second photon irradiates or irradiates the object 40. The third photon obtained by incident is detected with a delay time depending on the object as an example. Then, the analyzer 1 analyzes the characteristics of the object 40 with reference to the difference between the detection timing of the first photon and the detection timing of the third photon, so that the damage to the object is minimized. At the same time, the characteristics of the object can be suitably analyzed.

In the above description, the case where the first photon is detected in step S12 and then the second photon is detected in step S13 has been given as an example, but this does not limit the present embodiment. .. Depending on how the first path and the second path are configured, the second photon may be detected in step S13 before the first photon is detected in step S12. Such an example is also included in this embodiment.

Further, in any case, the wave function collapse of the other photon may occur by detecting one of the first photon and the second photon first.

(Interdisciplinary aspects of the invention described herein)
As described above, the analysis method and analyzer described in the present specification generate a plurality of photons in a quantum entangled state with each other as an example, and utilize the generated photons for spectroscopy (for example, molecular spectroscopy). doing. Here, the use of quantum optical objects such as a plurality of photons in a quantum entangled state has been limited to the use in the category of quantum optics, and has not been applied to spectroscopy. The inventor of the present application can come up with the invention described in the present specification only after obtaining a new finding that a quantum optical object called a plurality of photons in a quantum entangled state is applied to spectroscopy. It is an invention. As described above, the analysis method and the analysis device described in the present specification have a highly interdisciplinary aspect of fusing two fields that cannot be easily linked even by those skilled in the art.

[Embodiment 2]
The second embodiment of the present invention will be described below. The same reference numerals are given to the configurations already described in the above-described embodiment, and the description thereof will be omitted.

FIG. 6 is a block diagram showing the configuration of the luminescence analyzer 100 according to the present embodiment. As shown in FIG. 6, the luminescence analyzer 100 includes an analyzer 1a. The analyzer 1a includes a calculation unit 75a instead of the calculation unit 75 included in the analysis device 1 described in the first embodiment. Other configurations of the analyzer 1a are the same as those of the analyzer 1 according to the first embodiment.

The luminescence analyzer 100 is a device that analyzes the characteristics of the object 40 having luminescence. Here, the light emission includes fluorescence and phosphorescence (phosphorescence). The luminescence analyzer 100 specifies the luminescence lifetime (for example, fluorescence lifetime, phosphorescence lifetime) of the object 40 as an example.

FIG. 7 is a block diagram showing a configuration of a calculation unit 75a included in the analyzer 1a. As shown in FIG. 7, the calculation unit 75a includes a time difference specifying unit 751 and a light emitting life specifying unit 752. The light emission lifetime specifying unit 752 specifies the light emission life of the object 40 by referring to the detection timing of the first photon and the detection timing of the third photon specified by the time difference specifying unit 751.

In relation to FIG. 5 described in the first embodiment, in the present embodiment, in step S13 of FIG. 5, a photon associated with the light emission phenomenon of the object 40 is detected as a third photon.

FIG. 8 plots the difference between the detection timing of the first photon and the detection timing of the third photon detected by the luminescence analyzer 100 in a situation where the object 40 is not arranged on the second path for comparison. This is the result of the experiment.

As shown in FIG. 8, in the situation where the object 40 is not arranged on the second path, the difference (detection error) between the detection timing of the first photon and the detection timing of the third photon is about 0.23 ns. It is suppressed, and it can be seen that a high degree of simultaneity between the two photons is realized. The detection error shown in FIG. 7 is mainly due to the time resolution of the first detection unit 50 and the second detection unit 60, and the light source 10 has a higher simultaneity than the simultaneity shown in FIG. Has been realized.

FIG. 9 shows a fluorescence attenuation curve specified by the emission lifetime specifying unit 752 when a dye molecule (Rhodamine 6G), which is a fluorescent molecule, is used as the object 40. The fluorescence attenuation curve shown in FIG. 9 is a graph obtained by plotting the time difference specified by the time difference specifying unit 751 for each photon pair for a large number of photon pairs by the emission lifetime specifying unit 752. In the example shown in FIG. 9, the emission lifetime specifying unit 752 specifies that the fluorescence lifetime of the object 40 is 4.8 ns.

According to the luminescence analyzer 100 according to the present embodiment, it is possible to suitably analyze the characteristics related to the luminescence phenomenon of the object 40 while minimizing the damage to the object 40.

In the above example, the molecule is taken as an example of the object 40, but this does not limit the present embodiment, and the object 40 includes at least one of an atom, a molecule, a solid, and a crystal. Can include.

Even for such an object, according to the luminescence analyzer 100, it is possible to suitably analyze the characteristics of the object 40 regarding the luminescence phenomenon while minimizing the damage to the object 40.

[Embodiment 3]
Hereinafter, a third embodiment of the present invention will be described. The same reference numerals are given to the configurations already described in the above-described embodiment, and the description thereof will be omitted.

FIG. 10 shows a configuration example of the diffused light tomography apparatus 200. As shown in FIG. 10, the diffused light tomography apparatus 200 includes an analyzer 1b. The analyzer 1b includes a calculation unit 75b instead of the calculation unit 75 included in the analysis device 1 described in the first embodiment. Other configurations of the analyzer 1b are the same as those of the analyzer 1 according to the first embodiment.

The diffused light tomography device 200 is a device that generates a tomographic image of a transparent object 40. In the present embodiment, the object 40 is a substance having transparency, but the object 40 is not limited to a substance that transmits visible light, and a substance that transmits far ultraviolet rays and far infrared regions is also the object 40. include.

In this embodiment, the second photon is incident on the object and the first photon is used as a reference. The third photon according to the present embodiment is a photon obtained as a result of the second photon being repeatedly scattered in the object. It can be said that the third photon is a photon that has undergone repeated scattering processes in the object.

FIG. 11 shows the configuration of the calculation unit 75b included in the analyzer 1b of the diffused light tomography apparatus 200. The calculation unit 75b includes a time difference specifying unit 751 and a tomography analysis unit 753. The tomography analysis unit 753 refers to the detection timing of the first photon and the detection timing of the third photon specified by the time difference identification unit 751 and acquires information on how the photons are scattered in the object 40. do. Then, the tomography analysis unit 753 identifies the spatial distribution of the substance in the object 40 by analyzing the acquired information. Then, as an example, a tomographic image of an object showing a specified spatial distribution is generated.

Speaking in relation to FIG. 5 described in the first embodiment, in the present embodiment, in step S13 of FIG. 5, a photon associated with the transmission phenomenon of the object 40 is detected as a third photon.

The diffused light tomography apparatus 200 can suitably perform diffused light tomography while suppressing damage to an object. In addition, since there is no need for a device that generates pulsed light as in the prior art, there is an advantage that the configuration of the diffused light tomography device is simplified.

[Embodiment 4]
Hereinafter, a fourth embodiment of the present invention will be described. The same reference numerals are given to the configurations already described in the above-described embodiment, and the description thereof will be omitted.

FIG. 12 shows a configuration example of the imaging device 300. As shown in FIG. 12, the imaging device 300 includes an analyzer 1c. The analyzer 1c includes a calculation unit 75c instead of the calculation unit 75 included in the analysis device 1 described in the first embodiment. Other configurations of the analyzer 1c are the same as those of the analyzer 1 according to the first embodiment.

The imaging device 300 is a device that generates imaging information in an imaging range including an object 40 having reflexivity.

In this embodiment, the second photon is emitted toward the object, and the first photon is used as a reference. The third photon according to the present embodiment is a photon obtained by reflecting the second photon by an object.

FIG. 13 shows the configuration of the calculation unit 75c included in the analyzer 1c of the imaging device 300. The calculation unit 75c includes a time difference specifying unit 751 and an image generation unit 754. The image generation unit 754 refers to the detection timing of the first photon and the detection timing of the third photon specified by the time difference specifying unit 751, and specifies the distance to the object 40 as a characteristic of the object 40. .. Then, based on the characteristic distance, the imaging information including the distance information to the object 40, which is the imaging information of the imaging range including the object 40, is generated.

In relation to FIG. 5 described in the first embodiment, in the present embodiment, in step S13 of FIG. 5, a photon associated with the reflection phenomenon of the object 40 is detected as a third photon.

Conventionally, in a technique called Lidar (Light Imaging Detection and Ringing), scattered light with respect to laser irradiation is measured using pulsed light to analyze the distance to a target, the properties of the target, and the like. Since imaging information including distance information is generated using multiple single photons that are in a quantum entangled state with each other, it is possible to analyze the distance to the target, the properties of the target, etc. while reducing damage to the target. can.

The imaging information generated by the image generation unit 754 can be, for example, distance information and a two-dimensional captured image, but this does not limit the present embodiment. The image generation unit 754 may be configured to generate a left-eye image and a right-eye image for stereoscopic viewing by referring to the distance information and the two-dimensional captured image.

In the present embodiment, since a plurality of single photons in a quantum entangled state are used to generate an image for stereoscopic viewing, an image for stereoscopic viewing is preferably generated while reducing damage to an object. be able to. In addition, since there is no need for a device that generates pulsed light as in the prior art, there is an advantage that the configuration of the imaging device is simplified.

[Embodiment 5]
Hereinafter, a fifth embodiment of the present invention will be described. The same reference numerals are given to the configurations already described in the above-described embodiment, and the description thereof will be omitted.

FIG. 14 shows a configuration example of the reflectance measuring device 400. As shown in FIG. 14, the reflectance measuring device 400 includes an analyzer 1d. The analyzer 1d includes a calculation unit 75d instead of the calculation unit 75 included in the analysis device 1 described in the first embodiment. Other configurations of the analyzer 1d are the same as those of the analyzer 1 according to the first embodiment.

The reflectance measuring device 400 is a device that analyzes the characteristics of the object 40 having reflectivity.
Here, the object 40 is, for example, an optical fiber.

In this embodiment, the second photon is incident on the object and the first photon is used as a reference. The third photon according to the present embodiment is a photon obtained by transmitting or reflecting the second photon through an object. The third photon may also include backscattered light obtained by incident of the second photon on the object.

FIG. 15 shows the configuration of the calculation unit 75d included in the analyzer 1d of the reflectance measuring device 400. The calculation unit 75d includes a time difference specifying unit 751 and a reflectance measuring unit 755. The reflectance measuring unit 755 detects the reflectivity of the object 40 by referring to the detection timing of the first photon and the detection timing of the third photon specified by the time difference specifying unit 751.

In relation to FIG. 5 described in the first embodiment, in the present embodiment, in step S13 of FIG. 5, a photon associated with the reflection phenomenon of the object 40 is detected as a third photon.

Conventionally, in a technique called OTDR (Optical Time Domain Reflectometer), the quality of an optical fiber is controlled by backscattered light or the like using pulsed light, but in this embodiment, a plurality of photons in a quantum entangled state are used. Since quality control is performed, damage to the object can be reduced as compared with the case of using pulsed light. In addition, since there is no need for a device that generates pulsed light as in the prior art, there is an advantage that the configuration of the reflectance measuring device is simplified.

<Other application examples>
The application examples of the analyzer described above in the present specification are not limited to the above examples. As an example, the analyzer described above may be applied to the pump-probe method. More specifically, the object 40 may be excited by using the first photon, and the object may be observed by using the second photon as the probe light.

It has been impossible to perform pump-probe measurement using continuous light as a light source in the past, but by using the above-mentioned analyzer, continuous light is converted into a photon pair in an entangled state, thereby converting continuous light into a light source. Pump-probe measurement is possible.

As a more specific example, the analyzer according to this example irradiates the object 40, which is a molecule, with a first photon to initiate a photochemical reaction. Then, after a minute delay time (about femto seconds, pico seconds), the object 40 is irradiated with the second photon as probe light. As a result, the analyzer according to this example can measure molecular absorption (infrared light, visible light, ultraviolet light region) and Raman scattering. According to the analyzer according to this example, it is possible to track the progress of the chemical reaction with a time resolution of about femtoseconds and picoseconds in this way.

Further, as another example, the above-mentioned analyzer may be applied to the pump-dump-probe method.
Here, the three photons in a quantum entangled state with each other used in the pump-dump-probe method can be obtained, for example, by the following method.
That is, the analyzer is configured to include two nonlinear optical crystals. First, two photons (photon 1 and photon 2) in a quantum entangled state are incident on the first nonlinear optical crystal by SPDC. Call). Then, one of these two photons (for example, photon 1) is irradiated to the second nonlinear optical crystal, and the SPDC in the second nonlinear optical crystal converts it into two photons (referred to as photon 3 and photon 4). do.
The three photons (photon 2, photon 3, and photon 4) thus obtained are in a quantum entangled state with each other and are synchronized in time.
As an example, the analyzer according to this example excites the object 40 by irradiating the object 40, which is a molecule, with the first photon of the three photons in a quantum entangled state with each other. In general, a molecule in a high electron excited state has an equilibrium internuclear distance different from that in the ground state, so that the nuclear wave packet is given momentum and starts to move. After that, the analyzer according to this example irradiates the object 40 with the second photon of the above three photons to dump the wave packet to the ground state. After that, the analyzer according to this example irradiates the object 40 with the third photon of the above three photons as the probe light.
By executing the pump-dump-probe method as described above, the analyzer according to this example determines, for example, the deexcitation efficiency of the object 40, which is a molecule, and the dump light irradiation timing dependence of the deexcitation efficiency. Can be identified.
It has been impossible to perform pump-dump-probe measurement using continuous light as a light source, but by using the above-mentioned analyzer, continuous light can be used as a light source by converting it into three entangled photons. Allows pump-dump-probe measurements.

[Example of realization by software]
The control block of the analyzer 1 (particularly the analyzer 70, the arithmetic unit 75, 75a, 75b, 75c, 75d) may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like. , May be realized by software.

In the latter case, the analyzer 1 includes a computer that executes the instructions of a program that is software that realizes each function. The computer includes, for example, one or more processors and a computer-readable recording medium that stores the program. Then, in the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, in addition to a “non-temporary tangible medium” such as a ROM (Read Only Memory), a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (RandomAccessMemory) or the like for expanding the above program may be further provided. Further, the program may be supplied to the computer via an arbitrary transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. It should be noted that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the above program is embodied by electronic transmission.

〔summary〕
The analysis method according to one aspect of the present invention includes a generation step of generating a plurality of photons in a quantum entangled state with each other, a first detection step of detecting a first photon among the plurality of photons, and the plurality of photons. A second detection step for detecting a third photon obtained by irradiating or incident a second photon on an object, a detection timing in the first detection step, and the second detection step. It includes an analysis step of analyzing the characteristics of the object with reference to the difference from the detection timing in.

According to the above analysis method, it is possible to analyze the characteristics of the object including the temporal characteristics while reducing the damage to the object.

In the analysis method, in the analysis step, it is preferable to use the detection timing of the first photon as a reference for analyzing the characteristics of the object.

According to the above analysis method, since the detection timing of the first photon is used as a reference for the analysis of the characteristics related to the object, the characteristics of the object including the temporal characteristics can be analyzed more preferably.

In the above analysis method, in the generation step, it is preferable to generate the first photon and the second photon using a nonlinear optical crystal.

According to the above analysis method, the characteristics of the object can be detected with a simple configuration.

In the analysis method, it is preferable to detect the first photon and the third photon using a single photon detector in the first detection step and the second detection step.

According to the above analysis method, since the first photon and the third photon are detected using the single photon detector, the characteristics of the object including the temporal characteristics can be suitably detected.

The luminescence analyzer according to one aspect of the present invention is a luminescence analyzer that executes the above analysis method, and in the second detection step, a photon associated with a luminescence phenomenon of the object is detected as the third photon. It is preferable to do so.

According to the above-mentioned luminescence analyzer, the characteristics of the luminescence phenomenon of the object can be suitably analyzed.

In the luminescence analyzer that executes the above analysis method, it is preferable that the object contains at least one of an atom, a molecule, a solid, and a crystal.

According to the above-mentioned luminescence analyzer, the characteristics of the luminescence phenomenon of atoms, molecules, solids, and crystals can be suitably analyzed.

The diffused light tomography device according to one aspect of the present invention is a diffused light tomography device that executes the above analysis method, and in the second detection step, the transmitted light transmitted through the object is used as the third photon. It is preferable to detect it.

According to the diffused light tomography apparatus, the transmitted light transmitted through the object is detected as the third photon, so that the diffused light tomography can be preferably performed.

The imaging device according to one aspect of the present invention is an imaging device that executes the above analysis method, and detects the reflected light reflected by the object as the third photon in the second detection step. Is preferable.

According to the image pickup apparatus, since the reflected light reflected by the object is detected as the third photon, it is possible to suitably generate imaging information reflecting the temporal characteristics of the object.

The reflectance measuring device according to one aspect of the present invention is a reflectance measuring device that executes the above analysis method, and in the second detection step, the light emitted from the optical fiber that is the object is emitted from the third. It is preferable to detect it as a photon.

According to the reflectance measuring device, the light emitted from the optical fiber is detected as the third photon, so that the reflectance measurement can be suitably performed.

The analyzer according to one aspect of the present invention includes a generation unit that generates a plurality of photons in a quantum entangled state with each other, a first detection unit that detects a first photon among the plurality of photons, and the plurality of photons. A second detection unit that detects a third photon obtained by irradiating or incident a second photon on an object, a detection timing by the first detection unit, and the second detection unit. It is preferable to have an analysis unit that analyzes the characteristics of the object with reference to the difference from the detection timing according to the above.

According to the above analyzer, it is possible to analyze the characteristics of the object including the temporal characteristics while reducing the damage to the object.

The program according to one aspect of the present invention is a program for operating a computer as the analysis device, and it is preferable that the computer functions as the analysis unit. According to the above program, the same effect as that of the above method and apparatus is obtained.

[Additional notes]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1, 1a, 1b, 1c, 1d Analyzer 10 Light source 11 Continuous light source 12 Light source lens 13 Crystalline substance 40 Object 50 First detection unit 60 Second detection unit 70 Analysis unit 75, 75a, 75b, 75c, 75d Calculation unit 100 Light emission analyzer 200 Diffuse light tomography device 300 Imaging device 400 Reflectance measurement device 751 Time difference specification unit 752 Light emission life specification unit 753 Tomography analysis unit 754 Image generation unit 755 Reflectance measurement unit

Claims (11)

1. A generation step to generate multiple photons in entangled state with each other,
   The first detection step of detecting the first photon among the plurality of photons, and
   A second detection step of detecting a third photon obtained by irradiating or incident a second photon on an object among the plurality of photons, and a second detection step.
   An analysis method including an analysis step of analyzing the characteristics of the object with reference to the difference between the detection timing in the first detection step and the detection timing in the second detection step.
2. The analysis method according to claim 1, wherein in the analysis step, the detection timing of the first photon is used as a reference for analyzing the characteristics of the object.
3. The analysis method according to claim 1 or 2, wherein in the generation step, a nonlinear optical crystal is used to generate the first photon and the second photon.
4. Any of claims 1 to 3, wherein in the first detection step and the second detection step, a single photon detector is used to detect the first photon and the third photon. The analysis method according to item 1.
5. An luminescence analyzer that executes the analysis method according to any one of claims 1 to 4.
   A luminescence analyzer characterized in that, in the second detection step, a photon associated with a luminescence phenomenon of the object is detected as the third photon.
6. The luminescence analyzer according to claim 5, wherein the object contains at least one of an atom, a molecule, a solid, and a crystal.
7. A diffuse tomography apparatus for performing the analysis method according to any one of claims 1 to 4.
   A diffused light tomography apparatus according to the second detection step, in which transmitted light transmitted through the object is detected as the third photon.
8. An imaging device that executes the analysis method according to any one of claims 1 to 4.
   An imaging device characterized in that, in the second detection step, the reflected light reflected by the object is detected as the third photon.
9. A reflectance measuring device that executes the analysis method according to any one of claims 1 to 4.
   A reflectance measuring device, characterized in that, in the second detection step, light emitted from an optical fiber, which is the object, is detected as the third photon.
10. A generator that generates multiple photons in a quantum entangled state with each other,
    A first detection unit that detects the first photon among the plurality of photons,
    A second detection unit that detects a third photon obtained by irradiating or incident a second photon on an object among the plurality of photons, and a second detection unit.
    An analyzer including an analysis unit that analyzes the characteristics of the object by referring to the difference between the detection timing by the first detection unit and the detection timing by the second detection unit.
11. The program for operating a computer as the analyzer according to claim 10, wherein the computer functions as the first detection unit, the second detection unit, and the analysis unit.

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