KR102313685B1 - Fluorescence detection system using diamond nitrogen vacancy center - Google Patents

Abstract

The present invention relates to a fluorescence signal measurement system using a diamond DNV center, wherein the fluorescence signal measurement system according to one embodiment comprises: a light source that outputs light of a preset wavelength; a diamond structure having at least one diamond nitrogen-vacancy (DNV) center that receives the outputted light and emits a fluorescent signal in a first direction and a second direction; and a fluorescence re-emitting part having at least one fluorescence material absorbing the fluorescence signal emitted in the second direction and re-emitting thereof in the first direction. Therefore, the present invention is capable of improving an efficiency of measuring fluorescence.

Description

Fluorescence signal measurement system using DNV center {FLUORESCENCE DETECTION SYSTEM USING DIAMOND NITROGEN VACANCY CENTER}

The present invention relates to a fluorescence signal measurement system using a DNV center, and more particularly, to a technical idea for improving the fluorescence signal measurement efficiency of a DNV center for a magnetic field detector.

Conventionally, spin exchange relaxation-free (SERF) and superconducting quantum interference device (SQUID) have been used for magnetic field measurement. However, the SERF has a relatively large size and requires a lot of power, and the SQUID needs a low-temperature environment for operation, must be connected to a detection coil to be used as a magnetic field sensor, and is affected by noise from the external environment.

Accordingly, a technique for measuring a magnetic field using a carbon lattice structure having a diamond nitrogen-vacancy center (DNV) was proposed.

In a carbon lattice structure such as diamond, there may be some defects and vacancies that are different from the surroundings, and when nitrogen is injected into the carbon lattice structure, nitrogen is energy located next to the vacancy. DNV centers can be formed because they are structurally stable. When green light is applied to the DNV center in the ground state, a red fluorescence signal can be emitted, and the intensity of the magnetic field can be measured by monitoring the change in the intensity of fluorescence emitted from the DNV center through a photodetector.

Specifically, in a magnetic field detection technique using a DNV center, there are a method using a single DNV center and a method using a DNV center in an ensemble state.

Although the method using a single DNV center has the advantage that high spatial resolution is possible, it is difficult to obtain high magnetic field measurement sensitivity due to the limitation in the size of the fluorescence signal that can be obtained.

On the other hand, in the method using the DNV center in the ensemble state, it is possible to obtain a fluorescence signal of higher intensity, so that the magnetic field measurement sensitivity is improved by about 1,000 times compared to a single DNV center.

However, in this case, due to the high refractive index of the diamond, the fluorescence signal generated at the DNV center is trapped inside the diamond, making it difficult to efficiently measure the fluorescence signal from the outside. In particular, in the case of DNV centers aligned in the vertical direction, the efficiency in which the emitted fluorescence signal is formed in a waveguide mode inside the diamond is high, making it more difficult to measure from the outside.

Therefore, there is a need for a method for increasing the fluorescence signal measurement efficiency in DNV centers in an ensemble state aligned in several directions.

Specifically, a nano-pillar structure has been proposed as a method for increasing the fluorescence signal measurement efficiency in the DNV center in an ensemble state. In the nanopillar structure, the fluorescence measurement efficiency in the horizontally aligned DNV center is improved to about 54% compared to the conventional one, but the fluorescence measurement efficiency in the vertical DNV is about 36%, which is still very low. Additional solutions are required for

Korean Patent No. 10-2036322, "System and method for measuring magnetic field by detecting structural illumination light signal" US Patent Publication No. 2020-0088762, "Diamond probe hosting an atomic sized defect" US Patent Publication No. 2017-0343620, "Magneto-optical defect center device including light pipe with optical coatings" US Patent No. 10281550, "Spin relaxometry based molecular sequencing"

An object of the present invention is to provide a fluorescence signal measurement system capable of improving fluorescence measurement efficiency by absorbing and re-emitting a fluorescence signal generated from a DNV center using an aligned fluorescence material.

Another object of the present invention is to provide a fluorescence signal measurement system capable of obtaining high magnetic field measurement sensitivity through improvement of fluorescence measurement efficiency due to absorption and re-emission of a fluorescence signal.

Another object of the present invention is to provide a fluorescence signal measuring system capable of improving the efficiency of fluorescence signal measurement due to a phenomenon in which a fluorescence signal generated inside a diamond structure is trapped inside a diamond structure having a high refractive index.

A fluorescent signal measuring system according to an embodiment of the present invention includes a light source for outputting light of a preset wavelength, and at least one DNV center (diamond) receiving the output light and emitting a fluorescent signal in a first direction and a second direction. nitrogen-vacancy center) and a fluorescence re-emitting unit including at least one fluorescent material absorbing the fluorescence signal emitted in the second direction and re-emitting it in the first direction.

According to one side, the first direction may be a detection direction of the emitted fluorescent signal and the re-emitted fluorescent signal, and the second direction may be a direction orthogonal to the first direction.

According to one side, the diamond structure may include at least one nano-pillar, and the at least one nano-pillar may include at least one DNV center.

According to one side, the fluorescence re-emitting part may be provided on both sides of the at least one nanopillar to absorb the fluorescence signal emitted in the second direction.

According to one side, the fluorescence re-emitting units may be provided on both sides of the diamond structure to absorb the fluorescence signal emitted in the second direction through a waveguide mode according to total reflection.

According to one side, the fluorescent re-emitting part may be formed by mixing a fluorescent material with a low refractive index material.

According to one side, the low refractive index material may be a material having a refractive index smaller than the refractive index of the diamond structure and larger than the refractive index of air.

According to one side, the fluorescence re-emitting unit may further include a liquid crystal material for aligning directions of absorption dipoles of the fluorescent material.

According to one side, the liquid crystal material may align the direction of the absorption dipole of the fluorescent material in the first direction.

According to one side, the liquid crystal material may be a chiral liquid crystal material.

According to one embodiment, the present invention can improve fluorescence measurement efficiency by absorbing and re-emitting a fluorescence signal generated from a DNV center using an aligned fluorescence material.

According to an embodiment of the present invention, high magnetic field measurement sensitivity can be obtained through improvement of fluorescence measurement efficiency due to absorption and re-emission of a fluorescence signal.

According to an embodiment of the present invention, it is possible to improve the reduction in the efficiency of measuring the fluorescence signal due to the phenomenon that the fluorescence signal generated inside the diamond structure is trapped inside the diamond structure having a high refractive index.

1 is a view for explaining a fluorescence signal measuring system according to an embodiment.
2 is a view for explaining the fluorescence signal emission characteristics of the DNV center according to an embodiment.
3A to 3B are diagrams for explaining a fluorescence signal emission principle of a DNV center according to an embodiment.
4 is a view for explaining a fluorescence signal measuring system according to the first embodiment.
5 is a diagram for explaining a fluorescence signal measuring system according to a second embodiment.
6A to 6B are diagrams for explaining an example of absorbing and re-emitting a fluorescent signal through a fluorescent material in the fluorescent signal measuring system according to an exemplary embodiment.
7A to 7B are diagrams for explaining an example of a liquid crystal material of a fluorescence signal measuring system according to an embodiment.

Hereinafter, various embodiments of the present document will be described with reference to the accompanying drawings.

Examples and terms used therein are not intended to limit the technology described in this document to specific embodiments, and should be understood to include various modifications, equivalents, and/or substitutions of the embodiments.

Hereinafter, when it is determined that a detailed description of a known function or configuration related to various embodiments may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted.

In addition, the terms to be described later are terms defined in consideration of functions in various embodiments, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

In connection with the description of the drawings, like reference numerals may be used for like components.

The singular expression may include the plural expression unless the context clearly dictates otherwise.

In this document, expressions such as "A or B" or "at least one of A and/or B" may include all possible combinations of items listed together.

Expressions such as "first," "second," "first," or "second," can modify the corresponding elements regardless of order or importance, and to distinguish one element from another element. It is used only and does not limit the corresponding components.

When an (eg, first) component is referred to as being “connected (functionally or communicatively)” or “connected” to another (eg, second) component, that component is It may be directly connected to the element, or may be connected through another element (eg, a third element).

As used herein, "configured to (or configured to)" according to the context, for example, hardware or software "suitable for," "having the ability to," "modified to ," "made to," "capable of," or "designed to" may be used interchangeably.

In some circumstances, the expression “a device configured to” may mean that the device is “capable of” with other devices or parts.

For example, the phrase “a processor configured (or configured to perform) A, B, and C” refers to a dedicated processor (eg, an embedded processor) for performing the operations, or by executing one or more software programs stored in a memory device. , may refer to a general-purpose processor (eg, a CPU or an application processor) capable of performing corresponding operations.

Also, the term 'or' means 'inclusive or' rather than 'exclusive or'.

That is, unless stated otherwise or clear from context, the expression 'x employs a or b' means any one of natural inclusive permutations.

In the specific embodiments described above, elements included in the invention are expressed in singular or plural according to the specific embodiments presented.

However, the singular or plural expression is appropriately selected for the situation presented for convenience of description, and the above-described embodiments are not limited to the singular or plural component, and even if the component is expressed in plural, it is composed of a singular or , even a component expressed in a singular may be composed of a plural.

On the other hand, although specific embodiments have been described in the description of the invention, various modifications are possible without departing from the scope of the technical idea contained in the various embodiments.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the following claims as well as the claims and equivalents.

1 is a view for explaining a fluorescence signal measuring system according to an embodiment.

Referring to FIG. 1 , a fluorescence signal measuring system 100 according to an embodiment absorbs and re-emits a fluorescence signal generated from a DNV center using an aligned fluorescence material to improve fluorescence measurement efficiency.

In addition, the fluorescence signal measurement system 100 may acquire high magnetic field measurement sensitivity through improvement of fluorescence measurement efficiency due to absorption and re-emission of a fluorescence signal.

In addition, the fluorescence signal measuring system 100 can improve the reduction in fluorescence signal measurement efficiency due to the phenomenon that the fluorescence signal generated inside the diamond structure is trapped inside the diamond structure having a high refractive index.

For example, the fluorescence signal measurement system 100 may be a system for amplifying a fluorescence signal generated from a DNV center for magnetic field detection.

Specifically, the magnetic field detection technology based on the DNV center follows the method of inversely estimating the magnetic field change by observing the change in the fluorescence signal at the DNV center that occurs according to the change in the magnetic field. It is essential to efficiently measure the fluorescence signal in

The fluorescence signal generated inside the diamond structure is trapped inside the diamond having a high refractive index, so there is a problem in that the measurement efficiency from the outside is very low.

Accordingly, the fluorescence signal measurement system 100 according to an embodiment may increase the measurement efficiency of the fluorescence signal generated in the DNV center by applying an additional fluorescence material to the nano-pillar structure.

More specifically, by using the micro-pillar structure, it is possible to induce a fluorescence signal in the DNV center in the direction in which the measurement of the fluorescence signal is made, but it is still possible to induce a significant amount of the fluorescence signal in a direction that cannot be measured, including the waveguide mode of the diamond structure. A fluorescent signal may be emitted.

Accordingly, the fluorescence signal measurement system 100 may improve the final fluorescence signal measurement efficiency by forming an additional optical path using the fluorescent material absorbing the emission wavelength.

In addition, the fluorescence signal measuring system 100 may use a liquid crystal to align the absorption dipole directions of the fluorescent material, thereby increasing the operating efficiency.

To this end, the fluorescence signal measuring system 100 according to an embodiment may include a light source 110 , a diamond structure 120 , and a fluorescence re-emitting unit 130 .

Hereinafter, in order to more clearly distinguish the DNV center (first fluorescent material) provided in the diamond structure and the fluorescent material (second fluorescent material) provided in the fluorescent re-emitting unit, the fluorescent material provided in the fluorescence re-emitting unit is manufactured. 2 It will be named as a fluorescent substance.

The light source 110 according to an embodiment may output light of a preset wavelength.

For example, the light source 110 may be a laser light source that outputs green light having a wavelength of 532 nm, and may output green light in a direction in which the diamond structure 120 is located.

The diamond structure 120 according to an embodiment may include at least one DNV center that receives the light output from the light source 110 and emits a fluorescent signal in a first direction and a second direction.

For example, the DNV center may include at least one of a vertical DNV center in which a direction of an absorption dipole is aligned in a vertical direction and a horizontal DNV center in which a direction of an absorption dipole is aligned in a horizontal direction.

According to one side, the first direction is a detection direction (a fluorescent signal collection direction) of a fluorescent signal emitted from the DNV center and a fluorescent signal re-emitted from the second fluorescent material, and the second direction is a direction orthogonal to the first direction ( direction of non-collection of the fluorescence signal).

In other words, the first direction may refer to a direction corresponding to a collection optical axis of a photodetector that collects a fluorescent signal emitted for detecting a magnetic field.

According to one side, the first direction may mean a main emission direction of the fluorescent signal emitted from the DNV center.

For example, the DNV center may be a vertical DNV center, the first direction may be an up/down direction (z-axis direction), and the second direction may be a left/right direction (x-axis or y-axis).

The fluorescent re-emitting unit 130 according to an embodiment may include at least one second fluorescent material that absorbs the fluorescent signal emitted in the second direction and re-emits it in the first direction.

For example, the second fluorescent material may be a material having little light absorption at the excitation wavelength (eg, 532 nm) of the DNV center and high light absorption efficiency at the emission wavelength of the DNV center.

In other words, the second fluorescent material is a material that absorbs the emission spectrum of the DNV center, absorbs the fluorescent signal emitted in the second direction of the DNV center, and re-emits the fluorescent signal in the changed direction (first direction) (secondary fluorescence) signal emission), and through this, the photodetector may acquire an additional fluorescence signal to improve the signal intensity.

According to one side, the fluorescent re-emitting unit 130 may be formed by mixing a low refractive index material with a second fluorescent material.

For example, the low refractive index material may be a material having a refractive _{index smaller than the refractive index n dia} of the diamond structure 120 and larger than the refractive index n _{air of air.}

In addition, the low refractive index material may be formed at a position adjacent to the diamond structure 120 through a method such as sputtering, chemical vapor deposition (CVD), physical vapor deposition (PVD), or spin coating.

According to one side, the fluorescence re-emitting unit 130 may further include a liquid crystal for aligning the direction of the absorption dipole of the second fluorescent material, and the liquid crystal material aligns the direction of the absorption dipole of the second fluorescent material. Alignment may be performed in the first direction.

Specifically, the fluorescent re-emitting unit 130 aligns the absorption dipole of the second fluorescent material in the first direction along the long axis of the liquid crystal material by aligning the liquid crystal material in a direction perpendicular to the optical axis of the photodetector. .

For example, a liquid crystal material having a refractive index of 1.5 may be used as the liquid crystal material to improve efficiency according to the composition of the second fluorescent material. Preferably, the liquid crystal material may be a chiral liquid crystal.

In other words, the fluorescence re-emitting unit 130 may use a chiral liquid crystal material as a liquid crystal material to suppress the occurrence of a change in alignment according to a vertical magnetic field direction, thereby improving light collection efficiency.

The fluorescence signal measuring system 100 according to an embodiment will be described in more detail with reference to FIGS. 4 to 5 in the following embodiments.

2 is a view for explaining the fluorescence signal emission characteristics of the DNV center according to an embodiment.

Referring to FIG. 2, (a) of FIG. 2 shows the fluorescence signal emission characteristics of a horizontal DNV center in which the direction of the absorption dipole is aligned in the horizontal direction, and (b) of FIG. 2 is the direction of the absorption dipole. Shows the fluorescent signal emission characteristics of vertical DNV centers aligned in the vertical direction.

When forming DNV centers in an ensemble state in a diamond structure, it is difficult to control the alignment direction of each DNV center. /right) can be determined randomly.

Specifically, when the fluorescence measurement direction (the arrangement direction of the photodetector) is downward, the fluorescence signal emitted from the vertical DNV center may be mainly emitted in the horizontal direction according to the dipole emission form. In this case, the diamond structure (n _dia = 2.4) and external air (n _air = 1), most of the fluorescence signals are formed in the waveguide mode inside the diamond structure and cannot be emitted in the measurement direction due to total reflection occurring at the interface (n air = 1).

Although the efficiency can be increased by applying the nanopillar structure to the diamond structure, even in this case, more than 50% of the fluorescence signal generated in the vertical DNV center compared to the horizontal DNV center may be emitted to the left and right air layers.

Accordingly, the fluorescence signal measuring system according to an embodiment absorbs and re-emits the fluorescence signal exiting into the air layer through the second fluorescence material, and converts the fluorescence signal traveling direction to the collection direction, thereby amplifying the detected fluorescence signal. have.

3A to 3B are diagrams for explaining a fluorescence signal emission principle of a DNV center according to an embodiment.

3, the reference numeral 310 is an embodiment the second phosphor is emitted fluorescence signal from the DNV center according to (2 ^nd fluorescent material) references shown, and the discharge principle of re-emission by absorbing at numeral 320, see The emission wavelength of the light source (532 nm laser), the emission wavelength of the DNV center (NV-(diamond)), the absorption wavelength of the second fluorescent material (2 ^nd fluoro. abs.) and the emission wavelength (2 ^nd It shows the change of fluoro.emit.).

According to reference numerals 310 to 320, the DNV center may be excited with a laser light source having a wavelength of 532 nm, and the wavelength range of the emitted fluorescent signal may be about 550 nm to 700 nm.

Therefore, the absorption spectrum of the second fluorescent material should be defined in the range of about 550 nm to 700 nm, and should not be directly excited through the laser wavelength 532 nm, which is excitation light.

The amount of fluorescence of the second fluorescent material may be defined as Equation 1 below based on the Beer-Lambert law.

[Equation 1]

는 방출 형광량,

는 여기 광량,

는 내부양자효율,

는 분자흡수계수(M^-1Cm^-1),

는 샘플 농도,

은 길이,

는 외부측정효율을 의미한다. here,

is the amount of emitted fluorescence,

is the excitation light intensity,

is the internal quantum efficiency,

is the molecular absorption coefficient (M ^-1 Cm ^-1 ),

is the sample concentration,

silver length,

is the external measurement efficiency.

In addition, the internal quantum efficiency is an amount that is re-emitted as fluorescence compared to the amount of absorbed light (the number of photons), and the external measurement efficiency means an amount measured with respect to the total amount of emitted fluorescence.

The total measurement efficiency according to the use of the second fluorescent material can be divided into 1. absorption efficiency and internal quantum efficiency of fluorescent molecules, and 2. external measurement efficiency according to the overall system structure.

Specifically, IRDye® 700DX may be considered as the second fluorescent material, and in this case, the molecular absorption coefficient may be 165,000 M ⁻¹ Cm ⁻¹ , and the internal quantum efficiency may be given as 0.44.

4 is a view for explaining a fluorescence signal measuring system according to the first embodiment.

Referring to FIG. 4 , the fluorescence signal measuring system 400 according to the first embodiment may include a light source 410 , a diamond structure 420 , and a fluorescence re-emitting unit 430 .

The light source 410 according to the first embodiment may output light of a preset wavelength.

The diamond structure 420 according to the first embodiment may include at least one DNV center that receives the light output from the light source 410 and emits a fluorescent signal in a first direction and a second direction.

For example, the DNV center may include at least one of a vertical DNV center in which a direction of an absorption dipole is aligned in a vertical direction and a horizontal DNV center in which a direction of an absorption dipole is aligned in a horizontal direction.

According to one side, the first direction is a detection direction (a fluorescent signal collection direction) of a fluorescent signal emitted from the DNV center and a fluorescent signal re-emitted from the second fluorescent material 431 , and the second direction is orthogonal to the first direction. direction (non-collection direction of the fluorescent signal).

In other words, the first direction may refer to a direction corresponding to a collection optical axis of a photodetector that collects a fluorescent signal emitted for detecting a magnetic field.

According to one side, the diamond structure 420 may include at least one nano-pillar, and the at least one nano-pillar may include at least one DNV center.

In other words, the DNV center may be disposed on the nanopillars provided in the diamond structure 420 .

The fluorescent re-emitting unit 430 according to the first embodiment may include at least one second fluorescent material 431 absorbing the fluorescent signal emitted in the second direction and re-emitting it in the first direction.

According to one side, the fluorescence re-emitting unit 430 may be provided on both sides of the at least one nanopillar to absorb the fluorescence signal emitted in the second direction.

For example, the second fluorescent material 431 may be a material having little light absorption at the excitation wavelength of the DNV center and high light absorption efficiency at the emission wavelength of the DNV center.

That is, the second fluorescent material is a material that absorbs the emission spectrum of the DNV center. It absorbs the fluorescent signal emitted in the second direction of the DNV center and re-emits the fluorescent signal in the changed direction (first direction) (second fluorescent signal). emission), and through this, the photodetector may acquire an additional fluorescence signal to improve signal intensity.

According to one side, the fluorescent re-emitting part 430 may be formed by mixing the second fluorescent material 431 with a low refractive index material.

For example, the low refractive index material may be a material having a refractive _{index smaller than the refractive index n dia} of the diamond structure 420 and larger than the refractive index n _{air of air.}

According to one side, the fluorescent re-emitting unit 430 may further include a liquid crystal material 432 that aligns the direction of the absorption dipole of the second fluorescent material 431, and the liquid crystal material 432 includes the second fluorescent material ( 431), the direction of the absorption dipole may be aligned with the first direction.

Specifically, the fluorescence re-emitting unit 430 orients the liquid crystal material 432 in a direction perpendicular to the optical axis of the photodetector, so that the direction of the absorption dipole of the second fluorescent material 431 is the first along the long axis of the liquid crystal material. direction can be sorted.

For example, a liquid crystal material having a refractive index of 1.5 may be used as the liquid crystal material to improve efficiency according to the composition of the second fluorescent material. Preferably, the liquid crystal material may be a chiral liquid crystal.

5 is a diagram for explaining a fluorescence signal measuring system according to a second embodiment.

Referring to FIG. 5 , the fluorescence signal measuring system 500 according to the second embodiment may include a light source, a diamond structure 510 , and a fluorescence re-emitting unit 520 .

The light source according to the second embodiment may output light of a preset wavelength.

The diamond structure 510 according to the second embodiment may include at least one DNV center that receives light output from a light source and emits fluorescent signals in a first direction and a second direction.

For example, the DNV center may include at least one of a vertical DNV center in which the direction of the absorption dipole is aligned in a vertical direction and a horizontal DNV center in which the direction of the absorption dipole is aligned in a horizontal direction.

According to one side, the first direction is a detection direction (a fluorescent signal collection direction) of a fluorescent signal emitted from the DNV center and a fluorescent signal re-emitted from the second fluorescent material 521 , and the second direction is orthogonal to the first direction. direction (non-collection direction of the fluorescent signal).

In other words, the first direction may refer to a direction corresponding to a collection optical axis of a photodetector that collects a fluorescent signal emitted for detecting a magnetic field.

According to one side, the first direction may mean a main emission direction of the fluorescent signal emitted from the DNV center.

According to one side, the diamond structure 510 may be a structure based on a planar structure.

The fluorescence re-emitting unit 520 according to the first embodiment may include at least one second fluorescent material 521 absorbing the fluorescence signal emitted in the second direction and re-emitting it in the first direction.

According to one side, the fluorescence re-emitting part 520 is provided on both sides of the diamond structure 510 to absorb the fluorescence signal emitted in the second direction through the waveguide mode according to total reflection.

For example, the second fluorescent material 521 may be a material having little light absorption at the excitation wavelength of the DNV center and high light absorption efficiency at the emission wavelength of the DNV center.

That is, the second fluorescent material is a material that absorbs the emission spectrum of the DNV center. It absorbs the fluorescent signal emitted in the second direction of the DNV center and re-emits the fluorescent signal in the changed direction (first direction) (second fluorescent signal). emission), and through this, the photodetector may acquire an additional fluorescence signal to improve signal intensity.

According to one side, the fluorescent re-emitting unit 520 may be formed by mixing the second fluorescent material 521 with a low refractive index material.

For example, the low refractive index material may be a material having a refractive index smaller than _{the refractive index n dia . of the diamond structure 420 and larger than the refractive index of air n air .}

According to one side, the fluorescence re-emitting unit 520 may further include a liquid crystal material 522 that aligns directions of absorption dipoles of the second fluorescent material 521, and the liquid crystal material 522 includes the second fluorescent material ( 521) may align the direction of the absorption dipole in the first direction.

Specifically, the fluorescence re-emitting unit 520 orients the liquid crystal material 522 in a direction perpendicular to the optical axis of the photodetector, so that the absorption dipole of the second fluorescent material 521 is aligned with the first along the long axis of the liquid crystal material. direction can be sorted.

For example, the liquid crystal material 522 having a refractive index of 1.5 may be used as the liquid crystal material to improve efficiency according to the configuration of the second fluorescent material 521 . Preferably, the liquid crystal material 522 may be a chiral liquid crystal.

6A to 6B are diagrams for explaining an example of absorbing and re-emitting a fluorescent signal through a fluorescent material in the fluorescent signal measuring system according to an exemplary embodiment.

6A to 6B, reference numeral 610 denotes an example of absorbing and re-emitting a fluorescent signal through a second fluorescent material in the fluorescent signal measuring system according to an embodiment, and reference numeral 620 denotes an embodiment. An example of absorbing and re-emitting a fluorescent signal through the second fluorescent material aligned by the liquid crystal material is shown in the fluorescent signal measuring system according to the present invention.

Referring to reference numeral 610, the second fluorescent material 612 of the fluorescence signal measuring system according to an exemplary embodiment emits fluorescence in the second direction from the DNV center 611 provided in the nano-pillar of the diamond structure. A signal can be absorbed and re-emitted.

)을 향상시키 위해, 저굴절률 물질(n₂, n_air < n₂ < n_dia)에 혼합되어 나노 필라의 좌/우에 배치될 수 있다. 이는 고굴절률의 물질로 광이 더 커플링(coupling)되기 쉬운 성질이 있으며, 나노 필라 구조를 유지하기 위해서는 다이아몬드 구조체보다 굴절률이 낮은 매질이 필요하기 때문이다. According to one side, the second fluorescent material 612 has an external measurement efficiency (

), it may be mixed with a low-refractive-index material (n ₂ , n _air < n ₂ < n _dia ) and disposed on the left/right side of the nanopillars. This is because a material having a high refractive index has a property that light is more easily coupled, and a medium having a lower refractive index than a diamond structure is required to maintain the nanopillar structure.

The amount of fluorescence signal emitted from the vertical DNV center 611 of the nanopillar to the low-refractive index material was up to 44% when analyzed through the finite element method. Efficiency was further improved to a maximum of about 35%, and as a result, an efficiency increase of about 7% can be expected.

Referring to reference numeral 620, the second fluorescent material 622 of the fluorescent signal measuring system according to an embodiment absorbs the fluorescent signal emitted in the second direction from the DNV center 621 provided in the nanopillars of the diamond structure, and regenerates it. can be released

According to one side, in the second fluorescent material 622 , the direction of the absorption dipole may be aligned in the first direction through the liquid crystal material 623 . Preferably, the liquid crystal material may be a chiral liquid crystal material.

In other words, the second fluorescent material 622 may absorb the fluorescent signal emitted in the second direction from the DNV center 621 and re-emit the fluorescent signal absorbed in the first direction. Through this, it is possible to improve the measurement efficiency of the fluorescence signal.

In general, by using a guest-host interaction phenomenon, a material absorbing light of a specific wavelength is put into the cell of the liquid crystal material (host) 623 to control light absorption.

This is because, depending on the molecular arrangement of the liquid crystal of a certain arrangement, the molecular arrangement of the anisotropic dichroic dye (guest) also changes interlockingly, so that the amount of absorption of the dye can be controlled. Accordingly, by aligning the culture axis of the liquid crystal material with the second fluorescent material, the fluorescence capture efficiency can be improved.

7A to 7B are diagrams for explaining an example of a liquid crystal material of a fluorescence signal measuring system according to an exemplary embodiment.

7A to 7B, reference numeral 710 denotes a principle of aligning a general liquid crystal, and reference numeral 720 denotes a principle of aligning a chiral liquid crystal.

The fluorescent signal measuring system according to an embodiment may align the direction of the absorption dipole of the second fluorescent material by using a chiral liquid crystal material among the liquid crystal material.

In the case of a general liquid crystal material, it has the characteristic of being aligned according to the direction of the magnetic field, and the general DNV center has a wider FWHM (full width at half maximum) of the optically detected magnetic resonance (ODMR) spectrum in a horizontal magnetic field when measuring the magnetic field, so the sensitivity is high. unfavorable to

In general, a perpendicular magnetic field direction is formed. In this case, a problem in that the alignment direction of the liquid crystal material for aligning the second fluorescent material is changed due to the influence of the magnetic field to be measured may occur.

On the other hand, since the chiral liquid crystal material can be aligned in a structure perpendicular to the magnetic field direction, this problem can be improved, and high secondary fluorescence capture efficiency can be expected because the material can be efficiently aligned horizontally.

As a result, according to the present invention, the fluorescence measurement efficiency can be improved by absorbing and re-emitting the fluorescence signal generated from the DNV center using the aligned fluorescence material.

In addition, high magnetic field measurement sensitivity can be obtained through the improvement of fluorescence measurement efficiency due to absorption and re-emission of a fluorescence signal.

In addition, it is possible to improve the degradation of the fluorescence signal measurement efficiency due to the phenomenon that the fluorescence signal generated inside the diamond structure is trapped inside the diamond structure having a high refractive index.

On the other hand, the present invention can acquire a high optical signal by additionally capturing the fluorescence signal generated at the DNV center, so magnetic field-based signal detection such as magnetic resonance imaging (MRI), magnetic field quantum information technology, etc., which are state-of-the-art medical equipment can be applied to the system.

In addition, the present invention can be applied for the purpose of signal augmentation in various systems requiring measurement of fluorescence signals, and is expected to be applicable together with quasi-waveguide optical antenna technology, plasmon optical antenna technology, and the like. By improving the acquisition, it is expected that magnetic resonance technology-based medical and industrial imaging systems such as semiconductor process monitoring can be applied in various fields.

As described above, although the embodiments have been described with reference to the limited drawings, various modifications and variations are possible by those skilled in the art from the above description. For example, the described techniques are performed in a different order than the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

100: fluorescent signal measuring system 110: light source
120: diamond structure 130: fluorescence re-emitting unit

Claims (10)

a light source for outputting light of a predetermined wavelength;
a diamond structure having at least one DNV center (diamond nitrogen-vacancy center) for receiving the output light and emitting a fluorescent signal in a first direction and a second direction;
a fluorescence re-emitting unit having at least one fluorescent material absorbing the fluorescence signal emitted in the second direction and re-emitting it in the first direction;
A fluorescence signal measurement system comprising a. According to claim 1,
The first direction is a direction in which the emitted fluorescent signal and the re-emitted fluorescent signal are detected, and the second direction is a direction orthogonal to the first direction.
Fluorescence signal measurement system. According to claim 1,
The diamond structure includes at least one nano-pillar, and the at least one nano-pillar includes the at least one DNV center.
Fluorescence signal measurement system. 4. The method of claim 3,
The fluorescence re-emitting part is provided on both sides of the at least one nanopillar to absorb the fluorescence signal emitted in the second direction.
Fluorescence signal measurement system. According to claim 1,
The fluorescence re-emitting units are provided on both sides of the diamond structure to absorb the fluorescence signal emitted in the second direction through a waveguide mode according to total reflection.
Fluorescence signal measurement system. According to claim 1,
The fluorescent re-emitting part is formed by mixing the fluorescent material with a low refractive index material.
Fluorescence signal measurement system. 7. The method of claim 6,
The low refractive index material is a material having a refractive index smaller than the refractive index of the diamond structure and larger than the refractive index of air.
Fluorescence signal measurement system. According to claim 1,
The fluorescence re-emitting unit further comprises a liquid crystal material for aligning the direction of the absorption dipole of the fluorescent material
Fluorescence signal measurement system. 9. The method of claim 8,
The liquid crystal material aligns the direction of the absorption dipole of the fluorescent material to the first direction.
Fluorescence signal measurement system. 9. The method of claim 8,
The liquid crystal material is a chiral liquid crystal material.
Fluorescence signal measurement system.

Images