JP7253885B2 - Condensing optical system for spectroscope and Raman spectroscopic system including the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a spectroscope, and more particularly to a condensing optical system for a spectroscope and a Raman spectroscopic system including the same.

Recently, miniaturized Raman spectroscopy systems for analyzing components such as blood sugar in vivo have been developed as part of mobile health diagnostic sensors.

The technology to measure biological samples such as skin using such a small Raman spectroscopy system will dramatically improve the measurement range and number of times, which was previously possible only at specific positions and areas. can be done. However, due to the high fluorescence signal emitted from the living body, there is a need for a technique for selectively detecting and analyzing only the Raman signal from a very small amount of components in the living body, such as blood sugar.

U.S. Patent Application Publication No. 2017/0100064

A problem to be solved by the present invention is to provide a condensing optical system for a spectroscope and a Raman spectroscopic system including the same.

In one aspect of the invention, a collection optics system for a spectrometer that selectively collects Raman signals from scattered light emitted from a target object, collecting and emitting the Raman signals, a non-imaging collection unit including an incident surface on which the scattered light is incident and an output surface from which the Raman signal is emitted; and a partial area of the incident surface of the non-imaging collection unit. and a Raman filter for blocking the scattered light containing a fluorescence signal, wherein the fluorescence signal is suppressed from being received and the Raman signal is selectively collected from the scattered light. A system is provided.

The target object includes a substance having turbidity and can emit scattered light including the fluorescence signal and the Raman signal upon irradiation with incident light emitted from a light source. For example, the target object includes skin and the Raman signal includes a blood glucose Raman signal.

The Raman filter is provided in the central region of the entrance surface where most of the fluorescence signal is incident.

The incident surface of the non-imaging light-collecting unit may have a size of approximately 1 cm or less. The Raman filter may have a size of approximately 1 mm or less.

The Raman filter may transmit a wavelength band of incident light illuminating the target object, and block a wavelength band of scattered light emitted from the target object.

The Raman filter can transmit only one specific wavelength band of the incident light. The Raman filter may include a plurality of wavelength filters that transmit a plurality of specific wavelength bands of the incident light. In that case, the plurality of wavelength filters are also arranged in a grid or concentric rings, for example.

The incident surface around the Raman filter is provided with a transparent member for transmitting the scattered light including the Raman signal, or a band filter for transmitting only a specific Raman wavelength.

Said non-imaging concentrator unit is for example an elliptical hyperboloid concentrator, a circular hyperboloid concentrator, a circular cone concentrator, an elliptical cone concentrator It may also include an elliptical cone concentrator or a compound parabolic concentrator.

The entrance surface of the non-imaging condensing unit may have a smaller area than the exit surface. Also, the incident surface of the non-imaging light-collecting unit may have a larger area than the exit surface.

In another aspect, a light source for illuminating a target object with incident light, a collection optical system for selectively collecting Raman signals from scattered light emitted from the target object by the incident light, and the collection optical system. a spectroscope for receiving the Raman signal emanating from, the collection optics for collecting and emitting the Raman signal, the incident surface on which the scattered light is incident, and the Raman signal from the a non-imaging light-condensing unit comprising an exit surface for exiting, and a Raman filter provided in a partial region of the incident surface of the non-imaging-condensing unit for blocking the scattered light containing the fluorescence signal, A Raman spectroscopy system is provided that selectively collects the Raman signal while suppressing reception of the fluorescence signal of the scattered light.

The Raman filter is provided in the central region of the entrance surface where most of the fluorescence signal is incident.

The Raman filter may transmit a wavelength band of incident light illuminating the target object, and block a wavelength band of scattered light emitted from the target object.

The incident surface around the Raman filter is provided with a transparent member that transmits the scattered light containing the Raman signal, or a bandpass filter that transmits only a specific Raman wavelength.

Said non-imaging concentrator unit may for example comprise an elliptical hyperbolic concentrator, a circular hyperbolic concentrator, a conical concentrator, an elliptical cone concentrator or a compound parabolic concentrator.

The incident light emitted from the light source is applied perpendicularly to the surface of the target object, or is applied so as to be inclined with respect to the surface of the target object.

The spectroscope may include an on-chip spectroscope. The spectroscope includes a dispersive type spectroscope having a slit into which the Raman signal is incident, and the exit surface of the non-imaging focusing unit is inserted into the slit.

It is drawing which illustrated a mode that a laser beam is irradiated to a measurement sample and the scattered light emitted from a measurement sample is measured. 2 is a drawing illustrating a cross-section of the fiber illustrated in FIG. 1; FIG. 2 is a diagram illustrating a Raman spectrum collected in a fiber from scattered light emitted from a first silicon substrate in FIG. 1; FIG. Fig. 10 is a drawing illustrating a Raman spectrum collected in a fiber from scattered light emitted from a second silicon substrate; It is drawing which expanded and illustrated the illustrated Raman spectrum. FIG. 2 is a diagram illustrating a Raman spectrum collected in a fiber from scattered light emitted from a third silicon substrate in FIG. 1; FIG. 5B is an enlarged view of the Raman spectrum illustrated in FIG. 5A; FIG. 4A to 5B are graphs showing calculations of Raman signal, noise, and Raman signal-to-noise ratio (SNR) according to fiber positions; FIG. FIG. 2 is a drawing illustrating a fiber-collected Raman spectrum from scattered light emitted from a measurement sample with skin turbidity. FIG. 7B is a diagram illustrating the intensity of fluorescence signals calculated from the Raman spectrum illustrated in FIG. 7A; FIG. FIG. 4 is a drawing illustrating a fiber-collected Raman spectrum from scattered light emitted from real skin; FIG. FIG. 8B is a diagram illustrating the intensity of fluorescence signals in the Raman spectrum illustrated in FIG. 8A; FIG. FIG. 8B is a diagram illustrating the intensity of Raman signals in the Raman spectrum illustrated in FIG. 8A; FIG. 1 is a diagram illustrating a Raman spectroscopy system according to an exemplary embodiment; 10 is an enlarged perspective view of the non-imaging condensing unit shown in FIG. 9; FIG. FIG. 11 is a view illustrating an incident surface of the non-imaging light-collecting unit illustrated in FIG. 10; FIG. FIG. 10 is a diagram illustrating a path along which scattered light emitted from a target object travels in the Raman spectroscopy system illustrated in FIG. 9; FIG. FIG. 10 is a diagram illustrating a modification of the non-imaging focusing unit employed in the Raman spectroscopy system illustrated in FIG. 9; FIG. FIG. 10 is a diagram illustrating a modification of the non-imaging focusing unit employed in the Raman spectroscopy system illustrated in FIG. 9; FIG. FIG. 10 is a diagram illustrating a modification of the non-imaging focusing unit employed in the Raman spectroscopy system illustrated in FIG. 9; FIG. FIG. 10 is a diagram illustrating a modification of the non-imaging focusing unit employed in the Raman spectroscopy system illustrated in FIG. 9; FIG. FIG. 10 is a diagram illustrating a modification of a Raman filter employed in the Raman spectroscopy system illustrated in FIG. 9; FIG. FIG. 10 is a diagram illustrating a modification of a Raman filter employed in the Raman spectroscopy system illustrated in FIG. 9; FIG. FIG. 10 is a diagram illustrating another modification of the Raman filter employed in the Raman spectroscopy system illustrated in FIG. 9; FIG. FIG. 10 is a diagram illustrating another modification of the Raman filter employed in the Raman spectroscopy system illustrated in FIG. 9; FIG. FIG. 4 is a diagram illustrating a Raman spectroscopy system according to another exemplary embodiment; FIG. FIG. 5 is a diagram illustrating a Raman spectroscopy system according to yet another exemplary embodiment; FIG. FIG. 5 is a diagram illustrating a Raman spectroscopy system according to yet another exemplary embodiment; FIG.

Hereinafter, embodiments will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals refer to the same components, and the size and thickness of each component are exaggerated for clarity of explanation. In addition, when it is described that a given material layer exists on a substrate or another layer, the material layer can exist in direct contact with the substrate or other layer, with another third layer existing therebetween. You can also In addition, in the following embodiments, materials forming each layer are exemplary, and other materials may be used.

The skin is a medium with turbidity unlike common reflective media. The turbidity is also expressed by a scattering coefficient and a reduced scattering coefficient that takes into account the anisotropic factor, which is one of the skin characteristics. The reduced scattering coefficient of skin is approximately 1 to 3 mm ⁻¹ . In a medium with turbidity, the range over which the Raman signal spreads is much wider than in a typical reflective medium. In addition, on the surface of the skin, detection of glucose Raman signals and other signals concentrated in the dermis due to fluorescence signals emitted from the epidermis existing at a depth of approximately 100 to 400 μm. is difficult.

FIG. 1 illustrates how incident light is applied to a measurement sample having turbidity and scattered light emitted from the measurement sample is measured through a fiber. FIG. 2 shows a cross-section of the fiber shown in FIG. Here, as the measurement sample 10, a medium having a general skin scattering coefficient range was used. Specifically, the scattering coefficient and reduced scattering coefficient of the measurement sample 10 are approximately 2.4 mm ⁻¹ and 1.13 mm ⁻¹ at a wavelength of 755 nm, respectively. A laser beam with a wavelength of 785 nm was used as the incident light L with which the measurement sample 10 was irradiated.

Referring to FIG. 1 , a first silicon substrate 21 , a second silicon substrate 22 and a third silicon substrate 23 are provided in the depth direction from the surface of the measurement sample 10 . Here, the first silicon substrate 21 is provided on the surface of the measurement sample 10 . The second silicon substrate 22 is provided at a depth d of 0.5 mm from the surface of the measurement sample 10, and the third silicon substrate 23 is provided at a depth of 1.0 mm from the surface of the measurement sample 10. It is That is, no turbidity medium exists on the first silicon substrate 21 , and turbidity medium exists on the second silicon substrate 22 and the third silicon substrate 23 .

Incident light L of a laser beam emitted from a light source (not shown) irradiates the measurement sample 10 , and scattered light S emitted from the measurement sample 10 passes through a fiber bundle provided above the measurement sample 10 . bundle).

Specifically, the incident light L of the laser beam is focused by the focusing lens 40 and applied to the first silicon substrate 21, the second silicon substrate 22 and the third silicon substrate 23 of the measurement sample 10, respectively. Here, the distance f between the focusing lens 40 and the surface of the measurement sample 10 is 4.5 mm. By such irradiation of incident light L, scattered light S containing Raman signals is emitted from each of the first silicon substrate 21, the second silicon substrate 22, and the third silicon substrate 23. Such scattered light S is Above the measurement sample 10 are collected by nine fibers F1-F9 arranged in a line. Among the fibers F1 to F9, the central fifth fiber F5 may be positioned to correspond to the center of the scattered light. Each such fiber F1-F9 may include a core 31 and a cladding layer 32 surrounding the core 31 . In the nine fibers F1-F9 illustrated in FIG. 2, for example, the core 31 diameter is 200 μm and the spacing between adjacent fibers F1-F9 is 250 μm.

FIG. 3 illustrates a Raman spectrum collected in a fiber from scattered light emitted from the first silicon substrate in FIG. In FIG. 3, after the incident light L of the laser beam is irradiated to the first silicon substrate 21, the scattered light S emitted from the first silicon substrate 21 is collected by nine fibers F1 to F9. Spectra are shown.

Referring to FIG. 3, the Raman signals of the scattered light emitted from the first silicon substrate 21 provided on the surface of the measurement sample 10 and having no turbidity medium thereon are obtained from the fibers F1 to F9. It can be seen that the 5th fiber F5 located in the middle is concentratedly collected.

FIG. 4A illustrates a Raman spectrum collected in a fiber from scattered light emitted from the second silicon substrate in FIG. FIG. 4B is an enlarged view of the Raman spectrum shown in FIG. 4A. 4A and 4B, the second silicon substrate 22 provided at a depth d of 0.5 mm from the surface of the measurement sample 10 having turbidity similar to that of skin is irradiated with the incident light L of the laser beam. The spectrum of the scattered light S emitted from the second silicon substrate 22 after being collected by the nine fibers F1 to F9 is illustrated.

FIG. 5A illustrates a Raman spectrum collected in a fiber from scattered light emitted from the third silicon substrate in FIG. FIG. 5B is an enlarged view of the Raman spectrum shown in FIG. 5A. In FIGS. 5A and 5B, after the third silicon substrate 23 provided at a depth d of 1.0 mm from the surface of the measurement sample 10 is irradiated with the incident light L of the laser beam, the third silicon substrate 23 The spectrum collected in nine fibers of the scattered light S emitted from is shown.

4A and 4B and FIGS. 5A and 5B, when a medium having turbidity is present on the second silicon substrate 22 or the third silicon substrate 23, the second silicon substrate It can be seen that the scattered light signals emitted from the substrate 22 and the third silicon substrate 23 are widely dispersed and collected in the nine fibers F1-F9. Also, it can be seen that the farther away from the fifth fiber F5 located in the middle of the fibers F1 to F9, the weaker the fluorescence signal intensity and the Raman signal is observed.

FIG. 6 shows the calculated Raman signal, noise, and Raman signal-to-noise ratio (SNR) according to the position of the fiber in the Raman spectra shown in FIGS. 4A to 5B.

Referring to FIG. 6, noise consists of readout noise, shot noise and systematic noise. occupy Therefore, selectively reducing the fluorescence signal can reduce shot noise and improve the Raman signal-to-noise ratio. On the other hand, in the fifth fiber F5 located in the middle of the fibers F1 to F9, although the Raman signal is reduced, the fluorescence signal is also reduced and the noise is reduced. , it can be seen that the Raman signal-to-noise ratio is higher.

FIG. 7A illustrates a fiber-collected Raman spectrum from scattered light emitted from a measurement sample with skin turbidity. FIG. 7B illustrates the intensity of the fluorescence signal calculated from the Raman spectrum illustrated in FIG. 7A. In FIG. 7B, the intensity of the fluorescence signal is defined as the magnitude of the lower portion of the peak of interest, as illustrated in FIG. 7A. Referring to FIGS. 7A and 7B, the fluorescent signal increases sharply from the fifth fiber F5 located in the middle of the fibers F1 to F9 to the outermost fiber (the first fiber F1 or the ninth fiber F9). It can be seen that it decreases.

FIG. 8A illustrates a Raman spectrum collected in a fiber with scattered light emitted from real skin. FIG. 8B illustrates the intensity of fluorescence signals in the Raman spectrum illustrated in FIG. 8A. FIG. 8C illustrates the intensity of Raman signals in the Raman spectrum illustrated in FIG. 8A. In FIG. 8C, A shows the Raman signal collected by the fifth fiber F5 located in the middle among the fibers F1 to F9, and B shows the Raman signal collected by the outermost fiber (first fiber F1 or ninth fiber F9). Figure 3 shows the collected Raman signal. C is the Raman signal of B magnified by 10 times.

Referring to FIGS. 8A to 8C, the fluorescent signal increases sharply from the fifth fiber F5 located in the middle of the fibers F1 to F9 to the outermost fiber (first fiber F1 or ninth fiber F9). It can be seen that the Specifically, the fluorescence signal collected in the outermost fiber (first fiber F1 or ninth fiber F9) is approximately one-third the level of the fluorescence signal collected in the fifth fiber F5. I understand. Also, as shown in FIG. 8C, it can be confirmed that the resolution of the Raman peak is improved as the fluorescence signal is reduced.

As described above, when the measurement sample 10 including a substance having turbidity such as skin is irradiated with the incident light L of the laser beam, the measurement sample 10 emits the scattered light S due to the irradiation of the incident light L. , the scattered light S contains not only the Raman signal but also the fluorescence signal that interferes with the reception of the Raman signal. However, since the fluorescence signal is concentrated in the central part of the scattered light S emitted from the measurement sample 10, blocking the central part of the scattered light S containing most of the fluorescence signal reduces the Raman Only signals can be selectively collected.

FIG. 9 illustrates a Raman spectroscopy system according to an exemplary embodiment.

Referring to FIG. 9, the Raman spectroscopy system 100 includes a light source 110 that illuminates the target object 50 with incident light L, and collection optics that selectively collect Raman signals S1 from the scattered light emitted from the target object 50. and a spectrograph 150 that receives the Raman signal S1 emanating from the collection optics. Here, the target object 50 to be measured may include a substance having a predetermined turbidity. For example, the target object 50 may include, but is not limited to, human skin.

The light source 110 may emit incident light L that illuminates the target object 50 . As the incident light L emitted from the light source 110, for example, a laser beam having a wavelength band of 785 nm is used. The incident light L emitted from the light source 110 is reflected by the reflecting mirror 115 and then applied to a desired measurement area of the target object 50 . Here, the incident light L may be condensed by further providing a condensing lens on the optical path of the incident light L. FIG. The incident light L is transmitted through the Raman filter 130 provided on the incident surface 120a of the non-imaging condensing unit 120, and is irradiated onto the measurement area of the target object 50, as will be described later. Such incident light L is vertically incident on the surface of the target object 50 .

When the measurement area of the target object 50 is irradiated with the incident light L from the light source 110 , scattered light is emitted from the measurement area of the target object 50 . Here, since the target object 50 has turbidity, the scattered light emitted from the target object 50 includes not only the Raman signal S1 but also the fluorescence signal S2 that interferes with the reception of the Raman signal S1. included together.

The collection optics can selectively collect the Raman signal S1 from scattered light emitted from the target object 50 . To that end, the collection optics may include a non-imaging collection unit 120 and a Raman filter 130 .

10 is an enlarged perspective view of the non-imaging condensing unit shown in FIG. 9. FIG. 11 illustrates the incident surface of the non-imaging light gathering unit illustrated in FIG.

10 and 11, a non-imaging light collection unit 120 is used to collect the scattered light emitted from the target object 50. FIG. The non-imaging light-collecting unit 120 is a light-collecting system that does not use a lens, and means a system that transmits light between a light generation point and a final destination point in an optimized manner. Typical application fields of the non-imaging condensing unit 120 include the solar cell field and the lighting field. For example, in the solar cell field, solar energy concentrators are used to maximize the solar energy transferred to the solar cell.

FIG. 10 exemplarily shows a case where a compound parabolic concentrator (CPC) is used as the non-imaging condensing unit 120 . The non-imaging light-collecting unit 120 has an incident surface 120a on which scattered light emitted from the target object 50 is incident, and an incident surface 120a opposite to the incident surface 120a. 120b and .

The entrance surface 120a of the non-imaging focusing unit 120 can have a smaller area than the exit surface 120b. When the entrance surface 120a of the non-imaging light-collecting unit 120 is in contact with the surface of the target object 50 to perform a measurement task, the entrance surface 120a of the non-imaging light-collecting unit 120 has a diameter D1 of approximately 1 cm or less, for example. can have, but is not necessarily limited to, The diameter D1 may be any size as long as it can be formed.

A Raman filter 130 for blocking the fluorescence signal S2 is provided on a partial area of the incident surface 120a of the non-imaging light-condensing unit 120. As shown in FIG. That is, the Raman filter 130 may block the fluorescence signal S2 among the scattered light emitted from the target object 50. FIG.

As described above, most of the fluorescence signal S2 of the scattered light emitted from the target object 50 having turbidity is included in the central part of the scattered light S. As shown in FIG. Therefore, in order to suppress the reception of the fluorescence signal S2 emanating from the target object 50, the Raman filter 130 is arranged in the area of the incident surface 120a of the non-imaging focusing unit 120 where most of the fluorescence signal S2 is incident, i.e. It is provided in the central region of the incident surface 120a. A transparent member 140 surrounding the Raman filter 130 is further provided on the incident surface 120 a of the non-imaging light collecting unit 120 . The transparent member 140 may transmit scattered light emitted from the target object 50 and may serve to support the Raman filter 130 . Meanwhile, a band filter (not shown) that transmits only a specific Raman wavelength may be provided on the incident surface 120a of the non-imaging light gathering unit 120 surrounding the Raman filter 130 .

10 and 11 exemplarily illustrate the case where the Raman filter 130 is provided in a circular shape in the central region of the incident surface 120a of the non-imaging condensing unit 120. FIG. When the incident surface 120a of the non-imaging light-collecting unit 120 is in contact with the surface of the target object 50 to perform the measurement task, the Raman filter 130 can have a diameter D2 of approximately 1 mm or less, but not necessarily limited thereto. not to be The diameter D2 may be any size as long as it can be formed.

The Raman filter 130 can transmit a wavelength band of the incident light L emitted from the light source 110 and applied to the target object 50 and block a wavelength band of scattered light emitted from the target object 50 . That is, scattered light S is emitted from the measurement area of the target object 50 due to the irradiation of the incident light L. Such scattered light has a wavelength band different from that of the incident light L due to Raman shift. be able to. Accordingly, the Raman filter 130 can transmit the incident light L, but can block scattered light having a wavelength band different from that of the incident light L. FIG.

The Raman filter 130 may include, for example, a band pass filter that transmits only wavelengths in a specific band, or a short pass filter that transmits only wavelengths below a specific wavelength. For example, when using a bandpass filter as the Raman filter 130, Stokes Raman signals and anti-Stokes Raman signals can be measured. When a short-pass filter is used as the Raman filter 130, a Stokes Raman signal can be measured.

The Raman filter 130 is provided in the central region of the incident surface 120a of the non-imaging light-collecting unit 120. As shown in FIG. Incident light L from the light source 110 is transmitted through the Raman filter 130 and illuminates the measurement area of the target object 50, as shown in FIG. Due to such irradiation of the incident light L, scattered light is emitted from the measurement area of the target object 50 . Here, the central portion of the scattered light, that is, the scattered light including the fluorescence signal S2 directed toward the central region of the incident surface 120a of the non-imaging light-condensing unit 120 is blocked by the Raman filter 130. FIG.

FIG. 12 exemplarily illustrates the path along which the scattered light emitted from the target object 50 travels. Referring to FIG. 12, of the scattered light emitted from the target object 50, the fluorescence signal S2 directed toward the center region of the incident surface 120a of the non-imaging light-collecting unit 120 is blocked by the Raman filter 130, and the non-imaging light-collecting unit The Raman signal S1 directed to the edge region of the incident surface 120a of 120 is transmitted through the transparent member 140 and enters the non-imaging focusing unit 120. FIG. Then, the non-imaging condensing unit 120 transmits the incident Raman signal S1 to the exit surface 120b side.

The scattered light emitted from the target object 50 contains not only the Raman signal S1 but also the fluorescence signal S2 that interferes with the reception of the Raman signal S1 due to turbidity. Since such fluorescence signal S2 exists intensively in the central portion of the scattered light emitted from the target object 50, the Raman filter 130 is provided in the central region of the incident surface 120a of the non-imaging condensing unit 120. , the reception of the fluorescence signal S2 can be blocked, so that only the Raman signal S1 is collected inside the non-imaging collection unit 120 .

Since the angle of the scattered light emitted from the target object 50 is random due to the irradiation of the incident light L, the scattered light may be incident on the Raman filter 130 at a non-perpendicular angle. According to simulation experiment results, a short-pass filter that transmits only wavelengths of 790 nm or less is used as a Raman filter, and wavelengths of 800 nm to 900 nm that are incident on the Raman filter at an angle of 30° and 60° are almost transmitted. it wasn't. Therefore, it can be seen that the scattered light incident on the Raman filter 130 at an angle can be blocked.

In this way, the collection optical system including the non-imaging collection unit 120 and the Raman filter 130 selectively collects only the Raman signal S1 of the scattered light emitted from the target object 50, and outputs the Raman signal S1 through the exit surface 120b. can be released The collected Raman signal S1 is then received by the spectroscope 150 and analyzed. As a result, reception of the fluorescent signal S2 out of the scattered light emitted from the target object 50 is suppressed, and a Raman spectrum containing only the Raman signal S1 can be obtained. Here, as the spectroscope 150, an on-chip type spectroscope is used, which is manufactured in the form of a miniaturized chip in which resonators and filters are integrated on a substrate.

As described above, according to the Raman spectroscopy system 100 according to the present embodiment, the non-imaging light-condensing unit 120 and the Raman filter 130 are used to obtain the fluorescence signal S2 out of the scattered light emitted from the target object 50. The reception can be suppressed and selectively collected only the Raman signal S1. That is, when the target object 50 having turbidity such as skin is irradiated with the incident light L of the laser beam, the scattered light emitted from the target object 50 includes not only the Raman signal S1 but also the fluorescence signal S2. and such fluorescence signal S2 is mostly contained in the central portion of the emitted scattered light. Therefore, by providing the Raman filter 130 for blocking the reception of the fluorescence signal S2 in the area corresponding to the central portion of the scattered light on the incident surface 120a of the non-imaging condensing unit 120, that is, in the central area of the incident surface 120a, , the non-imaging collection unit 120 can selectively collect only the Raman signal S1. Therefore, by using such a Raman spectroscopy system 100, for example, only Raman signals related to blood sugar contained in skin can be effectively detected. In addition, when an on-chip spectroscope is used as the spectroscope 150, the Raman spectroscopic system 100 can be micro-embodied.

On the other hand, the case where a compound parabolic concentrator (CPC) is used as the non-imaging concentrator unit 120 has been described above. However, without being so limited, various forms of collectors can be used as the non-imaging collector unit 120 as well.

13A-13D illustrate variations of the non-imaging focusing unit employed in the Raman spectroscopy system illustrated in FIG. An elliptical hyperboloid concentrator (EHC) 121 is illustrated in FIG. 13A and a circular hyperboloid concentrator (CHC) 122 is illustrated in FIG. 13B. 13C illustrates a circular cone concentrator (CCC) 123, and FIG. 13D illustrates an elliptical cone concentrator (ECC) 124. FIG. On the other hand, the concentrators described above are merely examples, and various forms of concentrators can be used as the non-imaging condensing unit 120 .

The case where the Raman filter 130 transmits only one wavelength band of incident light has been described above. However, without limitation, the incident light emitted from the light source 110 includes multiple wavelength bands, and the Raman filter is also provided to transmit such multiple wavelength bands.

14A and 14B illustrate variations of Raman filters employed in the Raman spectroscopy system illustrated in FIG.

Referring to FIG. 14A, a rectangular Raman filter 131 is provided in the central region of the incident surface 120a of the non-imaging light gathering unit 120. As shown in FIG. The Raman filter 131 may include at least one first wavelength filter 131a and at least one second wavelength filter 131b. The first wavelength filter 131a can transmit a first wavelength band of the incident light L, and the second wavelength filter 131b can transmit a second wavelength band of the incident light L. FIG. The first and second wavelength filters 131a and 131b may each have a square shape, and the first and second wavelength filters 131a and 131b may be arranged in a grid.

Referring to FIG. 14B, a circular Raman filter 132 is provided in the central region of the incident surface 120a of the non-imaging light-collecting unit 120. As shown in FIG. The Raman filter 132 may include at least one first wavelength filter 132a that transmits a first wavelength band of the incident light L and at least one second wavelength filter 132b that transmits a second wavelength band of the incident light L. Here, the first wavelength filter 132a and the second wavelength filter 132b are also arranged in a concentric ring shape.

15A and 15B illustrate another variation of the Raman filter employed in the Raman spectroscopy system illustrated in FIG. 9. FIG.

Referring to FIG. 15A, the square Raman filter 133 may include at least one first wavelength filter 133a, at least one second wavelength filter 133b, and at least one third wavelength filter 133c. The first wavelength filter 133a can transmit the first wavelength band, the second wavelength filter 133b can transmit the second wavelength band, and the third wavelength filter 133c can transmit the third wavelength band. be able to. Here, the first wavelength filter 133a, the second wavelength filter 133b, and the third wavelength filter 133c may have a rectangular shape, and the first wavelength filter 133a, the second wavelength filter 133b, and the third wavelength filter 133c. are arranged in a grid.

Referring to FIG. 15B, the circular Raman filters 134 include at least one first wavelength filter 134a that transmits the first wavelength band, at least one second wavelength filter 134b that transmits the second wavelength band, and a third wavelength filter 134b. and at least one third wavelength filter 134c that transmits a wavelength band. Here, the first wavelength filter 134a, the second wavelength filter 134b and the third wavelength filter 134c are also arranged concentrically.

In the above, the cases where the Raman filters 131, 132, 133, and 134 transmit two wavelength bands or three wavelength bands have been exemplified. A Raman filter is also embodied that allows In the above description, the Raman filters 131, 132, 133, and 134 have been exemplified as square or circular, but the Raman filters may have various shapes.

Thus, Raman filters 131, 132, 133, and 134 that transmit multiple wavelength bands are used in the field of SERDS (shifted excitation Raman difference spectroscopy) and also for background subtraction. In addition, since the depth of penetration of the incident light into the skin differs depending on the wavelength, Raman filters 131, 132, 133, and 134 that transmit a plurality of wavelength bands are used to obtain Raman information according to the depth of the skin. be able to.

FIG. 16 illustrates a Raman spectroscopy stem according to another exemplary embodiment.

Referring to FIG. 16, the Raman spectroscopy system 200 includes a light source 210 that illuminates the target object 50 with incident light L, and a collection optical system that selectively collects Raman signals from scattered light emitted from the target object 50. and a spectrograph 250 that receives the Raman signal emanating from the collection optics.

The incident light L emitted from the light source 210 is reflected by the reflecting mirror 215, and then irradiated onto the measurement area of the target object 50 via the Raman filter 230, which will be described later. The collection optics can selectively collect Raman signals from scattered light emitted from the target object 50 . The collection optics may include a non-imaging collection unit 220 and a Raman filter 230 . The non-imaging concentrator unit 220 may be, for example, a compound parabolic concentrator (CPC), an elliptical hyperbolic concentrator (EHC), a circular hyperbolic concentrator (CHC), a conical concentrator (CCC) or An Elliptical Cone Concentrator (ECC) may also be included. However, it is not limited to them.

The non-imaging focusing unit 220 has an incident surface 220a on which scattered light emitted from the target object 50 is incident, and an exit surface 220b on the opposite side of the incident surface 220a from which Raman signals are emitted. and may include In this embodiment, the entrance surface 220a of the non-imaging focusing unit 220 can have a larger area than the exit surface 220b.

A Raman filter 230 for blocking fluorescence signals is provided on a partial area of the incident surface 220a of the non-imaging light-condensing unit 220 . Specifically, the Raman filter 230 is provided on the incident surface 220a of the non-imaging condensing unit 220 in a region where most of the fluorescence signal is incident, that is, in the central region of the incident surface 220a. The Raman filter 230 is provided to transmit one wavelength band or multiple wavelength bands. Meanwhile, a transparent member (not shown) surrounding the Raman filter 230 is further provided on the incident surface 220 a of the non-imaging light gathering unit 220 . Also, a bandpass filter (not shown) that transmits only a specific Raman wavelength may be provided on the incident surface 220a of the non-imaging light gathering unit 220 surrounding the Raman filter 230. FIG.

A collection optical system including the non-imaging collection unit 220 and the Raman filter 230 can selectively collect only the Raman signal among the scattered light emitted from the target object 50 . The Raman signals thus collected are then received and analyzed by a spectrometer 250, such as an on-chip spectrometer.

FIG. 17 illustrates a Raman spectroscopy system according to yet another exemplary embodiment.

17, Raman spectroscopy system 300 includes a light source (not shown), collection optics for selectively collecting Raman signals from scattered light emitted from target object 50, and and a spectrograph 350 that receives the Raman signal emanating from the system. Here, as the spectroscope 350, a general dispersive spectroscope having a slit 355 is used.

The collection optics may include a non-imaging collection unit 320 and a Raman filter 330 . The non-imaging light-collecting unit 320 has an incident surface 320a on which scattered light emitted from the target object 50 is incident, and an exit surface 320b on the opposite side of the incident surface 320a, where Raman signals are emitted. and may include In the present embodiment, the exit surface 320 b of the non-imaging condensing unit 320 is provided so as to be inserted into the slit 355 of the spectroscope 350 . Accordingly, the exit surface 320 b of the non-imaging light-collecting unit 320 is formed in a shape corresponding to the slit 355 of the spectroscope 350 .

The Raman filter 330 is provided on the incident surface 320a of the non-imaging light-collecting unit 320 in a region where most of the fluorescence signal is incident, that is, in the central region of the incident surface 320a. The Raman filter 330 is provided to transmit one wavelength band or multiple wavelength bands. A collection optical system including a non-imaging collection unit 320 and a Raman filter 330 can selectively collect only Raman signals from the scattered light emitted from the target object 50, and the collected Raman signals are: It is received and analyzed inside the spectroscope 350 via the slit 355 .

FIG. 18 illustrates a Raman spectroscopy system according to yet another exemplary embodiment. Referring to FIG. 18, a Raman spectroscopy system 400 includes a light source 410 that illuminates a target object 50 with incident light L, and collection optics that selectively collect Raman signals from the scattered light emitted from the target object 50. and a spectrograph 450 that receives the Raman signal emanating from the collection optics.

Incident light L emitted from the light source 410 is incident on the surface of the target object 50 so as to be inclined. The collection optics can selectively collect Raman signals from scattered light emitted from the target object 50 . The collection optics may include a non-imaging collection unit 420 and a Raman filter 430 . The non-imaging concentrator unit 420 may be, for example, a compound parabolic concentrator (CPC), an elliptical hyperbolic concentrator (EHC), a circular hyperbolic concentrator (CHC), a conical concentrator (CCC) or An Elliptical Cone Concentrator (ECC) may also be included. However, it is not limited to them.

The non-imaging light gathering unit 420 may include an entrance surface on which scattered light emitted from the target object 50 is incident and an exit surface from which Raman signals are emitted. Here, the incident surface of the non-imaging focusing unit 420 may have a smaller area than the exit surface. Also, the entrance surface of the non-imaging focusing unit 420 can have a larger area than the exit surface.

The Raman filter 430 is provided on the incident surface of the non-imaging focusing unit 420 in the area where most of the fluorescence signal is incident, ie, the central area of the incident surface. Such a Raman filter 430 is provided to transmit one wavelength band or multiple wavelength bands. A collection optical system including the non-imaging collection unit 420 and the Raman filter 430 can selectively collect only the Raman signal among the scattered light emitted from the target object 50 . The Raman signal thus collected is then received by spectroscope 450 and analyzed.

As described above, a non-imaging light gathering unit and a Raman filter are used to suppress reception of fluorescence signals and selectively collect only Raman signals among the scattered light emitted from the target object. can be done. Specifically, if a target object having turbidity such as skin is irradiated with a laser beam, the scattered light emitted from the target object contains not only Raman signals but also fluorescence signals that interfere with the reception of Raman signals. are also included, and such fluorescence signals are mostly contained in the central part of the scattered light. Therefore, by providing a Raman filter for blocking the reception of the fluorescence signal in the central region corresponding to the central portion of the scattered light on the incident surface of the non-imaging light collecting unit, the reception of the fluorescence signal is suppressed and the Raman signal is can be selectively collected. By using such a Raman spectroscopy system, it is possible to effectively detect Raman signals related to blood sugar contained in the skin. Also, if an on-chip spectroscope is applied, a micro-Raman spectroscopic system used as a mobile health scent diagnostic sensor can be implemented.

Raman spectroscopy systems employing Raman filters capable of transmitting multiple wavelength bands are also applied in the SERDS field and used for background subtraction. Since the incident light emitted from the light source penetrates the skin differently depending on the wavelength, if a Raman filter that transmits multiple wavelength bands is used, it is possible to obtain Raman information based on the depth of the skin. can be done.

INDUSTRIAL APPLICABILITY The condensing optical system for a spectroscope and the Raman spectroscopic system including the same according to the present invention are effectively applicable to, for example, technical fields related to medical examinations.

10 measurement sample 21 first silicon substrate 22 second silicon substrate 23 third silicon substrate 31 core 32 clad layer 40 focusing lens 50 object 100, 200, 300, 400 Raman spectroscopic system 110, 210, 410 light source 115, 215 reflecting mirror 120, 220, 320, 420 non-imaging condensing units 120a, 220a, 320a entrance planes 120b, 220b, 320b exit planes 130, 131, 132, 133, 134, 230, 330, 430 Raman filters 131a, 132a, 133a, 134a First wavelength filters 131b, 132b, 133b, 134b Second wavelength filters 133c, 134c Third wavelength filters 140 Transparent members 150, 250, 350, 450 Spectroscope 355 Slits F1 to F9 Fiber L Incident light S Scattered light S' Raman Scattered light containing signal

Claims (15)

In a collection optical system for a spectrometer that selectively collects Raman signals from scattered light emitted from a target object,
a non-imaging light-collecting unit for collecting and emitting the Raman signal, comprising an entrance surface on which the scattered light is incident and an exit surface from which the Raman signal is emitted;
a Raman filter provided on a partial region of the incident surface of the non-imaging light gathering unit and blocking the scattered light containing the fluorescence signal;
The Raman filter is provided in a region including the center of the incident surface,
suppressing reception of the fluorescence signal of the scattered light and selectively collecting the Raman signal;
the Raman filter transmits a wavelength band of incident light irradiated onto the target object and blocks a wavelength band of scattered light emitted from the target object;
The Raman filter is a condensing optical system for a spectroscope including a plurality of wavelength filters each transmitting a plurality of specific wavelength bands of the incident light . 2. The spectroscope according to claim 1, wherein said target object includes a substance having turbidity, and emits scattered light including said fluorescence signal and said Raman signal upon irradiation with incident light emitted from a light source. Dexterous condensing optics. 3. The condensing optical system for a spectroscope according to claim 2, wherein said target object includes skin, and said Raman signal includes a blood sugar Raman signal. 4. The condensing optical system for a spectrometer according to claim 1, wherein the incident surface of said non-imaging condensing unit has a size of 1 cm or less. 5. A condensing optical system for a spectrometer according to claim 4, wherein said Raman filter has a size of 1 mm or less. 2. A condensing optical system for a spectrometer according to claim 1 , wherein said Raman filter transmits only one specific wavelength band of said incident light. 2. The condensing optical system for a spectroscope according to claim 1, wherein said plurality of wavelength filters are arranged in a grid pattern or concentrically. 3. The incident surface around the Raman filter is provided with a transparent member that transmits the scattered light including the Raman signal, or a bandpass filter that transmits only a specific Raman wavelength. 8. The condensing optical system for a spectroscope according to any one of 1 to 7. 4. The non-imaging concentrator unit comprises an elliptical hyperboloid concentrator, a circular hyperboloid concentrator, a conical concentrator, an elliptical cone concentrator or a compound parabolic concentrator. 9. The condensing optical system for a spectroscope according to any one of 1 to 8. 10. The condensing optical system for a spectroscope according to claim 1, wherein the incident surface of said non-imaging condensing unit has a smaller area than said exit surface. 10. The condensing optical system for a spectroscope according to claim 1, wherein the incident surface of said non-imaging condensing unit has a larger area than said exit surface. a light source that irradiates the target object with incident light;
collection optics for selectively collecting Raman signals from scattered light emitted from the target object by the incident light;
a spectroscope for receiving the Raman signal emanating from the collection optics;
A Raman spectroscopic system, wherein the condensing optical system is the condensing optical system for a spectroscope according to any one of claims 1 to 11. 13. The Raman method according to claim 12, wherein the incident light emitted from the light source is applied perpendicularly to the surface of the target object, or applied so as to be inclined with respect to the surface of the target object. spectroscopy system. 14. The Raman spectroscopy system of claim 12 or 13, wherein the spectroscope comprises an on-chip spectroscope. 3. The spectroscope comprises a dispersive spectroscope having a slit into which the Raman signal is incident, and wherein the exit surface of the non-imaging condensing unit is inserted into the slit. 15. The Raman spectroscopy system according to any one of 12-14.

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