KR20230078360A - Raman Probe Capable of Moving The Objective Lens in the Horizontal Direction of The Sample - Google Patents

Abstract

The present invention relates to a Raman probe capable of moving an objective lens in a horizontal direction of a sample, a laser diode emitting excitation light, a collimator lens allowing the excitation light to converge to a focal point of a sample, and the collimator lens A reflective mirror for reflecting the excitation light converged from the incident at a reflection angle having the same magnitude as the incident angle, a sample holder for fixing the sample so that the excitation light reflected from the reflective mirror is incident on the sample, and a sample holder fixed to the sample holder. An objective lens that emits the excitation light reflected from the sample, an objective lens driver that finely adjusts the path of the excitation light by moving the objective lens in horizontal and vertical directions with respect to the sample, and the path is adjusted from the objective lens driver The present invention relates to a Raman probe including a condenser capable of moving the objective lens for collecting Raman scattered light generated when the excitation light generated when the excitation light is incident, and a Raman filter for separating Raman scattering.

Description

Raman Probe Capable of Moving The Objective Lens in the Horizontal Direction of The Sample}

The present invention relates to a Raman probe capable of moving an objective lens in the horizontal direction of a sample, and more specifically, by moving the objective lens in a horizontal direction within a range in which the focus of excitation light on the sample is maintained and out of focus of the sample, the fluorescence compared to the Raman signal It relates to a Raman probe capable of moving an objective lens in a horizontal direction of a sample that prevents a large signal from appearing and improves the resolution of a Raman signal.

Raman spectroscopy is an analysis technique that irradiates a target sample with a laser and determines the components of a material through a spectrum obtained from it. When a target sample is irradiated with a laser, a monochromatic light source, light is scattered. As such, most of the light is a signal corresponding to the wavelength of the laser, but some of the light is a Raman shift corresponding to the frequency of the vibration mode of the sample at the wavelength of the laser. There is a signal coming out. By analyzing this signal, information on the shape and symmetry of molecules or crystals of the sample can be obtained, and the degree of crystallization of the sample can be identified. Since the aspect of the wavelength change appears differently depending on the structural characteristics of the material and appears as a unique characteristic for each specific material, the Raman spectrum is useful for determining the material.

However, in the process of obtaining a Raman spectrum from a Raman spectrometer, the process of starting with the mounting of the sample, moving the detection position of the mounted sample, changing the main condition of the optical device, and adjusting the focus must be manually and repeatedly performed. It takes a lot of time and effort on the part of the operator, and when the Raman spectrum is acquired under inappropriate test conditions, the fluorescence signal compared to the Raman signal is obtained considerably larger, making it impossible to accurately acquire the Raman signal to be confirmed, and the resolution of the Raman signal is poor. There are limits.

In this regard, Related Documents 1 and 2 allow a light source to be irradiated to a sample to obtain Raman spectroscopy or to post-correct the acquired Raman spectroscopy signal, but there is a technical limitation in that the resolution of the signal cannot be improved in the process of acquiring the Raman spectrum. exist. Therefore, a technology capable of solving the conventional problems is required.

KR 10-2234113 KR 10-2088163

The present invention is to solve the above problems, and to prevent the fluorescence signal from appearing large compared to the Raman signal and to improve the resolution of the Raman signal, it is possible to move the objective lens in the horizontal direction within the range of maintaining the focus of the excitation light on the sample. It is an object of the present invention to obtain a Raman probe with reduced fluorescence intensity and increased resolution of a Raman signal by making it possible.

In order to achieve the above object, a Raman probe capable of moving an objective lens in a horizontal direction of a sample of the present invention includes a laser diode emitting excitation light; a collimator lens for converging the excitation light to a focal point of the sample; a reflection mirror for reflecting the excitation light converged from the collimator lens at a reflection angle having the same size as the incident angle; a sample holder for fixing a sample such that the excitation light reflected from the reflective mirror is incident on the sample; an objective lens that emits the excitation light reflected from the sample fixed to the sample holder; an objective lens driver for finely adjusting the path of the excitation light by moving the objective lens in horizontal and vertical directions with respect to the specimen; a Raman filter for generating the Raman scattered light using a Raman effect when the excitation light whose path is adjusted from the objective lens driver is incident; and a condensing lens condensing the Raman scattered light.

As described above, according to the present invention, by moving the objective lens in the horizontal direction within the range in which the focus of the excitation light on the sample is maintained, and changing the focused excitation light path only between the sample and the objective lens, additional equipment is provided or a Raman spectrum can be obtained through software. It has the effect of resolving the trouble of later correction, preventing the fluorescence signal from appearing large compared to the Raman signal in the Raman probe itself, and improving the resolution of the Raman signal.

1 is an internal configuration diagram of a conventional Raman spectroscopy system.
2 is a diagram showing the internal configuration of the Raman probe of the present invention.
3 is a plan view of an objective lens driving unit according to an embodiment of the present invention.
4 is a perspective view of an objective lens driving unit according to an embodiment of the present invention.
5 is a view showing that excitation light emitted from a laser diode is irradiated to a sample according to an embodiment of the present invention.
6 is a perspective view and a plan view of a reflective mirror according to an embodiment of the present invention.
7 is a view showing a manufacturing process of a reflective mirror according to an embodiment of the present invention.
8 is an external view of a Raman probe according to an embodiment of the present invention.
9 is a diagram showing a Raman spectrum graph obtained as a sample of acetone according to an embodiment of the present invention and a positional change of excitation light irradiated to the sample according to voltage.
10 is a Raman spectrum graph obtained as a sample of toluene according to an embodiment of the present invention.
11 is a Raman spectrum graph obtained as a sample of acetone according to an embodiment of the present invention.

The terms used in this specification have been selected from general terms that are currently widely used as much as possible while considering the functions in the present invention, but these may vary depending on the intention of a person skilled in the art, precedent, or the emergence of new technologies. In addition, in a specific case, there is also a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the invention. Therefore, the term used in the present invention should be defined based on the meaning of the term and the overall content of the present invention, not simply the name of the term.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, it should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. 1 is an internal configuration diagram of a conventional Raman spectroscopy system. 2 is an internal configuration diagram of the Raman probe 100 of the present invention. 3 is a plan view of an objective lens driving unit 160 according to an embodiment of the present invention. 4 is a perspective view of an objective lens driving unit 160 according to an embodiment of the present invention. FIG. 5 is a view showing that excitation light emitted from the laser diode 110 is irradiated to a sample according to an embodiment of the present invention. 6 is a perspective view and a plan view of a reflective mirror 130 according to an embodiment of the present invention. 7 is a view showing a manufacturing process of the reflective mirror 130 according to an embodiment of the present invention. 8 is an external view of the Raman probe 100 according to an embodiment of the present invention.

First, referring to FIG. 1, in the conventional Raman spectroscopy system, light emitted from a laser is reflected from a focusing lens, moved to a beam splitter, and then reaches a sample through an objective lens. And the light reflected by the sample is moved to the beam splitter again, and then enters a Raman spectrometer through a Raman filter, which is either a notch filter or a long-pass filter. A Raman spectrum can be obtained.

Here, the conventional Raman spectroscopy system has a technical limitation in that the sample itself or the substrate on which the sample is placed must be automatically or manually moved in the vertical direction to focus the laser light. In this case, scattering of the laser light occurs strongly, and a significantly large fluorescence signal excited by the laser light is obtained. In addition, when the optical path for concentrating the laser light on the lens is short, this phenomenon is particularly intensified, resulting in a problem that the Raman signal of the sample to be obtained is buried in unnecessary fluorescence signal.

In order to solve this problem, conventionally, a Raman filter is used to block laser light, but only a part of the laser light is blocked, and a significant amount of laser light passes through the Raman filter without being blocked. In addition, in order to solve this problem, a technology for using an additional filter or software-based post-correction of the acquired Raman spectrum has been developed, but additional equipment and software costs are incurred.

Accordingly, the Raman probe 100 of the present invention includes a laser diode 110, a collimator lens 120, a reflection mirror 130, a sample holder 140, an objective lens 150, and an objective lens driving unit 160. , By including the Raman filter 170 and the condensing lens 180, the objective lens 150 is moved in the horizontal direction within a range in which the convergence of the light source on the sample is maintained, and the focused excitation light path is changed between the sample and the objective lens 150. It is possible to prevent the fluorescence signal from appearing large compared to the Raman signal and improve the resolution of the Raman signal by changing only between the two.

2, the laser diode 110 emits monochromatic excitation light. The collimator lens 120 allows the excitation light to converge on the focal point of the sample. Before the excitation light is collimated, it is not incident on a single point but is incident on a wide point. When the excitation light is collimated from the collimator lens 120, it is incident on a point and determines the surface of the reflective mirror 130. There is an effect that can be incident on the point.

Next, when the excitation light converged from the collimator lens 120 is incident, the reflection mirror 130 reflects it at a reflection angle having the same size as the incident angle.

Most preferably, the reflective mirror 130 has a silver (Ag) circular pattern on one surface, so that the size of the excitation light when incident is the same as the size of the excitation light when reflected. More specifically, in the reflection mirror 130, silver (Ag) is applied to the surface of the glass substrate 131 to which the pattern paper 132 is bonded, and after a silver (Ag) curing reaction occurs, the pattern paper 132 is removed, and the glass substrate 131 from which the pattern paper 132 is removed is cut and manufactured in a similar size to the size of the perforation 191 formed on the central axis of the main body 190, so that the intensity of the incident light increases when reflected. can also be maintained.

In general, a beam splitter is used to change the optical path, but since only half of the light is reflected or transmitted, the intensity of the light is reduced to more than half each time it passes through, and finally Raman scattered light through a Raman spectrometer There is a problem that is difficult to observe. In order to solve this problem, the present invention may be provided with a reflective mirror 130 in which silver (Ag) is circularly patterned and hardened on the surface. Accordingly, the excitation light may be reflected on the surface on which silver (Ag) is circularly patterned, and the rest of the portion where silver (Ag) is not hardened may be transmitted. At this time, most preferably, the size of the circularly patterned and hardened silver (Ag) portion may be equal to or slightly larger than the beam size of the laser diode 110 . Meanwhile, the silver (Ag) may be replaced with an aluminum (Al) material.

In the manufacturing method of the reflective mirror 130, referring to FIG. 7, the pattern paper 132 is commercial waterproof label paper and may include a circular pattern having a diameter of about 2 mm. Silver (Ag) ions are sprayed onto the surface of the glass substrate 131 to which the pattern paper 132 is attached and soaked in a basic solution for about 5 minutes to adhere to the surface. When the curing reaction occurs, the pattern paper 132 is removed. In addition, the reflective mirror 130 having a circular pattern of silver (Ag) on one side surface can be manufactured by cutting to about 7 mm in width and 5 mm in width.

6 and 8, the upper end of the main body 190 may have an inner circumferential surface corresponding to the outer circumferential surface of the optical fiber 200 so that the optical fiber 200 can be coupled, and the lower end of the main body 190 is A laser diode 110, a collimator lens 120, a reflective mirror 130, an objective lens 150, an objective lens driving unit 160, a Raman filter 170, and a condensing lens 180 may be fastened. , Therefore, it may be formed integrally except for the sample holder 140 of the present invention. Also, a perforation part 191 is provided on the central axis of the main body 190 so that the excitation light can reach the optical fiber 200 .

In other words, the reflective mirror 130 cut to a width of 7 mm and 5 mm as described above and having a silver (Ag) circular pattern on one surface is aligned with the central axis of the perforation 191 of the main body 190. can be located in Accordingly, the reflective mirror 130 has a remarkable effect of allowing the excitation light to reach the optical fiber 200 while maintaining the intensity without reducing the intensity of the excitation light.

Referring to FIG. 1 again, the sample holder 140 fixes the sample so that the excitation light reflected from the reflection mirror 130 is incident on the sample.

On the other hand, although the sample holder 140 can move in up, down, left and right directions before and after the sample is placed, the excitation light path does not change even when the sample placed in the sample holder 140 moves through the sample holder 140 according to the present invention. It is difficult to obtain the effect of reducing the fluorescence signal and improving the resolution of the Raman signal claimed in . That is, the present invention focuses on moving the objective lens 150 itself through the objective lens driver 160 rather than moving the sample through the sample holder 140.

Next, the objective lens 150 emits the excitation light reflected from the sample fixed to the sample holder 140 . Further, the objective lens driver 160 finely adjusts the path of the excitation light by moving the objective lens 150 in horizontal and vertical directions with respect to the sample.

3 and 4, the objective lens driving unit 160 generates a magnetic field according to the applied voltage applied from the power supply unit 167 so that the objective lens 150 can move in the z-axis direction, a focus coil 163a, 163b) and a focus pivot 164 provided on one side of the objective lens 150 to drive the objective lens 150 in a vertical direction with respect to the sample according to the strength and direction of the magnetic field.

The focus coils 163a and 163b of the objective lens driving unit 160 use the principle of an electromagnet, and most preferably may be provided on both sides of the objective lens 150, respectively. Also, the focus coils 163a and 163b may be disposed horizontally with the magnets 166a and 166b provided in the objective lens driver 160 based on the central axis around which the coils are wound. In addition, the applied voltage within the range of -1.6V to 1.6V may be applied through a circuit connected to the focus coils 163a and 163b.

Then, current flows in the focus coils 163a and 163b, and a magnetic field is generated in one direction inside the focus coils 163a and 163b. At this time, the N pole and the S pole of the magnetic field are determined according to the direction of the applied current, and if the directions of the N pole and the S pole of the magnets 166a and 166b provided in the objective lens driving unit 160 are the same, a repulsive force is generated and the direction If this is different, a force will be generated.

That is, the objective lens 150 can be driven in the vertical direction according to the focus pivot 164 connected to one side of the objective lens 150 and serving as a driving shaft. At this time, since the applied voltage is most preferably within the range of -1V to 1V, fine adjustment is possible. 3 and 4, the tracking pivot 162 and the focus pivot 164 are integrally provided and displayed at the same time, but may be provided separately and are not limited to a specific arrangement position.

In addition, the objective lens driving unit 160 generates a magnetic field according to the applied voltage applied from the power supply unit 167 so that the objective lens 150 can move in the xy-axis direction Tracking coils 161a, 161b, 161c, 161d ) and a tracking pivot 162 provided on one side of the objective lens 150 to drive the objective lens 150 in a horizontal direction based on the sample according to the strength and direction of the magnetic field.

The tracking coils 161a, 161b, 161c, and 161d of the objective lens driving unit 160 also use the principle of an electromagnet, and most preferably, may be provided on both sides of the objective lens 150, respectively. In addition, the tracking coils 161a, 161b, 161c, and 161d may be disposed perpendicularly to the magnets 166a and 166b provided in the objective lens driver 160 based on the central axis around which the coils are wound. In addition, the applied voltage within the range of -1.6V to 1.6V may be applied through a circuit connected to the tracking coils 161a, 161b, 161c, and 161d.

Here, the objective lens driver 160 may include at least one of the tracking coils 161a, 161b, 161c, and 161d and the focus coils 163a and 163b. That is, if the two coils are provided at the same time as shown in FIGS. 3 and 4, the tracking coils 161a, 161b, 161c, and 161d are arranged so that the central axis of each coil is perpendicular to one side of the focus coils 163a and 163b It can be.

Then, current flows in the tracking coils 161a, 161b, 161c, and 161d, and a magnetic field is generated in one direction inside the tracking coils 161a, 161b, 161c, and 161d. At this time, the N pole and the S pole of the magnetic field are determined according to the direction of the applied current, and if the directions of the N pole and the S pole of the magnets 166a and 166b provided in the objective lens driving unit 160 are the same, a repulsive force is generated and the direction If this is different, a force will be generated.

That is, the objective lens 150 can be driven in the left and right directions according to the tracking pivot 162 connected to one side of the objective lens 150 and serving as a driving shaft. At this time, since the applied voltage is most preferably within the range of -1.6V to 1.6V, fine adjustment is possible. 3 and 4, the tracking pivot 162 and the focus pivot 164 are integrally provided and displayed at the same time, but may be provided separately and are not limited to a specific arrangement position.

Meanwhile, at least one of the tracking coils 161a, 161b, 161c, and 161d and the focus coils 163a and 163b of the present invention may include iron cores 165a and 165b on the central axis to improve the strength of the magnetic field. there is. This is, there is a size limitation in making an electromagnet by repeatedly winding a coil made of a material such as copper (Cu). Accordingly, the iron cores 165a and 165b may be provided to reduce the number of turns of the coil and to equalize the strength of the magnetic field.

Next, the Raman filter 170 generates the Raman scattered light by using the Raman effect when the excitation light whose path is adjusted from the objective lens driver 160 is incident. Here, Raman scattering is a phenomenon in which, in general, when a material is irradiated with light of a constant frequency, light of a frequency different from that of molecular natural vibration, rotational energy, or crystal lattice vibration energy is scattered.

Next, the condensing lens 180 condenses the Raman scattered light.

Next, the present invention may further include an optical fiber 200 for moving the collected Raman scattered light to a Raman spectrometer 300 so as to obtain a Raman spectrum.

Meanwhile, the Raman probe 100 of the present invention is different from a conventional Raman spectroscopy system in that it is a laser-integrated probe. Conventional Raman spectroscopy systems use an external laser connected to a Raman spectrometer, but as shown in FIG. 5, the Raman probe 100 of the present invention integrates the laser diode 110 with other components. There is a remarkable effect of obtaining a clearer Raman analysis spectrum by providing a constant excitation light path without shaking of the light source.

Next, a Raman spectrum obtained by moving the Raman scattered light generated from the Raman probe 100 of the present invention to the Raman spectrometer 300 through the optical fiber 200 is as follows.

9 is a diagram showing a Raman spectrum graph obtained as a sample of toluene according to an embodiment of the present invention and a positional change of excitation light irradiated to the sample according to voltage. 10 is a Raman spectrum graph obtained as a sample of toluene according to an embodiment of the present invention. 11 is a Raman spectrum graph obtained as a sample of acetone according to an embodiment of the present invention.

Referring to FIG. 9 , in one embodiment of the present invention, when the applied voltage of the objective lens driving unit 160 is -1.6V, -0.8V, 0V, 0.8V, or 1.6V, the portion where the excitation light hits the sample It can be seen that the is slightly different. As mentioned above, at least one of the tracking coils 161a, 161b, 161c, and 161d and the focus coils 163a and 163b of the objective lens driver 160 becomes an electromagnet, and each pivot according to the magnitude of the attractive or repulsive force. is the result of moving

Here, the focus coils 163a and 163b can focus the excitation light by adjusting the distance between the objective lens 150 and the sample. As the distance between the objective lens 150 and the sample increases, excitation light is concentrated on the sample, allowing a strong Raman signal. Conversely, as the distance between the objective lens 150 and the sample becomes closer, the excitation light is not concentrated on the sample and spreads, allowing a relatively weak Raman signal.

Most preferably, in the present invention, after focusing through the focus coils 163a and 163b, scattering and fluorescence signals can be remarkably reduced through the tracking coils 161a, 161b, 161c, and 161d. That is, a predetermined applied voltage is applied to the tracking coils 161a, 161b, 161c, and 161d, and the tracking pivot 162 moves according to the magnitude of the attractive force and repulsive force generated, thereby moving the objective lens 150 to x or y. direction, that is, it moves in a horizontal direction based on the sample.

Then, very strong scattering and fluorescence signals appear due to the short optical path. By artificially generating a fine mismatch of the optical path through the tracking coils 161a, 161b, 161c, and 161d, strong scattering and fluorescence signals It can be significantly reduced, and accordingly, there is a remarkable effect of improving the resolution of the Raman signal. As can be seen in FIG. 8, it can be confirmed that the intensity of the fluorescence signal changes according to the applied voltage in the Raman spectrum graph.

In addition, when the sample is an irregularly shaped solid, more accurate focusing is possible through the tracking coils 161a, 161b, 161c, and 161d.

Next, referring to (a) of FIG. 10, the applied voltage to the tracking coils 161a, 161b, 161c, and 161d of the objective lens driver 160 is -1.6V and -0.8 for a toluene sample. It is a diagram showing the Raman spectrum obtained when applied at V, 0V, 0.8V, and 1.6V. Referring to (b) of FIG. 10, it is an enlarged view of a Raman spectrum obtained when an applied voltage of 0.8V is applied. In the table, it was confirmed that the difference between the wave number obtained from the conventional Raman spectroscopy system (Ref) and the wave number obtained from one embodiment of the present invention may be within 10 cm ^-1 and is sufficient to determine each material in toluene. .

Next, referring to (a) of FIG. 11, the voltage applied to the tracking coils 161a, 161b, 161c, and 161d of the objective lens driver 160 is -1.6V and -0.8 for an acetone sample. It is a diagram showing the Raman spectrum obtained when applied at V, 0V, 0.8V, and 1.6V. Referring to (b) of FIG. 11, it is an enlarged view of a Raman spectrum obtained when an applied voltage of 1.6V is applied. In the table, it was confirmed that the difference between the wave number obtained from the conventional Raman spectroscopy system (Ref) and the wave number obtained from one embodiment of the present invention may be within 10 cm ^-1 and is sufficient to determine each material of the acetone sample. .

As described above, although the embodiments have been described with limited examples and drawings, those skilled in the art can make various modifications and variations from the above description. For example, the described techniques are performed in a different order than the described method, and/or the components of the system, structure, device, circuit, etc. described in are combined or combined in a different form than the described method, or in a different configuration. Appropriate results can be achieved even when substituted or substituted by elements or equivalents.

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

100.. Raman probe
110.. laser diode
120.. Collimator lens
130.. Reflecting mirror
131.. glass substrate
132.. pattern paper
140.. sample holder
150.. Objective
160.. Objective lens driving unit
161a, 161b, 161c, 161d.. tracking coil
162.. trekking pivot
163a, 163b.. focus coil
164.. Focus Pivot
165a, 165b.. iron core
166a, 166b.. Magnet
167.. power supply
170.. Raman filter
180.. condensing lens
190.. Body
191.. Perforation
200.. optical fiber
300.. Raman Spectrometer

Claims (5)

a laser diode that emits excitation light;
a collimator lens for converging the excitation light to a focal point of the sample;
a reflection mirror for reflecting the excitation light converged from the collimator lens at a reflection angle having the same size as the incident angle;
a sample holder for fixing a sample such that the excitation light reflected from the reflective mirror is incident on the sample;
an objective lens that emits the excitation light reflected from the sample fixed to the sample holder;
an objective lens driver for finely adjusting the path of the excitation light by moving the objective lens in horizontal and vertical directions with respect to the specimen;
a Raman filter for generating the Raman scattered light using a Raman effect when the excitation light whose path is adjusted from the objective lens driver is incident; and
A Raman probe capable of moving an objective lens in a horizontal direction of a sample including a; condensing lens for condensing the Raman scattered light. According to claim 1,
A Raman probe capable of moving an objective lens in a horizontal direction of a sample, characterized in that it further comprises; an optical fiber for moving the collected Raman scattered light to a Raman spectrometer so as to obtain a Raman spectrum. According to claim 1,
The objective lens driving unit,
a focus coil generating a magnetic field according to an applied voltage applied from a power supply unit; and
A focus pivot provided on one side of the objective lens to drive the objective lens in a vertical direction with respect to the specimen according to the strength and direction of the magnetic field; Raman probe. According to claim 1,
The objective lens driving unit,
A tracking coil generating a magnetic field according to the applied voltage applied from the power supply unit; and
A tracking pivot provided on one side of the objective lens to drive the objective lens in a horizontal direction with respect to the sample according to the strength and direction of the magnetic field; Object lens movement in the horizontal direction of the sample, characterized in that it is possible to move Raman probe. According to claim 1,
The reflective mirror is
A Raman probe capable of moving an objective lens in the horizontal direction of a sample, characterized in that by having a silver (Ag) circular pattern on one surface, the size of the excitation light at incident time and the size of the excitation light at reflection are the same.

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