KR102359863B1 - Auto-focusing Raman spectrometer and measuring method with the same Raman spectrometer - Google Patents

Abstract

The present invention relates to an auto-focusing Raman spectrometer and a measuring method using the Raman spectrometer. In the small handheld Raman spectrometer for measuring a measurement target having the form of an SERS strip, the principle of confocal microscope is applied and a more accurate and reliable result can be obtained simply by adding a simple configuration within a range not adversely affecting device miniaturization. According to the present invention, the principle is applied that only a signal at a focus is obtained by blocking a non-focal signal using a pinhole in a confocal microscope. As a result, the focal position is adjusted during a change in focal length by a detector detecting the point where the signal strength of the light passing through the pinhole is maximized.

Description

Auto-focusing Raman spectrometer and measuring method using the Raman spectrometer {Auto-focusing Raman spectrometer and measuring method with the same Raman spectrometer}

The present invention relates to an automatic focal length control Raman spectrometer and a measuring method using the Raman spectrometer, and more particularly, to obtain more accurate and reliable results in a handheld small Raman spectrometer for measuring a measurement object in the form of a SERS strip. It relates to an automatic focal length adjustment Raman spectrometer and a measurement method using the Raman spectrometer.

The Raman spectroscopy technique is an analysis technique that irradiates a laser onto a target sample and discriminates the material components from the spectrum obtained therefrom. When a sample is irradiated with a laser, which is a monochromatic light source, light is scattered. Most of the scattered light is a signal corresponding to the wavelength of the laser, but some of the scattered light is a Raman shift (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 can be obtained, and the degree of crystallization of the sample can be determined. This change in wavelength appears differently depending on the structural properties of the material, and appears as a unique property for each specific material, so the Raman spectrum is called the fingerprint of the material. In particular, recently, various Raman signal amplification techniques such as surface enhanced Raman scattering (SERS) have been actively studied, and the Raman spectroscopy technique is attracting attention as an excellent technology capable of discriminating ultra-fine concentration components. 1 illustrates the principle of Raman spectroscopy and an example of Raman spectrum as an example.

2 shows the structure of a conventional basic Raman spectrometer. As shown, the basic Raman spectrometer irradiates the laser light output from the short-wavelength light source 110 ′ to the specimen 500 ′ through the objective lens 130 ′, and the light scattered from the specimen 500 ′. Among them, only the component corresponding to the Raman shift is selected by the filter 140', and then the spectrum is obtained by the spectrometer 160'. In this case, a dichroic mirror or a dichroic beam splitter 120' is used to split the light by wavelength. In addition, a light receiving lens 150' is provided in front of the spectrometer 160' in order to smoothly enter the light into the spectrometer 160'.

Raman spectroscopy has been commercialized in various forms depending on the purpose and environment of use, and if we look at it broadly, it is a general microscope type for research and analysis used in a fixed state in laboratories, etc. It can be classified for field use.

As mentioned above, the Raman spectrometer for research and analysis is used in a stable and fully controllable environment such as a laboratory, and considering that the measurement results should be used for more in-depth analysis, it is designed for various functions and high performance. tends to happen. That is, an optical configuration such as using multiple filters is added, or a specimen stage and beam scanning mechanism are added so that a signal can be received from multiple points instead of only from one point of the specimen. Even if it becomes complicated, the focus tends to be on diversifying functions or improving performance. Of course, even if the overall device configuration of the Raman spectrometer for research and analysis becomes very complicated, it is natural that the structure of its core part is based on FIG. 2 .

In the case of on-site Raman spectroscopy, miniaturization is essential because the device itself needs to be portable and portable in the field. Accordingly, the laser light source also typically uses one wavelength, and additional components such as a specimen stage and a beam scanning mechanism are excluded. In fact, in the case of on-site Raman spectroscopy, the user holds the device by hand and approaches the device to the specimen to perform measurement. In the case of a field-use Raman spectrometer, it tends to have a simple and relatively low-spec configuration, and almost follows the configuration of FIG. 2 as it is.

Meanwhile, the SERS technique briefly introduced above has the characteristic of effectively amplifying the Raman signal so that it can detect even a very low concentration signal. Accordingly, by introducing SERS into a relatively low-spec Raman spectrometer, that is, a Raman spectrometer for the field, it is expected that its utility can be further improved. That is, it is a method of detecting a Raman signal after preparing a SERS signal amplification reaction material in the form of a strip or a substrate in advance, applying a target sample to be tested on it and reacting it. As shown in FIG. 3 , the method of using a handheld Raman spectrometer together with the SERS substrate is spotlighted as a potential technology that can satisfy both portability and sensitivity.

A method of using a handheld type small Raman spectrometer and a SERS substrate together is briefly described as follows. First, the sample to be measured is coated on the surface of the SERS substrate, and the intensity of the Raman spectrum generated therefrom is read with a handheld type small Raman spectrometer to enable detection of the sample. In addition, the result to be determined can be derived through this. For example, if Raman spectrum signal intensity data for each concentration of a specific chemical component measured in advance is secured to obtain a reference value, the signal measured for the actual target sample is obtained from this. Concentrations can be calculated from the data. Furthermore, when the target sample is a hazardous substance, various applications can be made, such as being able to determine whether it is safe from the concentration value converted from the data value.

On the other hand, in the case of a handheld type of small Raman spectrometer, as described above, since a design to improve miniaturization and portability is prioritized over high functionality, various functions are given up and the configuration is simplified as much as possible in many cases. Accordingly, performance limitations inevitably occur, and in some cases, a simple additional configuration is provided to solve such performance limitations. In the case of Korean Patent No. 1965803 (“Raman spectrometer with laser power regulator”, March 29, 2019), in the process of miniaturizing the Raman spectrometer, the sensitivity of the spectrometer is inevitably lowered, so the laser intensity is relatively increased. In the process of measuring, in order to prevent damage to the sample by laser irradiation during measurement, a technique for adding a component capable of adjusting the laser output intensity although simple enough not to affect the miniaturization is disclosed. In this way, even in a small Raman spectrometer for handheld use, many efforts are being made to improve the performance limit by adding a simple but essential configuration.

In the case of a handheld small Raman spectrometer and a SERS substrate utilization method as described above, the following performance limitations are pointed out. In the process of performing detection in the manner described above, it is necessary that all but the target sample be the same condition in order for the result to be reliable. In general, the optical device itself, which can be viewed as fixed hardware, can be regarded as the same condition if it operates normally, and the performance state of the SERS substrate itself can be assumed to be uniform if it is a mass-produced product. However, there is a high possibility that the focus position will be changed due to the sample application state, the difference in the flatness of the strip, and the thickness error of the slide glass, and therefore it is difficult to see that the focus position is uniformly maintained under the same condition. That is, when the intensity of the spectrum is weakened, it is difficult to determine whether this is because the concentration of the sample is lowered, or whether the sample plane and the focal plane are separated due to the occurrence of a thickness error. There is a risk of being sensitively reflected in the results because the change in the focal position can directly affect the value.

In the case of the Raman spectrometer for research and analysis described above, in order to eliminate the risk of such an error, measurement is performed after confirming that the substrate surface is in focus using an optical microscope image. However, it is cumbersome to repeat this process every time, and since a separate focusing device is not provided in the case of a handheld small Raman spectrometer, it is impossible to check if an error occurs in the initially designed focal length.

1. Korea Patent No. 1965803 ("Raman Spectrometer with Laser Power Adjuster", 2019.03.29.)

Accordingly, the present invention has been devised to solve the problems of the prior art as described above, and an object of the present invention is a handheld small Raman spectrometer for measuring a measurement object in the form of a SERS strip, the principle of a confocal microscope To provide an automatic focal length adjustment Raman spectrometer and a measurement method using the Raman spectrometer that allows more accurate and reliable results to be obtained just by applying a simple configuration within a range that does not adversely affect device miniaturization. . More specifically, by applying the principle of acquiring only the signal at the focus by blocking the signal outside the focus by using a pinhole in a confocal microscope, the signal strength of the light passing through the pinhole while changing the focal length is An object of the present invention is to provide an automatic focal length adjustment Raman spectrometer and a measuring method using the Raman spectrometer, which adjusts a focus position by detecting a maximum point with a detector.

Automatic focal length adjustment Raman spectrometer 100 of the present invention for achieving the above object, the light source 110 for irradiating a laser light; a light source pinhole 115 for making a point light source by passing the laser light irradiated from the light source 110; a dichroic light splitter 120 formed to reflect the laser light irradiated from the light source 110 and make it incident toward the sample 500 or transmit the light scattered from the sample 500; an objective lens 130 for condensing the light scattered from the dichroic light splitter 120 and irradiating the sample 500; a light splitter 140 for changing an optical path by branching a portion of the light scattered from the sample 500 and passing through the dichroic light splitter 120; a detector pinhole 155 for passing the light branched through the light splitter 140; a detector 150 for detecting the signal strength of the light passing through the detector pinhole 155; a filter 160 that filters and transmits a component corresponding to a Raman shift among the light scattered from the sample 500 and transmitted through the dichroic light splitter 120; a light receiving lens 170 for receiving the light transmitted through the filter 160 and entering the spectrometer 180; a spectrometer 180 that receives the light transmitted through the filter 160 and measures a spectrum; an actuator 200 for adjusting the relative distance between the sample 500 and the objective lens 130 along the optical axis direction; may include

At this time, the automatic focal length adjustment Raman spectrometer 100 is a light signal detected by the detector 150 as the actuator 200 adjusts the relative distance between the sample 500 and the objective lens 130 . A change in intensity may be measured, but a position at which the signal intensity has a maximum value may be determined as a focal position, and a Raman spectrum signal at the focal position may be selected as a measurement value.

In addition, in the light splitter 140 , the distribution ratio may be determined such that the amount of light that is branched from the splitter 140 to change the optical path is smaller than the amount of light transmitted to maintain the original optical path.

In addition, the automatic focal length adjustment Raman spectrometer 100 includes the light source 110 , the light source pinhole 115 , the dichroic light splitter 120 , the objective lens 130 , the light splitter 140 , and the detector a module 210 in which the pinhole 155, the detector 150, the filter 160, the light receiving lens 170, and the spectrometer 180 are integrated; a case 220 accommodating the module 210 and the actuator 200 and having a sample inlet 225 through which the sample 500 can enter and exit on one side; may include

In addition, the actuator 200 may be formed to move the module 210 in the optical axis direction.

Alternatively, the actuator 200 may be formed to move the sample 500 in the optical axis direction.

Alternatively, the actuator 200 may be formed to move the objective lens 130 in the optical axis direction.

In addition, the automatic focal length adjustment Raman spectrometer 100 may be a handheld type that a user can carry and use while moving.

In addition, the sample 500 may be applied on the SERS substrate or the base 550 in the form of a SERS strip.

Also, the actuator 200 may be implemented with at least one selected from a motorized stage, a piezoelectric actuator, and a voice coil motor (VCM).

In addition, in the measurement method using the automatic focal length adjustment Raman spectrometer of the present invention, in the measurement method using the automatic focal length adjustment Raman spectrometer 100 as described above, the sample 500 is positioned below the objective lens 130 . A sample arrangement step to be arranged; an intensity measuring step of measuring a change in signal intensity of light detected by the detector 150 as the actuator 200 adjusts the relative distance between the sample 500 and the objective lens 130; a signal determination step of determining a position at which the signal strength becomes a maximum value as a focal position and selecting a Raman spectrum signal at the focal position as a measurement value; may include

According to the present invention, in a small Raman spectrometer for a handheld, when measuring a measurement object in the form of a SERS strip, it is possible to obtain more accurate and reliable results by improving the conventional problem that the focus position could not be uniformly focused during each measurement. has a great effect. Specifically, in the present invention, the principle of acquiring only the signal at the focal point by blocking the signal outside the focal point using a pinhole in the present invention is applied, and the signal of light passing through the pinhole while changing the focal length The focus position is set by detecting the point where the intensity is maximum with the detector. Since the data is acquired in a state in which the focus alignment is secured in this way, the accuracy and reliability of the measurement result can be improved.

In particular, according to the present invention, since automatic focal length adjustment in the Raman spectrometer is realized using only small and inexpensive components such as pinholes and detectors, there is no factor in excessively increasing the device volume, specifications, and manufacturing cost. Therefore, when the present invention is applied to a small Raman spectrometer for a handheld that is aimed at low-spec miniaturization, it is economical and has a great effect of maximizing performance.

1 is an example of the principle of Raman spectroscopy and Raman spectrum.
Figure 2 is the structure of a conventional basic Raman spectrometer.
3 is an example of using a handheld small Raman spectrometer and a SERS substrate.
4 is a structure of a conventional basic confocal microscope.
5 is a graph of signal intensity change according to the change in the distance between the specimen and the objective lens in the confocal microscope.
6 to 8 is a configuration embodiment of the automatic focal length adjustment Raman spectrometer of the present invention.

Hereinafter, an automatic focal length adjustment Raman spectrometer according to the present invention having the configuration as described above and a measuring method using the Raman spectrometer will be described in detail with reference to the accompanying drawings.

[1] Technical purpose and principle of the automatic focal length adjustment Raman spectrometer of the present invention

The conventional problems described above are briefly summarized as follows. The Raman spectrometer irradiates light on the surface of the sample and receives the scattered light from the sample to obtain a spectral signal. At this time, it can be considered that the measured result has sufficient reliability when all other conditions such as optical device, SERS performance state, and focal position are the same in addition to the target sample. However, the optical device or SERS performance state can be regarded as the same condition in most cases. However, in the case of the focal position, there is a significant variability due to the sample coating state, the difference in the flatness of the strip, and the thickness error of the slide glass substrate. In the case of Raman spectrometers for research and analysis used in laboratories, etc., since high performance is pursued as much as possible without considering economic feasibility or volume. The problem does not have a significant adverse effect on the results. However, in the case of a small handheld Raman spectrometer used in the field, it seeks to be miniaturized and low-cost as much as possible in consideration of portability, convenience, and economy rather than performance, so it is a high-performance device that operates precisely like an automatic focusing function. and control algorithms are difficult to be provided.

The present invention is a technique for improving the reliability of results measured by a handheld small Raman spectrometer without requiring a complicated device configuration such as automatic focusing in such a limited situation. In the present invention, by applying the principle of acquiring only the signal at the focus by blocking the signal outside the focus by using a pinhole in the confocal microscope, the signal intensity of the light passing through the pinhole is maximized while changing the focal length. The focus position is set by detecting the point where the At this time, automatic focal length adjustment in the Raman spectrometer is realized by adding only small and inexpensive components such as pinholes and detectors. can be solved with

First, the principle of the confocal microscope is briefly described as follows. 4 shows the structure of a conventional basic confocal microscope. As shown, the basic confocal microscope passes the laser light output from the light source 110" through the pinhole 115", irradiates it to the specimen 500" through the objective lens 130", and is reflected. Light is introduced into the detector 150" through the pinhole 155" and sensed. At this time, a beam splitter 120" is used to properly form an optical path of the light irradiated to the specimen and the reflected light. Also, the light is smoothly transmitted through the pinhole 155" of the detector 150". A light receiving lens 140" is provided in front of the pinhole 155" of the detector 150" in order to enter it.

The basic principle of a confocal microscope is that by using a pinhole to block a signal outside the focal point, only the signal at the focal point is acquired. In the configuration shown in FIG. 4, only a signal at one point can be acquired. Accordingly, in order to construct a three-dimensional image in a confocal microscope, an XY scanner capable of moving in the plane direction and a Z capable of moving in the optical axis direction are included in the configuration of FIG. An additional scanner is required.

When the Z-scanner is added to the configuration of FIG. 4 and the intensity of the signal detected by the detector 150" is sensed while adjusting the distance between the specimen and the objective lens with the Z-scanner, a graph of the form shown in FIG. 5 is displayed. As shown in the graph of Fig. 5, the point at which the detector detection signal intensity is maximum is the optimal focus position. As such, the confocal microscope has an optical configuration that acquires only the signal at the focus in principle, Compared to the method of finding the focus position using the contrast analysis of a separate microscope optical system image, it is possible to find the focus position naturally by simply finding the position where the signal strength from the detector is maximum, making it much simpler, faster and more stable. The focus position can be found, that is, the detector detection signal strength is maximum when the surface of the specimen is at the focal position, so if you find the position where the detector detection signal strength is maximum while changing the distance between the specimen and the objective lens for a certain section , this is the focal point.

Meanwhile, comparing the configuration of the basic Raman spectrometer of FIG. 2 and the configuration of the basic confocal microscope of FIG. 4 , it can be seen that a laser is commonly used as a light source. In addition, the shape of the optical path is similar, and in addition to the light source, various optical components can be used in common. In other words, if you want to configure the confocal microscope separately, you will incur a significant extra cost, but since most of the parts necessary for the Raman spectrometer have already been secured, it is possible to integrate the Raman spectrometer and the confocal microscope by adding some parts such as a detector and a pinhole. it is possible

The automatic focal length adjustment Raman spectrometer 100 of the present invention is configured to focus by applying the principle of the confocal microscope. That is, using the point that the confocal microscope blocks signals other than the focus, the point at which the signal strength is maximized in the detector is recognized as the focus position.

As described above, in the present invention, in the case of a handheld small Raman spectrometer used in the field, it is difficult to provide high-performance parts that require precise operation such as an automatic focusing function due to various problems such as portability and economic feasibility. This is to solve the problem of a decrease in the reliability of the result value that occurs in the process of performing measurement in a state where it is not known whether the focus is correct. That is, in the present invention, high-performance, expensive, and large-sized parts are excluded as much as possible, and relatively low-performance, low-cost, and small-sized parts are used to realize focal length adjustment of a handheld Raman spectrometer.

In the present invention, this problem is solved by applying the principle of confocal microscopy. As described above, various components used in confocal microscopes are already commonly used in Raman spectroscopy, and the concept of the present invention can be realized by providing only a few more components such as a detector and a pinhole. That is, by additionally providing a component capable of applying the principle of a confocal microscope to the basic configuration of the Raman spectrometer, that is, the Raman spectrometer and the confocal microscope are formed in an integrated configuration.

The detector and pinhole mentioned above are very small parts by themselves. Another thing to consider is the actuator that adjusts the distance between the sample and the objective lens because the existing small Raman spectrometer for handheld does not have a focal length function. You may need more. Such actuators can also be easily used with relatively low-spec motorized stages, piezoelectric actuators, and VCM (Voice coil motors). do not lose

That is, by using the principle of the present invention, it is not necessary to apply an automatic focusing function that requires an expensive precision operation, and it is sufficient to provide a relatively low-cost and low-performance actuator along with a detector and a pinhole. There is hardly any adverse effect on cost reduction. Accordingly, ultimately, it will be possible to dramatically improve the accuracy and reliability of the measurement values while maintaining the portability, convenience, and economic feasibility of a small handheld Raman spectrometer.

[2] Configuration of automatic focal length adjustment Raman spectrometer of the present invention

6 to 8 show a configuration example of the automatic focal length adjustment Raman spectrometer of the present invention. In the automatic focal length adjustment Raman spectrometer 100 of the present invention, the optical system itself for measuring the Raman spectrum signal follows the basic configuration of the Raman spectrometer shown in FIG. 2 as it is. That is, the automatic focal length adjustment Raman spectrometer 100 is basically a light source 110 irradiating a laser light, a laser light irradiated from the light source 110 is reflected toward the sample 500, or the sample 500 is incident on the sample. A dichroic light splitter 120 formed to transmit the light scattered by 500, an objective lens 130 for condensing the light scattered from the dichroic light splitter 120 and irradiating it to the sample 500, the A filter 160 that filters and transmits a component corresponding to a Raman shift among the light scattered from the sample 500 and transmitted through the dichroic light splitter 120, and receives the light transmitted through the filter 160 to receive the light It includes a light-receiving lens 170 that enters the spectrometer 180 , and a spectrometer 180 that receives light transmitted through the filter 160 and measures a spectrum.

At this time, as described above, the automatic focal length adjustment Raman spectrometer 100 of the present invention is a light source pinhole 115, a light splitter 140, a detector pinhole 155, so that the principle of a confocal microscope can be applied. It further includes a detector 150 and an actuator 200 . By doing in this way, so to speak, a configuration in which the Raman spectrometer and the confocal microscope are integrated can be realized.

The actuator 200 serves to adjust the relative distance between the sample 500 and the objective lens 130 along the optical axis direction. At this time, as described above, the actuator 200 does not need to operate very precisely, so it can be formed with a relatively low-spec motorized stage, a piezoelectric actuator, a voice coil motor (VCM), etc. have.

The light source pinhole 115 serves to pass the laser light irradiated from the light source 110 to form a point light source. At this time, around the light source pinhole 115, the light source pinhole converging lens 115a and the light source pinhole 115 that converges the laser light irradiated from the light source 110 and passes it through the light source pinhole 115. It is preferable that a light source pinhole diverging lens 115b is further provided to generate parallel light by emitting the emitted light. For reference, the laser light irradiated from the light source 110 is determined by selecting optical characteristics such as a wavelength for Raman spectroscopy. At this time, even if the laser light irradiated from the light source 110 passes through the light source pinhole 115 to form a point light source, it does not affect the acquisition of the Raman signal itself.

The light splitter 140 serves to change a light path by branching a portion of the light scattered from the sample 500 and transmitted through the dichroic light splitter 120 . In this case, the distribution ratio may be appropriately determined as desired by the user, such as 5:5. At this time, as a part of the light is split by the light splitter 140, the signal entering the spectrometer 180 is inevitably reduced in part. Some disadvantages may arise. On the other hand, considering that the light split by the optical splitter 140 does not need to be precisely measured, the optical splitter 140 may reduce the adverse effect of reducing the signal entering the spectrometer 180 as much as possible. ), the distribution ratio of the light to change the optical path and the light to be transmitted to maintain the original optical path is 1:9. It is preferable that the light branching from the optical splitter 140 to change the optical path is determined such that the amount of light is small, such as 2:8.

The detector pinhole 155 serves to pass the light branched through the light splitter 140 . Also around the detector pinhole 155, similarly to the light source pinhole 115, a detector pinhole converging lens 155a that converges the light branched through the light splitter 140 and passes it through the detector pinhole 155. is preferably provided.

The detector 150 serves to detect the signal strength of the light passing through the detector pinhole 155 . As described in the principle of the confocal microscope, the intensity of the signal entering the detector 150 has a maximum value when it is in focus. Therefore, the detector 150 and the actuator 200 are configured to operate in conjunction, and as the actuator 200 adjusts the relative distance between the sample 500 and the objective lens 130, the detector 150 ), measure the change in the signal strength of the detected light, but if you find the position where the signal strength is the maximum, you just need to determine that position as the focus position. That is, the Raman spectrum signal at the focal position may be selected as a measurement value, and by doing so, automatic focal length adjustment can be realized with relatively low specifications and minimal addition of parts. Of course, by doing this, it is possible to stably acquire the Raman spectrum signal at the focal position, so that the accuracy and reliability of the measurement value can be significantly improved compared to the prior art.

On the other hand, depending on where the actuator 200 for adjusting the relative distance between the sample 500 and the objective lens 130 is actually provided, various exemplary configurations as shown in FIGS. 6 to 8 may come out.

6 shows an embodiment of the actuator 200 applied to a more specific configuration in the case where the automatic focal length adjustment Raman spectrometer 100 is a handheld small Raman spectrometer.

In the case of a handheld small Raman spectrometer, in order to minimize the change in conditions of the optical system, the light source 110 , the dichroic light splitter 120 , the objective lens 130 , the filter 160 , and the light receiving lens 170 . ), the spectrometer 180 is integrally modularized. That is, the various components described above are accommodated or supported in a certain container or frame. As such, the above-described respective parts are accommodated or supported in any container or frame, and the integrated body is referred to as a module 210 . In the case of the present invention, of course, in addition to the components for the Raman spectrometer in the module 210, additional components for a confocal microscope, that is, the light source pinhole 115, the light splitter 140, the detector pinhole 155, The detector 150 is provided together.

The small Raman spectrometer for handheld also includes a case 220 that protects the module 210 from the external environment and includes a handle so that a user can easily carry it and use it. That is, the case 220 basically serves to accommodate the module 210 and the actuator 200. At this time, of course, for a smooth measurement operation, the sample 500 enters and exits one side of the case 220. Possible sample inlet 225 is formed.

In the embodiment of FIG. 6 , the actuator 200 is formed to move the module 210 in the optical axis direction. In the case of a small Raman spectrometer for handheld use, the module 210 and the case 220 are basically provided as shown in FIG. 6, so the configuration shown in FIG. 6 can be the most intuitively designed and easy to realize configuration. have. However, there is a slight disadvantage that the performance of the actuator 200 should be higher as the target to which the actuator 200 should move becomes the entire module 210 .

In the embodiment of FIG. 7 , the actuator 200 is formed to move the sample 500 in the optical axis direction. In this case, since the sample 500 is substantially light in the form of a SERS strip or a substrate, the actuator 200 can be implemented with a device having a lower specification than the embodiment of FIG. 6 . However, in this case, since the sample 500 is not stably fixed, there is a fear that the possibility of error occurrence is slightly increased.

In the embodiment of FIG. 8 , the actuator 200 is formed to move the objective lens 130 in the optical axis direction. In this case, a condition must be added that the incident light to the objective lens 130 is configured to be a parallel light, but there is no need to move the entire module 210, so that the device specifications can be further lowered, and the sample 500 It has the advantage of more firmly securing the positional stability of

[3] Measurement method using automatic focal length adjustment Raman spectrometer of the present invention

The measurement method using the automatic focal length adjustment Raman spectrometer 100 of the present invention will be described in stages as follows. The measurement method using the automatic focal length adjustment Raman spectrometer 100 of the present invention includes a sample arrangement step, an intensity measurement step, and a signal determination step.

In the sample arrangement step, the sample 500 is disposed below the objective lens 130 . In an actual field, it will be an operation of pushing the SERS strip or substrate into the sample inlet 225 of the handheld small Raman spectrometer case 220 .

In the intensity measurement step, as the actuator 200 adjusts the relative distance between the sample 500 and the objective lens 130 , it is measured that the signal intensity of the light detected by the detector 150 changes.

In the signal determining step, a position at which the signal strength becomes the maximum is determined as a focal position, and a Raman spectrum signal at the focal position is selected as a measurement value. As described above, according to the principle of confocal microscopy that the signal intensity is the strongest when the surface of the sample 500 is precisely focused, when the signal intensity of the light detected by the detector 150 becomes the maximum value, the focus position It can be confirmed that the . That is, it is confirmed that the selected signal is a signal measured at the focal position, and accordingly, the accuracy and reliability of the measurement value are improved.

The present invention is not limited to the above-described embodiments, and the scope of application is varied, and anyone with ordinary knowledge in the field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims It goes without saying that various modifications are possible.

100: auto focus distance adjustment Raman spectrometer
110: light source 115: light source pinhole
115a: light source pinhole converging lens 115b: light source pinhole diverging lens
120: dichroic beam splitter 130: objective lens
140: light splitter 150: detector
155: detector pinhole 155a: detector pinhole converging lens
160: filter 170: light receiving lens
180: spectrometer
200: actuator 210: module
220: case 225: sample inlet
500: sample 550: base

Claims (11)

a light source 110 for irradiating laser light;
a light source pinhole 115 for making a point light source by passing the laser light irradiated from the light source 110;
a dichroic light splitter 120 formed to reflect the laser light irradiated from the light source 110 and make it incident toward the sample 500 or transmit the light scattered from the sample 500;
an objective lens 130 for condensing the light scattered by the dichroic light splitter 120 and irradiating it to the sample 500;
a light splitter 140 for changing an optical path by branching a portion of the light that is scattered from the sample 500 and has passed through the dichroic light splitter 120;
a detector pinhole 155 for passing the light branched through the light splitter 140;
a detector 150 for detecting the signal strength of the light passing through the detector pinhole 155;
a filter 160 that filters and transmits a component corresponding to a Raman shift among the light scattered from the sample 500 and transmitted through the dichroic light splitter 120;
a light receiving lens 170 for receiving the light transmitted through the filter 160 and entering the spectrometer 180;
a spectrometer 180 that receives the light transmitted through the filter 160 and measures a spectrum;
an actuator 200 for adjusting the relative distance between the sample 500 and the objective lens 130 along the optical axis direction;
Automatic focal length adjustment Raman spectrometer 100, characterized in that it comprises a.
According to claim 1, wherein the automatic focal length adjustment Raman spectrometer 100,
As the actuator 200 adjusts the relative distance between the sample 500 and the objective lens 130, the signal strength of the light detected by the detector 150 is changed.
An automatic focal length adjustment Raman spectrometer, characterized in that a position at which the signal strength becomes a maximum value is determined as a focal position, and a Raman spectrum signal at the focal position is selected as a measurement value.
According to claim 1, wherein the optical splitter 140,
Automatic focal length adjustment Raman spectrometer, characterized in that the distribution ratio is determined so that the amount of light that is branched from the splitter (140) to change the optical path is smaller than the amount of light transmitted to maintain the original optical path.
According to claim 1, wherein the automatic focal length adjustment Raman spectrometer 100,
The light source 110, the light source pinhole 115, the dichroic light splitter 120, the objective lens 130, the light splitter 140, the detector pinhole 155, the detector 150, the filter (160), the light-receiving lens 170, the spectrometer 180 is integrally formed module 210;
a case 220 accommodating the module 210 and the actuator 200 and having a sample inlet 225 through which the sample 500 can enter and exit on one side;
Automatic focal length adjustment Raman spectrometer comprising a.
According to claim 4, The actuator 200,
Automatic focal length adjustment Raman spectrometer, characterized in that formed to move the module (210) in the optical axis direction.
According to claim 1, wherein the actuator 200,
Automatic focal length adjustment Raman spectrometer, characterized in that it is formed to move the sample (500) in the optical axis direction.
According to claim 1, wherein the actuator 200,
Automatic focal length adjustment Raman spectrometer, characterized in that it is formed to move the objective lens 130 in the optical axis direction.
The method of claim 4, wherein the automatic focal length adjustment Raman spectrometer (100),
Automatic focal length adjustment Raman spectrometer, characterized in that it is for handheld use that can be carried and moved by the user.
According to claim 1, wherein the sample 500,
Automatic focal length adjustment Raman spectrometer, characterized in that applied on the SERS substrate or the base 550 in the form of a SERS strip.
According to claim 1, wherein the actuator 200,
An automatic focal length control Raman spectrometer, characterized in that it is implemented with at least one selected from a motorized stage, a piezoelectric actuator, and a voice coil motor (VCM).
In the measurement method using the automatic focal length adjustment Raman spectrometer 100 according to claim 1,
a sample arrangement step in which the sample 500 is disposed under the objective lens 130;
an intensity measuring step of measuring a change in signal intensity of light detected by the detector 150 as the actuator 200 adjusts the relative distance between the sample 500 and the objective lens 130;
a signal determination step of determining a position at which the signal strength becomes a maximum value as a focal position and selecting a Raman spectrum signal at the focal position as a measurement value;
A measurement method using an automatic focal length adjustment Raman spectrometer comprising a.

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