KR102442981B1 - Instant raman imaging apparatus - Google Patents

Abstract

A Raman imaging device according to an embodiment of the present invention includes: a monochromatic light source unit providing light of a single wavelength (λ0) to a target; a first imaging unit for reflecting and imaging light of a first wavelength (λ1) band from a Raman light provided from the target and transmitting light of a longer wavelength than the first wavelength band; and a third imaging unit for reflecting and imaging light of a second wavelength (λ2) band from light transmitted from the first imaging unit and transmitting light having a longer wavelength than the second wavelength band. An objective of the present invention is to provide the device capable of performing Raman imaging more quickly on a sample.

Description

Instantaneous Raman Imaging Apparatus {INSTANT RAMAN IMAGING APPARATUS}

The present technology relates to instantaneous Raman imaging devices.

When monochromatic light is incident on a sample, the light is scattered from the sample. Most of the scattered light has the same wavelength as the incident light, but some components of the scattered light have a different wavelength than the incident light. It was discovered by the Indian physicist Raman in 1928 and is called the Raman effect.

The Raman effect is because incident light is provided to the crystal structure of the sample, and the crystal structure is vibrated to form light having a wavelength different from that of the incident light and is provided as scattered light. Therefore, by illuminating a sample with monochromatic light and analyzing the scattered light for each wavelength, the crystal structure of materials included in the sample can be analyzed, which is called Raman spectroscopy.

Raman spectroscopy has the advantage of providing information on the structure of the target material rather than information on the constituent elements of the material to be measured, so that materials with different structures can be distinguished even from materials made of the same elements. As a monochromatic light source, high-quality solid-state lasers are readily available, and with the development of sensitive analyzers such as CCD, Raman spectroscopy is widely used in various fields such as basic academic fields as well as industrial fields.

From the presence or absence of a specific band in the spectrum obtained from Raman spectroscopy, the presence or absence of a corresponding material can be known. Therefore, by measuring Raman spectroscopy for each position, it is possible to know whether a specific substance is present at the corresponding position. Raman imaging is a technique that measures multiple locations while changing locations, and expresses the presence or absence of specific substances for each location.

The Raman imaging technique according to the prior art is performed by sequentially scanning various parts of a sample with a monochromatic light source to obtain a Raman spectral spectrum for each point, and drawing the intensity of a specific band of the Raman spectrum for each location of the sample.

However, according to the prior art, a large area of the sample is measured by providing a focused beam on a narrow area to the surface of the sample to be detected and scanning the beam to measure a large area of the sample. In particular, as in a semiconductor production line, when many samples are moved at a high speed, performing Raman imaging for each sample takes a long time, leading to a decrease in productivity as a result.

This embodiment is one of the problems to be solved to solve the above-described difficulties of the prior art. That is, one of the problems to be solved by this embodiment is to provide an apparatus capable of more rapidly performing Raman imaging on a sample.

The Raman imaging apparatus according to the present embodiment includes: a monochromatic light source unit providing light of a _single wavelength (λ ₀ ) to a target; A first imaging unit that transmits light having a wavelength longer than the first wavelength band, and the light transmitted by the first imaging unit reflects light of a second wavelength (λ ₂ ) band for imaging, and a wavelength longer than the second wavelength band and a third imaging unit that transmits the light.

According to any one aspect of the present embodiment, the monochromatic light source unit includes a monochromatic laser light source providing light of a single wavelength (λ ₀ ), a single wavelength (λ) of the scattered light formed in the target by reflecting light of a single wavelength and providing it to the target. ₀ ) includes a long pass filter that transmits Raman light having a longer wavelength.

According to one aspect of the present embodiment, the monochromatic light source unit further includes a collimator for collimating light of a single wavelength.

According to one aspect of the present embodiment, the long pass filter transmits light having a wavelength longer than a single wavelength (λ ₀ ), and reflects light having a wavelength shorter than or equal to the single wavelength (λ ₀ ).

According to one aspect of the present embodiment, the first imaging unit includes a first long-pass filter that reflects light of a first wavelength band and transmits light of a wavelength longer than the first wavelength band, and the reflected light of the first wavelength band. It includes a first band pass filter passing through (band pass filter) and an imaging device (imaging device) for imaging the light of the first wavelength band.

According to one aspect of the present embodiment, the second imaging unit includes a second long pass filter that reflects light of a second wavelength band and transmits light of a longer wavelength than the second wavelength band, and the reflected light of the second wavelength band. It includes a second band pass filter that transmits the light and an imaging device for imaging the light of the second wavelength band.

According to one aspect of the present embodiment, an optically acceptable imaging unit such as a third imaging unit, a fourth imaging unit, ... may be added in a similar manner.

According to one aspect of this embodiment, the single wavelength (λ0), the first wavelength (λ1), the second wavelength (λ2), ... the nth wavelength (λ _n ) is λ ₀ < λ ₁ < λ ₂ < · ··<λ _n to be.

Since the present embodiment uses a defocused beam, a collimated light, etc. as excitation light, an advantage is provided in that it is faster than the prior art using a scanning method. Furthermore, the present embodiment provides an advantage that a plurality of Raman images can be quickly obtained by simultaneously performing Raman imaging by connecting a plurality of imaging devices in a cascade.

1 is a diagram showing an outline of an instantaneous Raman imaging apparatus 10 according to the present embodiment.
2 is a diagram illustrating an outline of the monochromatic light source unit 100 .
3(a) is a diagram schematically illustrating a light path through which the monochromatic light source unit 100 provides excitation light to a target T, and FIG. 3(b) is a diagram schematically illustrating condensing Raman scattered light It is a drawing.
4 is a diagram illustrating an outline of the first imaging unit 200 and the second imaging unit 300 .

Since the description of the present invention is merely an embodiment for structural or functional description, the scope of the present invention should not be construed as being limited by the embodiment described in the text. That is, since the embodiment may have various changes and may have various forms, it should be understood that the scope of the present invention includes equivalents capable of realizing the technical idea.

On the other hand, the meaning of the terms described in the present application should be understood as follows.

The singular expression is to be understood as including the plural expression unless the context clearly dictates otherwise, and terms such as "comprises" or "have" refer to the specified feature, number, step, action, component, part or these It is to be understood that this is intended to indicate the existence of a combination, and does not preclude the possibility of the presence or addition of one or more other features or numbers, steps, operations, components, parts, or combinations thereof.

Each step may occur in a different order than the stated order unless the context clearly dictates a specific order. That is, each step may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

The drawings referenced to describe the embodiments of the present disclosure are intentionally exaggerated in size, height, thickness, and the like for convenience of description and ease of understanding, and are not enlarged or reduced according to proportions. In addition, certain components shown in the drawings may be intentionally reduced and expressed, and other components may be intentionally enlarged and expressed.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Terms such as those defined in commonly used dictionaries should be interpreted as being consistent with the meaning of the context of the related art, and cannot be interpreted as having an ideal or excessively formal meaning unless explicitly defined in the present application. .

Hereinafter, a Raman imaging apparatus according to the present embodiment will be described with reference to the accompanying drawings. 1 is a diagram showing an outline of a Raman imaging apparatus 10 according to the present embodiment. Referring to FIG. 1 , the Raman imaging apparatus 10 according to the present embodiment includes a monochromatic light source unit 100 that provides excitation light of a single wavelength λ ₀ to a target, and a Raman light provided from the target. The first imaging unit 200 reflects light of the first wavelength band (λ ₁ ) for imaging, and transmits light of a longer wavelength than the first wavelength band, and the light transmitted from the first imaging unit has a second wavelength ( λ ₂ ) and a second imaging unit 300 that reflects light in the band and transmits light having a longer wavelength than the second wavelength band.

2 is a diagram illustrating an outline of the monochromatic light source unit 100 . 3(a) is a diagram schematically illustrating a light path through which the monochromatic light source unit 100 provides excitation light to a target T, and FIG. 3(b) is a diagram schematically illustrating condensing Raman scattered light. It is a drawing. For easy understanding, in Fig. 3(a), the optical path due to the mirror reflection was straightened and expressed. Referring to FIGS. 2, 3A and 3B , the long pass filter 130 serves as a dichroic mirror for incident light.

The monochromatic light source unit 100 includes a monochromatic laser light source 110 providing excitation light of a single wavelength (λ ₀ ). For example, the light provided by the monochromatic laser light source 110 may be laser light in an infrared band, a visible light band, or an ultraviolet band.

In the embodiment illustrated in FIGS. 2 and 3 (a) and 3 (b), the light provided by the monochromatic laser light source 110 may provide the collimated light through the collimator 120 to the target T. have. The collimator 120 includes a first lens 122 and a second lens 124 according to an embodiment. The focal length of the first lens 122 is a focal length f0, and the focal length of the second lens 124 is f1. In one embodiment, when the distance d between the first lens 122 and the second lens 124 matches the focal length f0 of the first lens 122 and the focal length f1 of the second lens 124 The light provided to the target T is collimated and collimated light.

As another example, when the distance d between the first lens 122 and the second lens 124 does not match the focal length f0 of the first lens 122 and the focal length f1 of the second lens 124 , the target The light provided to (T) is a defocused beam.

As the single wavelength (λ ₀ ) light output from the monochromatic laser light source 110 is provided to the target T, the light scattered from the target T is a single wavelength (λ ₀ ) light and a single wavelength (λ ₀ ) light Contains Raman light of weaker intensity. The Raman light has a longer wavelength (λ ₁ , λ ₂ , λ ₃ , ...) component than the wavelength (λ ₀ ) of the light output from the monochromatic laser light source 110 . The wavelengths (λ ₁ , λ ₂ , λ ₃ , ...) of the light included in the Raman light may vary depending on the material and crystal structure of the target T. However, all of the Raman light components have a wavelength longer than the wavelength λ ₀ of the incident light provided to the target T.

As illustrated in FIG. 3( b ), the long-pass filter 130 reflects the light of the wavelength (λ ₀ ) of the excitation light output from the monochromatic laser light source 110, but has a wavelength longer than a single wavelength (λ ₀ +Δ) of light is transmitted. That is, the long pass filter 130 may be a filter or a mirror having a dichroic characer. Accordingly, the long pass filter 130 reflects the light of a single wavelength (λ ₀ ) output from the monochromatic laser light source 110 and provides it to the target T, and transmits the Raman light formed in the target T.

According to the embodiment of the monochromatic light source unit 100 illustrated in FIGS. 2, 3A and 3B , a defocused beam or collimated collimated light is provided to the target T. Therefore, compared to a case in which a focused beam is provided to a target in a conventional Raman spectrometer, an area to which a beam is provided is larger.

From this, analysis can be performed by providing excitation light with a larger area than that of the prior art to the target T, and performing Raman imaging with Raman light corresponding to desired Raman bands. Conventionally, several scanning processes are required depending on the surface area of the target T. However, according to the present embodiment, the analysis speed of Raman light increases because the area that can be analyzed at one time increases. Accordingly, the advantage of being able to improve productivity is provided.

4 is a diagram illustrating an outline of the first imaging unit 200 and the second imaging unit 300 . 1 to 4 , the first imaging unit 200 reflects light of a first wavelength band (λ ₁ ) and has a longer wavelength than the first wavelength band (λ ₁ ) (λ ₂ , λ ₃ , . ..) a first long pass filter 210 that transmits light, a first band pass filter 220 that transmits light of a reflected first wavelength (λ ₁ ) band, and a first wavelength band and an imaging device 230 for imaging the light of (λ ₁ ).

Similarly, the second imaging unit 300 reflects light of the second wavelength band (λ ₂ ) and transmits light of a longer wavelength (λ ₃ , ...) than the second wavelength band (λ ₂ ). The long-pass filter 310, the second band-pass filter 320 that transmits the reflected light of the second wavelength band (λ ₂ ), and an imaging device for imaging the light of the second wavelength band (λ ₂ ) , 330).

The first band pass filter 220 and the second band pass filter 320 provide a first wavelength band (λ ₁ ) provided by the first long pass filter 210 and the second long pass filter 310 reflecting, respectively, respectively. of light and the light of the second wavelength band (λ ₂ ) are provided. Each band-pass filter selectively transmits only light in a band to be detected, thereby blocking noise and unwanted light in an adjacent band.

The first imaging device 230 and the second imaging device 330 receive the light of the first wavelength band λ ₁ filtered by the first band pass filter 220 and the second band pass filter 320, respectively. and light of the second wavelength band (λ ₂ ) is provided to perform imaging.

Each of the first imaging device 230 and the second imaging device 330 may include an imaging device such as a charge coupled device (CCD) or a CMOS image sensor (CIS). In addition, according to an embodiment not shown, the first imaging device and the second imaging device each have a lens unit (Lens_n) that performs optical processing such as condensing and spectroscopy of the light provided by the first and second band-pass filters. , focal length f_n) may be further included.

The size of the Raman image in the imaging device is the focal length f1 of the second lens 124, the focal length f_n of the lens unit, the distance between the second lens 124 and the target T, the distance between the lens unit and the imaging device, and the distance between the lenses. is determined by the distance of Therefore, by controlling these parameters, the size of the Raman image can be controlled.

According to this embodiment, if the wavelength bands (λ ₁ , λ ₂ , λ ₃ , ...) of the Raman scattered light imaged by each imaging unit are adjusted to correspond to the target to be detected, the target detection target can be easily and quickly detected. can do.

The image captured by the imaging device 230 included in the first imaging unit 200 is an image of a material corresponding to a Raman shift corresponding to 1/λ ₀ - 1/λ ₁ , and the second imaging unit The image taken by the imaging device 330 included in 300 is an image of a material corresponding to a Raman shift corresponding to 1/λ ₀ - 1/λ ₂ .

As an example, copper oxide CuO has a Raman band at 282 cm ⁻¹ , so if the λ ₁ value for λ ₀ is controlled to be 1/λ ₀ − 1/λ ₁ = 282 cm ⁻¹ , the imaging device may determine the distribution of CuO You can take an image. Similarly, poly methyl methacrylate (PMMA) has a Raman band at 2930 cm ^-1 , so if the λ ₂ value for λ ₀ is selected to be 1/λ ₀ - 1/λ ₂ = 2930 cm ^-1 , the imaging device is Distribution images of PMMA residues can be taken.

1 to 3 , the Raman light transmitted from the monochromatic light source unit 100 is provided to the first imaging unit 200 and the second imaging unit 300 connected in a cascade for imaging. However, this is only an example, and a plurality of imaging units (not shown) that image light of a longer wavelength (λ ₃ , ...) than the second wavelength band (λ ₂ ) transmitted from the second imaging unit 300 . may be connected to the second imaging unit 300 in a cascade.

The present embodiment provides the advantage that Raman images of a plurality of desired bands can be simultaneously and quickly obtained through a plurality of imaging devices connected in a cascade, thereby improving productivity.

Although it has been described with reference to the embodiment shown in the drawings in order to help the understanding of the present invention, this is an embodiment for implementation, it is merely an example, and various modifications and equivalents from those of ordinary skill in the art It will be appreciated that other embodiments are possible. Accordingly, the true technical protection scope of the present invention should be defined by the appended claims.

10: Raman imaging device 100: Monochromatic light source unit
110: monochromatic laser light source 120: collimator
122: first lens 124: second lens
130: long pass filter 200: first imaging unit
210: first long-pass filter 220: first band-pass filter
230: first imaging element 300: second imaging unit
310: second long-pass filter 320: second band-pass filter
330: second imaging element T: target
λ ₀ : excitation light λ _{1 :} first wavelength
λ _{2 :} second wavelength λ _{3 :} third wavelength

Claims (7)

a monochromatic light source providing excitation light of a single wavelength (λ 0 ) to the target;
a first imaging unit reflecting and imaging Raman light of a first wavelength (λ1) band from Raman light provided from a target, and transmitting light of a longer wavelength than the first wavelength band;
a second imaging unit reflecting and imaging Raman light of a second wavelength (λ2) band from the light transmitted by the first imaging unit, and transmitting Raman light of a longer wavelength than the second wavelength band;
The target is exposed to the monochromatic light source,
The Raman light of the first wavelength (λ1) band and the Raman light of the second wavelength (λ2) band are Raman scattered light formed by providing the excitation light to the target,
The wavelength of the Raman light of the first wavelength (λ1) band and the wavelength of the Raman light of the second wavelength (λ2) band are longer than the wavelength of the excitation light. According to claim 1,
The monochromatic light source unit,
a monochromatic laser light source providing excitation light of the single wavelength;
and a long pass filter that reflects the excitation light of the single wavelength to provide it to the target, and transmits Raman light from the scattered light formed in the target. 3. The method of claim 2,
The monochromatic light source unit,
The Raman imaging apparatus further comprising a collimator (collimator) for collimating the excitation light of the single wavelength. 3. The method of claim 2,
The long pass filter,
A Raman imaging apparatus that transmits light having a longer wavelength than the single wavelength λ 0 and reflects light having a wavelength shorter than or equal to the single wavelength λ 0 . According to claim 1,
The first imaging unit,
a first long-pass filter that reflects Raman light of the first wavelength band and transmits light of a longer wavelength than the first wavelength band;
a first band pass filter that transmits the reflected Raman light of the first wavelength band; and
and an imaging device for imaging the Raman light of the first wavelength band. According to claim 1,
The second imaging unit,
a second long-pass filter that reflects Raman light of the second wavelength band and transmits light of a longer wavelength than the second wavelength band;
a second band pass filter that transmits the reflected Raman light of the second wavelength band; and
and an imaging device for imaging the light of the second wavelength band. According to claim 1,
The single wavelength (λ ₀ ), the first wavelength (λ ₁ ) and the second wavelength (λ ₂ ) are
λ ₀ < λ ₁ < λ ₂ In-Raman imaging device.

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