KR20110077598A - Interference system and detecting system of using partial reflect - Google Patents

Abstract

PURPOSE: An interference system and a measurement system using partial reflection are provided to measure the phase change of light regardless of the interference length of the light by successively arranging route interference units. CONSTITUTION: An interference system using partial reflection comprises a light source unit(10), a first route interference unit(20), and a second route interference unit(30). The light source generates light. The first route interference unit emits light by partially reflecting the generated light. The emitted light is inputted to the second route interference unit. The second route interference unit emits light by partially reflecting the inputted light.

Description

Interference system and measurement system using partial reflection {INTERFERENCE SYSTEM AND DETECTING SYSTEM OF USING PARTIAL REFLECT}

The present invention relates to an interference system and a measurement system using partial reflection, and more particularly, to measure a phase change of light irrespective of an interference length of light by sequentially arranging path interferers that partially reflect a part of light to delay a part of the light. The present invention relates to an interference system and a measurement system using partial reflection.

In recent years, not only the sample but also the minute change of the sample can be measured using the phase change of light. Accordingly, a phase microscope capable of measuring the phase change of light and imaging even minute changes in the surface of a biosample or material is currently being developed.

These phase microscopes include a phase contrast microscope, a differential interference contrast microscope, and the like, but all have disadvantages of not obtaining quantitative phase measurements. In addition, technologies such as phase shifting interferometry, digital holography, and the like have excellent phase stability, but it is impossible to measure phase change with sample depth.

In order to overcome these limitations, a method of measuring phase using optical coherence tomography (OCT) has recently been attempted. The optical coherence tomography technique is a technique capable of non-invasive real-time imaging of the interior as well as the surface of the biosample or material.

In particular, with the development of related technologies, such as the technique of varying the wavelength, it is possible to acquire data at a repetition rate of several hundred kHz per second. In the past, imaging was performed using the size information of the interference signal, and the resolution is determined by the bandwidth of the light source used, and usually has a resolution of about 10 micrometers.

Common-path interferometers are commonly used to measure phase stably when using optical coherence tomography techniques. Because the common path interferometer moves the reference signal and the sample signal through a common path, the phase noise of the two signals is changed in common, so that even nanometer-level changes can be measured.

However, there is a problem in that there is a part generating a reference signal between the objective lens and the sample to be measured due to the characteristics of the common path interferometer. In addition, when a high magnification objective lens is used, it is difficult to locate a part generating the reference signal due to a short focal length, which causes a problem that a low magnification objective lens should be used.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the present invention uses a high magnification objective lens by sequentially arranging path interferers that reflect a part of input light that can be provided, and measuring a phase change of light regardless of the interference length of the light. To provide an interference system using partial reflection that can implement a high resolution.

The present invention has been made in view of the above problems, and the present invention provides a measurement system using partial reflection capable of measuring a sample using the interference system.

An interference system according to embodiments of the present invention includes a light source unit for generating light, a first path interference unit for partially reflecting a part of light generated from the light source unit, and emitting light including light delayed by a first delay time; A second path configured to receive light emitted from the first path interferer and partially reflect some of the input light to emit light including light delayed by the first delay time and light delayed by a second delay time It includes an interference portion.

In embodiments of the present invention, the light source may emit light by periodically changing the wavelength by scanning the wavelength of the light.

The difference between the first delay time and the second delay time is set to be smaller than the coherence time of the light source unit.

In example embodiments, the first path interference part may pass through the first partial reflection layer for reflecting some of the light generated from the light source unit, and the unreflected light from the first partial reflection layer to enter the sample. It includes a first objective lens for. In addition, the second path interference part may include a second partial reflection film reflecting some of the light emitted from the first path interference part, and a reflection film for reflecting light not reflected by the second partial reflection film.

Here, the first partial reflective film is disposed to be spaced apart from the sample by a first distance so that the light emitted from the first path interference part has the first delay time. In addition, the second partial reflective film is disposed to be spaced apart from the reflective film by a second distance so that the light emitted from the second path interference part has the second delay time. In this case, the difference between the first distance and the second distance is set to be smaller than the coherence length of the light source unit.

The measurement system according to the embodiments of the present invention includes a light source unit generating light, and partially reflecting a portion of the light generated from the light source unit before being incident on a sample, thereby emitting a light including light delayed by a first delay time. A path interfering unit receives light emitted from the first path interfering unit, partially reflects some of the input light, and emits light including light delayed by the first delay time and light delayed by a second delay time. A second path interferer, and a detector configured to sense light emitted from the second path interferer.

In embodiments of the present invention, the difference between the first delay time and the second delay time is set to be smaller than the coherence time of the light source unit.

In example embodiments, the detector may include a spectrometer for sensing light emitted from the second path interferer and measuring a phase change of the lights.

In embodiments of the present disclosure, the system may further include a variable filter disposed between the light source unit and the first path interference unit and periodically scanning a wavelength of light generated from the light source unit and varying the wavelength. . Alternatively, the system may further include a variable filter disposed between the second path interferer and the detector and configured to periodically scan a wavelength of light emitted from the second path interferer and to vary the wavelength.

In embodiments of the present invention, the system is located between the light source unit and the first path interferer to transfer light generated from the light source unit to the first path interferer and to be emitted from the first path interferer. A first circulator for transmitting the second path interferer to the second path interferer, and the light received from the first circulator between the first circulator and the second path interferer to receive the second path interference. The apparatus may further include a second circulator for transmitting to the detector and transmitting the light emitted from the second path interferer to the detector.

According to another aspect of the present invention, a measurement system includes a light source unit emitting light including light delayed by a predetermined delay time, partially reflecting some of the light emitted from the light source unit, and incident the rest of the light into a sample. And a path interferer configured to emit light including light delayed by a time equal to a delay time from the light source unit, and a detector configured to sense light emitted from the path interferer.

In embodiments of the present invention, the delay time is set to be smaller than the coherence time of the light source unit.

In embodiments of the present invention, the light source unit generates a light source for generating light, a first partial reflective film for reflecting a portion of the light generated from the light source, and the light that is not reflected by the first partial reflective film by the delay time. And a reflecting film for delayed reflection. The first partial reflecting film is spaced apart from the reflecting film by a predetermined distance such that the light reflected by the reflecting film is delayed by the set delay time than the light reflected by the first partial reflecting film.

According to the interference system and the measurement system using the partial reflection according to the present invention as described above has the following advantages.

First, by partially reflecting a part of the light generated from the light source unit using the partial reflection film, light delayed by a set delay time can be realized.

Second, by sequentially arranging path interferers using partial reflection, it is possible to measure the phase change of light regardless of the interference length of the light.

Third, by generating a light interference phenomenon by sequentially arranging path interferers using partial reflection, a separate signal generator for generating a reference signal between the objective lens and the sample may be removed.

Fourth, by implementing a light source unit that delays a part of the light by using partial reflection, the sample can be measured in high resolution using a high magnification objective lens.

Fifth, by adjusting the position of the partial reflecting film which partially reflects a part of the light, the interference length of the light can be controlled simply and efficiently.

Sixth, by placing the variable filter for changing the wavelength of the light in front of the sensing unit, it is possible to measure the sample using a relatively high light energy.

Seventh, by using a spectrometer to measure the phase change of light, the error of the phase value of the light can be reduced.

An interference system and a measurement system using partial reflection according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. As the inventive concept allows for various changes and numerous modifications, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structure is shown to be larger than the actual size for clarity of the invention, or to reduce the actual size to understand the schematic configuration.

In addition, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. On the other hand, 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. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 is a block diagram illustrating a measurement system using partial reflection according to embodiments of the present invention.

Referring to FIG. 1, a measurement system 1a (hereinafter referred to as “the present system”) according to an exemplary embodiment of the present invention is a system for measuring sample information such as a state of a sample, a change, etc. using an interference system using partial reflection. to be.

The system 1a includes a light source unit 10, a first path interferer 20, a second path interferer 30, and a detector 40.

The light source unit 10 generates light. For example, the light source unit 10 includes a light emitting diode (LED) and a super luminescent diode (SLD). In contrast, the light source unit 10 may be formed of various elements capable of generating light.

On the other hand, the light source unit 10 may emit light by periodically changing the wavelength by scanning the wavelength of the light. Accordingly, the light source unit 10 may include a variable filter 70. Alternatively, the light source unit 10 may perform the same function as that of the variable filter 70 by itself.

The first path interference unit 20 receives the light generated by the light source unit 10 through the first circulator 50. The first circulator 50 has three ports, receives light from the light source unit 10 through one port, and transmits the light to the first path interferer 20 using another port. The light reflected by the first path interferer 20 is emitted to the second path interferer 30 using another port.

)만큼 지연시켜 방출한다. The first path interferer 20 partially reflects a part of the input light, and transmits the remaining non-reflected light to the first delay time (

Delay by) to release.

To this end, the first path interference part 20 includes a first partial reflection film 21, a first objective lens 22, and a sample part 23.

)를 반사시킨다. 예를 들어, 제1 부분 반사막(21)은 광섬유의 끝단에 위치한다. 이에 공기를 통과한 광이 제1 경로 간섭부(20)의 제1 부분 반사막(21)에 도달한 경우, 광의 일부(

)가 공기와 광섬유의 굴절률의 차이에 의하여 반사된다. The first partial reflective film 21 may include a portion of the light generated from the light source unit 10 (

B). For example, the first partial reflective film 21 is located at the end of the optical fiber. When the light passing through the air reaches the first partial reflective film 21 of the first path interference part 20, a part of the light (

) Is reflected by the difference in refractive index between air and the optical fiber.

The first objective lens 22 transmits the light passing through the first partial reflection film 21 without being reflected by the first partial reflection film 21. At this time, the magnification of the first objective lens 22 is determined according to its size. For example, as the length of the first objective lens 22 increases, the magnification increases. In the embodiments of the present invention, the first objective lens 22 is made of a relatively high magnification objective lens.

The sample unit 23 includes a sample to be measured. The sample unit 23 is positioned on the focal point of the first objective lens 22. In the embodiments of the present invention, the light passing through the first objective lens 22 is incident on the sample unit 23 and reflects the light.

)를 샘플부(23)에 입사되기 전에 반사시킨다. 이에 샘플부(23)에서 반사된 광(

)은 제1 부분 반사막(21)에서 반사된 광(

)보다 제1 지연시간(

)만큼 지연된다. 즉, 샘플부(23)에서 반사된 광(

)은 제1 부분 반사막(21)과 샘플부(23)의 이격 거리의 두 배에 해당하는 만큼의 경로를 더 진행되므로, 상기 경로 차이에 의하여 제1 부분 반사막(21)에서 반사된 광(

)보다 제1 지연시간(

)만큼 지연된다. As such, the first path interference part 20 may use a portion of light input by using the first partial reflection film 21.

) Is reflected before being incident on the sample part 23. Accordingly, the light reflected from the sample unit 23 (

) Is the light reflected from the first partial reflecting film 21

First delay time

Delay). That is, the light reflected from the sample unit 23 (

) Further travels a path corresponding to twice the separation distance between the first partial reflecting film 21 and the sample part 23, and thus, the light reflected from the first partial reflecting film 21 by the path difference (

First delay time

Delay).

)이 제1 지연시간(

)을 갖도록 샘플부(23)로부터 제1 거리만큼 이격되도록 배치될 수 있다. In addition, the first partial reflective film 21 may reflect light reflected from the sample unit 23.

) Is the first delay time (

) May be spaced apart from the sample unit 23 by a first distance.

)은 제1 부분 반사막(21)과 샘플부(23)의 이격 거 리에 의하여 결정된다. 본 발명의 실시예들에 있어서, 고배율의 제1 대물렌즈(22)를 사용함으로써, 제1 지연시간(

)은 광원부(10)의 가간섭시간(coherence time)보다 크다. 따라서 샘플부(23)에서 반사된 광(

)과 제1 부분 반사막(21)에서 반사된 광(

)은 서로 간섭을 일으키지 않는다.At this time, the first delay time (

) Is determined by the separation distance between the first partial reflecting film 21 and the sample part 23. In embodiments of the present invention, by using the high magnification of the first objective lens 22, the first delay time (

) Is greater than the coherence time of the light source unit 10. Therefore, the light reflected from the sample unit 23 (

) And the light reflected from the first partial reflecting film 21

) Do not interfere with each other.

,

)은 제1 서큘레이터(50)를 통하여 제2 경로 간섭부(30)로 전달된다. Subsequently, the light reflected by the first path interferer 20 (

,

) Is transmitted to the second path interferer 30 through the first circulator 50.

,

)을 제2 서큘레이터(60)를 통하여 전달받는다. 제2 서큘레이터(60)는 제1 서큘레이터(50)와 마찬가지로 3 개의 포트를 구비한다. 예를 들어, 제2 서큘레이터(60)는 하나의 포트를 통하여 제1 경로 간섭부(20)로부터 광을 입력받고, 다른 포트를 이용하여 광을 제2 경로 간섭부(30)로 전달하며, 또 다른 포트를 이용하여 제2 경로 간섭부(30)에서 반사된 광을 감지부(40)로 방출한다.The second path interferer 30 may reflect light reflected from the first path interferer 20.

,

) Is received through the second circulator 60. The second circulator 60 has three ports similarly to the first circulator 50. For example, the second circulator 60 receives light from the first path interferer 20 through one port and transmits light to the second path interferer 30 using another port. Another port is used to emit the light reflected from the second path interferer 30 to the detector 40.

)만큼 지연시켜 방출한다. The second path interferer 30 partially reflects some of the lights received from the first path interferer 20, and the second path interferer 30 provides a second delay time (

Delay by) to release.

To this end, the second path interference part 30 includes a second partial reflective film 31, a second objective lens 32, and a reflective film 33.

)를 반사시킨다. 예를 들어, 제2 부분 반사막(31)은 제1 부분 반사막(21)과 실질적으로 동일하다고 할 수 있다. 즉, 제2 경로 간섭부(30)에 입력된 광의 일부(

)가 굴절률의 차이에 의하여 반사된다. The second partial reflecting film 31 may include some of the input light.

B). For example, the second partial reflective film 31 may be said to be substantially the same as the first partial reflective film 21. That is, part of the light input to the second path interferer 30 (

) Is reflected by the difference in refractive index.

The second objective lens 32 transmits the light passing through the second partial reflection film 31 without being reflected by the second partial reflection film 31. Here, the second objective lens 32 is substantially the same as the first objective lens 22. However, since the second objective lens 32 is not intended to focus on the sample to be measured, it will not necessarily be provided. Accordingly, the second path interferer 30 may be configured to exclude the second objective lens 32.

)을 반사시킨다. 본 발명의 실시예들에 있어서, 제2 부분 반사막(31)과 반사막(33)은 제2 거리만큼 이격되어 배치된다. 예를 들어, 상기 제2 거리는 반사막(33)에서 반사된 광(

)이 제2 부분 반사막(31)에서 반사된 광(

)보다 제2 지연시간(

)만큼 지연되도록 설정된다. The reflecting film 33 is light that is not reflected by the second partial reflecting film 31.

B). In embodiments of the present invention, the second partial reflective film 31 and the reflective film 33 are spaced apart by a second distance. For example, the second distance is the light reflected from the reflective film 33

Light reflected by the second partial reflection film 31

Second delay time

It is set to delay by).

)를 부분 반사시킨다. 이에 반사막(33)에서 반사된 광(

)은 제2 부분 반사막(31)에서 반사된 광(

)보다 제2 지연시간(

)만큼 지연된다. 즉, 반사막(33)에서 반사된 광(

)은 제2 부분 반사막(31)과 반사막(33)의 이격 거리인 제2 거리의 두 배에 해당하는 만큼의 경로를 더 진행한다. 따라서 상기 경로 차이에 의하여 반사막(33)에서 반사된 광(

)은 제2 부분 반사막(31)에서 반사된 광(

)보다 제2 지연시간(

)만큼 지연된다. As such, the second path interferer 30 may use a portion of light input by using the second partial reflection film 31 (

) Partially reflects. Accordingly, the light reflected from the reflective film 33

) Is the light reflected from the second partial reflecting film 31

Second delay time

Delay). That is, the light reflected from the reflective film 33

) Further travels a path corresponding to twice the second distance, which is a separation distance between the second partial reflection film 31 and the reflection film 33. Therefore, the light reflected from the reflective film 33 by the path difference (

) Is the light reflected from the second partial reflecting film 31

Second delay time

Delay).

The detector 40 detects light emitted from the second path interferer 30. Accordingly, the sensing unit 40 may obtain information of a sample by using the phase change of the detected light.

The electrical signal of the lights detected by the detector 40 will be described in detail.

,

)의 전기적 신호는 아래의 수학식 1에 의해서 정의될 수 있다. First, the light emitted from the first path interferer 20 (

,

) Can be defined by Equation 1 below.

은 제1 경로 간섭부(20)에서 방출되는 광들(

,

)의 전기적 신호의 합이고, 첫 번째 항은 제1 부분 반사막(21)에서 반사된 광(

)의 전기적 신호이며, 두 번째 항은 샘플부(23)로부터 반사된 광(

)의 전기적 신호이다.In Equation 1,

Is light emitted from the first path interferer 20 (

,

Is the sum of the electrical signals, and the first term is the light (reflected by the first partial reflection film 21).

) Is the electrical signal, and the second term is the light (reflected from the sample section 23).

) Is an electrical signal.

,

)의 전기적 신호는 아래의 수학식 2에 의해서 정의될 수 있다. Meanwhile, the light emitted from the second path interferer 20 (

,

) Can be defined by Equation 2 below.

는 제2 경로 간섭부(30)에서 방출되는 광들(

,

)의 전기적 신호의 합이고, 첫 번째 항은 제1 부분 반사막(21)과 제2 부분 반사막(31)에서 반사된 광의 전기적 신호이고, 두 번째 항은 샘플부(23)와 제2 부분 반사막(31)에서 반사된 광의 전기적 신호이고, 세 번째 항은 제1 부분 반사막(21)과 반사 막(33)에서 반사된 광의 전기적 신호이며, 네 번째 항은 샘플부(23)와 반사막(33)에서 반사된 광의 전기적 신호이다. In Equation 2,

Is the light emitted from the second path interferer 30 (

,

The first term is the electrical signal of the light reflected from the first partial reflecting film 21 and the second partial reflecting film 31, and the second term is the sample part 23 and the second partial reflecting film ( 31 is an electrical signal of the light reflected from the third term, the third term is an electrical signal of the light reflected from the first partial reflecting film 21 and the reflecting film 33, and the fourth term is the reflecting film 33 of the sample section 23 and the reflecting film 33 It is an electrical signal of reflected light.

)과 제2 지연시간(

)의 시간 차이가 광원부(10)의 가간섭시간(coherence time)보다 작은 경우 감지부(40)가 간섭무늬를 관찰할 수 있다. Therefore, the first and fourth terms in the electrical signal of the light detected by the detector 40 are irrelevant to the interference phenomenon, and the second and third terms are terms in which the interference phenomenon may occur. That is, the term where the interference may occur is the sum of the second term and the third term, and the first delay time (

) And second delay time (

If the time difference is less than the coherence time of the light source unit 10, the detector 40 may observe the interference fringe.

)과 제2 지연시간(

)의 차이를 광원부(10)의 가간섭시간보다 작게 설정된다. 또한, 제1 지연시간(

)은 제1 부분 반사막(21)과 샘플부(23) 사이의 이격 거리인 제1 거리에 의하여 결정되고, 제2 지연시간(

)은 제2 부분 반사막(31)과 반사막(33) 사이의 이격 거리인 제2 거리에 의하여 결정된다. 이에 본 발명의 실시예들에 있어서, 상기 제1 거리와 제2 거리의 차이도 광원부(10)의 가간섭거리(coherence length)보다 작게 설정된다. Therefore, in embodiments of the present invention, the first delay time (

) And second delay time (

) Is set smaller than the interference time of the light source unit 10. In addition, the first delay time (

) Is determined by a first distance, which is a separation distance between the first partial reflective film 21 and the sample part 23, and a second delay time (

) Is determined by a second distance, which is a separation distance between the second partial reflective film 31 and the reflective film 33. Thus, in embodiments of the present invention, the difference between the first distance and the second distance is also set smaller than the coherence length of the light source unit 10.

)과 제2 지연시간(

)의 차이가 광원부(10)의 가간섭시간보다 작은 경우, 감지부(40)는 간섭무늬를 관찰하여 샘플 표면의 형상과 형상의 변화 등 샘플의 정보를 획득할 수 있다. 이에 제1 대물렌즈(22)가 고배율로 이루어진 경우, 제1 경로 간섭부(20) 및 제2 경로 간섭부(30)의 부분 반사를 통하여 나노미터(㎚) 급의 해상도를 갖는 위상 현미경 등의 측정 시스템을 구현할 수 있다. As such, the first delay time through the partial reflection (

) And second delay time (

) Is smaller than the interference time of the light source unit 10, the sensing unit 40 may acquire the information of the sample such as the shape of the sample surface and the change in shape by observing the interference fringe. Accordingly, when the first objective lens 22 has a high magnification, such as a phase microscope having a nanometer (nm) resolution through partial reflection of the first path interference part 20 and the second path interference part 30. A measurement system can be implemented.

Meanwhile, the first path interferer 20 may further include a first collimator 24 for maintaining the parallelism of the light generated by the light source 10. When the light source unit 10 is a point light source, the first collimator 24 adjusts the light to progress horizontally and transmits the light to the first path interference unit 20.

In addition, the second path interferer 30 may further include a second collimator 34 for maintaining parallelism of light input from the first path interferer 20.

In addition, the system 1a may further include a variable filter 70 disposed between the light source unit 10 and the first path interference unit 20. The variable filter 70 periodically scans the wavelength of the light generated from the light source unit 10 and varies the wavelength. Accordingly, the measurement system by the variable filter 70 may obtain a phase value in the frequency domain rather than the time domain.

2 is a block diagram illustrating a measurement system using partial reflection according to another embodiment of the present invention. The measurement system using the partial reflection according to other embodiments of the present invention differs only in the position of the variable filter and the measurement system described with reference to FIG. 1 and the remaining components are substantially the same. Therefore, detailed description of the other components except the variable filter will be omitted.

Referring to FIG. 2, the measurement system 1b using the partial reflection according to other embodiments of the present invention includes a variable filter 75 disposed between the second circulator 60 and the sensing unit 40. do.

In general, since the power of the light incident on the variable filter is limited to about 10 kW, the light source unit 10 limits the power of the light to a predetermined value or less by the variable filter 70 located at the rear end of the light source unit 10 in FIG. Should be generated.

However, the variable filter 75 of another embodiment of the present invention is located in front of the sensing unit 40. Accordingly, since the light generated from the light source unit 10 passes through the first path interference unit 20 and the second path interference unit 30 and then enters the variable filter 75, the light source unit 10 is compared with the case of FIG. 1. ) May generate light having a relatively high power.

3 is a block diagram illustrating a measurement system using partial reflection according to still another embodiment of the present invention. The measurement system using the partial reflection according to still another embodiment of the present invention is substantially the same as the measurement system described with reference to FIGS. 1 and 2 except for the sensing unit and the variable filter. Therefore, detailed description of other components except for the detector and the variable filter will be omitted.

Referring to FIG. 3, a spectrometer for measuring light emitted from the second path interferer 30 without using a variable filter according to another exemplary embodiment of the present invention may include a variable filter. (45, spectrometer).

In general, when Fourier transforming from the time domain to the frequency domain by the operation of the variable filter in an interference system having a variable filter, nonlinearity may occur and an error in the phase value may occur.

In still other embodiments of the invention, the spectrometer 45 includes a prism and a CD camera. The spectrometer 45 detects the phase value of the light by the wavelength band by dividing the light by the wavelength band by using the prism.

Therefore, by detecting the phase value of the light through the spectrometer 45, the system 1c can reduce the error of the detected phase value, the amount of light, etc. and obtain a relatively accurate value.

4 is a configuration diagram illustrating a light source unit for delaying a part of light emitted by using partial reflection according to embodiments of the present disclosure.

Referring to FIG. 4, the light source unit 80 according to embodiments of the present invention partially reflects a part of the light emitted from the light source 81, and emits the remaining non-reflected light by a predetermined delay time.

To this end, the light source unit 80 includes a light source 81, a third circulator 82, a third partial reflective film 83, a reflector 84, a connector 85, and a third collimator 86.

The light source 81 generates light. For example, the light source 81 includes a super luminescent diode (SLD).

The third circulator 82 transmits dispersion of the input light. For example, the third circulator 82 transmits the light generated from the light source 81 to the third partial reflecting film 83. In addition, the third circulator 82 emits light reflected from the third partial reflecting film 83 or the reflecting mirror 84 to the outside through the connector 85.

The third partial reflection film 83 reflects a part of the light received from the third circulator 82.

The reflector 84 reflects the light passing through the third partial reflection film 83 without being reflected by the third partial reflection film 83.

Therefore, the light reflected by the reflector 84 and the light reflected by the third partial reflector 83 are delayed by the delay time by the path difference.

The connector 85 emits light received from the third circulator 82 to the outside.

The third collimator 86 is disposed between the third circulator 82 and the third partial reflecting film 83. The third collimator 86 adjusts the incident light to proceed horizontally and transmits the light to the outside. Accordingly, the third collimator 86 adjusts the light transmitted from the third circulator 82 to have parallelism, and transmits the light to the third partial reflective film 83 and the reflector 84.

In addition, the light source unit 80 may further include a variable filter 87a for periodically scanning the light and varying the wavelength of the light.

As such, the light source unit 80 partially reflects a part of the light generated from the light source 81 to emit the light including the light delayed by the set delay time to the outside. In particular, the light source unit 80 may vary the delay time by adjusting the separation distance between the third partial reflecting film 83 and the reflecting mirror 84.

Accordingly, the light source unit 80 emits light having the interference time of the light source 81 by the delay time. In other words, the light source unit 80 emits light having the interference length (distance) of the light source 81 by the separation distance between the third partial reflecting film 83 and the reflecting mirror 84.

5 and 6 are configuration diagrams for describing embodiments of the measurement system using the light source unit of FIG. 4.

Referring to FIG. 5, a measurement system according to an exemplary embodiment of the present invention includes a light source unit 80, a fourth partial reflective film 92, a third objective lens 94, a sample unit 96, and a detector 98. do.

)를 부분 반사시킨다.The fourth partial reflective film 92 receives the light emitted from the light source 80 through the fourth circulator 90, and a portion of the received light (

) Partially reflects.

The third objective lens 94 transmits the light passing through the fourth partial reflection film 92 without being reflected. For example, the third objective lens 94 may be formed of a relatively high magnification objective lens.

)은 샘플부(96)에서 반사된다. The sample unit 96 is positioned on the focal point of the third objective lens 94. Light passing through the third objective lens 94

) Is reflected by the sample unit 96.

In example embodiments, the fourth partial reflective film 92 and the sample part 96 may be spaced apart from each other by an interference length of the light source part 80. That is, the separation distance between the fourth partial reflection film 92 and the sample unit 96 is substantially the same as the separation distance between the third partial reflection film 83 and the reflector 84.

)과 샘플부(96)에서 반사되는 광(

)은 광원부(80)에서 방출되는 광들과 동일한 지연시간을 가지면서 진행한다. Therefore, the light reflected from the fourth partial reflection film 92 (

) And the light reflected from the sample section 96 (

) Proceeds with the same delay time as the light emitted from the light source 80.

)과 샘플부(96)에서 반사되는 광(

)을 입력받는다. 그리고 감지부(98)는 입력된 광들의 위상 차이 값 등을 측정하여 샘플부(96)에 대한 다양한 정보를 획득 할 수 있다. The detector 98 may reflect light reflected from the fourth partial reflection film 92 through the fourth circulator 90.

) And the light reflected from the sample section 96 (

) Is inputted. In addition, the detector 98 may obtain various information about the sample unit 96 by measuring a phase difference value of the input lights.

As described above, the light source unit 80 is adjusted by adjusting the separation distance between the third partial reflection film 83 and the reflector 84 of the light source unit 80 and the separation distance between the sample unit 96 and the fourth partial reflection film 92. The delay time of the light emitted from the may be applied to the sample unit 96 so that the detector 98 may observe the interference fringe.

Therefore, by generating an interference phenomenon in the light source unit 80 to emit light and applying it as it is to the sample unit, the measurement system may include a high magnification third objective lens 94. Furthermore, by using the high magnification third objective lens 94, it is possible to implement a measurement system having a resolution of several nanometers (nm) as a whole.

Referring to FIG. 6, the variable filter 87b is not disposed at the rear end of the light source 81, but is disposed at the front end of the detector 98. This is because, as mentioned with reference to FIG. 2, the variable filter 87b is disposed in front of the sensing unit 98, so that light is incident on the variable filter 87b after passing through components for implementing path interference. . Therefore, the light source 81 can generate light having a relatively high power.

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

1 is a block diagram illustrating a measurement system using partial reflection according to embodiments of the present invention.

2 is a block diagram illustrating a measurement system using partial reflection according to another embodiment of the present invention.

3 is a block diagram illustrating a measurement system using partial reflection according to still another embodiment of the present invention.

4 is a configuration diagram illustrating a light source unit for delaying a part of light emitted by using partial reflection according to embodiments of the present disclosure.

5 and 6 are configuration diagrams for describing embodiments of the measurement system using the light source unit of FIG. 4.

<Description of the symbols for the main parts of the drawings>

1a, 1b, 1c: measuring system

10: light source unit 20: first path interference unit

21: first partial reflecting film 22: first objective lens

30: second path interference part 31: second partial reflection film

32: second objective lens 33: reflecting film

40: detection unit 70, 75: variable filter

Claims (24)

A light source unit generating light; A first path interference part that partially reflects a part of the light generated from the light source part and emits light including the light delayed by a first delay time; And A second path configured to receive light emitted from the first path interferer and partially reflect some of the input light to emit light including light delayed by the first delay time and light delayed by a second delay time Interference system using partial reflection including an interference portion. The method of claim 1, And the light source unit periodically scans the wavelength of the light to change the wavelength to emit light. The method of claim 1, And the difference between the first delay time and the second delay time is smaller than a coherence time of the light source unit. The method of claim 1, wherein the first path interference portion A first partial reflecting film for reflecting some of the light generated from the light source unit; And And a first objective lens for passing unreflected light from the first partial reflecting film and entering the sample. The method of claim 4, wherein the second path interferer A second partial reflecting film reflecting some of the light emitted from the first path interference part; And And a reflection film for reflecting light not reflected by the second partial reflection film. The method of claim 5, A second objective lens disposed between the second partial reflecting film and the reflecting film, the second objective lens configured to pass light not reflected by the second partial reflecting film to the reflecting film; system. The method of claim 5, The first partial reflecting film is disposed to be spaced apart from the sample by a first distance so that the light emitted from the first path interference part has the first delay time, And the second partial reflecting film is disposed to be spaced apart from the reflecting film by a second distance so that the light emitted from the second path interference part has the second delay time. The method of claim 7, wherein And a difference between the first distance and the second distance is smaller than a coherence length of the light source unit. A light source unit generating light; A first path interference part that partially reflects a part of the light generated from the light source part before being incident on the sample, and emits light including the light delayed by a first delay time; A second path configured to receive light emitted from the first path interferer and partially reflect some of the input light to emit light including light delayed by the first delay time and light delayed by a second delay time Interference unit; And And a detector for sensing light emitted from the second path interferer. 10. The method of claim 9, And the light source unit periodically scans the wavelength of the light to change the wavelength to emit light. 10. The method of claim 9, And a difference between the first delay time and the second delay time is smaller than a coherence time of the light source unit. The method of claim 9, wherein the first path interference portion A first partial reflecting film for reflecting some of the light generated from the light source unit; And And a first objective lens for passing the unreflected light from the first partial reflecting film and entering the sample. The method of claim 9, wherein the second path interference portion A second partial reflecting film reflecting some of the light emitted from the first path interference part; And And a reflecting film for reflecting light not reflected from the second partially reflecting film. 10. The method of claim 9, And the detector is a spectrometer for sensing light emitted from the second path interferer and measuring a phase change of the lights. 10. The method of claim 9, And a variable filter disposed between the light source unit and the first path interference unit to periodically scan a wavelength of light generated from the light source unit and vary the wavelength. 10. The method of claim 9, And a variable filter disposed between the second path interferer and the detector and configured to periodically scan a wavelength of light emitted from the second path interferer and vary the wavelength. system. 10. The method of claim 9, A first position positioned between the light source unit and the first path interferer to transfer light generated from the light source unit to the first path interferer, and to transmit light emitted from the first path interferer to the second path interferer Circulators; And Located between the first circulator and the second path interferer to transmit the light received from the first circulator to the second path interferer and to transmit the light emitted from the second path interferer to the detector. And a second circulator for the measurement system using partial reflection. A light source unit emitting light including light delayed by a preset delay time; A path interference part that partially reflects some of the light emitted from the light source part and enters the rest of the light as a sample, and emits light including the light delayed by the same time as the delay time in the light source part; And And a sensing unit for sensing the light emitted from the path interference unit. The method of claim 18, The delay time is a measurement system using the partial reflection, characterized in that less than the coherence time (coherence time) of the light source. The method of claim 18, wherein the light source unit A light source for generating light; A first partial reflecting film for reflecting a part of the light generated from the light source; And And a reflecting film for delaying and reflecting the light not reflected by the first partial reflecting film by the delay time. 21. The method of claim 20, And the light source periodically scans the wavelength of the light to vary the wavelength to emit light. 21. The method of claim 20, And the first partial reflecting film is spaced apart from the reflecting film by a predetermined distance such that the light reflected by the reflecting film is delayed by the set delay time than the light reflected by the first partial reflecting film. 19. The method of claim 18, wherein the path interferer A second partial reflecting film for reflecting some of the light emitted from the light source unit; And And an objective lens for passing the unreflected light from the second partial reflecting film and entering the sample. The method of claim 18, And a variable filter disposed between the light source unit and the path interference unit or arranged between the path interference unit and the sensing unit to periodically scan a wavelength of the input light and change the wavelength. Measuring system.

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