JP2013142700A - Optical probe and optical interference tomographic apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical probe capable of controlling an optical path length, and to provide an optical interference tomographic apparatus including the optical probe.SOLUTION: An optical probe includes: an optical route control part for controlling an advancing route of light transmitted from the outside; an optical path length control member for generating a difference in optical path length as the light advancing route is controlled by the optical route control part; and a light output part for outputting light passed through the optical path length control member.

Description

  The present invention relates to an optical coherence tomography apparatus, and more particularly to an optical probe capable of adjusting an optical path length and an optical coherence tomography apparatus including the same.

  Recently, methods and apparatuses that can observe the internal structure of an object such as a human body organization or various materials are widely used in various fields. Examples include various internal transmission imaging and tomographic imaging apparatuses such as an X-ray apparatus, a CT (Computerized Tomography) scanner, an MRI (Magnetic Resonance Image) apparatus, and an ultrasonic apparatus. These devices occupy an important position in the medical field by grasping the cause, position and progress of various diseases without directly incising the internal structure of the human body and the living body. Therefore, in these diagnostic apparatuses, low harmfulness to living organisms, acquisition of high-resolution images, reasonable cost and convenience of movement and use are recognized as important factors.

  In particular, the optical coherence tomography apparatus is an apparatus that can capture the internal structure of an object using an interference phenomenon between light that is irradiated and reflected on the object and light that serves as a reference, and obtains an image of that resolution. It has the advantage of being harmless to the human body and is widely used in the medical field.

  The present invention has been made in view of the above prior art, and an object of the present invention is to provide an optical probe capable of adjusting the optical path length necessary for a full range optical coherence tomography apparatus, and An optical coherence tomography apparatus is provided. In particular, it is an object of the present invention to provide an optical probe capable of downsizing a product.

  To achieve the above object, an optical probe according to an aspect of the present invention includes an optical path adjusting unit that adjusts a traveling path of light transmitted from the outside, and a light traveling path that is adjusted by the optical path adjusting unit. An optical path length adjusting member that generates a difference in the optical path length, and a light output unit that outputs light that has passed through the optical path length adjusting member.

The light path adjusting unit adjusts a light traveling path so that a point at which the light output from the light output unit is irradiated on the object repeatedly moves in a predetermined direction by a predetermined length, and the optical path The length adjusting member may increase the optical path length of the light constantly each time the point where the light is irradiated onto the object moves.
The optical path length adjusting member may allow the light whose traveling path is adjusted by the optical path adjusting unit to pass therethrough and generate a difference in the optical path length depending on a point through which the light passes.
The optical path length adjusting member may be formed of a material having the same refractive index and may not have a constant thickness.
The optical path length adjusting member may have a wedge shape in a cross section cut in parallel with the traveling direction of the light.
Alternatively, the optical path length adjusting member may have a meniscus cross section on one or both sides.
The optical path length adjusting member may be formed of two or more materials having different refractive indexes.
Alternatively, the optical path length adjusting member may have a protrusion on the surface.
The optical path length adjusting member improves the optical path length adjusting effect relatively than before blocking by blocking a part of the light whose traveling path is adjusted by the optical path adjusting unit and reducing the diameter of the light. Can be.
The optical path length adjusting member may change the diameter of the light according to the light traveling path adjusted by the optical path adjusting unit.
The optical path adjusting unit may be a mirror that rotates about a fixed radius about a fixed axis.

  In order to achieve the above object, an optical coherence tomography apparatus according to an aspect of the present invention includes a light generator for generating light, and separating the generated light into a measurement light beam and a reference light beam. Is transmitted to the optical probe, and an optical coupler that receives the response light beam reflected from the measurement object and returned from the optical probe, and a detection that detects an interference signal generated by the response light beam and the reference light beam. And a video signal processor that generates a tomographic image of the object using the detected interference signal, and the optical probe adjusts a traveling path of light transmitted from the optical coupler. An optical path adjusting unit that generates a difference in optical path length as the light traveling path is adjusted by the optical path adjusting unit, and a light output unit that outputs light that has passed through the optical path length adjusting member And comprising.

The light path adjusting unit adjusts a light traveling path so that a point at which the light output from the light output unit is irradiated on the object repeatedly moves in a predetermined direction by a predetermined length, and the optical path The length adjusting member may increase the optical path length of the light constantly each time the point where the light is irradiated onto the object moves.
The optical path length adjusting member may allow the light whose traveling path is adjusted by the optical path adjusting unit to pass therethrough and generate a difference in the optical path length depending on a point through which the light passes.
The optical path length adjusting member may be formed of a material having the same refractive index and may not have a constant thickness.
The optical path length adjusting member may have a wedge shape in a cross section cut in parallel with the traveling direction of the light.
Alternatively, the optical path length adjusting member may have a meniscus shape on one or both sides.
The optical path length adjusting member may be formed of two or more materials having different refractive indexes.
Alternatively, the optical path length adjusting member may have a protrusion on the surface.
The optical path length adjusting member improves the optical path length adjusting effect relatively than before blocking by blocking a part of the light whose traveling path is adjusted by the optical path adjusting unit and reducing the diameter of the light. Can be.
The optical path length adjusting member may change the diameter of the light according to the light traveling path adjusted by the optical path adjusting unit.
The optical path adjusting unit may be a mirror that rotates about a fixed radius about a fixed axis.

According to the present invention, there is an advantage that a product can be reduced in size by adjusting the optical path length of the output light by using the optical path length adjusting member without pivoting off the galvano scanner inside the optical probe. .
In addition, modulation for realizing a full range can be performed by providing an optical path length adjusting member in an optical probe using a piezoelectric actuator.

1 is a diagram illustrating a configuration of an optical coherence tomography apparatus according to an embodiment of the present invention. 2 is a diagram illustrating a path along which measurement light travels inside an optical probe according to an exemplary embodiment of the present invention. FIGS. 3A to 3C are diagrams illustrating an internal configuration of an optical probe including an optical path length adjusting member according to various embodiments of the present invention. FIGS. 4A to 4C are cross-sectional views of optical path length adjusting members according to various embodiments of the present invention. FIGS. 3A to 3E are cross-sectional views of optical path length adjusting members according to various embodiments of the present invention. 4 is a diagram illustrating an internal configuration of an optical probe using a piezoelectric actuator according to another embodiment of the present invention. (A) and (B) are drawings showing paths through which measurement light and response light travel inside an optical probe according to still another embodiment of the present invention. (A) and (B) are drawings showing paths through which measurement light and response light travel inside an optical probe according to still another embodiment of the present invention. 6 is a diagram illustrating a path through which measurement light travels inside an optical probe according to still another embodiment of the present invention. (A), (B) is drawing which shows the internal structure of the optical probe by further another embodiment of this invention.

  Hereinafter, specific examples of embodiments for carrying out the present invention will be described in detail with reference to the drawings. In order to more clearly describe the features of the present embodiment, detailed descriptions of matters widely known to those skilled in the art are omitted.

  FIG. 1 is a diagram showing a configuration of an optical coherence tomography apparatus according to an embodiment of the present invention. Referring to FIG. 1, the optical coherence tomography apparatus according to the present embodiment includes a light generator 110, an optical coupler 120, an optical probe 130, a detector 140, and a video signal processor 150. The operation characteristics of the optical coherence tomography apparatus according to the present embodiment will be described with reference to FIG.

  The light generator 110 generates light and transmits it to the optical coupler 120. The optical coupler 120 includes a beam splitter 122 and a reference mirror 124. The light transmitted from the light generator 110 is separated into measurement light and reference light by the beam splitter 122. Of the light separated by the beam splitter 122, the measurement light is transmitted to the optical probe 130, and the reference light is transmitted to the reference mirror 124 and reflected, and then returns to the beam soup plate 122 again. On the other hand, the measurement light transmitted to the optical probe 130 is applied to the target object 10 to be imaged through the optical probe 130, and the response light reflected by the target object 10 is reflected by the light. The light is transmitted to the beam splitter 122 of the optical coupler 120 through the probe 130. The transmitted response light and the reference light reflected by the reference mirror 124 cause interference by the beam splitter 122, and the detector 140 detects the interference signal. When the interference signal detected by the detector 140 is transmitted to the video signal processor 150, the video signal processor 150 converts the interference signal into a video signal indicating a tomographic image of the object 10.

  On the other hand, the present embodiment is based on the premise that it is a full-range optical coherence tomography apparatus, and in the following, the description of the full-range optical coherence tomography apparatus and the internal configuration of the optical probe 130 for embodying this will be described. The operating characteristics will be described.

  The full-range optical coherence tomography apparatus changes the optical path length of the measurement light as the point where the measurement light is irradiated onto the object 10 moves in the horizontal direction. More specifically, scanning is performed while continuously moving the point where the measurement light is irradiated on the object 10 by the same length in the horizontal direction, and the point where the measurement light is irradiated on the target 10 is determined in the horizontal direction. Modulation is performed in such a manner that the optical path length of the measurement light increases by the same length each time the light moves. Here, the direction in which the measurement light is applied to the object 10, that is, the depth direction of the object 10 is referred to as the vertical direction, and the direction perpendicular to the direction is the horizontal direction. The optical path length is the product of n and l when light passes through a medium having a refractive index n by a distance l. That is, it is the same as the distance that the light passes through the vacuum within the same time as it took to pass through the medium. Thus, the optical probe 130 performs a role of moving the point where the measurement light is irradiated onto the object 10 in the lateral direction while changing the optical path length of the measurement light.

  Referring to FIG. 1, the optical probe 130 includes a collimator lens 132, a galvano scanner 134, an optical path length adjusting member 136, and a lens 138. Here, the galvano scanner 134 is a mirror capable of rotating at a constant radius around a fixed axis, and is embodied as a MEMS scanner that obtains a driving force necessary for rotation from a MEMS (Micro Electro Mechanical System). Further, the optical path length adjusting member 136 is a member manufactured in various shapes using one material having a constant refractive index or two or more materials having different refractive indexes, and the light adjusts the optical path length. The optical path length is changed depending on the point passing through the member 136.

  The measurement light transmitted from the optical coupler 120 is collimated by passing through the collimator lens 132 of the optical probe 130 and reflected by the galvano scanner 134 to adjust the traveling direction, so that the optical path length adjusting member 136 and After sequentially passing through the lens 138, the object 10 is irradiated. When the galvano scanner 134 rotates about a certain axis, the point where the measurement light is irradiated onto the object 10 moves in the horizontal direction. At this time, the galvano scanner 134 rotates to measure Since the point where the light passes through the optical path length adjusting member 136 also moves, the optical path length of the measurement light changes.

  On the other hand, although not shown in the drawing, the optical probe 130 includes a housing (not shown) that includes a collimator lens 132, a galvano scanner 134, an optical path length adjusting member 136, and a lens 138 therein. Then, the measurement light that has passed through the optical path length adjusting member 136 and the lens 138 is output from an opening of a housing (not shown) and irradiated onto the object 10. Therefore, an opening of a housing (not shown) through which measurement light is output is referred to as a light output unit.

The detailed contents of scanning the measurement light in the lateral direction on the object 10 while changing the optical path length will be described with reference to FIG. FIG. 2 is a diagram illustrating a path along which measurement light travels inside the optical probe 130 according to an embodiment of the present invention. Referring to FIG. 2, it can be seen that the galvano scanner 134 rotates to move the traveling direction of the measurement light by a certain length in the lateral direction. Galvano scanner 134 is rotated so that the traveling direction of the measuring light is adjusted from a first direction to the second direction N, the measurement light in the first direction, the optical path length corresponding to the d ₁₁ and d ₁₂ in Fig. 2 2, the measurement light in the second direction travels along the optical path length corresponding to d ₂₁ and d ₂₂ in FIG. 2, and the measurement light in the Nth direction travels along the optical path length corresponding to d _N1 and d _N2 in FIG. 2. To proceed. That is, when the measurement light is adjusted in the i-th direction (i = 1, 2,..., N), the optical path length that is reflected by the galvano scanner 134 and passes through the optical path length adjustment member 136 is di. The following mathematical formula is established.

  Here, n is the refractive index of the material forming the optical path length adjusting member 136.

  Further, the difference in optical path length between two measurement lights whose traveling directions are adjacent, that is, the measurement light in the (i + 1) th direction and the measurement light in the i-th direction is expressed by the following formula.

を調節してモジュレーションを変更することができる。 Accordingly, by adjusting the angle between the inclined upper surface of the optical path length adjusting member 136 and the lower surface, the refractive index of the material forming the member, the position of the axis that is the center of rotation of the galvano scanner 134, or the curvature of the member. ,

Can be used to change the modulation.

を用いてモジュレーションを行う具体的な方法は、下記の数式を用いて詳細に説明する。

A specific method of performing modulation using the will be described in detail using the following mathematical formula.

を

とすると、図１の光干渉断層撮影装置の検出器１４０で受信する干渉信号のパワーは、次のような数式で示される。 Equation 2 above

The

Then, the power of the interference signal received by the detector 140 of the optical coherence tomography apparatus shown in FIG.

は、測定光の進行方向が移動する横方向をｘ軸とする時、測定光が対象体１０に照射される地点の座標を示し、

は、第ｉ方向に調節された測定光の波数を示す。また、

は、検出器１４０で受信する干渉信号のパワーであり、

は、光源の波長別振幅を示し、

は、横方向振幅を示す。そして

は、ビームスプリッター１２２から対象体１０まで光が移動する距離から、ビームスプリッター１２２から基準ミラー１２４まで光が移動する距離を差し引いた差を意味する。 In Equation 3 above

Indicates the coordinates of the point where the measurement light is irradiated onto the object 10 when the horizontal direction in which the traveling direction of the measurement light moves is the x-axis.

Indicates the wave number of the measurement light adjusted in the i-th direction. Also,

Is the power of the interference signal received by the detector 140;

Indicates the amplitude of the light source by wavelength,

Indicates lateral amplitude. And

Means a difference obtained by subtracting a distance from which the light travels from the beam splitter 122 to the reference mirror 124 from a distance from which the light travels from the beam splitter 122 to the object 10.

  On the other hand, the above formula 3 becomes the following formula when expanded and rearranged with terms including complex exponents using Euler's formula.

  In order to perform modulation in this way, as described above, the optical path length that increases every time the traveling direction of the measurement light is changed must be constant. In other words, so that the following mathematical formula is established, the angle between the inclined upper surface of the optical path length adjusting member 136 and the lower surface, the refractive index of the material forming the member, and the axis that is the center of rotation of the galvano scanner 134 The desired modulation is performed by adjusting the position or the curvature of the member.

を一定にするために、本実施形態の光路長調節部材１３６のような構成を含まず、ガルバノ・スキャナ１３４の回転軸を移動させる、即ちガルバノ・スキャナ１３４をピボット・オフさせる方法を使っていた。従って、ガルバノ・スキャナ１３４をピボット・オフさせる空間を確保しなければならないため、製品の小型化に限界があるという問題点があった。具体的に、全体幅の長さが３ｍｍであり、ミラーの直径が１．５ｍｍであるＭＥＭＳスキャナをガルバノ・スキャナとして使う場合、ピボット・オフのためには、５００μｍ〜７００μｍの追加空間が必要になるため、直径２．８ｍｍ〜３．０ｍｍが標準として定められた内視鏡のワーキングチャネルに光プローブが挿入され得ないという問題点があり、今後の技術の適用範囲の拡大及び応用において問題点を持っていた。しかし、本実施形態による場合、ガルバノ・スキャナ１３４をピボット・オフさせずに光路長調節部材１３６を備える方式でモジュレーションを行うことで、光プローブのサイズを増大させずにフルレンジを具現できるという長所がある。 Conventionally, when implementing a full-range optical coherence tomography apparatus, the difference in optical path length between two measuring beams whose traveling directions are adjacent to each other

In order to maintain a constant value, the optical path length adjusting member 136 of the present embodiment is not included, and the rotation axis of the galvano scanner 134 is moved, that is, the galvano scanner 134 is pivoted off. . Accordingly, a space for pivoting off the galvano scanner 134 must be secured, and there is a problem in that there is a limit to downsizing of the product. Specifically, when a MEMS scanner having an overall width of 3 mm and a mirror diameter of 1.5 mm is used as a galvano scanner, an additional space of 500 μm to 700 μm is required for pivot-off. Therefore, there is a problem that the optical probe cannot be inserted into the working channel of the endoscope whose diameter is 2.8 mm to 3.0 mm as a standard, and there is a problem in the expansion and application of the future technology. I had. However, according to the present embodiment, the modulation is performed using the optical path length adjusting member 136 without pivoting off the galvano scanner 134, so that the full range can be realized without increasing the size of the optical probe. is there.

  Hereinafter, various embodiments of an optical path length adjusting member 136 for performing the above-described role and an optical probe including the same will be described with reference to the drawings.

  3A to 3C are views illustrating an internal configuration of an optical probe including an optical path length adjusting member 136 according to various embodiments of the present invention. More specifically, FIGS. 3A to 3C illustrate an embodiment in which the position, direction, and the like provided with the optical path length adjusting member 136 are changed. Referring to FIG. 3A, it can be seen that the optical path length adjusting member 136 is disposed on the lower side of the lens 138 unlike the embodiment shown in FIGS. 1 and 2, and referring to FIG. The position at which the optical path length adjusting member 136 is disposed is the same as in the embodiment shown in FIGS. 1 and 2, but it can be seen that the left and right sides of the optical path length adjusting member 136 are reversed. 3C, the optical path length adjusting member 136 is disposed at the same position as the embodiment shown in FIGS. 1 and 2, but the optical path length adjusting member 136 is upside down. You can see that As described above, the position and direction of the optical path length adjusting member 136 can be changed in various ways as necessary. At this time, the angle and the member formed by the inclined upper surface of the optical path length adjusting member 136 with the lower surface are changed. The desired modulation is performed by adjusting the refractive index of the material to be formed, the position of the axis that is the center of rotation of the galvano scanner 134, or the curvature of the member.

  4A to 4C are cross-sectional views of an optical path length adjusting member 136 according to various embodiments of the present invention. More specifically, FIGS. 4A to 4C illustrate an embodiment of an optical path length adjusting member 136 formed using two materials having different refractive indexes. In FIGS. 4A to 4C, 136a and 136b mean different materials having different refractive indexes. Referring to FIG. 4A, the boundary line formed by the material 136a and the material 136b has a curved shape that is recessed from the upper surface of the optical path length adjusting member 136. FIGS. , Boundary lines formed by the material 136a and the material 136b are formed in parallel to the upper and lower surfaces of the optical path length adjusting member 136, respectively. As described above, the material forming the optical path length adjusting member 136 can be variously changed as necessary. At this time, the angle between the inclined upper surface of the optical path length adjusting member 136 and the lower surface, the refractive index of the material forming the member, The desired modulation is performed by adjusting the position of the axis serving as the center of rotation of the galvano scanner 134 or the curvature of the member. 4A to 4C show an embodiment in which the optical path length adjusting member 136 is formed using two materials having different refractive indexes, the optical path length is adjusted using three or more materials. The member 136 may be formed.

  5A to 5E are views illustrating cross-sectional shapes of an optical path length adjusting member 136 according to various embodiments of the present invention. Until now, the embodiment in which the cross-sectional shape of the optical path length adjusting member 136 is a wedge shape has been described with reference to FIGS. However, as shown in FIGS. 5A to 5E, the cross section of the optical path length adjusting member 136 can be changed to various forms other than the wedge shape. Referring to FIG. 5A, the upper and lower surfaces of the optical path length adjusting member 136 have a meniscus shape. Referring to FIG. 5B, a protrusion 136c is formed on the upper surface of the optical path length adjusting member 136. You can see that Referring to FIG. 5C, it can be seen that the optical path length adjusting member 136 has a rectangular cross section, and two layers 136a and 136b are formed using two different materials having different refractive indexes. FIG. 5D shows an embodiment in which the optical path length adjusting member 136 has a rectangular cross section and the refractive index gradually changes. In FIG. 5D, the light and darkness expressed in the optical path length adjusting member 136 corresponds to the refractive index, and referring to FIG. 5D, the change in light and dark occurs gradually, and the refractive index changes gradually. I understand that. Finally, FIG. 5 (E) shows an embodiment in which the optical path length adjusting member 136 has a stepped cross section. Here, although not shown in the drawing, unlike FIG. 5A, only one surface of the optical path length adjusting member 136 may be formed in a meniscus shape. In this way, by changing the cross-sectional shape of the optical path length adjusting member 136 in various ways, it is possible to correct non-linear characteristics generated at the time of modulation using the optical probe including the optical path length adjusting member 136, and the optical path length adjusting member 136. By adjusting the angle between the inclined upper surface and the lower surface, the refractive index of the material forming the member, the position of the axis that is the center of rotation of the galvano scanner 134, or the curvature of the member, desired modulation is performed. .

  FIG. 6 is a diagram showing an internal configuration of an optical probe using a piezo actuator according to another embodiment of the present invention. The optical probe shown in FIG. 6 adjusts the traveling direction of light using a piezo actuator 135 that is not a galvano scanner. More specifically, when an electrical signal is applied to the piezoelectric elements 135a provided at the upper and lower parts of the piezoelectric actuator 135, the piezoelectric elements are bent upward or downward, and the support layer 135b of the piezoelectric actuator 135 is also deformed by the piezoelectric element 135a. Is bent upward or downward. The support layer 135b includes an optical fiber 135c. Since the optical fiber 135c is also bent upward or downward along the support layer 135b, the traveling direction of light output from the optical fiber 135c is adjusted upward or downward. The Since these types of optical probes do not use a galvano scanner, modulation by pivot-off is impossible. However, as shown in FIG. 6, the modulation as described above can be performed by providing the optical path length adjusting member 136 so as to be positioned on the traveling path of the light. At this time, the optical path length adjusting member 136 may be embodied in various forms as shown in FIGS. 4 (A) to 5 (E). That is, by using the optical path length adjusting member 136, it is possible to realize a full range even when using an optical probe in which the galvano scanner cannot be pivoted off.

  On the other hand, the adjustment of the optical path length for phase modulation may be realized by adjusting the size of the light diameter, and the details will be described below.

  FIG. 7A is a diagram illustrating a path through which measurement light travels inside an optical probe according to still another embodiment of the present invention, and FIG. 7B is a diagram illustrating light according to still another embodiment of the present invention. It is drawing which shows the path | route which response light advances inside a probe.

  First, referring to FIG. 7A, the measurement light is reflected by the galvano scanner 134 so that its traveling direction is adjusted and irradiated to the object 10. At this time, the optical path length adjusting member 136 is used for the measurement light. Not on the path. Therefore, the measurement light is irradiated to the object 10 without being affected by the optical path length adjusting member 136. Referring to FIG. 7B, the response light that is reflected by the measurement light 10 reflected by the object 10 is also reflected by the galvano scanner 134 without being affected by the optical path length adjusting member 136 and is external to the optical probe. Proceed to.

  FIG. 8A is a diagram illustrating a path along which measurement light travels inside an optical probe according to still another embodiment of the present invention, and FIG. 8B is a diagram illustrating light according to still another embodiment of the present invention. It is drawing which shows the path | route which response light advances inside a probe.

  In FIG. 8A, it can be seen that the galvano scanner 134 is rotated with the center 134a as a reference, and the traveling direction of the measurement light is slightly changed to the right as compared with FIG. 7A. Referring to FIG. 8A, the measurement light is reflected by the galvano scanner 134 so that the traveling direction is adjusted and irradiated to the object 10. At this time, the optical path length adjusting member 136 is irradiated with the measurement light. Located on the travel path. Therefore, it can be seen that a part of the measurement light is refracted by the optical path length adjusting member 136 and deviates from the traveling path, and only the remaining measurement light is irradiated to the object 10 along the traveling path. That is, the diameter of the measurement light reaching the object 10 is reduced as compared with FIG. 7A. At this time, the optical path length adjusting member 136 is a member manufactured in various shapes using one material having a constant refractive index or two or more materials having different refractive indexes, or blocks light. It is a member made of a material to be used. Referring to FIG. 8B, the response light that is reflected when the measurement light is reflected by the object 10 is reflected by the galvano scanner 134 and travels outside the optical probe. At this time, the diameter of the response light shown in FIG. 8B is also reduced by the optical path length adjusting member 136 as compared with FIG. 7B.

  As described above, the optical path length adjusting member 136 changes the diameters of the measurement light and the response light, which has the effect of substantially changing the optical path length. The reason why the change in the diameter of the light causes a substantial change in the optical path length will be described in detail with reference to FIGS. 7B and 8B. A center point 701 of the diameter at which the response light shown in FIG. 7B contacts the galvano scanner 134 and a center point 801 of the diameter at which the response light shown in FIG. A comparison shows that the positions are different. That is, as the diameter of the response light changes, the position of the center point of the diameter at which the response light contacts the galvano scanner 134 also changes. However, since the substantial distance that the light travels is the distance that the center of the light diameter travels, the optical path lengths of the response light are different from each other in FIGS. 7B and 8B. As a result, when the diameter size of the measurement light and the response light is adjusted using the optical path length adjusting member 136, the optical path length along which the measurement light and the response light travel is also adjusted.

A specific method for performing phase modulation by adjusting the diameter of light will be described. FIG. 9 is a diagram illustrating a path along which measurement light travels inside an optical probe according to still another embodiment of the present invention. Referring to FIG. 9, the measurement light in the first direction, the diameter is that r _1, the measurement light of the second direction, the diameter is the r _2, measurement light of the N direction, is a r _N diameter I understand that. Such a change in diameter is caused by the optical path length adjusting member 136 as described with reference to FIGS. 7A to 8B. If the diameter size when the measurement light is adjusted in the i-th direction (i = 1, 2,..., N) is r _i , two measurement lights whose traveling directions are adjacent, that is, measurement light in the i + 1-th direction The difference in diameter between the measurement light in the i-th direction and the measurement light in the i-th direction is expressed by the following mathematical formula.

を

とすると、上記数式３及び数式４によってフェーズモジュレーションを行うことができる。詳細な内容は、上記数式３及び数式４についての説明部分を参考にする。 Equation 6 above

The

Then, the phase modulation can be performed by the above formulas 3 and 4. For details, refer to the explanation part of the above formulas 3 and 4.

  On the other hand, the embodiment can be implemented so as to use a lens that changes the shape of the lens and performs the role of the lens and the optical path length adjusting member at the same time. For this, refer to FIG. 10 (A) and FIG. This will be described in detail below.

  FIGS. 10A and 10B are diagrams showing an internal configuration of an optical probe according to still another embodiment of the present invention. 10A and 10B are compared with FIGS. 3A to 3C, the optical path length adjusting member 136 and the lens 138 are separately provided in FIGS. 3A to 3C. 10A and 10B, only the lens 138 is provided without the separate optical path length adjusting member 136. Here, the lens 138 shown in FIGS. 10A and 10B is formed with one side cross-section inclined, and an optical path length adjusting member on the upper side or the lower side of the lens 138 in FIGS. 3A to 3C. It can be seen that the shape is similar to the combined shape of 136. That is, the lens 138 in FIGS. 10A and 10B simultaneously performs the roles performed by the optical path length adjusting member 136 and the lens 138 in FIGS. Thus, by obtaining the effect of adjusting the optical path length by the deformation of the lens, the configuration of the optical probe is simplified.

  As mentioned above, although embodiment of this invention was described referring drawings, this invention is not limited to the above-mentioned embodiment, A various change implementation is carried out within the range which does not deviate from the technical scope of this invention. It is possible.

  The present invention is suitably used in a technical field related to an optical probe and an optical coherence tomography apparatus including the same.

DESCRIPTION OF SYMBOLS 10 Target object 110 Light generator 120 Optical coupler 122 Beam splitter 124 Reference mirror 130 Optical probe 132 Collimator lens 134 Galvano scanner 134a Center 135 Piezo actuator 135a Piezo element 135b Support layer 135c Optical fibers 136, 136a, 136b Optical path length adjustment Member 136c Projection 138 Lens 140 Detector 150 Video signal processor 701, 801 Center point

Claims (22)

An optical probe for irradiating an object with light,
An optical path controller that adjusts the traveling path of light transmitted from the outside;
An optical path length adjusting member that generates a difference in optical path length as the light path is adjusted by the optical path adjusting unit;
An optical probe comprising: an optical output unit that outputs light that has passed through the optical path length adjusting member. The light path adjusting unit adjusts the traveling path of light so that a point irradiated with the light output from the light output unit repeatedly moves in a predetermined direction for a predetermined length,
2. The optical probe according to claim 1, wherein the optical path length adjusting member increases the optical path length of the light constantly whenever the point where the light is irradiated onto the object moves.   2. The optical probe according to claim 1, wherein the optical path length adjusting member passes light whose traveling path is adjusted by the optical path adjusting unit, and generates a difference in optical path length depending on a point through which the light passes. .   The optical probe according to claim 3, wherein the optical path length adjusting member is made of a material having the same refractive index and has a constant thickness.   The optical probe according to claim 4, wherein the optical path length adjusting member has a wedge shape in a cross section cut in parallel with the light traveling direction.   The optical probe according to claim 4, wherein the optical path length adjusting member has a meniscus shape on one or both sides.   The optical probe according to claim 3, wherein the optical path length adjusting member is formed of two or more materials having different refractive indexes.   The optical probe according to claim 3, wherein the optical path length adjusting member has a protrusion formed on a surface thereof.   The optical path length adjusting member improves the optical path length adjusting effect relatively than before blocking by blocking a part of the light whose traveling path is adjusted by the optical path adjusting unit and reducing the diameter of the light. The optical probe according to claim 1, wherein:   The optical probe according to claim 9, wherein the optical path length adjusting member changes a diameter of light according to a traveling path of light adjusted by the optical path adjusting unit.   The optical probe according to claim 1, wherein the optical path adjustment unit is a mirror that rotates about a fixed radius about a fixed axis. An optical coherence tomography apparatus that performs tomography by irradiating a target with light,
A light generator for generating light;
Optical coupling that separates the generated light into a measurement beam and a reference beam, transmits the measurement beam to an optical probe, and receives a response beam returned from the measurement beam reflected from the object. And
A detector for detecting an interference signal generated by the response beam and the reference beam;
A video signal processor that generates a tomographic image of the object using the detected interference signal,
The optical probe is
An optical path controller that adjusts a traveling path of light transmitted from the optical coupler;
An optical path length adjusting member that generates a difference in optical path length as the light path is adjusted by the optical path adjusting unit;
An optical coherence tomography apparatus comprising: a light output unit that outputs light that has passed through the optical path length adjusting member. The light path adjusting unit adjusts the traveling path of light so that a point irradiated with the light output from the light output unit repeatedly moves in a predetermined direction for a predetermined length,
The optical coherence tomography apparatus according to claim 12, wherein the optical path length adjusting member increases the optical path length of the light constantly every time a point where the light is irradiated onto the object moves.   The optical interference according to claim 12, wherein the optical path length adjusting member passes light whose travel path is adjusted by the optical path adjusting unit, and generates a difference in optical path length depending on a point through which the light passes. Tomography equipment.   The optical coherence tomography apparatus according to claim 14, wherein the optical path length adjusting member is formed of a material having the same refractive index and has a constant thickness.   The optical coherence tomography apparatus according to claim 15, wherein the optical path length adjusting member has a wedge shape in a cross section cut in parallel with the traveling direction of the light.   The optical coherence tomography apparatus according to claim 15, wherein the optical path length adjusting member has a meniscus shape on one or both sides.   The optical coherence tomography apparatus according to claim 14, wherein the optical path length adjusting member is formed of two or more materials having different refractive indexes.   The optical coherence tomography apparatus according to claim 14, wherein a projection is formed on a surface of the optical path length adjusting member.   The optical path length adjusting member improves the optical path length adjusting effect relatively than before blocking by blocking a part of the light whose traveling path is adjusted by the optical path adjusting unit and reducing the diameter of the light. The optical coherence tomography apparatus according to claim 12, wherein:   21. The optical coherence tomography apparatus according to claim 20, wherein the optical path length adjusting member changes the diameter of the light according to the traveling path of the light adjusted by the optical path adjusting unit.   The optical coherence tomography apparatus according to claim 12, wherein the optical path adjustment unit is a mirror that rotates about a fixed radius about a fixed axis.

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