JP2003172690A - Optical imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an optical imaging device which is not influenced by a change in a polarization state and in which an optical path length is adjusted easily even when an optical probe is replaced and used. <P>SOLUTION: In the optical imaging device 3, low-coherence light generated by a low-coherence light source 21 in a device mainframe 10 is transmitted to an optical fiber 25 in the optical probe 9 via an optical connector part 20 from an optical fiber 22. The greater part of the low-coherence light transmitted to a tip-side end face 25a of the optical fiber 25 is transmitted as observation light to an objective lens 26 arranged and installed on the tip side of the optical probe 9 so as to be condensed in a target part on a specimen 8. Reflected light and scattered light in the target part on the specimen 8 are partly returned again to the device mainframe 10 as return observation light. A part of the low-coherence light transmitted to the tip-side end face 25a of the optical fiber 25 is reflected and separated in the tip-side end face 25a as a first light separation means so as to be returned again to the device mainframe 10 as return reference light. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical imaging apparatus that collects low-coherence light on a subject and constructs a tomographic image of the subject from information on the return light from the subject.

[0002]

2. Description of the Related Art In recent years, OCT (Optical Coherence Tom)
An optical imaging device called "ography" is widely used. The optical imaging device condenses the low-coherence light generated by the light source onto the subject, and at that time scans the focal position to construct a tomographic image of the inside of the subject from the information of the return light from the subject. To do.

Such an optical imaging apparatus focuses low coherence light from a low coherence light source on a subject and returns from the subject as described in, for example, Japanese Patent Application Laid-Open No. 11-72431. It has been proposed to have an insertion unit that takes in light and a device body that connects the insertion unit and constructs a tomographic image of a subject from the returned light that has been taken in.

The optical system of the conventional optical imaging apparatus separates the low coherence light generated by the low coherence light source into the observation light and the reference light by the light separating means, and scans the separated observation light with respect to the subject. And focus it on the subject. And
Part of the reflected light and scattered light of the subject from the focus passes through the optical path as return observation light and returns to the light separation means side again.

On the other hand, the reference light separated by the light separating means is reflected by the reference light transmitting means and returned to the light separating means side again. At this time, the optical path length of the reference light is adjusted to be almost equal to the optical path length of the observation light. Then, the return reference light and the return observation light from the subject side that have almost the same optical path length interfere with each other and are detected by the photodetector which is the photodetection means. The output of this detector is demodulated and the interfering light signal is extracted. The extracted light signal is converted into a digital signal and then signal-processed to generate image data corresponding to the tomographic image. Then, the generated image data is displayed on the monitor as a tomographic image of the subject.

[0006]

However, in the above-mentioned conventional optical imaging apparatus, since the observation light and the reference light have different optical paths, when the observation light and the reference light interfere with each other, their polarization states are different from each other. And the intensity of the interference light changes depending on the change of each polarization state.

Further, the above conventional optical imaging apparatus is
When the insertion section is exchanged from the main body of the apparatus, if the optical path length at the insertion section changes greatly due to individual differences or types, it is difficult to adjust the optical path length of the reference light path.

The present invention has been made in view of the above-mentioned circumstances, and an optical imaging apparatus in which the optical path length can be easily adjusted even when the insertion section is replaced and used without being affected by the change in the polarization state. The purpose is to provide.

[0009]

According to a first aspect of the present invention, an insertion portion that collects low-coherence light from a low-coherence light source onto a subject and takes in return light from the subject,
In an optical imaging apparatus having an apparatus body for constructing a tomographic image of a subject from return light captured by connecting the insertion portion, light transmission for transmitting low coherence light generated by the low coherence light source and irradiating the subject Means and a light splitting means for splitting the low coherence light into observation light and reference light, for adjusting the polarization states of the observation light and the reference light, the inside of the light transmission means or the light transmission The light separating means is provided at the end of the means or between the light transmitting means and the subject. According to a second aspect of the present invention, in the optical imaging device according to the first aspect, the observation light and the reference light separated by the light separating means are:
The optical axis is the same in at least a part of the inside of the light transmitting unit or between the light transmitting unit and the subject. The claim 3 of the present invention is the claim 1.
In the optical imaging device of, having a light interference means for interfering the return observation light and the reference light by scattering or reflection of the observation light from the subject, the observation light and the reference light separated by the light separation means However, they have the same optical axis inside the light transmitting means or between the light transmitting means and the subject and at least in part in front of the interference means. Further, a fourth aspect of the present invention is characterized in that, in the optical imaging apparatus of the first aspect, an optical path length difference generating means for generating an optical path length difference between the observation light and the reference light is provided. With this configuration, it is possible to realize an optical imaging apparatus in which the optical path length can be easily adjusted even when the insertion section is replaced and used without being affected by the change in the polarization state.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 10 show a first embodiment of the present invention.
1 is a block diagram showing an optical imaging system including the first embodiment of the present invention, and FIG. 2 is a schematic configuration showing an optical imaging apparatus of the first embodiment of the present invention. FIG. 3, FIG. 3 is a detailed configuration diagram of the optical imaging apparatus of FIG. 2, FIG. 4 is a configuration diagram of the tip side of the optical probe of FIG. 3, and FIG. 5 is a configuration diagram of the tip side of the optical probe showing the first modified example of FIG. ,
6 is a configuration diagram of the tip side of an optical probe showing a second modified example of FIG. 4, FIG. 7 is a configuration diagram showing a modified example of the optical path length difference generation unit, and FIG. 8 is an explanatory diagram showing the filter turntable of FIG. 9, FIG. 9 is a configuration diagram showing a modified example of the dispersion adjusting unit, FIG. 10 is a configuration diagram of the tip side of an optical probe showing a modified example of the first light separating means, and FIG. 11 shows a third modified example of FIG. FIG. 12 is a schematic enlarged view of FIG. 11 showing the configuration of the tip side of the optical probe.

As shown in FIG. 1, an optical imaging system 1 equipped with a first embodiment of the present invention comprises an endoscope apparatus 2
And the optical imaging device 3. Although the optical imaging system 1 according to the present embodiment is configured to be combined with the endoscope device 2, the system can be configured with only the optical imaging device 3.

In the endoscope device 2, an endoscope light source device 6 and a video processor 7 can be attached to and detached from an electronic endoscope (hereinafter referred to as an endoscope) 4 having an image pickup means (not shown) via a universal cable 5. Configured by connecting to.

The optical imaging device 3 is flexible so that it can be inserted into a living body, and is an optical probe as an insertion portion that focuses low-coherence light from a low-coherence light source, which will be described later, onto a target portion of the subject 8. 9 and a device main body 10 that detachably connects the optical probe 9 and constructs a tomographic image of the subject 8 from the return light from the target portion of the subject 8.

The endoscope 4 has an elongated insertion portion 11 that can be inserted into a body cavity, and a wide operation portion 12 is provided at the rear end of the insertion portion 11. The endoscope 4 has a forceps insertion opening 13 provided near the rear end of the insertion portion 11.
The inside 3 communicates with the forceps insertion channel 14.

The endoscope 4 has a light guide (not shown) inserted through the insertion portion 11. The light guide is adapted to pass through the universal cable 5, transmit illumination light from the light source device 6 for an endoscope, and illuminate a subject such as a diseased part through an illumination window provided at the distal end of the insertion section 11. There is. Further, the endoscope 4 is provided with an objective optical system and an image pickup device (not shown) in an observation window attached adjacent to the illumination window,
An image of a subject such as an illuminated affected area is captured. An image pickup signal from the image pickup device of the endoscope 4 is transmitted to the video processor 7 through a signal line (not shown) which passes through the universal cable 5. Then, the video processor 7 processes the transmitted image pickup signal and transmits it to the monitor 15 to display the endoscopic image 15a.

In the optical imaging system 1, the optical probe 8 constituting the optical imaging device 3 is probed from the forceps insertion port 13 of the endoscope 4 constituting the endoscope device 2 through the forceps insertion channel 14 to the tip opening thereof. The tip side is projected and used. Then, the optical imaging system 1 obtains tomographic image data of the target site by irradiating the target site of the subject such as a diseased part with low coherence light while observing the endoscope 4. The OCT image 15b can be displayed on the display surface of the monitor 15.

In the optical imaging apparatus 3, the probe side optical connector section 20b of the optical probe 9 is detachably connectable to the main body side optical connector section 20a of the apparatus main body 10 as shown in FIG. The main body 10 is replaceable.

The apparatus main body 10 has a low coherence light source 21 such as an ultra-high brightness light emitting diode (hereinafter referred to as a super luminescent diode, abbreviated as SLD). The low coherence light generated by this low coherence light source has a wavelength of 1310 nm and a coherence length of 17 for example.
It has a characteristic of low coherence that exhibits coherence only in a short distance range such as about μm. That is, when the low coherence light is separated into, for example, two and then mixed again, when the difference between the two optical path lengths from the separated point to the mixed point is within a short distance range of about 17 μm, It is detected as interfering light, and shows the characteristic of not interfering when the optical path length is larger than that.

The low-coherence light is made incident on one end of a single-mode fiber (hereinafter simply referred to as an optical fiber) 22 from the low-coherence light source 21 and is transmitted to the other end face (end face on the tip side). This optical fiber 22 is used as an optical coupler 2 as a second light separating means on the way.
It is optically coupled to the optical fiber 24 at 3. Therefore, the low-coherence light in the optical coupler 23 is adapted so that the return light from the subject is branched to the optical fiber 24 and is transmitted to the photodetection section side described later. The device body 1
0 may be configured such that the return light from the subject is branched to the optical fiber 24 without using the optical coupler 23.

Of the optical fiber 22 (from the optical coupler 23)
The low coherence light transmitted to the tip end side is transmitted to the optical probe 9 via the optical connector section 20 when the probe side optical connector section 20b is connected to the main body side optical connector section 20a. There is.

The low coherence light transmitted to the optical probe 9 is transmitted to the other end face (tip end side end face) 25a of the optical fiber 25 extending from the probe side optical connector portion 20b. Most of the low-coherence light transmitted to the end face 25a of the optical fiber 25 on the tip side is transmitted to the objective lens 26 arranged on the tip side of the optical probe 9 as observation light, and the objective lens 26 focuses the light. Subject 8
It is focused on the target part of. Then, a part of the reflected light and the scattered light of the target portion of the subject 8 from the focus passes through the optical path as return observation light and returns to the optical coupler 23 side of the apparatus body 10 again.

On the other hand, the end face 25a of the optical fiber 25 on the tip side
Part of the low coherence light transmitted to the
Of the optical coupler 2 of the apparatus main body 10 again as the return reference light after being reflected and separated by the end face 25a as the light separating means.
It is designed to return to side 3. And the optical coupler 23
The return observation light and the return reference light that have returned to the side are branched to the optical fiber 24 by the optical coupler 23 and are transmitted to the end surface of the optical fiber 24 on the tip side.

The optical path length of the return observation light and the return reference light transmitted to the end face of the optical fiber 24 is adjusted by the optical path length difference generating section 31 so that the optical path length difference between them coincides. At this time, the optical path length difference generation unit 31 is driven by the drive unit 34 controlled by the control unit 33 in synchronization with the signal from the light detection unit 32.
Thus, the optical path length is adjusted.

The reference light and the observation light having the same optical path length interfere with each other in the optical path of the optical path length difference generating section 31.
This interference light is received by the photodetector 32 such as a photodiode. The photodetector 32 photoelectrically converts the interference light into an interference electrical signal, and the photoelectrically converted interference electrical signal is amplified by an amplifier or the like and input to the signal processor 35. The signal processing unit 35 performs demodulation processing for extracting only the signal portion of the observation light from the input interference electric signal, and A / A
The D conversion is performed and the digital signal is output to the control unit 33.

The control unit 33 generates image data corresponding to the tomographic image from the input digital signal. Then, the generated image data is output to the monitor 15 via the video processor 6, and the OCT of the subject 8 is displayed on this display screen.
The image 15b is displayed.

Next, the detailed configuration of the optical imaging apparatus 3 will be described with reference to FIGS. 3 and 4. First, the configuration on the tip side of the optical probe 9 will be described. As shown in FIGS. 3 and 4, the objective lens 26 and the end face 25a of the optical fiber 25 are formed.
Are integrally provided in the optical scanning unit 36. The optical scanning unit 36 is provided with an actuator 37 such as a PZT element as an optical scanning unit, which performs a two-dimensional scanning (XY scanning) on a target portion of the subject 8 and an optical axis direction (Z axis). Direction), and the vertical scanning is performed in the deep direction with respect to the target site of the subject 8. The actuator 37 is driven by the drive unit 34.

On the other hand, the end face 25a of the optical fiber 25 as the first light separating means is adapted to reflect and separate a part of the transmitted low coherence light as return reference light. As a result, the end face 2 of the optical fiber 25 on the tip side
The return observation light incident on the optical fiber 5a and the return reference light reflected and separated by the end face 25a of the optical fiber 25 are 2 × Δ.
The optical path length difference is L. The optical path length difference generation unit 31 adjusts the optical path length so that the optical path length difference between the return observation light and the return reference light matches.

Next, the optical path length difference generator 31 will be described. As described above, the return observation light and the return reference light transmitted to the end surface of the optical fiber 24 on the distal end side are provided with the optical path length difference generation unit 3
The parallel light is collimated by the first parallel lens 41, and is separated into the observation light and the reference light by the half mirror 42 which is the third light separating means.

The return observation light separated by the half mirror 42 is incident on the observation light side reflection mirror 43. The observation light side reflection mirror 43 has a piezoelectric element 44 bonded to the lower side thereof as a light modulating means. The piezoelectric element 44 is configured to vibrate the observation light side reflection mirror 43 in the optical axis direction when a drive signal is applied from the drive unit 34. The observation light incident on the observation light side reflection mirror 43 is light-modulated and reflected, and returns to the half mirror 42 side again.

On the other hand, the return reference light separated by the half mirror 42 is dispersed and adjusted by a light dispersion adjusting section 45 as a light dispersion adjusting means, and is reflected by a reference light side reflection mirror 46 which can move forward and backward in the optical axis direction. , Is returned to the half mirror 42 side again. The reference light side reflection mirror 46 is provided on a reference light side stage 47 that can move back and forth in the optical axis direction.
The optical path length of the reference light is adjusted.

The reference light side stage 47 includes a drive unit 34.
The optical path length of the entire observation optical path and the optical path length of all the reference optical paths are moved in the optical axis direction so that the optical path lengths of all the observation optical paths match. Further, specifically, the half mirror 42-
The optical path length with the reference light side reflection mirror 46 is Lr / 2. Further, the half mirror 42 to the observation light side reflection mirror 43
The optical path length between and is Ls / 2.

The control unit 33 sets the optical path length of the reference light and the optical path length of the observation light to Lr = Ls + 2 in order to eliminate the optical path length difference 2 × ΔL of the optical fiber 25 in the optical probe 9 described above.
The drive unit 34 is driven so as to be ΔL, and the reference light side stage 47 is moved back and forth in the optical axis direction. The reference light and the observation light, which have almost the same optical path length, are separated by the half mirror 42.
It is designed to interfere with the optical path from the side. That is, the half mirror 42 serves not only as the third light separating means but also as the interference means. Then, the interference light is condensed by the detection-side condenser lens 48 and received by the photodetector 32.

As a result, in the present embodiment, the observation light and the reference light have the same optical path from the low coherence light source 21 to the end face 25a of the optical fiber 25 of the optical probe 9, so that the observation light and the reference light are the same. The light and the light interfere with each other in a state where the polarization state is substantially the same, and the intensity of the interference light does not change due to the change in the polarization state. Further, in the present embodiment, the optical path length can be easily adjusted even when the optical probe 9 is replaced and used.

In the optical imaging system 1 thus constructed, as described above, the optical probe 8 is inserted into the body cavity from the forceps insertion port 13 through the forceps insertion channel 14 to the tip opening thereof. It is used with the tip of the probe protruding. The optical imaging system 1 is
The optical probe 9 of the optical imaging device 3 may be used by itself being inserted into the body cavity or the like. Further, the optical imaging device 3 may be integrated with the endoscope or the like. Furthermore, the optical imaging device 1 may be used in combination with other observation means or treatment means. Then, the optical imaging device 3
Collects low-coherence light from the optical probe 9 on the living tissue of the subject 8, obtains tomographic image data inside the living tissue, and displays the OCT image 15b on the display surface of the monitor 15.

Here, the optical imaging apparatus 3 may be used by exchanging optical probes 9 having extremely different lengths because the subject 8 and the observation target site are different. As described above, the optical imaging device 3 includes the low coherence light source 2
1 to the end face 25a of the optical fiber 25 of the optical probe 9
Since the observation light and the reference light have the same optical path, even when the optical probe 9 is exchanged and used, the observation light and the reference light interfere with each other in a state where the polarization states of the observation light and the reference light are substantially the same, and the intensity of the interference light is increased. Is not changed by the change of the polarization state, and the optical path length can be easily adjusted.

As a result, the optical imaging apparatus 3 according to the present embodiment can be used even when the optical probe 9 is replaced and used.
Without being affected by the polarization state of low coherence light,
It is possible to easily obtain the OCT tomographic image by easily adjusting the optical path length.

As shown in FIG. 5, the optical fiber 25 inside the optical probe 9 may be constructed by providing a reflection coating film 50 on the end face 25a on the tip side which is the first light separating means. Thereby, the return reference light reflected from the end surface 25a of the optical fiber 25 on the tip side can be further increased.

Further, as shown in FIG. 6, the optical scanning unit 3
6B may be configured to perform horizontal scanning by using an XY reflection mirror scan 51 instead of the actuator 37 as the optical scanning means. This XY reflection mirror scan 5
1 is provided on the tip side of the condenser lens 26.

The observation light from the condenser lens 26 is
The light enters the XY reflection mirror scan 51, and the subject is scanned in the horizontal direction by the XY reflection mirror scan 51. Here, the observation light is scanned in the Y direction by the Y scanning mirror 51a with respect to the subject, and then the X scanning mirror 51a is scanned.
Scan in the X direction at b. Incidentally, these X scanning mirrors 15
The 1b, Y scanning mirror 51a is adapted to be driven by the drive unit 34 similarly to the actuator 37.

Then, these XY reflection mirror scans 5
The observation light scanned at 1 (51a, 51b) is reflected by the observation window 5
The target site of the subject 8 is irradiated with the light through the beam line 2. In this case, the optical path length difference between the observation light and the reference light is 2 × Δ
L is twice the optical path from the end face 25a of the optical fiber 25 to the target site of the subject 8. The XY reflection mirror scan 51 (51a, 51b) is configured to perform vertical scanning in the deep direction with respect to the target site of the subject 8 by moving back and forth in the optical axis direction (Z axis direction). Is also good.

Further, as shown in FIGS. 7 and 8, the optical path length difference generation section 31 uses the half mirror 42 and the reference light side reflection mirror when the reference light incident on the light detection section 32 is too strong as compared with the observation light. A filter rotating table 53 provided with variable neutral density filters 53a to 53f may be provided as a light attenuating means for reducing the amount of transmitted light. The filter turntable 53 is driven by the drive unit 34. Thereby, the optical path length difference generation unit 31 can obtain the optimum OCT tomographic image because the reference light has an appropriate intensity as compared with the observation light.

In addition, the optical path length difference generator 31 has a grating 5 instead of the optical dispersion adjuster 45 as shown in FIG.
4a, 54b and lenses 55a, 55b may be used. In this case, the lens 55a is provided on the stage 56 that can move back and forth in the optical axis direction, and is driven by the drive unit 34 so that optimum dispersion adjustment is performed. As a result, the return reference light is optimally dispersion-adjusted and can interfere with the observation light from the optical path of the half mirror 42.

Further, as shown in FIG. 10, the reference light is not separated by the end face 25a of the optical fiber 25 as the first light separating means, but the end face 25 of the optical fiber 25 is separated.
The reference light may be reflected and separated on the optical path from a to the condenser lens 26. The optical scanning unit 36C provided on the tip side of the optical probe 9 includes a parallel lens 57 and a half mirror 58 between the tip end surface 25a of the optical fiber 25 and the condenser lens 26.

The low coherence light transmitted to the end face 25a of the optical fiber 25 on the tip side is collimated by the parallel lens 57. Then, most of the low-coherence light converted into the parallel light passes through the half mirror 58 as observation light and is focused on the target portion of the subject 8 at the focus of the objective lens 26.

A part of the reflected light and the scattered light of the target portion of the subject 8 from the focus passes through the optical path as return observation light and returns to the optical coupler 23 side of the apparatus body 10 again. There is. On the other hand, part of the low-coherence light that has been made into parallel light is reflected and separated by the half mirror 58, and again serves as return reference light, again on the end face 25a of the optical fiber 25 on the tip side.
To the optical coupler 23 side of the apparatus body 10.

As a result, the optical path length difference 2 × ΔL between the reference light and the observation light is doubled between the half mirror 58 and the target portion of the subject 8, which is shorter than the optical path length difference described with reference to FIG. can do. Therefore, the optical path length adjustment in the optical path length difference generation unit 31 can be shortened, and the optical path length adjustment becomes easier.

Further, as shown in FIG. 11, the optical probe 9B
Alternatively, the optical fiber 25 may be inserted into the flexible shaft 110 to perform rotational scanning. The flexible shaft 110 is detachably connected to the main body 10 of the apparatus by an optical rotary joint (not shown) on the base end side. In this optical rotary joint, a non-rotating portion and a rotating portion are coupled so that light can be transmitted.

The flexible shaft 110 has a gradient index lens (GRIN lens) on the tip side of the optical fiber 25.
A Gradient Index lens) 111 and a prism 112 are rotatably connected. That is, the optical probe 9B uses the optical rotary joint to move the flexible shaft 110.
The gradient refractive index lens 111 and the prism 112 scan the target portion of the subject 8 in the Rθ direction.

The low coherence light transmitted to the end face 25a of the optical fiber 25 passes through the gradient refractive index lens 111 and the prism 112 and enters the observation window 52.

Then, as shown in FIG. 12, most of the low coherence light passes through the observation window 52 as observation light and is condensed on the target portion of the subject 8.

Then, a part of the reflected light and scattered light of the target portion of the subject 8 from the focus passes through the optical path as return observation light and returns to the optical coupler 23 side of the apparatus body 10 again. There is. On the other hand, a part of the low coherence light is reflected and separated by the observation window 52 and becomes return reference light. Then, the light passes through the optical path and returns to the optical coupler 23 side of the apparatus body 10 again.

At this time, the optical path length difference between the observation light and the reference light is 2
× ΔL is doubled from the observation window 52 to the target site of the subject 8. Therefore, as described above, the return reference light has the same optical path length difference 2 × ΔL as the observation light, so that the device main body 10 has the same optical path length difference.
The optical path length is adjusted by the optical path length generation unit 31 inside. Therefore, the optical probe 9B can be adjusted so that the optical path length differences between the observation light and the reference light match.

(Second Embodiment) FIGS. 13 and 14 relate to a second embodiment of the present invention, and FIG. 13 is a block diagram showing an optical imaging apparatus according to the second embodiment of the present invention. FIG. 14 is a block diagram of the tip side of the optical probe of FIG. The second embodiment is configured so that the polarization states of the reference light and the observation light are more matched than in the first embodiment. The rest of the configuration is almost the same as that of the first embodiment, so the description thereof will be omitted, and the same configurations will be denoted by the same reference numerals.

That is, as shown in FIG. 13, the optical imaging apparatus 3B of the second embodiment has a linearly polarized low coherence light source (hereinafter referred to as low coherence light source) 21B for generating linearly polarized low coherence light. Configured.
The linearly polarized low-coherence light generated by the coherence light source 21B is incident on one end of the optical fiber 22 and passes through the optical connector unit 20 to the optical fiber 25 in the optical probe 9 as in the first embodiment. It is transmitted to the front end side end surface 25a. The optical coupler 23 used in this embodiment is a polarization-maintaining fiber coupler.

Then, as shown in FIG. 14, the optical fiber 2
The linearly polarized low-coherence light transmitted to the front end side end surface 25a of No. 5 is emitted from the front end side end surface 25a and is focused on the target site of the subject 8 by the condenser lens 26. A part of the reflected light and the scattered light passes through the optical path as return observation light and returns to the optical coupler 23 side of the apparatus body 10 again.

Here, the end surface 25 of the optical fiber 25 on the tip side
The polarization plane of the observation light emitted from a is λ / 4 polarized by a polarization plane rotating element 69 such as a Faraday rotator provided in the optical scanning unit 36D, and the return observation light from the subject 8 is λ / It is four-polarized and combined to be λ / 2 polarized. On the other hand, a part of the low-coherence light transmitted to the tip end surface 25a of the optical fiber 25 is reflected and separated by the tip end surface 25a as in the first embodiment, and again the optical coupler 23 side of the apparatus main body 10 side. To return to. The return observation light and the return reference light that have returned to the optical coupler 23 side are the optical coupler 23.
Is branched to the optical fiber 24 and transmitted to the optical path length difference generation unit 60, and the optical path length is adjusted so that the optical path length differences between the return observation light and the return reference light match.

The transmitted return observation light and return reference light are
The parallel lens 41 of the optical path length difference generation unit 60 converts the light into parallel light,
The polarization beam splitter 61, which is the third light separating unit, separates the observation light and the reference light.

The separated return reference light is reflected by the reflection mirror 62.
It is reflected by and is incident on the half mirror 64. At this time, the return reference light is adjusted by the optical path length difference adjusting lens 63 provided between the polarization beam splitter 61 and the reflection mirror 62 so that the optical path length difference with the observation light is matched. There is.

At this time, the return observation light is an electro-optical modulator (EOM) 66 provided between the polarization beam splitter 61 and the reflection mirror 65.
The light is modulated by, and the polarization plane is polarized by a polarization plane rotation element 67 provided between the reflection mirror 65 and the half mirror 64. By this,
The return observation light is λ / 2 polarized by the polarization plane rotating element 67 on the tip side of the optical probe 9 and then λ / is generated by the optical path length difference generation unit 60.
It is polarized two times and is also λ-polarized together.

Then, the return reference light and the return observation light interfere with each other at the half mirror 64. One of the interference lights is condensed by the detection-side condensing lens 48a, and the photodetector 32
Light is received at A. The other of the interference light is condensed by the detection-side condenser lens 48b and received by the photodetector 32B.

Then, the photodetector 32A and the photodetector 32B
Photoelectrically convert the received light into an electric signal, and the photoelectrically converted electric signal is subtracted by a subtracter 68 to obtain a difference, which is amplified by an amplifier or the like and input to the signal processing unit 35. The signal processing unit 35 performs demodulation processing and performs A / D
The converted digital signal is output to the control unit 33.

The control unit 33 generates image data corresponding to the tomographic image from the input digital signal. Then, the generated image data is output to the monitor 15 via the video processor 6, and the OCT of the subject 8 is displayed on this display screen.
The image 15b is displayed. As a result, in the optical imaging apparatus 3B of the second embodiment, the polarization states are completely matched, the optical path length can be easily adjusted, and the OCT tomographic image can be reliably obtained, as compared with the first embodiment. Is.

(Third Embodiment) FIGS. 15 to 23
15 relates to the third embodiment of the present invention, FIG. 15 is a schematic configuration diagram showing an optical imaging apparatus of the third embodiment of the present invention, and FIGS. 16 to 23 are views of the optical path length difference generation unit of FIG. 16 shows a specific configuration example, FIG. 16 is a configuration diagram of a first optical path length difference generation unit, FIG. 17 is a configuration diagram of a second optical path length difference generation unit, and FIG.
8 is a block diagram of a third optical path length difference generating unit, FIG. 19 is a block diagram of a fourth optical path length difference generating unit, FIG. 20 is a block diagram of a fifth optical path length difference generating unit, and FIG. 22 is a configuration diagram of the optical path length difference generation unit, FIG. 22 is a configuration diagram of a seventh optical path length difference generation unit, and FIG. 23 is a configuration diagram of an eighth optical path length difference generation unit.

In the first and second embodiments, the optical path length difference generator is provided between the optical coupler 23, which is the second light separating means, and the photodetector 31. In the third embodiment, the optical path length difference generation unit is provided between the low coherence light source 21 and the optical coupler 23 which is the second light separation means. The rest of the configuration is almost the same as that of the first embodiment, so the description thereof will be omitted, and the same configurations will be denoted by the same reference numerals.

That is, as shown in FIG. 15, the optical imaging apparatus 3C according to the third embodiment has an optical path length difference generation section 71.
Is provided between the low coherence light source 21 and the optical coupler 23 which is the second light separating means. The low coherence light from the low coherence light source 21 is transmitted through the optical fiber 72.
And is separated into observation light and reference light by an optical coupler 73 in the optical path length difference generation unit 71 as third light separation means. Then, the observation light and the reference light are transmitted to the optical probe 9 via the optical fiber 22 with the optical path length difference adjusted. The optical path length difference generation unit 71 uses the optical coupler 2 in the same manner as described in the first embodiment.
3 and the photodetector 31 may be provided.

The optical path length difference generator 71 (71A to 71H) used in the optical imaging apparatus 3C of the third embodiment will be described below with reference to FIGS. As shown in FIG. 16, in the optical path length difference generation unit 71A, the low coherence light transmitted through the optical fiber 72 is separated by the optical coupler 73 into observation light and reference light.

The separated observation light is collimated from one end face 72B of the optical fiber by the observation light side lens 74b, reflected by the observation light side reflection mirror 43, and returned to the optical coupler 73 side again. It has become. On the other hand, the separated reference light is the end surface 72A on one tip side of the optical fiber 72.
Is collimated by the reference light side lens 74a, reflected by the reference light side reflection mirror 46, and returned to the optical coupler 73 side again.

A piezoelectric element 75 capable of vibrating in the optical axis direction is bonded to the reference light side reflection mirror 46. When a drive signal is applied from the drive unit 34, the piezoelectric element 75 vibrates the reference light side reflection mirror 46 in the optical axis direction,
The adjustment is made so that the optical path length difference with the observation light is the same. Further, the reference light side reflection mirror 46 is adapted to optically modulate the reflected reference light by vibrating by the piezoelectric element 75.

Then, the return observation light and the return reference light returning to the optical coupler 73 side are branched to the optical fiber 22 by this optical coupler 73 and transmitted to the optical probe 9 through this optical fiber 22. It has become. This allows
The optical path length difference generation unit 71A adjusts the optical path length difference such that the reference light and the observation light have the same optical path length difference.

Further, as shown in FIG. 17, in the optical path length difference generation unit 71B, the low coherence light is separated into the observation light and the reference light by the optical coupler 73 similarly to the optical path length difference generation unit 71A. Side lens 74b, reference light side lens 7
It is collimated by 4a.

The reference light collimated by the reference light side lens 74a is optically modulated by the electro-optic modulator (EOM) 76, and then reflected by the reference light side reflection mirror 46 which can move back and forth in the optical axis direction. Then, it returns to the third optical branching portion 73 side again. The reference light side reflection mirror 46 is provided on the reference light side stage 47 described in the first embodiment, and the optical path length of the reference light is adjusted. On the other hand, the observation light is the same as that of the optical path length difference generation unit 71A. Accordingly, the optical path length difference generation unit 71B can adjust the optical path length difference so that the reference light and the observation light have the same optical path length difference.

Further, as shown in FIG. 18, in the optical path length difference generation section 71C, similarly to the optical path length difference generation section 71A, the reference light and the observation light separated by the optical coupler 73 are respectively observed by the reference light side lens 74a. After being collimated by the light side lens 74b, an acousto-optic modulator (AOM)
tor) 77a, 77b. These acousto-optic modulators (AOM) 77a and 77b are adjusted so that the optical path length differences between the reference light and the observation light match.

The reference light and the observation light whose optical path length differences have been adjusted are respectively incident on the incident end faces 22A and 22B of the optical fiber 22 by the reference light side lens 78a and the observation light side lens 78b.
The light is incident on the optical probe 9, and is optically coupled by the optical coupler 79 and transmitted to the optical probe 9. Thereby, the optical path length difference generation unit 71C can adjust the optical path length difference so that the optical path length differences between the reference light and the observation light match.

Further, as shown in FIG. 19, in the optical path length difference generating section 71D, the low coherence light transmitted by the optical fiber 72 is condensed by the condenser lens 81 from the end face 72a on the tip side,
Acousto-optic modulator (AOM) 8 as third light separating means
At 2, the reference light and the observation light are separated. The separated reference light and observation light are respectively dispersed and adjusted by the transmission type grating 83, condensed and incident on the incident end face 22a of the optical fiber 22 by the condenser lens 84, and transmitted to the optical probe 9. . Thereby, the optical path length difference generation unit 71D
Can adjust the optical path length difference so that the reference light and the observation light have the same optical path length difference.

Further, as shown in FIG. 20, in the optical path length difference generator 71E, the low coherence light is separated into the observation light and the reference light by the optical coupler 73 as in the optical path length difference generator 71A. It is adapted to be transmitted to the end face 72a on the front end side.

The observation light is reflected by the end face 72a of the optical fiber 72 on the tip side and returns to the optical coupler 73 side. On the other hand, the reference light is collimated by the parallel lens 85 from the end face 72a of the optical fiber 72 on the front end side similarly to the optical path length difference generation unit 71A, and the reference light side reflection mirror 4 is provided.
It is reflected at 6 and returns to the optical coupler 73 side again. At this time, as described above, the reference light side reflection mirror 46 is adapted to optically modulate the reflected reference light by vibrating by the piezoelectric element 75. As a result, the optical path length difference generation unit 71E can adjust the optical path length difference from the tip end surface 72a of the optical fiber 72 to the reference light side reflection mirror 46 so that the optical path length difference is the same.

Further, as shown in FIG. 21, the optical path difference generator 71F includes a parallel lens 85 of the optical path difference generator 71E.
A half mirror 86 that reflects the observation light is provided between the reflection mirror 46 and the reference light side reflection mirror 46. Therefore, the optical coupler 7
The reference light separated by 3 is collimated by the parallel lens 85, reflected by the half mirror 86, and returned to the optical coupler 73 side again.

On the other hand, the reference light separated by the optical coupler 73 is the same as the optical path length difference generator 71E.
Is converted into parallel light by the parallel lens 85 from the end surface 72a on the tip side of the reference light, passes through the half mirror 86, and is reflected by the reference light side reflection mirror 4
It is reflected at 6 and returns to the optical coupler 73 side again. At this time, as described above, the reference light side reflection mirror 46 is adapted to optically modulate the reflected reference light by vibrating by the piezoelectric element 75. As a result, the optical path length difference generation unit 71F can adjust the optical path length difference from the half mirror 86 to the reference light side reflection mirror 46 to match the optical path length difference.

The optical path length difference generation unit 71E of FIG. 20 and the optical path length difference generation unit 71F of FIG. 21 use an optical circulator instead of the optical coupler 73 when the separated observation light and reference light are supplied. You may comprise using.

Further, as shown in FIG. 22, the optical path length difference generator 71G is constructed by providing a half mirror 88 and a half mirror 90 as a third light separating means between the parallel lens 87 and the condenser lens 91. It Half mirror 88 is PZT
A piezoelectric element 89 such as is bonded to the side portion so that it can vibrate in the optical axis direction. The piezoelectric element 89 is adapted to vibrate the half mirror 88 in the optical axis direction when a drive signal is applied from the drive section 34.

Most of the low-coherence light converted into parallel light by the parallel lens 87 passes through the half mirror 88 and the half mirror 90, is condensed by the condenser lens 91, and is incident on the incident end surface of the optical fiber 22 as observation light. 22a. On the other hand, a part of the low-coherence light is reflected and separated by the half mirror 90 and is again reflected by the half mirror 88.
Is reflected by and passes through the half mirror 90, and the condenser lens 9
The light is converged at 1, and is incident on the incident end face 22a of the optical fiber 22 as reference light.

At this time, in the half mirror 88, the drive unit 34 drives the piezoelectric element 89 by the control of the control unit 33 so that the difference in the optical path length between the observation light and the reference light is matched, and the half mirror 88 vibrates in the optical axis direction. It is like this. Accordingly, the optical path length difference generation unit 71G can adjust the optical path length difference between the reference light and the observation light.

Further, as shown in FIG. 23, in the optical path length difference generation unit 71H, the low coherence light is separated by the optical coupler 73 into the observation light and the reference light as in the case of the optical path length difference generation unit 71A. There is. Then, the separated reference light is collimated by the reference light side lens 74a from one end side end surface 72A of the optical fiber 72, is condensed by the reference light side lens 78a, and is collected on the incident end surface 22A of the optical fiber 22. It is supposed to be illuminated. On the other hand, the separated observation light is transmitted from the other side of the optical fiber 72 to the optical fiber 22 optically coupled to the optical coupler 79. The other side of the optical fiber 72 has a piezoelectric element 8 such as a PZT element.
1 is provided and is optically modulated by the piezoelectric element 81.

The optical paths from the optical coupler 73 to the optical coupler 79 are formed so that the optical path length differences between the observation light and the reference light are the same. Accordingly, the optical path length difference generation unit 71H can adjust the optical path length difference so that the reference light and the observation light have the same optical path length difference.

(Fourth Embodiment) FIGS. 24 and 25 relate to a fourth embodiment of the present invention, and FIG. 24 is a schematic configuration diagram showing an optical imaging apparatus according to the fourth embodiment of the present invention. 25 is a configuration diagram of the tip side of the optical probe of FIG. In the fourth embodiment, an optical path length difference generator is provided on the tip side of the optical probe 9. The rest of the configuration is almost the same as that of the first embodiment, so the description thereof will be omitted, and the same configurations will be denoted by the same reference numerals.

That is, as shown in FIG. 24, the optical imaging apparatus 3D according to the fourth embodiment has the optical path length difference generating section 10
0 is provided on the tip side of the optical probe 9. Figure 25
As shown in FIG. 3, the optical scanning unit 101 provided on the tip side of the optical probe 9 includes an advancing / retreating half mirror that moves in the optical axis direction between the parallel lens 57 and the condenser lens 26 as the optical path length difference generation unit 100. 102 and a half mirror 103 are provided. A piezoelectric element 104 is bonded to the forward / backward movement half mirror 102. This piezoelectric element 104
When a drive signal is applied from the drive unit 34, the half mirror 102 is moved back and forth in the optical axis direction.

In the present embodiment, the separated reference beam is moved between the forward / backward moving half mirror 102 and the half mirror 103.
The optical path length difference is adjusted so as to match by reciprocating the number of times.

Optical imager device 3 having such a configuration
In D, the low coherence light from the low coherence light source 21 is transmitted to the optical fiber 25 in the optical probe 9 in the same manner as described in the first embodiment. Optical fiber 25
The low-coherence light transmitted to the tip end face 25a of
The optical scanning unit 36B described in the first embodiment
Similarly, the parallel lens 57 collimates the light. Then, most of the low-coherence light converted into the parallel light passes through the advancing / retreating half mirror 102 and the half mirror 103,
The observation light is focused on the target portion of the subject 8 at the focus of the objective lens 26.

A part of the reflected light and scattered light of the target portion of the subject 8 from the focal point passes through the optical path as return observation light and returns to the optical coupler 23 side of the apparatus body 10 again. There is. On the other hand, a part of the low coherence light made into parallel light passes through the advancing / retreating half mirror 102,
It is reflected and separated by the half mirror 103 and becomes the return reference light. Then, it is reflected by the advancing / retreating half mirror 102, further reflected by the half mirror 103, and again reflected by the optical fiber 25.
The light is incident on the end surface 25a on the front end side and returns to the optical coupler 23 side of the apparatus body 10.

At this time, the difference in optical path length between the observation light and the reference light is 2
× ΔL is doubled from the half mirror 103 to the target site of the subject 8. In addition, the optical path length of the return reference light in the advancing / retreating half mirror 102 to the half mirror 103 is 2 × ΔL.
r. Then, the piezoelectric element 103 uses 2 × ΔL = 2 in order to eliminate the optical path length difference of 2 × ΔL between the observation light and the reference light.
The drive unit 34 is controlled by the control unit 33 so that xΔLr.
Is driven and moved back and forth in the optical axis direction.

Therefore, the optical path length difference generator 100 can be adjusted so that the optical path length difference between the observation light and the reference light is the same. As a result, the optical imaging device 3D of the present embodiment obtains the same effect as that of the first embodiment.

(Fifth Embodiment) FIGS. 26 and 27 relate to a fifth embodiment of the present invention, and FIG. 26 is a schematic configuration diagram showing an optical imaging apparatus of the fifth embodiment of the present invention. 27 is a block diagram of the optical path length difference generation unit in FIG.
The fifth embodiment is configured such that the low coherence light source also serves as the second light separating means. The rest of the configuration is almost the same as that of the first embodiment, so the description thereof will be omitted, and the same configurations will be denoted by the same reference numerals.

That is, as shown in FIG. 26, the optical imaging apparatus 3E of the fifth embodiment is provided with a low coherence light source 121 which also serves as a second light separating means.
The low-coherence light source 121 has a low-coherence light supply portion covered with an active layer having a high refractive index, and an optical fiber 22 is inserted through this portion. The low coherence light source 121 has a property that when the return light is optically coupled with the active layer, it is emitted from the other end surface.

Optical imaging apparatus 3E of the present embodiment
Has an optical probe 9 having the same configuration as described in the first embodiment, and the optical fiber 25 in the optical probe 9 is
A part of the low-coherence light is reflected and separated by the end face 25a of the front side and returns to the low-coherence light source 121 side of the apparatus main body 10 as return reference light.

Further, the optical imaging apparatus 3E of the present embodiment is provided with the optical path length difference generator 122.
This optical path length difference generation unit 122 is composed of two half mirrors 122a and 122b as shown in FIG.

In the optical imaging apparatus 3E configured as described above, the low coherence light generated by the low coherence light source 121 is incident on one end of the optical fiber 22, and the optical fiber 25 in the optical probe 9 is passed through the optical connector section 20. Transmitted to. Then, a part of the low coherence light is reflected and separated by the end face 25a of the optical fiber 25 in the optical probe 9 and returns to the low coherence light source 121 side of the apparatus body 10 as return reference light.

The return observation light and the return reference light which have returned to the low coherence light source 121 side are the low coherence light source 12
At 1, the light is optically coupled to the active layer and emitted from the other end surface. The return observation light and the return reference light emitted from the other end surface of the low-coherence light source 121 have an optical path length difference generation unit 12
At 2, the optical path length differences are adjusted to match. At this time,
The return observation light passes through the half mirrors 122a and 122b and is transmitted to the light detection unit 32.

On the other hand, the return reference light is the half mirror 122.
After passing through a, the light is reflected by the half mirror 122b and heads again for the half mirror 122a.
The light is reflected by a, passes through the half mirror 122b, and is transmitted to the photodetector 32. At this time, the half mirror 122a
~ The optical path length of the return reference light at the half mirror 122b is 2
× ΔLr. The optical path length 2 × ΔLr of this return reference light is
The optical path length difference between the observation light and the reference light is equal to 2 × ΔL.

Then, the reference light and the observation light, which have almost the same optical path length, interfere with each other in the state where the polarization states are substantially the same in the optical path from the half mirror 1222b side, and are received by the photodetector 32. As a result, the optical imaging apparatus 3E of the fifth embodiment can be miniaturized because the low coherence light source 121 also serves as the second optical coupler, in addition to obtaining the same effect as that of the first embodiment. .

(Sixth Embodiment) FIGS. 28 to 30.
28 relates to a sixth embodiment of the present invention, FIG. 28 is a schematic configuration diagram showing an optical imaging apparatus of a sixth embodiment of the present invention, FIG. 29 is a configuration diagram of an optical path length difference generation unit of FIG. 28, Figure 30
FIG. 30 is an enlarged view of the optical path length difference generation unit in FIG. In the sixth embodiment, an optical system including a low coherence light source, a second optical branching unit, an optical path length difference generating unit, and a photodetecting unit is provided inside the tip side of the optical probe. The rest of the configuration is almost the same as that of the first embodiment, so the description thereof will be omitted, and the same configurations will be denoted by the same reference numerals.

That is, as shown in FIG. 28, in the optical imaging apparatus of the sixth embodiment, the low coherence light source, the second optical branching portion, the optical path length difference generating portion and the optical detection are provided on the tip side of the optical probe 9D. Optical unit 15 with optical system up to
It is configured by providing 0. In the present embodiment, the optical unit 150 is integrally formed with an optical path by an LN (LiNbO3 crystal) waveguide.

The optical unit 150 has a cable 151 extending through which the optical probe 9D is inserted. The cable 151 is provided with a power line and a signal line which are not shown. An XY reflection mirror scan 152 that performs horizontal scanning is provided on the front end side of the optical unit 150, and the observation light emitted from the optical unit 150 is horizontally scanned. The observation light horizontally scanned by the XY reflection mirror scan 152 is focused by the condenser lens 153 on the target site of the subject 8 through the observation window 154. Then, part of the reflected light and scattered light of the subject from the focus passes through the optical path as return observation light and returns to the optical unit 150 side again.

Next, the optical unit 150 will be described with reference to FIGS. 29 and 30. As shown in FIG. 29, in the optical unit 150, the low coherence light from the low coherence light source 21 enters the optical path 161, and is transmitted to the optical path 164 via the second optical coupler 162 on the way.

The optical path 161 is optically coupled to the optical path 163 by the second optical coupler 162. Therefore, the low-coherence light from the optical coupler 162 is adapted so that the return light from the subject is branched to the optical path 163 and is transmitted to the photodetector 32 side. The optical path 161 is also optically coupled to the optical path 165 by the second optical coupler 162. The end of the optical path 165 is provided with a non-reflection end 166 such as a resistance plate so that a standing wave is not generated in the optical path.

As shown in FIG. 30, most of the low-coherence light transmitted to the tip end face 164a of the optical path 164 is emitted as observation light from this tip end face 164a. Then, the observation light emitted from the optical unit 150 is horizontally scanned by the XY reflection mirror scan 152 as described above, and then the observation lens 153 is transmitted through the observation window 154 to the subject 8 through the observation window 154. The light is focused on the target area.

Then, a part of the reflected light and scattered light of the subject from the focus passes through the optical path as return observation light,
It returns to the second optical coupler 162 side in the optical unit 150 again. On the other hand, a part of the low-coherence light transmitted to the tip-side end surface 164a of the optical path 164 is reflected and separated by the tip-side end surface 164a as the first light separating means, and the second optical coupler 1 in the optical unit 150 is again provided.
It is designed to return to the 62 side.

Then, the return observation light and the return reference light returning to the second optical coupler 162 side are branched to the optical path 163 by the second optical coupler 162, and the optical coupler as the third optical separating means. 167 is transmitted to the optical path length difference generation unit 170.

In the optical path length difference generator 170, the optical paths 171 and 173 are optically coupled to the optical coupler 167. These optical paths 171 and 173 are formed to have a length such that the optical path length differences between the reference light and the observation light match. Therefore, the optical path length difference generator 170 is adjusted so that the optical path length differences between the observation light and the reference light match.

The return reference light is transmitted to the front end side end surface of the optical path 171, is reflected by the reference light side mirror 172 provided at the end of the front end side end surface, and returns to the optical coupler 167 side. On the other hand, the return observation light is transmitted to the tip end side end surface of the optical path 173, is reflected by the observation light side mirror 174 provided at the end of the tip end side end surface, and returns to the optical coupler 167 side.

The reference light and the observation light having the same optical path length interfere with each other in the optical path from the optical coupler 167, and the optical path 17 optically coupled to the optical coupler 167.
5, and is received by the photodetector 32. Photodetector 32
Photoelectrically converts the interference light into an interference electrical signal, and the photoelectrically converted interference electrical signal is output to the signal processing unit 35 via the signal line in the cable 151.

As a result, the optical imaging apparatus of the sixth embodiment obtains the same effect as that of the first embodiment, and additionally has an optical path integrally inside the tip side of the optical probe 9D. Since the formed optical unit 150 is provided and configured, further miniaturization can be realized.

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the gist of the invention.

[Additional Remarks] (Additional Remark 1) The low coherence light from the low coherence light source is focused on the subject, and the insertion portion that takes in the return light from the subject and the return that is obtained by connecting this insertion portion In an optical imaging apparatus having an apparatus body for constructing a tomographic image of a subject from light, a light transmitting unit that transmits the low coherence light generated by the low coherence light source and irradiates the subject, and the low coherence light is an observation light. And a light separation means for separating the observation light and the reference light, in order to match the polarization states of the observation light and the reference light, the inside of the light transmission means, the end of the light transmission means, or the light transmission means and An optical imaging apparatus, characterized in that the light separating means is provided between the sample and the sample.

(Additional Item 2) The observation light and the reference light separated by the light separating means have the same optical axis in at least a part inside the light transmitting means or between the light transmitting means and the subject. The optical imaging device according to item 1, further comprising:

(Additional Item 3) An observation light separated by the light separation means and a reference are provided, which has an optical interference means for interfering the return observation light by scattering or reflection of the observation light from the subject and the reference light. The light and the light transmitting means have the same optical axis in the light transmitting means or between the light transmitting means and the subject, and at least a part in front of the interference means. Optical imaging device.

(Additional Item 4) The optical imaging apparatus according to Additional Item 1, further comprising an optical path length difference generating means for generating an optical path length difference between the observation light and the reference light. (Additional Item 5) A second optical separation unit for separating the low coherence light into observation light and reference light is provided between the low coherence light source and the light transmission unit. The optical imaging device described.

(Additional Item 6) The optical imaging apparatus according to Additional Item 1, wherein the light transmitting means is an optical fiber. (Additional Item 7) The optical imaging apparatus according to Additional Item 1, wherein the light separating means is a half mirror.

(Additional Item 8) The optical imaging apparatus according to Additional Item 1, wherein the light transmitting means is an optical waveguide. (Additional Item 9) The optical imaging device according to Additional Item 1, wherein the terminal surface of the light transmitting unit is provided with a reflecting film.

(Additional Item 10) The optical imaging apparatus according to Additional Item 1, wherein the light detecting means for detecting the return observation light and the low coherence light source are provided outside the insertion portion. (Additional Item 11) The optical imaging apparatus according to Additional Item 1, wherein a light detection unit that detects the return observation light and the low coherence light source are provided inside the insertion portion.

(Additional Item 12) The optical imaging apparatus according to Additional Item 1, wherein the insertion portion is detachably connectable to a portion including the low coherence light source. (Additional Item 13) The optical imaging apparatus according to Additional Item 1, further comprising at least one light modulator.

(Additional Item 14) The optical imaging apparatus according to Additional Item 1, further comprising optical scanning means for scanning the position of the light to be irradiated on the subject on the subject. (Additional Item 15) The optical imaging apparatus according to Additional Item 1, wherein a condensing unit that condenses the irradiation light is provided between the light transmitting unit and the subject.

(Additional Item 16) The optical imaging apparatus according to Additional Item 1 is provided with a light attenuation means for reducing the amount of transmitted light. (Additional Item 17) The optical imaging apparatus according to Additional Item 1, comprising at least one polarization plane rotating element. (Additional Item 18) The optical imaging apparatus according to Additional Item 1, further comprising a light dispersion adjusting unit.

(Additional Item 19) The optical imaging apparatus according to Additional Item 1, wherein the insertion portion can be inserted into a body cavity. (Additional Item 20) The optical imaging apparatus according to Additional Item 1, wherein the insertion portion is an endoscope. (Additional Item 21) The additional item 1 characterized in that the insertion portion is a probe that can be inserted into a channel of an endoscope.
The optical imaging device according to item 1.

(Additional Item 22) The optical imaging apparatus according to Additional Item 4, wherein the optical path length difference generating unit is provided between the light transmitting unit and the subject. (Additional Item 23) An optical path length difference generation unit that generates an optical path length difference between the observation light and the reference light is provided between the light detection unit that detects the return observation light and the second light separation unit. Item 6. The optical imaging device according to item 5, which is characterized in that

(Additional Item 24) The optical imaging apparatus according to Additional Item 6, wherein the light separating means is an end face of the optical fiber. (Additional Item 25) The optical imaging apparatus according to Additional Item 7, wherein the half mirror is provided between the light transmitting unit and the subject.

(Additional Item 26) The optical imaging apparatus according to Additional Item 16, wherein the optical attenuation means is capable of varying the optical attenuation factor. (Additional Item 27) The optical imaging apparatus according to Additional Item 16, wherein the light attenuating unit attenuates the intensity of the reference light.

(Additional Item 28) The optical imaging apparatus according to Additional Item 22, wherein the optical path length difference generating means and the light separating means have at least the same common member. (Additional Item 29) The low coherence light source, and the second
24. The optical imaging apparatus according to appendix 23, wherein the optical separation means and the optical path length difference generation means are arranged on the same optical axis.

(Additional Item 30) The optical path length difference generating means includes a third light separating means, a first optical path length difference generating optical path separated by the third light separating means, and the first optical path. 24. The optical imaging apparatus according to item 23, further comprising a second optical path length difference generation optical path having an optical path length longer than that of the length difference generation optical path.

(Additional Item 31) The optical imaging apparatus according to Additional Item 29, wherein the second light separating means is the low coherence light source. (Additional Item 32) The optical imaging apparatus according to Additional Item 30, wherein the first optical path length difference generation optical path and the second optical path length difference generation optical path are optical fibers.

(Additional Item 33) Among the light passing through the interference means, the light detecting means returns the return observation light passing through the first optical path length difference generating optical path and the second optical path length difference generating optical path. 31. The optical imaging apparatus according to appendix 30, wherein the returning light of the reference light that has passed through is detected.

(Additional Item 34) The optical imaging apparatus according to Additional Item 30, wherein the third light separating means is a polarization beam splitter. (Additional Item 35) The optical imaging according to Additional Item 30, wherein an optical path length varying means is provided in at least one of the first optical path length difference generating optical path and the second optical path length difference generating optical path. apparatus.

(Additional Item 36) The optical imaging apparatus according to Additional Item 32, wherein the optical fiber is a polarization-maintaining fiber. (Additional Item 37) The polarization beam splitter is provided so that all of the observation light is guided to the first optical path length difference generation optical path and all of the reference light is guided to the second optical path length difference generation optical path. 35. The optical imaging apparatus according to appendix 34, wherein:

(Additional Item 38) An additional item 3 is characterized in that a polarization plane rotating element is provided in at least one of the first optical path length difference generating optical path and the second optical path length difference generating optical path.
4. The optical imaging device according to item 4. (Additional Item 39) The optical imaging apparatus according to Additional Item 35, wherein the optical path length varying means is an optical path length scanning mechanism.

[0134]

As described above, according to the present invention, it is possible to realize an optical imaging apparatus which can easily adjust the optical path length even when the optical probe is exchanged and used without being affected by the change in the polarization state. it can.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an optical imaging system including a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing an optical imaging device according to a first embodiment of the present invention.

3 is a detailed configuration diagram of the optical imaging apparatus of FIG.

4 is a block diagram of the tip side of the optical probe of FIG.

5 is a configuration diagram of the tip side of the optical probe showing the first modification of FIG.

FIG. 6 is a block diagram of the tip side of an optical probe showing a second modification of FIG.

FIG. 7 is a configuration diagram showing a modification of an optical path length difference generation unit.

8 is an explanatory view showing the filter turntable of FIG. 7.

FIG. 9 is a configuration diagram showing a modified example of the dispersion adjusting unit.

FIG. 10 is a configuration diagram of a tip side of an optical probe showing a modified example of the first light separating means.

FIG. 11 is a configuration diagram of the tip side of the optical probe showing the third modification example of FIG.

FIG. 12 is a schematic enlarged view of FIG.

FIG. 13 is a configuration diagram showing an optical imaging device according to a second embodiment of the present invention.

FIG. 14 is a block diagram of the tip side of the optical probe of FIG.

FIG. 15 is a schematic configuration diagram showing an optical imaging device according to a third embodiment of the present invention.

FIG. 16 is a configuration diagram of a first optical path length difference generation unit.

FIG. 17 is a configuration diagram of a second optical path length difference generation unit.

FIG. 18 is a configuration diagram of a third optical path length difference generation unit.

FIG. 19 is a configuration diagram of a fourth optical path length difference generation unit.

FIG. 20 is a configuration diagram of a fifth optical path length difference generation unit.

FIG. 21 is a configuration diagram of a sixth optical path length difference generation unit.

FIG. 22 is a configuration diagram of a seventh optical path length difference generation unit.

FIG. 23 is a configuration diagram of an eighth optical path length difference generation unit.

FIG. 24 is a schematic configuration diagram showing an optical imaging device according to a fourth embodiment of the present invention.

FIG. 25 is a block diagram of the tip side of the optical probe of FIG.

FIG. 26 is a schematic configuration diagram showing an optical imaging device according to a fifth embodiment of the present invention.

27 is a configuration diagram of an optical path length difference generation unit in FIG. 26.

FIG. 28 is a schematic configuration diagram showing an optical imaging device according to a sixth embodiment of the present invention.

29 is a configuration diagram of an optical path length difference generation unit in FIG. 28.

FIG. 30 is an enlarged view of the optical path length difference generation unit in FIG. 29 on the optical path tip side.

[Explanation of symbols]

1 ... Optical imaging system 2 ... Endoscopic device 3 ... Optical imaging device 9 ... Optical probe 10 ... Device body 21 ... Low coherence light source 22, 24, 25 ... Optical fiber 25a ... End face of optical fiber on the tip side (first light separating means) 23 ... Optical coupler (second light separating means) 26 ... Objective lens 31 ... Optical path length difference generation unit 32 ... Photodetector 33 ... Control unit 34 ... Drive unit 35 ... Signal processing unit 36 ... Optical scanning unit 41 ... Parallel lens 42 ... Half mirror (third light separating means) 43 ... Observation light side reflection mirror 45 ... Dispersion adjusting unit 46. Reference light side reflection mirror 48 ... Detection-side condensing lens

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akihiro Horii             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. F-term (reference) 2G059 AA06 BB12 EE09 FF02 GG02                       GG06 HH01 JJ12 JJ15 JJ17                       JJ19 JJ22 KK01 MM01 MM09                       MM10 NN10

Claims (4)

[Claims] 1. An insertion section that collects low-coherence light from a low-coherence light source onto a subject and receives return light from the subject, and a cross-section of the subject from the return light captured by connecting the insertion portion. In an optical imaging apparatus having an apparatus body for constructing an image, an optical transmission unit that transmits low coherence light generated by the low coherence light source to irradiate a subject, and separates the low coherence light into observation light and reference light. And a light separating unit for adjusting the polarization states of the observation light and the reference light, the light separating unit being provided inside the light transmitting unit, at the end of the light transmitting unit, or between the light transmitting unit and the subject. An optical imaging apparatus comprising a light separating means. 2. The observation light and the reference light separated by the light separating means have the same optical axis inside the light transmitting means or at least a part between the light transmitting means and the subject. The optical imaging apparatus according to claim 1, wherein: 3. The observation light and the reference light separated by the light separation means have an optical interference means for interfering the return observation light by scattering or reflection of the observation light from the subject and the reference light. The optical imaging device according to claim 1, wherein the optical imaging device has the same optical axis inside the light transmitting unit or between the light transmitting unit and the subject, and at least in a part in front of the interference unit. apparatus. 4. The optical imaging apparatus according to claim 1, further comprising an optical path length difference generation unit that generates an optical path length difference between the observation light and the reference light.