JP2011047815A - Oct system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an OCT system capable of obtaining a good tomographic image. <P>SOLUTION: The OCT system 1 is equipped with a light source 11, an optical isolator 12, an optical coupler 13, an optical coupler 21, a variable light attenuator 22, a polarization controller 23, a fiber stretcher 24, an optical path length adjusting part 25, a Faraday rotor mirror 26, a variable light attenuator 27, a polarization controller 31, an optical path length adjusting part 32, optical switches 33<SB>0</SB>-33<SB>6</SB>, an optical fiber array 34, an arranging jig 35, lenses 36 and 37, a photodetector 41, a filter 42, a logarithmic amplifier 43, an AD converter 44, a control part 45 and a memory part 46. The control part 45 controls the optical path length adjusting device 25 or the optical path length adjusting part 32 on the basis of the adjustment quantity stored in the memory part 46 corresponding to the changeover of an optical path in seven respective optical switches 33<SB>0</SB>-33<SB>6</SB>to adjust the optical path length of a reference optical system or measuring optical system. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an OCT apparatus.

  An optical coherence tomography (OCT) device is an interferometer that uses low-coherence light, and uses the intensity distribution of the light reflected or scattered at a position specified with a position resolution of about the coherence length in the light traveling direction as a tomographic image. For example, it is used for diagnosis of an eyeball or a tooth.

  The OCT apparatus disclosed in Patent Document 1 bifurcates light output from a light source into first branched light and second branched light, reflects the first branched light with a mirror, and converts the second branched light into an object. Then, the intensity of the light that is reflected or scattered by the two superimposed light beams is detected by a photodetector.

  In particular, the OCT apparatus disclosed in this document uses a plurality of optical fibers, and guides light to be irradiated to an object by an optical fiber selected from these optical fibers. It also guides reflected or scattered light. This OCT apparatus attempts to obtain a tomographic image of an object at high speed by sequentially switching and using a plurality of optical fibers.

JP-A-6-160272

  However, in the OCT apparatus disclosed in Patent Document 1, when a plurality of optical fibers are sequentially switched and selected, the optical path length differs depending on the selected optical fibers, and distortion may occur in the obtained tomographic image. As a result, this OCT apparatus cannot obtain a good tomographic image.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an OCT apparatus that can obtain a good tomographic image.

The OCT apparatus according to the present invention includes (1) a light source that outputs light, and (2) first to fourth ports, and divides the light output from the light source and input to the first port into two. First branched light and second branched light are output, the first branched light is output from the third port, the second branched light is output from the fourth port, and the light input to each of the third port and the fourth port is the second An interference optical system that outputs from the two ports; and (3) a mirror that reflects and reaches the light that is output from the third port of the interference optical system and inputs the reflected light to the third port of the interference optical system; ) Having ports P _{0 to} P _N , the light output from the fourth port of the interference optical system and input to the port P ₀ is output from the selected port among the ports P _{1 to} P _N and selected an optical switch for outputting the light input to the port from a port P ₀ was, (5), each first end and It has two ends, and one to be optically connected, respectively the N second end is arranged parallel to the optical fiber of the ports P ₁ to P _N of the light first end of each switch, (6) The light output from the second end of any one of the N optical fibers is irradiated onto the object, and the light reflected or scattered by the object due to the irradiation is applied to the first of the optical fibers. (7) The light that is reflected by the mirror and input to the third port of the interference optical system and output from the second port of the interference optical system, and the port P of the optical switch ₀ enter the output light output from the second port of the input interference optical system to the fourth port of the interference optical system from the light detection for detecting the intensity of light obtained by superimposing the two light these input And (8) the optical path between the third port of the interference optical system and the mirror ( Under the "first optical path" hereinafter.) Additionally, or the optical path between the fourth port and the port P ₀ of the optical switch of the interference optical system (hereinafter referred to as "second light path".) Provided on, the optical switch An optical path length adjusting unit that adjusts the optical path length of the first optical path or the second optical path so as to compensate for a change in the optical path length caused by which of the ports P _{1 to} P _N is selected. It is characterized by. However, N is an integer of 2 or more.

  In this case, the OCT apparatus according to the present invention is such that the light source outputs broadband light, and further includes an optical path length operation unit that changes the optical path length between the third port of the interference optical system and the mirror. Is preferred. Alternatively, in the OCT apparatus according to the present invention, it is preferable that the light source outputs narrow-band light and the center wavelength of the output light can be scanned.

Alternatively, the OCT apparatus according to the present invention includes (1) a light source that outputs broadband light, and (2) first to fourth ports, and outputs light output from the light source and input to the first port. The first branch light is output from the third port, the second branch light is output from the fourth port, and is input to the third port and the fourth port, respectively. An interference optical system that outputs the reflected light from the second port, and (3) a mirror that reflects the light that is output from the third port of the interference optical system and that inputs the reflected light to the third port of the interference optical system (4) having ports P _{0 to} P _N and outputting the light output from the fourth port of the interference optical system and input to the port P ₀ from the selected port among the ports P _{1 to} P _N an optical switch, and outputs the input to the selected port light from a port P _0, (5) S has a first end and a second end, the first end of each being optically connected to either of the ports P ₁ to P _N of the optical switch, the second end of each being arranged in parallel N The optical fiber and (6) the light output from the second end of any one of the N optical fibers is irradiated onto the object, and reflected or scattered by the object along with the irradiation. An irradiation optical system for inputting light to the second end of the optical fiber; and (7) inputting the light reflected by the mirror and input to the third port of the interference optical system and output from the second port of the interference optical system. The light output from the port P _{0 of the} optical switch, input to the fourth port of the interference optical system and output from the second port of the interference optical system is input, and the input light of these two lights is superimposed. A photodetector for detecting the intensity, and (8) the third port of the interference optical system and the mirror Features with changing the optical path length, the optical path length adjusting unit for adjusting an optical path length change range by any of the ports of the ports P ₁ to P _N of the optical switch is selected, in that it comprises between the And However, N is an integer of 2 or more.

The OCT apparatus according to the present invention further includes a storage unit that stores an adjustment amount of the optical path length of the first optical path or the second optical path for each of the ports P _{1 to} P _N of the optical switch, and the optical path length adjustment unit is configured by the storage unit. It is preferable to adjust the optical path length of the first optical path or the second optical path based on the stored adjustment amount. In the OCT apparatus according to the present invention, N optical fibers are preferably arranged in a fiber array, and it is also preferable that N optical fibers are bundled and bundled.

  The OCT apparatus according to the present invention can obtain a good tomographic image.

It is a figure which shows the structure of the OCT apparatus 1 which concerns on 1st Embodiment. It is a figure which shows the structure of the OCT apparatus 2 which concerns on 2nd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  (First embodiment)

FIG. 1 is a diagram illustrating a configuration of an OCT apparatus 1 according to the first embodiment. The OCT apparatus 1 shown in this figure includes a light source 11, an optical isolator 12, an optical coupler 13, an optical coupler 21, a variable optical attenuator 22, a polarization controller 23, a fiber stretcher 24, an optical path length adjustment unit 25, and a Faraday rotator mirror. 26, variable optical attenuator 27, polarization controller 31, optical path length adjustment unit 32, optical switches 33 _{0 to} 33 ₆ , optical fiber array 34, arrangement jig 35, lenses 36 and 37, photodetector 41, filter 42, A logarithmic amplifier 43, an AD converter 44, a control unit 45, and a storage unit 46 are provided.

  The light source 11 outputs broadband low-coherence light, and is preferably, for example, a superluminescent diode (SLD). The optical isolator 12 passes the light output from the light source 11 to the optical coupler 13 but does not pass the light in the reverse direction.

  The optical coupler 13 has first to fourth ports. The first port of the optical coupler 13 is optically connected to the optical isolator 12. The second port of the optical coupler 13 is optically connected to the photodetector 41. The third port of the optical coupler 13 is optically connected to the optical coupler 21. The fourth port of the optical coupler 13 is optically connected to the polarization controller 31.

  The optical coupler 13 bifurcates the light output from the light source 11 and input to the first port via the optical isolator 12 into the first branched light and the second branched light, and the first branched light from the third port to the optical coupler. 21, and the second branched light is output from the fourth port to the polarization controller 31. The optical coupler 13 outputs the light input to the third port from the optical coupler 21 and the light input to the fourth port from the polarization controller 31 to the photodetector 41 from the second port. That is, the optical coupler 13 acts as a Michelson type interference optical system.

  In the reference optical system from the third port of the optical coupler 13 to the Faraday rotator mirror 26, an optical coupler 21, a variable optical attenuator 22, a polarization controller 23, a fiber stretcher 24, and an optical path length adjustment unit 25 are provided in this order. ing.

  The optical coupler 21 outputs the light reaching from the optical coupler 13 to the variable optical attenuator 22 and outputs the light reaching from the variable optical attenuator 22 to the variable optical attenuator 27. The variable optical attenuator 22 attenuates the passing light. The amount of attenuation in the variable optical attenuator 22 is variable. The polarization controller 23 adjusts the polarization of light passing therethrough.

  The fiber stretcher 24 is obtained by winding an optical fiber around a piezo element, and changes the optical path length of the optical fiber by the action of the piezo element. The optical path length of the reference optical system can be changed within a range of about 4 mm by the fiber stretcher 24. The optical path length adjustment unit 25 also changes the optical path length of the reference optical system. The optical path length adjustment unit 25 is used for coarse adjustment of the optical path length. The fiber stretcher 24 is used as an optical path length operation unit that changes the optical path length of the reference optical system in order to specify the reflection position or scattering position in the object.

  The Faraday rotator mirror 26 inputs the light output from the third port of the optical coupler 13 and reaching through the optical coupler 21, the variable optical attenuator 22, the polarization controller 23, the fiber stretcher 24, and the optical path length adjustment unit 25. The input light is reflected to the optical path length adjustment unit 25, and the polarization plane of the light is rotated by 90 degrees.

  The variable optical attenuator 27 receives the light that has arrived from the optical coupler 21, attenuates the light, and outputs the attenuated light to the photodetector 41. The amount of attenuation in the variable optical attenuator 27 is variable.

The measurement optical system from the fourth port of the optical coupler 13 to the object includes a polarization controller 31, an optical path length adjustment unit 32, optical switches 33 _{0 to} 33 ₆ , an optical fiber array 34, an array jig 35, and a lens 36. And the lens 37 is provided in order.

  The polarization controller 31 adjusts the polarization of light passing therethrough. The optical path length adjustment unit 32 adjusts the optical path length of the measurement optical system.

Each of the optical switches 33 _{0 to} 33 ₆ is a 1 × 8 optical switch. 8 ports of the optical switch 33 ₀ is connected to the six optical switches ₃₃ to 333 ₆ each 1 port and the optical system. Accordingly, the entire seven optical switches 33 _{0 to} 33 ₆ are 1 × 48 optical switches having the ports P _{0 to} P _48, and the light input to the port P ₀ is converted into the ports P _{1 to} P _48. output from the selected port of the outputs of the light input to the selected port from the port P _0.

The optical fiber array 34 includes 48 optical fibers. The first end of each of the 48 optical fibers is optically connected to _one of the ports P _{1 to} P ₄₈ of the 1 × 48 optical switch composed of the entire seven optical switches 33 _{0 to} 33 _6. ing. The second ends of the 48 optical fibers are arranged in parallel and fixed by the arrangement jig 35. The 48 optical fibers may be bundled and bundled.

  The lens 36 and the lens 37 irradiate the object with light output from the second end of any one of the 48 optical fibers included in the optical fiber array 34, and the object is accompanied by the irradiation. It is used as an irradiation optical system for inputting reflected or scattered light to the second end of the optical fiber.

  The photodetector 41 receives the light that has been output from the second port of the optical coupler 13 and arrived, and also receives the light that has arrived from the optical coupler 21 via the variable optical attenuator 27. By taking the difference, the noise component is removed, and the signal after the noise removal is amplified and an electric signal is output. The filter 42 selectively outputs a component in a predetermined frequency band in the electrical signal output from the photodetector 41 to the logarithmic amplifier 43.

  The logarithmic amplifier 43 logarithmically amplifies the electrical signal output from the filter 42 and outputs the amplified electrical signal to the AD converter 44. The AD converter 44 converts the electric signal value (analog value) output from the logarithmic amplifier 43 into a digital value, and outputs the digital value to the control unit 45.

The control unit 45 inputs the digital value output from the AD converter 44. Further, the control unit 45 selects one of the 48 optical fibers included in the optical fiber array 34 by controlling the optical path switching in each of the seven optical switches 33 _{0 to} 33 _6. Then, the measurement light is guided to the selected optical fiber. The control unit 45 adjusts the optical path length of the reference optical system by controlling the optical path length adjustment unit 25, and changes the optical path length of the reference optical system by controlling the fiber stretcher 24. Further, the control unit 45 adjusts the optical path length of the measurement optical system by controlling the optical path length adjustment unit 32.

The storage unit 46 stores the adjustment amount of the optical path length of the reference optical system or the measurement optical system for each of the ports P _{1 to} P _N of the optical switch. The amount of adjustment of the optical path length depends on the length of the optical fiber connected to each of the ports P _{1 to} P _N of the optical switch. The control unit 45 adjusts the optical path length of the reference optical system or the measurement optical system by controlling the optical path length adjustment unit 25 or the optical path length adjustment unit 32 based on the adjustment amount stored in the storage unit 46. The optical path length change caused by the optical path switching in each of the optical switches 33 _{0 to} 33 ₆ is compensated.

  The OCT apparatus 1 configured as described above is controlled by the control unit 45 and operates as follows. The broadband low-coherence light output from the light source 11 passes through the optical isolator 12, is input to the first port of the optical coupler 13, and is branched into two by the optical coupler 13, and the first branched light and the second branched light. Is done. The first branched light is output from the third port of the optical coupler 13 to the optical coupler 21. The second branched light is output from the fourth port of the optical coupler 13 to the polarization controller 31.

  The light output from the third port of the optical coupler 13 to the optical coupler 21 passes through the optical coupler 21, the variable optical attenuator 22, the polarization controller 23, the fiber stretcher 24, and the optical path length adjustment unit 25 in order, and the Faraday rotator mirror 26. And is reflected by the Faraday rotator mirror 26. The light reflected by the Faraday rotator mirror 26 returns to the optical couplers 21 and 13 through the reverse path, and part of the light reaches the photodetector 41 via the variable optical attenuator 27 from the optical coupler 21 and part of the light. The light reaches the photodetector 41 from the optical coupler 13. During this time, the light is attenuated by the variable optical attenuator 22 and the variable optical attenuator 27, the polarization is adjusted by the polarization controller 23 and the Faraday rotator mirror 26, and the fiber stretcher 24 and the optical path length adjustment unit 25. To adjust the optical path length.

Light output from the fourth port of the optical coupler 13 to the polarization controller 31 passes through the polarization controller 31 and the optical path length adjustment unit 32, and is selected from the optical fiber array 34 selected by the optical switches 33 _{0 to} 33 ₆ . It is guided by one of the optical fibers, passes through the lens 36 and the lens 37, and is focused and irradiated on the object. The light reflected or scattered by the object along with the irradiation returns to the optical coupler 13 through the reverse path, and reaches the photodetector 41 from the optical coupler 13. During this time, the polarization of the light is adjusted by the polarization controller 31, and the optical path length is adjusted by the optical path length adjustment unit 32.

  The light output from the second port of the optical coupler 13 arrives at the photodetector 41 and the light from the optical coupler 21 via the variable optical attenuator 27 arrives. The light that is output from the second port of the optical coupler 13 and reaches the photodetector 41 is light in which the light reflected by the Faraday rotator mirror 26 and the light reflected or scattered by the object are superimposed. The light reaching the photodetector 41 from the optical coupler 21 via the variable optical attenuator 27 is light reflected by the Faraday rotator mirror 26.

  The difference between the intensities of both lights received by the photodetector 41 is amplified and an electric signal is output. A component in a predetermined frequency band in the electrical signal output from the photodetector 41 is selectively output by the filter 42 and logarithmically amplified by the logarithmic amplifier 43. The electric signal value (analog value) output from the logarithmic amplifier 43 is converted into a digital value by the AD converter 44, and this digital value is input to the control unit 45.

The control unit 45 controls optical path switching in each of the seven optical switches 33 _{0 to} 33 _{6, and} selects one of the 48 optical fibers included in the optical fiber array 34. Measurement light is guided to the selected optical fiber. Further, the control unit 45 controls the fiber stretcher 24 to change the optical path length of the reference optical system. By selecting the optical fiber and changing the optical path length of the reference optical system, a tomographic image of the object can be obtained.

Further, the control unit 45 controls the optical path length adjustment unit 25 or the optical path length adjustment unit 32, and depending on which port is selected by the seven optical switches 33 _{0 to} 33 ₆ (that is, 48 optical signals). The optical path length of the reference or measurement optical system is adjusted to compensate for the change in optical path length that occurs (depending on which optical fiber is selected from the fibers). Thus, when the optical fiber is selected from among the 48 optical fibers included in the optical fiber array 34 is switched by the optical switch 33 _{0-33 6,} it changes the length of the optical fiber with its switching Even so, the change in the length of the optical fiber is compensated by the optical path length adjustment unit 25 or the optical path length adjustment unit 32. Therefore, the OCT apparatus 1 according to the present embodiment can obtain a good tomographic image in which distortion is suppressed.

  (Second Embodiment)

FIG. 2 is a diagram illustrating a configuration of the OCT apparatus 2 according to the second embodiment. The OCT apparatus 2 shown in this figure includes a light source 11, an optical isolator 12, an optical coupler 13, an optical coupler 21, a variable optical attenuator 22, a polarization controller 23, an optical path length adjustment unit 25, a Faraday rotator mirror 26, a variable light. Attenuator 27, polarization controller 31, optical path length adjustment unit 32, optical switches 33 _{0 to} 33 ₆ , optical fiber array 34, arrangement jig 35, lenses 36 and 37, photodetector 41, filter 42, logarithmic amplifier 43, An AD converter 44, a control unit 45, and a storage unit 46 are provided.

  Compared with the configuration of the OCT apparatus 1 according to the first embodiment shown in FIG. 1, the OCT apparatus 2 according to the second embodiment shown in FIG. 2 has a light source 11 that outputs narrowband light. The difference is that the center wavelength of the output light can be scanned, the difference is that the fiber stretcher 24 is not provided, and the control unit 45 converts the digital value output from the AD converter 44 into the intensity for each frequency component. It is different in that the distribution of strength vs. depth is obtained by decomposing into two. The OCT apparatus 2 according to the second embodiment can obtain a tomographic image of an object by scanning the center wavelength of the narrowband light output from the light source 11 instead of changing the optical path length of the reference optical system. it can.

In the present embodiment, when the optical fiber is selected from among the 48 optical fibers included in the optical fiber array 34 is switched by the optical switch 33 _{0-33 6,} the length of the optical fiber with its switching Is changed by the optical path length adjusting unit 25 or the optical path length adjusting unit 32. Therefore, the OCT apparatus 2 according to the present embodiment can also obtain a good tomographic image in which distortion is suppressed.

  (Modification)

In the said 1st Embodiment, the fiber stretcher 24 and the optical path length adjustment part 25 are. You may be comprised by the integrated optical path length adjustment part. The integrated optical path length adjustment unit in this case changes the optical path length of the reference optical system between the third port of the optical coupler 13 and the mirror 26, and also includes the optical switch ports P _{1 to} P ₄₈ . The optical path length change range is adjusted according to which port is selected. The adjustment of the optical path length change range in the integrated optical path length adjustment unit corresponds to the adjustment of the optical path length of the reference optical system by the optical path length adjustment unit 25.

DESCRIPTION OF SYMBOLS 1, 2 ... OCT apparatus, 11 ... Light source, 12 ... Optical isolator, 13 ... Optical coupler, 21 ... Optical coupler, 22 ... Variable optical attenuator, 23 ... Polarization controller, 24 ... Fiber stretcher, 25 ... Optical path length adjustment part , 26 ... Faraday rotator mirror, 27 ... Variable optical attenuator, 31 ... Polarization controller, 32 ... Optical path length adjustment unit, 33 _{0 to} 33 ₆ ... Optical switch, 34 ... Optical fiber array, 35 ... Arrangement jig, 36 , 37 ... lens, 41 ... photodetector, 42 ... filter, 43 ... logarithmic amplifier, 44 ... AD converter, 45 ... control unit, 46 ... storage unit.

Claims (7)

A light source that outputs light;
A first to a fourth port; the light output from the light source and input to the first port is bifurcated into a first branched light and a second branched light; and the first branched light is the first branched light. An interference optical system that outputs from the third port, outputs the second branched light from the fourth port, and outputs light input to each of the third port and the fourth port from the second port;
A mirror that reflects and reaches the light output from the third port of the interference optical system and that inputs the reflected light to the third port of the interference optical system;
The light having the ports P _{0 to} P _N and outputted from the fourth port of the interference optical system and inputted to the port P ₀ is outputted from the selected port among the ports P _{1 to} P _N An optical switch for outputting the light input to the selected port from the port P ₀ ;
Each has a first end and a second end, and each of the first ends is optically connected to _{one of the} ports P _{1 to} P _N of the optical switch, and each of the second ends is in parallel N optical fibers arranged,
The light output from the second end of any one of the N optical fibers is irradiated onto the object, and the light reflected or scattered by the object due to the irradiation is applied to the second end of the optical fiber. An irradiation optical system to input,
The light reflected by the mirror and input to the third port of the interference optical system and output from the second port of the interference optical system is input, and also output from the port P _{0 of the} optical switch and the interference. A photodetector that receives light input to the fourth port of the optical system and output from the second port of the interference optical system, and detects the intensity of the light superimposed by the two input lights; ,
On the optical path (hereinafter referred to as “first optical path”) between the third port of the interference optical system and the mirror, or on the fourth port of the interference optical system and the port P _{0 of the} optical switch. Between the optical switches (hereinafter referred to as “second optical path”) to compensate for a change in the optical path length caused by which of the ports P _{1 to} P _N of the optical switch is selected. An optical path length adjustment unit for adjusting the optical path length of the first optical path or the second optical path,
An OCT apparatus (where N is an integer of 2 or more). The light source outputs broadband light, and
An optical path length operation unit for changing an optical path length between the third port of the interference optical system and the mirror;
The OCT apparatus according to claim 1.   The OCT apparatus according to claim 1, wherein the light source outputs narrow band light and can scan the center wavelength of the output light. A light source that outputs broadband light;
A first to a fourth port; the light output from the light source and input to the first port is bifurcated into a first branched light and a second branched light; and the first branched light is the first branched light. An interference optical system that outputs from the third port, outputs the second branched light from the fourth port, and outputs light input to each of the third port and the fourth port from the second port;
A mirror that reflects and reaches the light output from the third port of the interference optical system and that inputs the reflected light to the third port of the interference optical system;
The light having the ports P _{0 to} P _N and outputted from the fourth port of the interference optical system and inputted to the port P ₀ is outputted from the selected port among the ports P _{1 to} P _N An optical switch for outputting the light input to the selected port from the port P ₀ ;
Each has a first end and a second end, and each of the first ends is optically connected to _{one of the} ports P _{1 to} P _N of the optical switch, and each of the second ends is in parallel N optical fibers arranged,
The light output from the second end of any one of the N optical fibers is irradiated onto the object, and the light reflected or scattered by the object due to the irradiation is applied to the second end of the optical fiber. An irradiation optical system to input,
The light reflected by the mirror and input to the third port of the interference optical system and output from the second port of the interference optical system is input, and also output from the port P _{0 of the} optical switch and the interference. A photodetector that receives light input to the fourth port of the optical system and output from the second port of the interference optical system, and detects the intensity of the light superimposed by the two input lights; ,
The optical path length change range varies depending on which of the ports P _{1 to} P _N of the optical switch is selected while changing the optical path length between the third port of the interference optical system and the mirror. An optical path length adjustment unit for adjusting
An OCT apparatus (where N is an integer of 2 or more). A storage unit for storing an adjustment amount of the optical path length of the first optical path or the second optical path for each of the ports P _{1 to} P _{N of the} optical switch;
The optical path length adjustment unit adjusts the optical path length of the first optical path or the second optical path based on the adjustment amount stored by the storage unit;
The OCT apparatus according to claim 1 or 4, wherein   The OCT apparatus according to claim 1, wherein the N optical fibers are arranged in a fiber array. The OCT apparatus according to claim 1, wherein the N optical fibers are bundled and bundled.

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