CN114847869A - Dual-band imaging system and method for large-field visible light OCT - Google Patents
Dual-band imaging system and method for large-field visible light OCT Download PDFInfo
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Abstract
The invention discloses a dual-waveband imaging system and a method of large-field visible light OCT, which comprises the following steps: the light beam is incident on the detection sample through the sample arm and reflected, and generates interference with the light beam reflected in the reference arm, and the interference light beam is incident into the spectrometer; in the spectrometer, interference light beams are split after sequentially passing through a second collimator and a grating, the split interference light beams are focused through a third focusing lens, part of the interference light beams are reflected to a first CCD array through a reflector, and the rest interference light beams are incident to a second CCD array, so that large-depth imaging and high-resolution imaging are respectively carried out according to the interference light beams of different wave bands. The invention solves the problem that the imaging range is difficult to align due to the small detection depth of the visible light OCT in the large-field scanning detection.
Description
Technical Field
The invention relates to the technical field of optical coherence tomography, in particular to a two-waveband imaging system and method of large-field visible light OCT.
Background
The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.
Optical coherence tomography (OCT for short) is a new medical imaging method proposed in the nineties of the last century, and has the advantages of high resolution, strong chromatographic capacity, non-contact, non-invasive and the like. The OCT technology is widely applied to the field of ophthalmic diagnosis, can be used for fundus imaging, retinal cross section imaging and the like, and has important functions and significance for early diagnosis and clinical diagnosis of ophthalmic diseases such as glaucoma, diabetic retinopathy and the like.
The visible light OCT technology uses a light source in a visible light band for scanning imaging, because the wavelength of light waves in the visible light band is shorter and the frequency of the light waves is higher, compared with a conventional OCT system using a near-infrared light source, the OCT system has higher image resolution, but the increase of the frequency of the light source causes the reduction of the imaging depth. When a large field of view scan is performed, the retina exceeds the imaging range due to the curvature of the eyeball, and the retina exceeds the imaging range, which causes a problem of difficult alignment.
Disclosure of Invention
In order to solve the problems, the invention provides a dual-band imaging system and a dual-band imaging method for large-field visible light OCT, which are used for acquiring a large-depth image and a high-resolution image simultaneously and solving the problem that the imaging range is difficult to align due to the small detection depth of the visible light OCT in large-field scanning detection.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a dual-band imaging system for large-field visible light OCT, comprising: the device comprises a light-emitting device, a sample arm, a reference arm and a spectrometer;
the light-emitting device is used for generating light beams and irradiating the light beams into the sample arm and the reference arm;
the sample arm comprises a first collimator, a scanning galvanometer, a first focusing lens and a second focusing lens, and incident light beams are incident on the detection sample and reflected through the first collimator, the scanning galvanometer, the first focusing lens and the second focusing lens in sequence; after reflecting the incident light beam, the reference arm interferes with the light beam reflected in the sample arm, and the generated interference light beam is incident into the spectrometer;
the spectrometer comprises a second collimator, a grating, a first CCD array, a reflecting mirror, a second CCD array, a beam expander and a third focusing lens, interference light beams are split after sequentially passing through the second collimator and the grating, the split interference light beams are focused through the third focusing lens, part of the interference light beams are reflected to the first CCD array through the reflecting mirror and the beam expander, and the rest interference light beams are incident to the second CCD array, so that large-depth imaging and high-resolution imaging are respectively carried out according to the interference light beams of different wave bands.
As an alternative embodiment, the light emitting device comprises a light source and an optical coupler; the optical coupler is respectively connected with the sample arm, the reference arm and the spectrometer, the light source emits light beams in a continuous spectrum range, and the light beams enter the reference arm and the sample arm after passing through the optical coupler; and the light beam reflected in the reference arm and the light beam reflected in the sample arm pass through the optical coupler, interfere in the optical coupler, and then the interference light beam is incident into the spectrometer.
As an alternative embodiment, the light emitting device comprises a light source, a fourth collimator, a light splitting element, a fifth collimator, and a sixth collimator; the light source is connected with the input end of a fourth collimator, the output end of the fourth collimator is arranged opposite to the input end of the light splitting element, the plane mirror of the reference arm is arranged opposite to the reflection output end of the light splitting element, and the input end of the fifth collimator is arranged opposite to the transmission output end of the light splitting element; the output end of the fifth collimator is connected with the first collimator; the input end of the sixth collimator is opposite to the coherent output end of the light splitting element, and the output end of the sixth collimator is connected with the spectrometer.
As an alternative embodiment, the incident light beam is collimated by the first collimator and then converted into a parallel light beam, the parallel light beam is incident into the scanning galvanometer, the parallel light beam is scanned by the scanning galvanometer and then reflected into the 4f system, and the parallel light beam is refracted by the 4f system and then incident on the detection sample.
As an alternative embodiment, the 4f system includes a first focusing lens and a second focusing lens; parallel light beams pass through an object space focal point of the first focusing lens and are focused on an image space focal plane of the first focusing lens after being refracted, the image space focal plane of the first focusing lens is superposed with an object space focal plane of the second focusing lens, and the parallel light beams are incident on a detection sample through the image space focal point of the second focusing lens after passing through the object space focal plane of the second focusing lens.
As an alternative embodiment, the relative positions of the first collimator, the scanning galvanometer, and the 4f system are adjusted by the focal lengths of the first focusing lens and the second focusing lens.
As an alternative embodiment, the splitting of the different wavelength bands of the light beams by the reflecting mirror includes that when the third focusing lens refracts the interference light beams, a part of the longer wavelength band of the interference light beams is reflected by the reflecting mirror to the first CCD array, and the rest of the interference light beams are directly incident to the second CCD array.
As an alternative embodiment, the wavelength band of the interference light beam reflected into the first CCD array is larger than the wavelength band of the interference light beam incident into the second CCD array, and the spectral width of the interference light beam reflected into the first CCD array is smaller than the spectral width of the interference light beam in the second CCD array.
As an alternative embodiment, large depth imaging is performed based on the characteristic that the spectral resolution of the interference light beam reflected into the first CCD array is high; and performing high-resolution imaging based on the characteristic of large spectral width of the interference light beam incident into the second CCD array.
As an alternative embodiment, a beam expander is provided between the mirror and the first CCD array for expanding the diameter of the interfering light beam reflected into the first CCD array, thereby increasing the spectral resolution.
In a second aspect, the present invention provides an imaging method of a dual-band imaging system using the large-field visible light OCT of the first aspect, including:
the incident light beam is incident on the detection sample after passing through the sample arm and is reflected, and the imaging position of the detection sample in the depth direction and the imaging range of high resolution are adjusted by adjusting the optical path of the reference arm;
after reflecting the incident light beam, the reference arm interferes with the light beam reflected in the sample arm, and the generated interference light beam is incident into the spectrometer;
in the spectrometer, interference light beams are split after sequentially passing through a second collimator and a grating, the split interference light beams are focused through a third focusing lens, part of the interference light beams are reflected to a first CCD array through a reflector, and the rest interference light beams are incident to a second CCD array, so that large-depth imaging and high-resolution imaging are respectively carried out according to the interference light beams of different wave bands.
Compared with the prior art, the invention has the beneficial effects that:
the invention provides a two-waveband imaging system and a two-waveband imaging method of a large-visual-field visible light OCT (optical coherence tomography), which are used for simultaneously acquiring a large-depth image and a high-resolution image by reflecting light beams of different wavebands on a detection sample and respectively detecting spectral information of the two different wavebands by utilizing a grating and two CCD (charge coupled device) arrays and solving the problem that the imaging range is difficult to align due to the small detection depth of the visible light OCT in the large-visual-field scanning detection.
The invention provides a double-waveband imaging system and a method of large-field-of-view visible light OCT.
Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.
FIG. 1 is a schematic diagram of a dual-band imaging system of large-field visible light OCT provided by embodiment 1 of the present invention;
FIG. 2 is a schematic diagram of a dual-band imaging system of large-field visible light OCT provided by embodiment 2 of the present invention;
fig. 3 is a schematic diagram of dual-band imaging provided in embodiments 1 and 2 of the present invention.
Detailed Description
The invention is further described with reference to the following figures and examples.
It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise, and it should be understood that the terms "comprises" and "comprising", and any variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.
Example 1
As shown in fig. 1, the present embodiment provides a dual-band imaging system of large-field visible light OCT, including: the device comprises a light-emitting device, a sample arm, a reference arm, a spectrometer, a first image processing system and a second image processing system;
the light-emitting device is used for generating a light beam and comprises a light source and an optical coupler; the optical coupler is respectively connected with the sample arm, the reference arm and the spectrometer, light beams emitted by the light source enter the optical coupler, the light beams are light beams in a continuous spectrum range, and the light beams are incident into the sample arm and the reference arm after passing through the optical coupler;
the sample arm comprises a first collimator, a scanning galvanometer, a first focusing lens and a second focusing lens, and incident light beams are incident on the detection sample and reflected through the first collimator, the scanning galvanometer, the first focusing lens and the second focusing lens in sequence; after reflecting the incident light beam, the reference arm interferes with the light beam reflected in the sample arm, and the generated interference light beam is incident into the spectrometer;
the spectrometer comprises a second collimator, a grating, a first CCD array, a reflecting mirror, a second CCD array, a beam expander and a third focusing lens, interference light beams are split after sequentially passing through the second collimator and the grating, the split interference light beams are focused by the third focusing lens, part of the interference light beams are reflected to the first CCD array by the reflecting mirror, and the rest of the interference light beams are incident to the second CCD array, so that large-depth imaging and high-resolution imaging are respectively carried out according to the interference light beams of different wave bands.
In this embodiment, the reference arm includes a third collimator and a plane mirror, and after the light beam enters the reference arm, the light beam is collimated by the third collimator and then reflected to the optical coupler by the plane mirror; during large-field scanning, due to the eyeball curvature, when different positions of a retina are scanned, the alignment position of an imaging range needs to be adjusted in real time according to the scanning position, and because the reference light reflected by the reference arm only interferes with the sample arm scattered light with a specific optical path difference, the imaging position of the OCT in the depth direction is adjusted by adjusting the optical path of the reference arm.
In the embodiment, in the sample arm, the light beam reflected back by the human eye sequentially passes through the second focusing lens, the first focusing lens, the scanning galvanometer and the first collimator to be incident into the optical coupler, the light beam reflected or scattered back by the reference arm and the sample arm interferes at the optical coupler, and the optical coupler is connected with the second collimator of the spectrometer to be incident into the spectrometer.
Example 2
As shown in fig. 2, the present embodiment provides a dual-band imaging system of large-field visible light OCT, including: the device comprises a light-emitting device, a sample arm, a reference arm, a spectrometer, a first image processing system and a second image processing system;
the light-emitting device is used for generating a light beam and comprises a light source, a fourth collimator, a light splitting element, a fifth collimator and a sixth collimator; the light beam emitted by the light source sequentially enters the sample arm through the fourth collimator, the light splitting element and the fifth collimator and is reflected into the reference arm through the light splitting element;
the sample arm comprises a first collimator, a scanning galvanometer, a first focusing lens and a second focusing lens, and incident light beams are incident on the detection sample and reflected through the first collimator, the scanning galvanometer, the first focusing lens and the second focusing lens in sequence; after reflecting the incident light beam, the reference arm interferes with the light beam reflected in the sample arm, and the generated interference light beam is incident into the spectrometer;
the spectrometer comprises a second collimator, a grating, a first CCD array, a reflecting mirror, a second CCD array, a beam expander and a third focusing lens, interference light beams are split after sequentially passing through the second collimator and the grating, the split interference light beams are focused through the third focusing lens, part of the interference light beams are reflected to the first CCD array through the reflecting mirror, and the rest interference light beams are incident to the second CCD array, so that large-depth imaging and high-resolution imaging are respectively carried out according to the interference light beams of different wave bands.
In this embodiment, the light source is connected to an input end of a fourth collimator through an optical fiber, an output end of the fourth collimator is opposite to an input end of a light splitting element (a spectroscope or a beam splitter), and the light splitting element (the spectroscope or the beam splitter) is configured to receive output light of the fourth collimator;
the plane mirror of the reference arm is opposite to the position of the reflection output end of the light splitting element (the spectroscope or the beam splitter), and the input end of the fifth collimator is opposite to the position of the transmission output end of the light splitting element (the spectroscope or the beam splitter); the output end of the fifth collimator is connected with the input end of the first collimator;
the input end of the sixth collimator is opposite to the coherent output end of the light splitting element (spectroscope or beam splitter), and the output end of the sixth collimator is connected with the second collimator of the spectrometer.
During large-field scanning, due to the eyeball curvature, when different positions of a retina are scanned, the alignment position of an imaging range needs to be adjusted in real time according to the scanning position, and because the reference light reflected by the reference arm only interferes with the sample arm scattered light with a specific optical path difference, the imaging position of the OCT in the depth direction is adjusted by adjusting the optical path of the reference arm.
The reference arm comprises a plane mirror, and light beams are incident on the reference arm and then reflected by the plane mirror; in the sample arm, a light beam sequentially passes through the second focusing lens, the first focusing lens, the scanning galvanometer and the first collimator to be reflected, the reflected light beam passes through the fifth collimator and then interferes with a light beam reflected by the reference arm, and then the interference light beam passes through the sixth collimator and then enters the spectrometer.
The two-band imaging system of the large-field-of-view visible light OCT provided in the above embodiments 1 and 2 is different from the two-band imaging system in that the light emitting device and the reflected light interfere with each other, and the rest of the structural compositions and principles are consistent. Specifically, the sample arm comprises a first collimator, a scanning galvanometer and a 4f system; the incident light beam is collimated by the first collimator and then converted into a parallel light beam, the parallel light beam is incident into the scanning galvanometer, the parallel light beam is scanned by the scanning galvanometer and then reflected into the 4f system, and the parallel light beam is refracted by the 4f system and then incident onto a detection sample;
specifically, the 4f system includes a first focusing lens and a second focusing lens; firstly, parallel light beams pass through an object space focal point of a first focusing lens, are refracted by the first focusing lens and then are focused on an image space focal plane of the first focusing lens;
then, the image space focal plane of the first focusing lens is superposed with the object space focal plane of the second focusing lens, and the parallel light beams focused on the image space focal plane of the first focusing lens are changed into parallel light beams passing through the image space focal plane of the second focusing lens after passing through the object space focal plane of the second focusing lens;
finally, the parallel light beams are incident on the detection sample through the image side focus of the second focusing lens.
Taking fundus imaging as an example, the pupil of the human eye is located at the image space focus of the second focusing lens, and then the parallel light beam passing through the image space focus of the second focusing lens enters the human eye and is focused on the retina through refraction of the crystalline lens of the human eye, so that fundus imaging is performed.
As an alternative embodiment, the relative position relationship of the first collimator, the scanning galvanometer and the 4f system is related to the 4 focal lengths of the first focusing lens and the second focusing lens.
In an alternative embodiment, the scanning galvanometer uses an X-Y scanning galvanometer to scan the light beam along both X and Y directions.
Through the refraction of the 4f system, the scanning beam of the scanning galvanometer is changed into a parallel beam which always passes through the detection sample, and the range of the scanning beam is ensured to be always within the range of the detection sample. By taking fundus imaging as an example, through refraction of the 4f system, the scanning beam of the scanning galvanometer is changed into a parallel beam which always passes through the pupils of human eyes, so that the eye entering range of the scanning beam is always within the range of the pupils of the human eyes, and the pupils of the human eyes play a role in limiting the parallel beam entering the eyes, so that the beam irradiating out of the range of the pupils cannot enter the human eyes.
In embodiment 1 and embodiment 2, the spectrometer includes: the system comprises a second collimator, a grating, a first CCD array, a reflector, a beam expander, a second CCD array and a third focusing lens;
the second collimator is connected with the optical coupler or the sixth collimator, interference beams are collimated by the second collimator and then enter the grating, the grating is used for splitting the incident interference beams, and then the split beams are focused on the second CCD array through the third focusing lens;
the light splitting is to transmit interference light beams with different wavelengths at different angles, the interference light beams with the same wavelength are transmitted at the same angle, the light wavelengths of the interference light beams refracted out from the third focusing lens are continuously distributed from small to large after the interference light beams pass through the grating and the third focusing lens, namely, the light beams with different wavelengths are focused at different positions of the second CCD array, and the light beams with the maximum wavelength and the minimum wavelength are respectively positioned at two sides, so that the light splitting is realized, and the light intensities with different wavelengths can be detected.
The light splitting of the light beams with different wave bands is carried out through the reflector, namely when the interference light beams are refracted by the third focusing lens, a part of first interference light beams with longer wave bands are reflected into the first CCD array through the reflector, and the other part of second interference light beams are directly incident into the second CCD array, so that the light splitting of the light beams with different wave bands is realized; the wave band of the first interference light beam is larger than that of the second interference light beam, and the spectral width of the first interference light beam is smaller than that of the second interference light beam.
Compared with the second CCD array, the first CCD array has a narrower spectral range corresponding to the same pixel, so that the spectral resolution of the first CCD array is higher, and the imaging depth of the first CCD array is larger; the spectral width of the second CCD array is larger, so that the imaging resolution is higher; the large-depth imaging is carried out based on the characteristic that the spectral resolution of the first interference light beam is high; and performing high-resolution imaging based on the characteristic of large spectral width of the second interference light beam.
As an alternative embodiment, a beam expander is arranged between the mirror and the first CCD array, said beam expander comprising a concave lens and a fourth focusing lens for enlarging the diameter of the first interfering light beam, thereby increasing the spectral resolution of the spectrometer;
specifically, when the first interference light beam is reflected to the first CCD array by the reflector, since the spectral range of the reflected first interference light beam is small, a beam expander is added between the first CCD array and the reflector to increase the photosensitive area of the first CCD array, and the detection wavelength band of each CCD photosensitive element in the first CCD array is smaller on average, that is, the detection resolution of the spectrum is higher, so as to increase the imaging depth of OCT; and the second interference beam is directly incident into the second CCD array, the resolution is high due to its large spectral range, but the imaging depth is reduced.
In an alternative embodiment, the beam expander is a galileo type beam expander, or a keplerian type beam expander, or other similar functional beam expander.
As an alternative embodiment, the cross section of the reflector is trapezoidal, when the first interference light beam in the long wavelength band is reflected, the detection resolution of the first interference light beam can be improved, and the detection of the light in the other wavelength band is not blocked, and the light splitting detection of the first interference light beam and the second interference light beam is performed through the reflector, so that the utilization of the full-wavelength band light source is realized.
In an alternative embodiment, the grating used is a transmission grating with a groove density of 1800l/mm, the grating constant d is 555.56nm, the diameter of the beam collimated by the second collimator is 1mm, the wavelength range of the beam is 500nm to 600nm, and the grating incidence angle i is 45 °.
The grating equation is: d (sin i-sin θ) ═ m λ; where d is the grating constant, i is the incident angle, θ is the diffraction angle, m is the spectral order, where m is 1 and λ is the wavelength of the incident light.
Calculated according to the grating equation, when the wavelength of light is 500nm, the diffraction angle is theta 1 At-11.12 deg. and a light wavelength of 600nm, theta 2 ＝-21.89°。
The diameter of the third focusing lens is 30mm, the focal length f is 100mm, the object space focal plane of the third focusing lens coincides with the surface of the grating, the focal point coincides with the center of the grating, and the light beam distribution length at the image space focal plane of the third focusing lens can be calculated to be 18.85 mm.
The spectrometer adopts a linear CCD array as a photosensitive element, the number of effective image sensing pixels of the first CCD array is 4500 pixels multiplied by 3 lines, the size of the image sensing pixels is 4.7 microns multiplied by 4.7 microns, the effective photosensitive area of the first CCD array is 21.15mm multiplied by 14.1 microns, and the parameters of the second CCD array are the same as those of the first CCD array.
The size of the reflector is 3mm multiplied by 3mm, the reflector reflects 10% of the light beams in the wave band range to the first CCD array, and the rest 90% of the light beams are detected by the second CCD array. The distance between the reflecting plane of the reflecting mirror and the central plane of the fourth focusing lens is 70mm, the diameter of the light beam reflected by the reflecting mirror is about 1.9mm, and the incident angle of the light beam refracted by the fourth focusing lens on the reflecting mirror is 30 degrees.
The light beam reflected by the reflector utilizes a Galileo type beam expander, the focal length of a concave lens of the Galileo type beam expander is 5mm, the focal length of a convex lens is 50mm, and the beam expansion ratio is 1: 10, the beam diameter is enlarged by 10 times, and the enlarged beam diameter is about 19 mm. The distance between the concave lens and the reflector of the beam expander is 25mm, the divergence angle of the light beam is changed into 1/10 after passing through the beam expander, and the distance between the center plane of the focusing lens of the beam expander and the second CCD array is 50mm and is positioned on the focusing plane of the light beam.
Through the design, the spectral resolution of the first CCD array is 9 times that of the second CCD array, the detection signal is used for high-depth imaging, the spectral width detected by the second CCD array is 9 times that of the first CCD array, and the detection signal is used for high-resolution imaging.
It is understood that the above-described design is only an implementable embodiment, and a practical application is given, wherein the elements, positions, parameters and the like can be changed according to the practical application, and the invention is not limited by the elements, the positions, the parameters and the like.
In the present embodiment 1 and the embodiment 2, the interference light beams of different wave bands are respectively detected by the first CCD array and the second CCD array, and then are respectively processed by the corresponding first image processing system and the second image processing system; the first CCD array is connected to the first image processing system, the second CCD array is connected to the second image processing system, the first image processing system performs large-depth imaging, and the second image processing system performs high-resolution imaging, as shown in fig. 3, which is a schematic diagram of dual-band imaging.
In this embodiment, during scanning imaging, the position of the retina is determined according to the large-depth image obtained by the first image processing system, so as to obtain the front and rear positions of the high-resolution imaging field relative to the retina, and then the imaging field of the high-resolution image is located on the retina by adjusting the optical path of the reference arm.
The spectrometer provided by the embodiment measures spectral information of two different wavebands by using one grating and two CCD arrays, simultaneously acquires a large-depth image (low resolution) and a high-resolution image (small depth), and solves the problem that the imaging range is difficult to align due to the small detection depth of the visible light OCT during large-field scanning detection.
In further embodiments, based on the dual-band imaging system of large-field visible light OCT described in embodiments 1 and 2, there is also provided an imaging method of the system, including:
the incident light beam is incident on the detection sample after passing through the sample arm and is reflected, and the imaging position of the detection sample in the depth direction and the imaging range of high resolution are adjusted by adjusting the optical path of the reference arm;
after reflecting the incident light beam, the reference arm interferes with the light beam reflected in the sample arm, and the generated interference light beam is incident into the spectrometer;
in the spectrometer, interference light beams are split after sequentially passing through a second collimator and a grating, the split interference light beams are focused through a third focusing lens, part of the interference light beams are reflected to a first CCD array through a reflector, and the rest interference light beams are incident to a second CCD array, so that large-depth imaging and high-resolution imaging are respectively carried out according to the interference light beams of different wave bands.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.
Claims (10)
1. A dual-band imaging system for large field of view visible OCT, comprising: the device comprises a light-emitting device, a sample arm, a reference arm and a spectrometer;
the light-emitting device is used for generating light beams and irradiating the light beams into the sample arm and the reference arm;
the sample arm comprises a first collimator, a scanning galvanometer, a first focusing lens and a second focusing lens, and incident light beams are incident on the detection sample and reflected through the first collimator, the scanning galvanometer, the first focusing lens and the second focusing lens in sequence; after reflecting the incident light beam, the reference arm interferes with the light beam reflected in the sample arm, and the generated interference light beam is incident into the spectrometer;
the spectrometer comprises a second collimator, a grating, a first CCD array, a reflecting mirror, a second CCD array, a beam expander and a third focusing lens, interference light beams are divided after sequentially passing through the second collimator and the grating, the divided interference light beams are focused by the third focusing lens, part of the interference light beams are reflected to the first CCD array by the reflecting mirror and the beam expander, and the rest interference light beams are incident to the second CCD array, so that large-depth imaging and high-resolution imaging are respectively carried out according to the interference light beams of different wave bands.
2. The dual-band imaging system of large-field visible OCT of claim 1, wherein said light emitting means comprises a light source and a light coupler; the optical coupler is respectively connected with the sample arm, the reference arm and the spectrometer, the light source emits light beams in a continuous spectrum range, and the light beams enter the reference arm and the sample arm after passing through the optical coupler; the light beam reflected in the reference arm and the light beam reflected in the sample arm pass through the optical coupler to interfere in the optical coupler, and then the interference light beam is incident into the spectrometer;
or, the light emitting device comprises a light source, a fourth collimator, a light splitting element, a fifth collimator and a sixth collimator; the light source is connected with the input end of a fourth collimator, the output end of the fourth collimator is arranged opposite to the input end of the light splitting element, the plane mirror of the reference arm is arranged opposite to the reflection output end of the light splitting element, and the input end of the fifth collimator is arranged opposite to the transmission output end of the light splitting element; the output end of the fifth collimator is connected with the first collimator; the input end of the sixth collimator is opposite to the coherent output end of the light splitting element, and the output end of the sixth collimator is connected with the spectrometer.
3. The dual-band imaging system of the large visual field visible light OCT of claim 1, wherein the incident beam is collimated by the first collimator and converted into a parallel beam, and the parallel beam is incident into the scanning galvanometer, and after the parallel beam is scanned by the scanning galvanometer, the parallel beam is reflected into the 4f system, and the parallel beam is refracted by the 4f system and incident on the detection sample.
4. The dual-band imaging system of large-field visible OCT of claim 3, wherein said 4f system comprises a first focusing lens and a second focusing lens; parallel light beams pass through an object space focal point of the first focusing lens and are focused on an image space focal plane of the first focusing lens after being refracted, the image space focal plane of the first focusing lens is superposed with an object space focal plane of the second focusing lens, and the parallel light beams are incident on a detection sample through the image space focal point of the second focusing lens after passing through the object space focal plane of the second focusing lens.
5. The dual-band imaging system of large-field visible OCT of claim 4, wherein the relative positions of the first collimator, scanning galvanometer, and 4f system are adjusted by the focal lengths of the first and second focusing lenses.
6. The dual-band imaging system of claim 1, wherein the splitting of the different wavelength bands of the light beam by the mirror comprises reflecting a portion of the longer wavelength band of the light beam by the mirror to the first CCD array and the remaining light beam is directly incident to the second CCD array when the interference light beam is refracted by the third focusing lens.
7. The dual band imaging system of large field of view visible OCT of claim 1, wherein the wavelength band of the interference beam reflected into the first CCD array is larger than the wavelength band of the interference beam incident into the second CCD array, and the spectral width of the interference beam reflected into the first CCD array is smaller than the spectral width of the interference beam in the second CCD array.
8. The dual-band imaging system of the large-field-of-view visible light OCT of claim 1, wherein the large-depth imaging is based on the characteristic of high spectral resolution of the interference beam reflected into the first CCD array; and performing high-resolution imaging based on the characteristic of large spectral width of the interference light beam incident into the second CCD array.
9. The dual band imaging system of large field of view visible OCT of claim 1, wherein a beam expander is disposed between the mirror and the first CCD array for expanding the diameter of the interference beam reflected into the first CCD array, thereby increasing spectral resolution.
10. An imaging method of a dual band imaging system using the large field of view visible OCT of any one of claims 1-9, comprising:
the incident light beam is incident on the detection sample after passing through the sample arm and is reflected, and the imaging position of the detection sample in the depth direction and the imaging range of high resolution are adjusted by adjusting the optical path of the reference arm;
after reflecting the incident light beam, the reference arm interferes with the light beam reflected in the sample arm, and the generated interference light beam is incident into the spectrometer;
in the spectrometer, interference light beams are split after sequentially passing through a second collimator and a grating, the split interference light beams are focused through a third focusing lens, part of the interference light beams are reflected to a first CCD array through a reflector, and the rest interference light beams are incident to a second CCD array, so that large-depth imaging and high-resolution imaging are respectively carried out according to the interference light beams of different wave bands.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114847882A (en) * | 2022-05-06 | 2022-08-05 | 山东探微医疗技术有限公司 | High-resolution jump type multiband spectrometer and working method |
| CN115024696A (en) * | 2022-08-12 | 2022-09-09 | 北京心联光电科技有限公司 | OCT imaging method, system and equipment |
| CN115778318A (en) * | 2022-11-09 | 2023-03-14 | 山东大学 | Visible light OCT system based on double-spectrometer detection and image reconstruction method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6134003A (en) * | 1991-04-29 | 2000-10-17 | Massachusetts Institute Of Technology | Method and apparatus for performing optical measurements using a fiber optic imaging guidewire, catheter or endoscope |
| CN101793823A (en) * | 2002-01-24 | 2010-08-04 | 通用医疗公司 | Apparatus and method for rangings and noise reduction of low coherence interferometry (LCI) and optical coherence tomography (OCT) signals |
| CN101862180A (en) * | 2009-04-16 | 2010-10-20 | 南京理工大学 | Near infrared spectrum (NIR) dual field interference imaging device |
| JP2018033506A (en) * | 2016-08-29 | 2018-03-08 | キヤノン株式会社 | Tomographic imaging device, image forming device, tomographic imaging method, image forming method, and program |
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6134003A (en) * | 1991-04-29 | 2000-10-17 | Massachusetts Institute Of Technology | Method and apparatus for performing optical measurements using a fiber optic imaging guidewire, catheter or endoscope |
| CN101793823A (en) * | 2002-01-24 | 2010-08-04 | 通用医疗公司 | Apparatus and method for rangings and noise reduction of low coherence interferometry (LCI) and optical coherence tomography (OCT) signals |
| CN101862180A (en) * | 2009-04-16 | 2010-10-20 | 南京理工大学 | Near infrared spectrum (NIR) dual field interference imaging device |
| JP2018033506A (en) * | 2016-08-29 | 2018-03-08 | キヤノン株式会社 | Tomographic imaging device, image forming device, tomographic imaging method, image forming method, and program |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114847882A (en) * | 2022-05-06 | 2022-08-05 | 山东探微医疗技术有限公司 | High-resolution jump type multiband spectrometer and working method |
| CN115024696A (en) * | 2022-08-12 | 2022-09-09 | 北京心联光电科技有限公司 | OCT imaging method, system and equipment |
| CN115778318A (en) * | 2022-11-09 | 2023-03-14 | 山东大学 | Visible light OCT system based on double-spectrometer detection and image reconstruction method |
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