Optical coupling device and imaging system

Abstract

The utility model provides an optical coupling device and an imaging system. The optical coupling device comprises a light shaping lens assembly which is optically coupled with an emergent end of a light source and is used for shaping and expanding emergent light from the emergent end into parallel light; and the focus-adjustable lens is arranged on one side, far away from the emergent end, of the light shaping lens assembly and is used for focusing the parallel light into a focused light beam. In this way, the light emitted by the light source can be converted into different focused light beams to adapt to optical fibers of different specifications. When the lens is applied to an imaging system, the focus-adjustable lens can be adjusted to be matched with different internal light path optical systems. Therefore, the reusability of the optical coupling device is higher, and the overall structure of the imaging system is simpler and lighter.

Description

Technical Field

[0001] The utility model relates to the technical field of photoacoustic imaging, in particular to an optical coupling device and an imaging system. Background Art

[0002] Photoacoustic imaging is an emerging technology in modern medical imaging. It cleverly combines the high lateral resolution of optical imaging with the characteristics of ultrasonic depth imaging. Compared with traditional biomedical imaging technology, it can achieve high-resolution, non-destructive, and selective tissue imaging in deep tissues. Among them, photoacoustic endoscopic imaging is mainly used for internal organs and tissues of the human body, such as the digestive tract and blood vessels. It is an imaging method that intervenes in the human body, so it has higher requirements for the high precision, stability, and safety of equipment such as light sources and ultrasonic transducers. Laser has the advantages of high brightness, good monochromaticity, and good spatiotemporal controllability. It is the core element of the photoacoustic endoscopic imaging system. However, the laser emitted by the light source cannot directly meet the requirements of photoacoustic endoscopic imaging. It needs to go through optical systems such as beam shaping and spatial modulation to transmit the light to the remote end and focus it on the tissue surface.

[0003] Currently, the optical systems used in imaging systems include external optical systems and internal optical systems. The external optical system couples the laser into the optical fiber through free-space beam shaping. The internal optical system emits the beam to the part to be imaged.

[0004] In practice, the requirements of internal optical systems vary, which necessitates different optical fiber types for connecting them. This necessitates the design of corresponding optical coupling devices for each type of optical fiber. This results in a complex imaging system with numerous components. Utility Model Content

[0005] To at least partially address the problems existing in the prior art, according to one aspect of the present invention, an optical coupling device is provided. The optical coupling device includes: a light shaping lens assembly optically coupled to an output end of a light source to shape and expand the light emitted from the output end into parallel light; and a focus-adjustable lens disposed on a side of the light shaping lens assembly away from the output end to focus the parallel light into a focused beam.

[0006] The optical coupling device provided in this application, by providing a light shaping lens assembly and an adjustable focus lens, can convert the light emitted by the light source into different focused beams to adapt to optical fibers of different specifications. In other words, the optical coupling device can adapt to different types of optical fibers simultaneously. When applied to an imaging system, the adjustable focus lens can be adjusted to adapt to different internal optical systems. In other words, a single optical coupling device can be adapted to different internal optical systems. This makes the optical coupling device more reusable and the overall structure of the imaging system simpler and more lightweight.

[0007] Exemplarily, the light shaping lens assembly includes a first shaping lens and a second shaping lens. The first shaping lens is closer to the output end than the second shaping lens and adjusts the diameter of the light emitted by the light source. The second shaping lens is arranged on the side of the first shaping lens away from the output end and adjusts the light with adjusted diameter into parallel light.

[0008] Exemplarily, the optical coupling device further includes a packaging cylinder, in which the light shaping lens assembly and the focus-adjustable lens are both packaged.

[0009] Exemplarily, at least one end of the packaging cylinder has a socket for connecting to a fiber optic plug.

[0010] Exemplarily, at least one end portion of the packaging cylinder has a thread, and the optical coupling device further includes an end cap threadedly connected to the packaging cylinder for connecting to the optical fiber connector.

[0011] According to another aspect of the present invention, an imaging system is provided, comprising: a light source; an internal optical path component, the distal end of which is configured to emit a light beam to a portion to be imaged; and any of the above optical coupling devices, configured to couple light emitted by the light source to the internal optical path component.

[0012] Exemplarily, the inner optical path component has a rear end surface away from the optical coupling device, and the focused light beam is totally reflected at the rear end surface to the part to be imaged.

[0013] Exemplarily, the internal optical path component includes a second optical fiber, a third optical fiber and a fourth optical fiber, the third optical fiber is connected between the second optical fiber and the fourth optical fiber, the end of the second optical fiber away from the third optical fiber is connected to the optical coupling device, and the tail end face is located at the end of the fourth optical fiber away from the third optical fiber.

[0014] Illustratively, the second optical fiber includes at least one of a single-mode optical fiber or a multi-mode optical fiber.

[0015] Illustratively, the second optical fiber and the third optical fiber are fusion-spliced, and / or the third optical fiber and the fourth optical fiber are fusion-spliced.

[0016] The Summary of the Utility Model introduces a series of simplified concepts, which will be further described in detail in the Detailed Description of the Utility Model. The Summary of the Utility Model does not attempt to define the key features and essential technical features of the claimed technical solution, nor does it attempt to determine the scope of protection of the claimed technical solution.

[0017] The advantages and features of the present invention are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following drawings of the present invention are used as part of the present invention for understanding the present invention. The drawings show the embodiments of the present invention and their descriptions, and are used to explain the principles of the present invention. In the drawings,

[0019] Figure 1 is a schematic structural diagram of an imaging system according to an exemplary embodiment of the present utility model; and

[0020] Figure 2-3 It is a schematic structural diagram of a portion of an imaging system according to an exemplary embodiment of the present utility model.

[0021] The above drawings include the following reference numerals:

[0022] 10. Optical coupling device; 120. Light shaping lens assembly; 1210. First shaping lens; 1220. Second shaping lens; 130. Adjustable focus lens; 150. Package barrel; 1510. Jack; 1530. Barrel body; 1540. End cap; 20. Optical fiber assembly; 210. Tail end face; 220. Second optical fiber; 230. Third optical fiber; 240. Fourth optical fiber; 250. Optical fiber connector; 30. Light source; 310. Output end; 320. First optical fiber; 3210. Optical fiber plug. DETAILED DESCRIPTION

[0023] In the following description, numerous details are provided to facilitate a thorough understanding of the present invention. However, those skilled in the art will appreciate that the following description merely illustrates preferred embodiments of the present invention, and that the present invention may be practiced without one or more of these details. Furthermore, to avoid confusion with the present invention, some technical features well known in the art have not been described in detail.

[0024] To thoroughly understand the embodiments of the present invention, a detailed structure will be provided in the following description. Obviously, the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art. Preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other embodiments.

[0025] An embodiment of the present invention provides an optical coupling device. The optical coupling device can be applied to an imaging system. For example, the optical coupling device can be applied to a photoacoustic endoscopic imaging system.

[0026] Combined with reference Figure 1 and 2The optical coupling device 10 may include a light shaping lens assembly 120 and a focusable lens 130. The light shaping lens assembly 120 may be optically coupled to the output end 310 of the light source 30 to shape and expand the light emitted from the output end 310 into parallel light. The emitted light includes, but is not limited to, infrared, ultraviolet, and green light waves. Exemplarily, the light source 30 may be any one of a solid-state laser, a diode laser, a photonic crystal laser, a semiconductor laser, a gas laser, a chemical laser, an excimer laser, or other suitable light sources. Exemplarily, the light source 30 may include a first optical fiber 320. The light shaping lens assembly 120 may be connected to the output end 310 via the first optical fiber 320 to shape and expand the light emitted from the light source 30 into parallel light. One end of the first optical fiber 320 is connected to the light source 30, and the other end is connected to the light shaping lens assembly 120. The diameter of the first optical fiber 320 may be between 1 μm and 2000 μm, and the length may be between 1 m and 10 m. The adjustable focus lens 130 is disposed on the side of the light-shaping lens assembly 120 away from the output end 310 and is used to focus parallel light into a focused beam. That is, the light is shaped by the light-shaping lens assembly 120, and the shaped parallel light is focused by the adjustable focus lens 130. The light-shaping lens assembly 120 and the adjustable focus lens 130 can be understood as an external optical path optical system. In an imaging system employing the optical coupling device 10, the optical coupling device 10 can be connected to an internal optical path optical system. Light is shaped and focused into a focused beam in the external optical path optical system, and the focused beam is then focused onto the target surface by the internal optical path optical system. Depending on the internal optical path optical system, the type of optical fiber connected between the optical coupling device 10 and the internal optical path optical system may vary, such as single-mode fiber, multimode fiber, etc. Exemplarily, the adjustable focus lens 130 may be a liquid focusing lens. The current can be controlled externally, and the internal liquid can be controlled according to the strength of the electric field to adjust the lens focal length. Diffraction-limit theory shows that the Airy disk radius of the minimum convergent beam spot is d = 1.22 wavelength * focal length / diameter. Since the size of the expanded parallel light, i.e., its diameter, is fixed, adjusting the focal length of the adjustable focus lens 130 can change the size of the convergent beam spot. A larger focal length results in a larger beam spot, allowing convergence into multimode fibers with large cores; a smaller focal length results in a smaller beam spot, allowing convergence into single-mode fibers with small cores.

[0027] The optical coupling device 10 provided in this application, by providing a light shaping lens assembly 120 and a focus-adjustable lens 130, allows the light emitted by the light source 30 to be converted into different focused beams to accommodate optical fibers of different specifications. In other words, the optical coupling device 10 can simultaneously accommodate different types of optical fibers. When used in an imaging system, the focus-adjustable lens 130 can be adjusted to accommodate different internal optical systems. In other words, a single optical coupling device 10 can be adapted to different internal optical systems. This increases the reusability of the optical coupling device 10 and makes the overall structure of the imaging system simpler and more lightweight.

[0028] For example, with reference to Figure 1 and 2 The light shaping lens assembly 120 may include a first shaping lens 1210 and a second shaping lens 1220. The first shaping lens 1210 can be closer to the output end 310 than the second shaping lens 1220 and adjust the diameter of the light emitted by the light source 30. The second shaping lens 1220 is disposed on the side of the first shaping lens 1210 away from the output end 310 and adjusts the light after the diameter is adjusted into parallel light. A small hole structure is disposed between the first shaping lens 1210 and the second shaping lens 1220. The first shaping lens 1210 and the second shaping lens 1220 can shape the light. Specifically, the first shaping lens 1210 can converge the light, and the converged light diverges after passing through the small hole structure, resulting in a larger diameter light beam (compared to the light beam emitted from the light source 30). The light beam with a larger diameter passes through the second shaping lens 1220 and converges into parallel light, which is then emitted to the focus-adjustable lens 130. In this way, the light beam is adjusted into a parallel beam with a larger diameter by the first shaping lens 1210 and the second shaping lens 1220, so as to facilitate the subsequent focusing of the adjustable focus lens 130, and the structural arrangement is simpler. In an embodiment not shown, the beam shaping lens assembly can use any other combination of shaping lenses to shape and expand the light emitted by the light source into parallel light.

[0029] For example, with reference to Figure 1 and 2 The optical coupling device 10 may further include an encapsulating cylinder 150, within which both the light shaping lens assembly 120 and the focus-adjustable lens 130 may be encapsulated. In embodiments where the light shaping lens assembly 120 includes a first shaping lens 1210 and a second shaping lens 1220, both the first shaping lens 1210 and the second shaping lens 1220 are encapsulated within the encapsulating cylinder 150. The encapsulating cylinder 150 provides a more enclosed installation space for the light shaping lens assembly 120 and the focus-adjustable lens 130, enabling more stable operation of the light shaping lens assembly 120 and the focus-adjustable lens 130 therein and preventing environmental interference. The provision of the encapsulating cylinder 150 makes the overall structure of the external optical path optical system more compact and simple.

[0030] For example, with reference to Figure 1 and 2At least one end of the packaging cylinder 150 may have a socket 1510 for connecting to the optical fiber plug 3210. The optical fiber plug 3210 may be the end of the first optical fiber 320. For example, the end of the packaging cylinder 150 facing the first optical fiber 320 may have a protruding structure, and the socket 1510 may be formed within the protruding structure. This arrangement ensures the secure installation of the first optical fiber 320. Inserting the first optical fiber 320 into the socket 1510 further ensures the sealing of the packaging cylinder 150.

[0031] For example, referring to Figure 2 At least one end of the packaging cylinder 150 may have threads, and the optical coupling device 10 may further include an end cap 1540 threadedly connected to the packaging cylinder 150 for connection to the optical fiber connector 250. Specifically, the packaging cylinder 150 may include a cylinder body 1530. The end of the cylinder body 1530 away from the first optical fiber 320 may be provided with threads. The end cap 1540 is provided with mating threads. The end cap 1540 can be screwed to achieve connection between the end cap 1540 and the cylinder body 1530, making the installation and connection method simpler and more efficient. The end cap 1540 can be connected to the optical fiber connector 250, that is, the optical fiber assembly 20 can be connected to the cylinder body 1530 by screwing the end cap 1540. In addition, the threaded connection of the end cap 1540 further ensures the sealing of the packaging cylinder 150. When an optical fiber is connected to the optical fiber connector 1520, the optical fiber assembly 20 can be installed in the predetermined position by screwing the end cap 1540, further simplifying the installation process and improving installation efficiency.

[0032] According to another aspect of the present invention, an imaging system is provided. The imaging system may include a light source 30, an inner optical path component 20, and any of the aforementioned optical coupling devices 10. The distal end of the inner optical path component 20 is configured to emit a light beam to a portion to be imaged, and the optical coupling device 10 is configured to couple the light emitted by the light source 30 to the inner optical path component 20. Because the optical coupling device 10 employs the technical solutions of any of the aforementioned embodiments, the imaging system at least exhibits the beneficial effects of the technical solutions of the aforementioned embodiments, which will not be further detailed here.

[0033] For example, with reference to Figure 2 and 3The internal optical path component 20 can have a rear end face 210 that is distal to the optical coupling device 10. The focused light beam can be totally reflected at the rear end face 210 to the portion to be imaged. It is understood that light has a total reflection angle α during transmission within the optical fiber. Total reflection occurs when the inclination angle of the rear end face 210 is greater than α, and total reflection can reflect all light energy. The optical component can better focus the focused light beam to the portion to be imaged, ensuring image quality. The total reflection setting of the rear end face 210 can reduce energy loss of the focused light beam, further ensuring image quality.

[0034] Exemplarily, the inner optical path assembly 20 may include a second optical fiber 220, a third optical fiber 230, and a fourth optical fiber 240. The third optical fiber 230 is connected between the second and fourth optical fibers 220, 240. The end of the second optical fiber 220 remote from the third optical fiber 230 is connected to the optical coupling device 10, and the tail end face 210 is located at the end of the fourth optical fiber 240 remote from the third optical fiber 230. In other words, the focused light beam passes through the second optical fiber 220, the third optical fiber 230, and the fourth optical fiber 240 in sequence. The third and fourth optical fibers 230, 240 can be combined to form an inner optical path optical system. In imaging systems, the inner optical path optical system can be understood as a probe. The inner optical path optical system and the outer optical path optical system are connected via the second optical fiber 220. One or more of the second optical fiber 220, the third optical fiber 230, and the fourth optical fiber 240 can be any type of optical fiber to accommodate a wider range of application scenarios and provide greater adaptability. Exemplarily, the third optical fiber 230 can be a graded-index fiber, the length of which can be confirmed through simulation. The fourth optical fiber 240 may be a coreless optical fiber, which has only a cladding but no core.

[0035] Exemplarily, the second optical fiber 220 includes at least one of a single-mode optical fiber or a multi-mode optical fiber. That is, the optical coupling device 10 can be applicable to an imaging system with a single-mode optical fiber, and can also be applicable to an imaging system with a multi-mode optical fiber. In the imaging system, the light spot finally converged by the multi-mode optical fiber is large, the resolution is low, and the imaging depth is shallow, and it is often used to observe superficial vascular tissue. The light spot finally converged by the single-mode optical fiber is small, the resolution is high, and the imaging depth is deep, and it is used to observe deep tissue. The optical coupling device 10 can be arbitrarily adapted to multi-mode optical fiber or single-mode optical fiber, and has a wider adaptability. Whether it is a multi-mode optical fiber or a single-mode optical fiber, the coupled light directly reaches the internal optical path optical system through the second optical fiber 220. Exemplarily, the core diameter of the second optical fiber 220 can be between 1μm and 2000μm, and the length can be between 1m and 10m.

[0036] For example, referring to Figure 3The second optical fiber 220 and the third optical fiber 230 are fused together. In this way, the transmission loss of light between the second optical fiber 220 and the third optical fiber 230 is smaller, and the connection between the second optical fiber 220 and the third optical fiber 230 after fusion is more stable and less affected by external factors.

[0037] For example, continue to refer to Figure 3 , the third optical fiber 230 and the fourth optical fiber 240 are fused. In this way, the light transmission loss between the third optical fiber 230 and the fourth optical fiber 240 is smaller, and the connection between the third optical fiber 230 and the fourth optical fiber 240 after fusion is more stable and less affected by external factors. Preferably, the second optical fiber 220, the third optical fiber 230 and the fourth optical fiber 240 are all fused. In some application scenarios, the outer diameter of the inner optical path optical system needs to be controlled within a certain size (for example, the outer diameter needs to be less than 1 mm). Under this limitation, assembly is difficult and the efficiency is low. The converged spot size and back focal length are affected by the tolerance of the optical system, the consistency is poor, and the photoacoustic signal fluctuates greatly. The inner optical path optical system can realize a more lightweight, efficient, and consistent photoacoustic imaging optical system through the fusion of the third optical fiber 230 and the fourth optical fiber 240, and the fusion between the second optical fiber 220 and the inner optical path optical system.

[0038] Exemplarily, the working process of the imaging system can be as follows: the light source 30 emits light through the output end 310, and the light is directed to the first shaping lens 1210; the first shaping lens 1210 can converge the light, and the converged light diverges and is directed to the second shaping lens 1220; the second shaping lens 1220 converges the diverged light into parallel light, and the parallel light is directed to the adjustable focus lens 130; the adjustable focus lens 130 focuses the flat light, and the focused light beam is directed to the second optical fiber 220; the focused light beam passes through the second optical fiber 220 and enters the graded refractive index optical fiber (third optical fiber 230) and the coreless optical fiber (fourth optical fiber 240) in turn, and is totally reflected by the tail end face 210 to the part to be imaged.

[0039] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front", "back", "up", "down", "left", "right", "horizontal", "vertical", "vertical", "horizontal", "top", "bottom", etc. are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself.

[0040] For ease of description, area-relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the regional positional relationship between one or more components or features shown in the figures and other components or features. It should be understood that area-relative terms include not only the orientation of the components as described in the figures, but also different orientations in use or operation. For example, if the components in the drawings are inverted as a whole, the situation where the components are "above other components or features" or "above other components or features" will include the situation where the components are "below other components or structures" or "below other components or structures". Thus, the exemplary term "above" may include both the orientations "above" and "below". In addition, these components or features may also be positioned at other different angles (e.g., rotated 90 degrees or other angles), and this document is intended to include all of these situations.

[0041] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, parts, components and / or combinations thereof.

[0042] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0043] The present invention has been described through the above embodiments. However, it should be understood that the above embodiments are for illustrative and illustrative purposes only and are not intended to limit the present invention to the described embodiments. Furthermore, those skilled in the art will appreciate that the present invention is not limited to the above embodiments and that various variations and modifications may be made based on the teachings of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An optical coupling device, characterized in that: include: A light shaping lens assembly is optically coupled to the output end of the light source to shape and expand the light output from the output end into parallel light; as well as A focus-adjustable lens is provided on a side of the light-shaping lens assembly away from the emission end, and is used to focus the parallel light into a focused beam; The light shaping lens assembly includes a first shaping lens and a second shaping lens. The first shaping lens is closer to the exit end than the second shaping lens and adjusts the diameter of the light emitted by the light source. The second shaping lens is arranged on the side of the first shaping lens away from the exit end and adjusts the light with adjusted diameter to the parallel light.

2. The optical coupling device according to claim 1, wherein: The optical coupling device further includes a packaging cylinder, in which the light shaping lens assembly and the focus-adjustable lens are both packaged.

3. The optical coupling device according to claim 2, wherein: At least one end of the packaging cylinder is provided with a socket for connecting with an optical fiber plug.

4. The optical coupling device according to claim 2, wherein: At least one end of the packaging cylinder has a thread, and the optical coupling device further comprises an end cap threadedly connected to the packaging cylinder for connecting to an optical fiber connector.

5. An imaging system, characterized in that: include: light source; An inner optical path component, the distal end of which is used to emit a light beam to a part to be imaged; The optical coupling device according to any one of claims 1 to 4, used to couple light emitted by the light source to the inner optical path component.

6. The imaging system according to claim 5, wherein: The inner optical path component has a rear end surface away from the optical coupling device, and the focused light beam is totally reflected at the rear end surface to the part to be imaged.

7. The imaging system according to claim 6, wherein: The internal optical path component includes a second optical fiber, a third optical fiber and a fourth optical fiber, the third optical fiber is connected between the second optical fiber and the fourth optical fiber, the end of the second optical fiber away from the third optical fiber is connected to the optical coupling device, and the tail end face is located at the end of the fourth optical fiber away from the third optical fiber.

8. The imaging system according to claim 7, wherein: The second optical fiber includes at least one of a single-mode optical fiber and a multi-mode optical fiber.

9. The imaging system according to claim 7, wherein: The second optical fiber and the third optical fiber are fusion-spliced, and / or the third optical fiber and the fourth optical fiber are fusion-spliced.

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