Dual-wavelength laser dental handle and fiber coupling method thereof

Abstract

This invention proposes a dual-wavelength laser dental handpiece and its fiber coupling method, relating to the field of laser therapy device technology. The dual-wavelength laser dental handpiece includes a first beam combiner, a second beam combiner, a third beam combiner, a focalless coupling component, a coupling fiber, a handpiece body, a coupling lens, and a laser needle. A YAG laser, an Er:YAG laser, and an indicator semiconductor laser are combined by the beam combiner system composed of the first, second, and third beam combiners to obtain a coaxial combined laser output beam. The focalless coupling component includes a convex lens and a concave mirror, which are coaxially arranged between the coaxial combined laser output beam and the coupling fiber. The coupling fiber is installed at the input end of the handpiece body; the coupling lens is installed inside the handpiece body; and the laser needle is installed at the output end of the handpiece body. The absence of a focal point in the coupling region improves the incident laser energy density distribution at the coupling end face of the coupling fiber, making it easier to couple the Er:YAG laser into the coupling fiber and transmit it.

Description

Technical Field

[0001] This invention relates to the field of laser therapy device technology, and in particular to a dual-wavelength laser dental handpiece and its fiber optic coupling method. Background Technology

[0002] In dental procedures, two laser wavelengths are frequently used: a 1064nm YAG laser and a 2940nm Er:YAG laser. Because different biological tissues within the oral cavity have significantly different absorption rates for these two laser wavelengths, different wavelengths can be applied to different applications in dental treatment. YAG lasers have mature fiber-optic coupling transmission technology, while Er:YAG laser coupling transmission is relatively more technically challenging. Currently, the common approach is to use two optical paths, one for transmitting the YAG laser and the other for transmitting the Er:YAG laser, with different laser handpieces at the ends.

[0003] Optical fibers used for transmitting Er:YAG lasers typically fall into three categories: fluoride fiber, sapphire fiber, and hollow fiber. Among these, sapphire fiber can withstand higher coupled radiation power densities, but its residual reflection loss and transmission loss are relatively large, and it is prone to breakage during bending. Hollow fiber has too high a transmission loss and should be considered a last resort. Fluoride glass fiber, however, has lower residual reflection loss than sapphire fiber, and its transmission loss is also lower than both sapphire and hollow fiber, making it the optimal choice.

[0004] Currently, dual-wavelength dental laser (including YAG laser and Er:YAG laser) treatment devices typically use two sets of laser handpieces. Different treatment procedures require changing the handpiece, making the operation relatively complex. Furthermore, when the pulsed Er:YAG laser is coupled into the fluoride fiber for transmission, the incident laser energy density distribution at the coupling end face of the fluoride fiber is uneven, making it difficult to couple large laser energies. Summary of the Invention

[0005] In view of this, the present invention proposes a dual-wavelength laser dental handpiece and its fiber coupling method to solve the technical problems mentioned in the background art. The dual-wavelength dental laser treatment equipment usually uses two sets of laser handpieces, which require changing the handpiece for different treatment procedures, making the operation relatively complicated. In addition, when the pulsed Er:YAG laser is coupled into the fluoride fiber for transmission, the incident laser energy density distribution at the coupling end face of the fluoride fiber is uneven, making it difficult to couple a large laser energy.

[0006] The technical solution of this invention is implemented as follows: In a first aspect, the present invention proposes a dual-wavelength laser dental handpiece, comprising a first beam combiner, a second beam combiner, a third beam combiner, a focal-free coupling assembly, a coupling fiber, a handpiece body, a coupling lens, and a laser needle, wherein: The first beam combiner is used to reflect the YAG laser into the second beam combiner; it is also used to transmit the indicator semiconductor laser reflected by the third beam combiner. The second beam combiner is used to transmit Er:YAG laser and to refract and reflect the YAG laser incident through the first beam combiner and the indicator semiconductor laser transmitted through the second beam combiner to obtain a coaxial beam combiner laser output beam. The third beam combiner is used to refract and reflect the indicating semiconductor laser; The focal-free coupling component includes a convex lens and a concave mirror, which are coaxially arranged between the coaxial combined laser output beam and the coupling fiber. All the coupling optical fibers are fluoride optical fibers; the coupling optical fibers are installed at the input end of the handle body and are used to transmit the fine laser beam obtained after passing through the convex lens and the concave mirror in sequence to the coupling lens; The coupling lens is installed in the handle body, and the optical axis of the coupling lens is coaxial with the incident end of the thin laser beam and the optical needle, and is used to couple the laser in the coupling fiber to the incident end of the optical needle. The optical needle is installed at the output end of the handle body, and the end of the optical needle is used to output YAG laser and / or Er:YAG laser with indicator semiconductor laser.

[0007] In some alternative embodiments, preferably, the optical needle is curved and includes a horizontal segment and an inclined segment that are smoothly connected. The horizontal segment is coaxial with the optical axis of the coupling lens, and the inclined segment and the horizontal segment are provided at an angle.

[0008] In some alternative implementations, the included angle is preferably 120 degrees.

[0009] In some alternative embodiments, preferably, the handle body is provided with a water-air mixing chamber located on the outer periphery of the inclined section, for forming water mist or spraying water separately at the end of the handle body.

[0010] In some alternative embodiments, preferably, a protective window is also included, which is installed inside the handle body and located on the side of the coupling lens away from the optical needle, and the protective window is installed on the outside of the output end of the coupling optical fiber.

[0011] In some alternative embodiments, preferably, the optical needle is a low-hydroxyl quartz optical needle.

[0012] In some alternative embodiments, preferably, the coupling optical fiber is a zirconium fluoride glass optical fiber.

[0013] In a second aspect, the present invention proposes an optical fiber coupling method for a dual-wavelength laser dental handpiece as described in the first aspect, comprising: The YAG laser and / or Er:YAG laser in the coaxial combined laser output beam are transmitted to the convex lens, and then pass through the concave mirror to obtain a nearly unfocused thin laser beam. A thin laser beam is incident on the end face of the coupling fiber for coupling and is then transmitted to the coupling lens via the coupling fiber. The laser light in the coupling fiber is coupled to the incident end of the optical needle through a coupling lens; The output of the optical needle includes a YAG laser and / or an Er:YAG laser with an indicator semiconductor laser.

[0014] The dual-wavelength laser dental handpiece and its fiber coupling method proposed in this invention have the following advantages over existing technologies: (1) The YAG laser and / or Er:YAG laser in the coaxial combined laser output beam are transmitted to the convex lens, and then through the concave mirror to obtain a nearly unfocused thin laser beam. The thin laser beam is incident on the end face of the coupling fiber for coupling and is transmitted to the coupling lens through the coupling fiber. Since there is no focal point in the coupling region near the incident surface of the coupling fiber, the incident laser energy density distribution of the coupling fiber at the coupling end face is improved, making it easier to couple larger laser energy, especially pulsed Er:YAG laser, into the coupling fiber and transmit it; and the YAG laser surgical handle and the Er:YAG laser surgical handle are combined into one, providing a new treatment possibility for the simultaneous use of dual-wavelength YAG laser and Er:YAG laser. (2) The optical needle is curved and includes a horizontal section and an inclined section that are smoothly connected. The horizontal section is coaxial with the optical axis of the coupling lens. An angle is provided between the inclined section and the horizontal section. The optical axis of the coupling lens is coaxial with the horizontal section of the optical fiber and the optical needle. This avoids the difficult-to-process reflective focusing lens in the reflective structure, making the structure simpler and the processing cost lower. (3) A steam-water mixing chamber is provided in the handle body. The steam-water mixing chamber is located on the outer periphery of the inclined section and is used to form water mist or spray water separately at the end of the handle body to meet the requirements of dental treatment. (4) The light needle uses a low-hydroxyl quartz light needle, which can transmit a single YAG laser, or a single Er:YAG laser, or a combination of YAG laser and Er:YAG laser, to meet the needs of laser treatment of different wavelengths and to treat different biological tissues inside the oral cavity. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the dual-wavelength laser dental handpiece in an embodiment of the present invention; Figure 2 For the present invention Figure 1 Enlarged view of part A in the middle; Figure 3 For the present invention Figure 1 Enlarged view of part B in the middle; Figure 4 This is a schematic flowchart of the fiber optic coupling method for a dual-wavelength laser dental handpiece in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1-First beam combiner, 2-Second beam combiner, 3-Third beam combiner, 4-Focusless coupling assembly, 5-Coupled fiber, 6-Handle body, 7-Coupled lens, 8-Optical needle, 9-Soda-water mixing chamber, 10-Protective window, 20-Coaxial beam combiner laser output beam; 41 - Convex lens, 42 - Concave mirror; 81 - Horizontal section, 82 - Inclined section. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0020] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0024] The technical solution will now be explained in detail: Reference Figures 1-3 As shown, a first aspect of the present invention provides a dual-wavelength laser dental handpiece, comprising a first beam combiner 1, a second beam combiner 2, a third beam combiner 3, a focal-free coupling assembly 4, a coupling fiber 5, a handpiece body 6, a coupling lens 7, and a laser needle 8, wherein: The first beam combiner 1 is used to reflect the YAG laser incident at 45° to the second beam combiner 2, and to transmit the indicator semiconductor laser reflected by the third beam combiner 3. The indicator semiconductor laser is incident at 45° to the first beam combiner 1. The first beam combiner 1 and the third beam combiner 3 combine to form a first beam combining region, which coaxially combines the indicator semiconductor laser and the YAG laser. YAG laser usually refers to a solid-state laser based on yttrium aluminum garnet (YAG) crystal, especially neodymium-doped Nd:YAG laser, which outputs a solid-state laser with a wavelength of 1064nm. Due to its stable performance and wide application, it has become an important tool in industrial processing and medical fields. The indicator laser is a red or green semiconductor laser.

[0025] The second beam combiner 2 forms a second beam combining region, used to transmit the Er:YAG laser incident at 45° and to reflect the coaxial combined laser beam from the first beam combining region, forming a coaxial laser output beam 20 consisting of three laser beams: YAG laser, Er:YAG laser, and indicator semiconductor laser. Er:YAG laser, also known as erbium-doped yttrium aluminum garnet laser, is a mid-infrared solid-state laser with an output wavelength of 2940 nanometers. Its core characteristic is that this wavelength is highly matched with the absorption peaks of water and hydroxyapatite, making it an ideal tool for achieving precise and minimally invasive treatments in medical fields (especially dermatology, dentistry, and ophthalmology) and some materials processing fields. The third beam combiner 3 is used to reflect and refract the pilot laser, which is incident on the third beam combiner 3 at a 45° angle. The pilot laser can be a semiconductor green light or a semiconductor red light, and is used to indicate the laser's position during surgical treatment, so that the operator can observe the laser's point of action in real time during the operation. In different dental procedures, the coaxially combined laser output beam 20 can be coaxially combined with one or both of the indicator semiconductor laser and the treatment laser, namely YAG laser and Er:YAG laser. All coupling optical fibers 5 are fluoride optical fibers; furthermore, the coupling optical fibers 5 may be zirconium fluoride glass optical fibers. The afocal coupling component 4 includes a convex lens 41 and a concave mirror 42, which are coaxially arranged between the coaxial combined laser output beam 20 and the coupling fiber 5. The real focal point of the convex lens 41 and a virtual focal point of the concave mirror 42 form a virtual confocal point, forming a beam expander mechanism similar to an inverted one. The Er:YAG laser and / or the YAG laser enter the convex lens 41 in the afocal coupling system after passing through the beam combiner, and then pass through the concave mirror 42 to form a near-focal thin laser beam. The thin laser beam is incident on the end face of the fluoride glass fiber for coupling and is transmitted in the fluoride glass fiber. The convex lens 41 can be made of sapphire or zinc selenide, and the concave mirror 42 is made of zinc selenide. The choice of materials for the convex lens 41 and the concave mirror 42 makes it easy to achieve spherical aberration design, and also provides good transmission in the YAG laser, Er:YAG laser and indicator semiconductor laser bands, while meeting the laser energy power density required for dental surgery. The coupling fiber 5 is installed at the input end of the handle body 6 and is used to transmit the thin laser beam obtained after passing through the convex lens 41 and the concave mirror 42 in sequence to the coupling lens 7; the coupling fiber 5 can transmit YAG laser and Er:YAG laser separately or simultaneously. The coupling lens 7 is installed inside the handle body 6. The optical axis of the coupling lens 7 is coaxial with the incident end of the thin laser beam and the optical needle 8. It is used to couple the laser in the coupling fiber 5 to the incident end of the optical needle 8, thus avoiding the difficult-to-process reflective focusing lens in the reflective structure. The optical needle 8 is installed at the output end of the handle body 6, and the end of the optical needle 8 is used to output YAG laser and / or Er:YAG laser.

[0026] The dual-wavelength laser dental handpiece proposed in this embodiment transmits the YAG laser and / or Er:YAG laser, which are coaxial with the indicating semiconductor laser, from the coaxial beam-combining laser 3 to the convex lens 41. Then, it passes through the concave mirror 42 to obtain a nearly unfocused thin laser beam. The thin laser beam is incident on the end face of the coupling fiber 5 for coupling and is transmitted to the coupling lens 7 via the coupling fiber 5. Since there is no focal point in the coupling region near the incident surface of the coupling fiber 5, the incident laser energy density distribution at the coupling end face of the coupling fiber 5 is improved, making it easier to couple larger laser energy, especially pulsed Er:YAG laser, into the coupling fiber 5 for transmission.

[0027] In some embodiments, the optical needle 8 is curved and includes a smoothly connected horizontal segment 81 and an inclined segment 82. The horizontal segment 81 is coaxial with the optical axis of the coupling lens 7, and the inclined segment 82 is at an angle to the horizontal segment 81. The optical axis of the coupling lens is coaxial with the optical fiber and the horizontal segment 81 of the optical needle 8, avoiding the difficult-to-process reflective focusing lens in reflective structures, making the structure simpler and the processing cost lower.

[0028] In some embodiments, the included angle is 120 degrees. This parameter setting allows the optical fiber to transmit signals well while also meeting the requirement of a smaller footprint, resulting in a more compact structure.

[0029] In some embodiments, the handle body 6 is provided with a water-air mixing chamber 9, which is located on the outer periphery of the inclined section 82, and is used to form a water mist or spray water separately at the end of the handle body 6. The water-air mixing chamber 9 is provided with water passages and air passages, which can form a water mist or spray water separately at the end of the handle according to the needs of dental treatment.

[0030] In some embodiments, a protective window 10 is also included, which is installed inside the handle body 6 and located on the side of the coupling lens 7 away from the optical needle 8, and is installed on the outside of the output end of the coupling optical fiber 5.

[0031] In some embodiments, the light needle 8 is a low-hydroxyl quartz light needle. The low-hydroxyl quartz light needle can deliver a single YAG laser, or a single Er:YAG laser, or a combination of YAG and Er:YAG lasers, to meet the needs of laser treatment at different wavelengths and to treat different biological tissues within the oral cavity.

[0032] Based on the same concept, a second aspect of the present invention, combined with... Figure 4 As shown, a fiber optic coupling method for a dual-wavelength laser dental handpiece as described in the first aspect embodiment is proposed, comprising: Step S1: The YAG laser and / or Er:YAG laser in the coaxial combined laser output beam 20 are transmitted to the convex lens 41, and then pass through the concave mirror 42 to obtain a fine laser beam that is approximately unfocused. Step S2: A thin laser beam is incident on the end face of the coupling fiber 5 for coupling and is transmitted to the coupling lens 7 via the coupling fiber 5; Step S3: Couple the laser in the coupling fiber 5 to the incident end of the optical needle 8 through the coupling lens 7; Step S4: Output YAG laser and / or Er:YAG laser with indicator semiconductor laser through the end of the optical needle 8.

[0033] The fiber coupling method for the dual-wavelength laser dental handpiece proposed in this embodiment transmits the YAG laser and / or Er:YAG laser in the coaxial combined laser beam 20 to the convex lens 41, and then through the concave mirror 42 to obtain a near-focal thin laser beam. Since there is no focal point in the coupling region, the incident laser energy density distribution at the coupling end face of the coupling fiber 5 is improved, making it easier to couple larger laser energy, especially pulsed Er:YAG laser, into the coupling fiber 5 and transmit it.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-wavelength laser dental handpiece, characterized in that, It includes a first beam combiner, a second beam combiner, a third beam combiner, a focal-free coupling assembly, a coupling fiber, a handle body, a coupling lens, and a light needle, wherein: The first beam combiner is used to reflect the YAG laser into the second beam combiner; it is also used to transmit the indicator semiconductor laser reflected by the third beam combiner. The second beam combiner is used to transmit Er:YAG laser and to refract and reflect the YAG laser incident through the first beam combiner and the indicator semiconductor laser transmitted through the second beam combiner to obtain a coaxial beam combiner laser output beam. The third beam combiner is used to refract and reflect the indicating semiconductor laser; The focal-free coupling component includes a convex lens and a concave mirror, which are coaxially arranged between the coaxial combined laser output beam and the coupling fiber. All the coupling optical fibers are fluoride optical fibers; the coupling optical fibers are installed at the input end of the handle body and are used to transmit the fine laser beam obtained after passing through the convex lens and the concave mirror in sequence to the coupling lens; The coupling lens is installed in the handle body, and the optical axis of the coupling lens is coaxial with the incident end of the thin laser beam and the optical needle, and is used to couple the laser in the coupling fiber to the incident end of the optical needle. The optical needle is installed at the output end of the handle body, and the end of the optical needle is used to output YAG laser and / or Er:YAG laser with indicator semiconductor laser.

2. The dual-wavelength laser dental handpiece as described in claim 1, characterized in that, The optical needle is curved and includes a horizontal segment and an inclined segment that are smoothly connected. The horizontal segment is coaxial with the optical axis of the coupling lens, and the inclined segment and the horizontal segment are at an angle.

3. The dual-wavelength laser dental handpiece as described in claim 2, characterized in that, The included angle is 120 degrees.

4. The dual-wavelength laser dental handpiece as described in claim 2, characterized in that, The handle body is provided with a steam-water mixing chamber, which is located on the outer periphery of the inclined section and is used to form water mist or spray water separately at the end of the handle body.

5. The dual-wavelength laser dental handpiece as described in claim 1, characterized in that, It also includes a protective window, which is installed inside the handle body and located on the side of the coupling lens away from the optical needle. The protective window is installed on the outside of the output end of the coupling optical fiber.

6. The dual-wavelength laser dental handpiece as described in claim 1, characterized in that, The optical needle is a low-hydroxyl quartz optical needle.

7. The dual-wavelength laser dental handpiece as described in claim 1, characterized in that, The coupling optical fiber is a zirconium fluoride glass optical fiber.

8. A fiber optic coupling method for a dual-wavelength laser dental handpiece as described in any one of claims 1-7, characterized in that, include: The YAG laser and / or Er:YAG laser in the coaxial combined laser output beam are transmitted to the convex lens, and then pass through the concave mirror to obtain a nearly unfocused thin laser beam. A thin laser beam is incident on the end face of the coupling fiber for coupling and is then transmitted to the coupling lens via the coupling fiber. The laser light in the coupling fiber is coupled to the incident end of the optical needle through a coupling lens; The output of the optical needle includes a YAG laser and / or an Er:YAG laser with an indicator semiconductor laser.

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