Multipath laser

Abstract

The utility model provides a multi-path laser, which comprises a plurality of resonant cavities. The beam combining system is located on the light emitting sides of the multiple resonant cavities and provided with multiple light paths corresponding to the multiple resonant cavities, and at least part of the light paths are different in light path; the coupling system is located on the light emitting side of the beam combining system; wherein the distances from at least part of the resonant cavities to the same reference plane are different, so that the optical paths from the light emitting sides of the plurality of resonant cavities to the coupling system are the same, and the reference plane is located between the laser unit and the beam combining system.

Description

Technical Field

[0001] The utility model mainly relates to a laser, in particular to a multi-channel laser. Background Art

[0002] Laser therapy machines based on laser devices have been widely used in medical surgery due to their non-invasive or minimally invasive advantages.

[0003] The power, energy and / or frequency output by a single laser sometimes cannot meet the application requirements. For example, for high-power holmium lasers used in medical treatment, due to the obvious thermal lens effect of Ho:YAG laser crystals when working under high repetition rate conditions, the output power of a single laser crystal cannot be high, so it is necessary to solve the problem of beam combining of multiple laser crystals. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a multi-channel laser device capable of combining multi-channel laser beams.

[0005] In order to solve the above technical problems, the utility model provides a multi-channel laser, a laser unit, comprising a plurality of resonant cavities; a beam combining system, located at the light-emitting side of the plurality of resonant cavities, and having a plurality of optical paths corresponding to the plurality of resonant cavities, wherein at least some of the optical paths have different optical paths; a coupling system, located at the light-emitting side of the beam combining system; wherein at least some of the resonant cavities have different distances to the same reference plane, so that the optical paths from the light-emitting sides of the plurality of resonant cavities to the coupling system are the same, and the reference plane is located between the laser unit and the beam combining system.

[0006] In one embodiment of the present application, the plurality of resonant cavities are holmium laser resonant cavities.

[0007] In one embodiment of the present application, the multiple optical paths include: a central optical path, having at least one bracket, each bracket having a first reflector at one end; at least one peripheral optical path, having a second reflector for reflecting laser light to the first reflector, wherein after the laser light is reflected from the second reflector to the first reflector, it is reflected from the first reflector and propagates forward along the optical axis of the central optical path.

[0008] In one embodiment of the present application, the multi-channel laser also includes at least one motor for driving the at least one bracket to rotate, each bracket also has a hollow portion, and each motor is used to drive the corresponding bracket to rotate, so that the first reflector and the hollow portion are alternately located on the optical axis of the central light path.

[0009] In one embodiment of the present application, the first reflector and the hollow portion are respectively located at two ends of the bracket, and the bracket adopts a counterweight balance design.

[0010] In one embodiment of the present application, each resonant cavity has a xenon lamp and a crystal, and two ends of each resonant cavity are respectively configured with a water inlet and a water outlet for guiding a cooling fluid to flow through the interior of each resonant cavity.

[0011] In one embodiment of the present application, the multi-channel laser further includes a temperature control system connected to the water inlet and the water outlet for supplying the cooling fluid.

[0012] In an embodiment of the present application, the structures of the multiple resonant cavities are the same.

[0013] In an embodiment of the present application, the plurality of resonant cavities extend in a horizontal direction and are arranged in parallel and spaced apart.

[0014] In one embodiment of the present application, the number of the multiple resonant cavities and the multiple optical paths is 3.

[0015] Compared with the prior art, in the multi-channel laser of the utility model, the distances from the semi-reflective lenses of some laser units to the same reference surface are different, so that the optical paths from the light-emitting sides of multiple laser units to the coupling system are the same. This further makes the spot sizes after being focused by the coupling lens basically the same, avoiding the difference in coupling efficiency of different resonant cavities. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present utility model. In the accompanying drawings:

[0017] Figure 1 It is a structural schematic diagram of a multi-channel laser according to an embodiment of the utility model.

[0018] Figure 2 It is a schematic diagram of a laser unit according to an embodiment of the utility model.

[0019] Figure 3 It is a schematic diagram of a beam combining system according to an embodiment of the utility model.

[0020] Figure 4 It is a schematic diagram of the support structure of an embodiment of the utility model.

[0021] Figure 5 It is a schematic diagram of the internal structure of the resonant cavity of an embodiment of the utility model. DETAILED DESCRIPTION

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0023] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0024] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0025] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application 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, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0026] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0027] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0028] It should be understood that when a component is referred to as being "on another component," "connected to another component," "coupled to another component," or "contacting another component," it may be directly on, connected to, coupled to, or contacting the other component, or there may be intervening components. In contrast, when a component is referred to as being "directly on another component," "directly connected to," "directly coupled to," or "directly contacting" another component, there are no intervening components. Similarly, when a first component is referred to as being "electrically in contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between conductive components.

[0029] Figure 1 Schematic diagram of the structure of a multi-channel laser according to an embodiment of the present invention. Figure 1As shown in the figure, the multi-channel laser of this embodiment includes a laser power supply 110, a laser unit 120, a beam combining system 130, a coupling system 140, an optical fiber 150, and a temperature control system 160. The laser power supply 110 is used to supply power to the laser unit 120, and a high-frequency, high-power power supply with adjustable output voltage is selected. For example, the discharge frequency reaches 50 Hz, 70 Hz or higher, the transient peak power reaches more than 5 kVA, and the output voltage range is adjustable between 0 and 2000 V. The laser unit 120, the beam combining system 130, the coupling system 140, and the optical fiber 150 are arranged in the optical path direction. The temperature control system 160 is used to control the temperature of the laser unit 120.

[0030] With reference to Figure 2 As shown in the figure, the laser unit 120 includes a plurality of resonant cavities. Each resonant cavity includes a pumping system (not shown in the figure), a working substance 121, and a total reflection mirror 122 and a semi-reflection mirror 123 respectively located at both ends of the working substance 121, wherein the semi-reflection mirror 123 is located on the light output side of the resonant cavity. For example, the total reflection mirror 122 is a circular thin sheet, including a substrate and a total reflection film plated on the substrate. The reflectivity of the total reflection mirror 122 is generally greater than 99%. The semi-reflection mirror 123 is also a circular thin sheet, including a substrate and a semi-reflection film plated on the substrate. The semi-reflection mirror 123 partially reflects light, and the remaining light is projected. The reflectivity is usually designed according to the actual output power. The pumping system of the resonant cavity includes a condenser cavity, a pulsed xenon lamp, and a power supply system. Its specific structure is well known to those skilled in the art and will not be elaborated here. Under the excitation of the laser power supply 110, each resonant cavity works alternately, thereby emitting laser beams.

[0031] As Figure 2 As shown in the figure, a plurality of resonant cavities extend in the horizontal direction and are arranged in parallel at intervals. In one embodiment, the intervals between the plurality of resonant cavities are equal. In one embodiment, the distances from at least some of the resonant cavities to the same reference plane S are different. In this example, the distances from these resonant cavities to the same reference plane S are L1, L2, and L3 respectively, where L2 < L2 < L3, so that the optical paths from the light output sides of the respective resonant cavities to the coupling system 140 are the same. The principle of this design will be described later. Here, the reference plane S is located between the laser unit 120 and the beam combining system 130 and is a vertical plane.

[0032] In one embodiment, in order to improve the utilization rate of the light energy of the xenon lamp, the xenon lamp and the working substance can be installed together in the condenser cavity, and the condenser cavity is generally made into an ellipse or a cylinder.

[0033] In order to meet the threshold condition for generating lasers, that is, to make the light gain in the active medium after one round trip in the resonant cavity sufficient to compensate for the light loss caused by various factors, the resonant cavity not only creates a high photon density and meets the threshold condition for lasers, but also plays a selective role. That is, only light can output lasers after multiple reflections of the vertical cavity mirror, so the laser has good reversibility, and the longer the cavity, the better the directionality.

[0034] In one embodiment, the resonant cavity is a holmium laser resonant cavity. The wavelength of the holmium laser is 2100nm, and it is generated by Cr, Tm, Ho:YAG laser crystals pumped by a xenon lamp. Since the wavelength of the holmium laser is just at the absorption sub-peak of water, its energy can be efficiently absorbed by the water in human tissue, so it has great application value in medicine, and is currently mainly used in the fields of stone crushing and tissue cutting.

[0035] The beam combining system 130 is located at the light output side of the laser unit 120 and has multiple optical paths corresponding to multiple resonant cavities, and at least some of these optical paths have different optical paths. The reason for the different optical paths is that different lights pass through different optical devices during the propagation process. For example, in combination with reference Figure 3 As shown, the plurality of optical paths include a central optical path 130a and at least one peripheral optical path 130b. Figure 3 Two peripheral optical paths 130b are shown in the figure, but the number can also be one or more than two. The central optical path 130a has an optical axis X, and the peripheral optical paths 130b are arranged around the central optical path 130a. The central optical path 130a has at least one bracket 131 and at least one motor 132 for driving at least one turntable to rotate. Figure 4 As shown, each bracket 131 has a first reflector 131a and a hollow portion 131b. The peripheral optical path 130b has a second reflector 133 for reflecting the laser to the first reflector 131a. After the laser is reflected to the first reflector 131a by the second reflector 133, it is reflected by the first reflector 131a and propagates forward along the optical axis X of the central optical path. In this example, there are two peripheral optical paths 130b, so two brackets 131, two motors 132 and two first reflectors 131a are set. The first reflector 131a and the second reflector 133 are both 45 degrees to the horizontal plane.

[0036] Each motor 132 is used to drive the corresponding bracket 131 to rotate, so that the first reflector 131a and the hollow portion 131b are alternately located on the optical axis X of the central optical path 130a. When the first reflector 131a is located on the optical axis X, it will reflect the light from the resonant cavity, and when the hollow portion 131b is located on the optical axis X, the light from the resonant cavity will pass directly. Therefore, when the hollow portions 131b of the two brackets 131 of the beam combining system 130 are located on the optical axis X, the light from the middle resonant cavity can pass directly. When the first reflector 131a of the left bracket 131 of the beam combining system 130 is located on the optical axis X, and the hollow portion 131b of the right bracket 131 is located on the optical axis X, the light from the upper peripheral optical path 130b can be combined through the optical axis X. When the first reflector 131a of the right bracket 131 of the beam combining system 130 is located on the optical axis X, the light from the lower peripheral optical path 130b can be combined through the optical axis X. Finally, the three light beams from different resonant cavities are combined in the beam combining system 130 and their powers are superimposed under high frequency switching to achieve power enhancement.

[0037] In one embodiment, the first reflector 131a and the hollow portion 131b are respectively located at two ends of the bracket 131, and the bracket 131 adopts a counterweight balance design. The bracket 131 rotates at a constant speed around its center point O driven by the motor 132. The entire bracket 131 adopts a counterweight balance to maintain a dynamic balance structure when the motor 132 rotates, so that the entire motor 132 rotates smoothly, and there will be no problem of affecting the output power of the laser due to unbalanced jitter.

[0038] According to the characteristics of the laser beam, the distance before the coupling system 140, i.e., the optical path length, needs to be kept consistent so that the spot size after being focused by the coupling system 140 is substantially the same. Figure 3 As shown, the inventors of the present application discovered that due to the different settings of the optical devices, the optical paths of the three optical paths 130a and 130b are actually different, and the impact of this difference on the spot size and coupling efficiency difference after focusing of the coupling system 140 has not been taken seriously. For this reason, the inventors of the present application redesigned the position of each resonant cavity in the laser unit 120. After design, the distance from each resonant cavity to the reference plane S is at least partially different, thereby compensating for the difference in the optical path of the beam combining system. Ultimately, the optical path from the light-emitting side of each resonant cavity in the laser unit 120 to the coupling system 140 is the same, so that the spot size after focusing fully meets the requirements of the optical fiber, avoiding the difference in coupling efficiency of different resonant cavities. It can be understood that each optical path is also greater than a certain design distance.

[0039] The coupling system 140 is located at the light output side of the beam combining system 130 , and includes a coupling mirror for collecting each laser beam and coupling it into the optical fiber 150 .

[0040] In order to reduce the thermal lens effect of the laser, a temperature control system 160 is also introduced in the embodiment of the present application. Figure 5 As shown, each resonant cavity has a xenon lamp 124 and a crystal 125, and each resonant cavity is provided with a water inlet 126 and a water outlet 127 at both ends, respectively, for guiding the cooling fluid to flow through each resonant cavity. The temperature control system 160 is connected to the water inlet 126 and the water outlet 127, for supplying cooling fluid. Specifically, the constant temperature water flow formed by the temperature control system 160 enters the cavity from the water inlet 126, cools the xenon lamp 124 and the crystal 125, takes away the generated heat energy, reduces the negative impact of the thermal lens, and realizes precise temperature control of the crystal. In one embodiment, the temperature control system 160 includes a water circulation system, a refrigerant circulation system and a control system. The water circulation system includes a water tank, a refrigeration system, a water pump, etc. A certain amount of water is injected into the water tank, and the water is cooled by the refrigeration system, and then sent to the equipment to be cooled by the water pump. After the cooling water takes away the heat, the temperature rises and then flows back to the water tank to achieve the cooling effect. The refrigerant circulation system includes an evaporator, a compressor and a condenser. The liquid refrigerant in the evaporator absorbs the heat in the aforementioned circulating water and begins to evaporate. Eventually, a certain temperature difference is formed between the refrigerant and the water. The liquid refrigerant also completely evaporates and becomes gaseous, which is then sucked into the compressor and compressed (pressure and temperature increase). The gaseous refrigerant absorbs heat through the condenser (air-cooled / water-cooled), condenses into liquid, and becomes low-temperature and low-pressure refrigerant after throttling through the thermal expansion valve (or capillary tube), completing the refrigerant cycle. The control system includes a power supply to supply power to the compressor, evaporator, water pump, etc. The control system also has functions such as temperature control, pressure protection, and overload protection.

[0041] In one embodiment, the structures of the multiple resonant cavities are the same, so the cooling is uniform and the temperature accuracy is higher, for example, it can reach ±0.1 degrees.

[0042] The basic concepts have been described above. Obviously, for those skilled in the art, the above utility model disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to the present application. Such modifications, improvements and corrections are suggested in the present application, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of the present application.

[0043] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0044] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more utility model embodiments, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, drawing or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0045] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0046] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A multi-channel laser, characterized in that include: A laser unit including a plurality of resonant cavities; a beam combining system, located at the light-emitting side of the plurality of resonant cavities, and having a plurality of optical paths corresponding to the plurality of resonant cavities, wherein at least some of the optical paths have different optical lengths; A coupling system, located at the light-emitting side of the beam combining system; Among them, at least some of the resonant cavities have different distances to the same reference plane, so that the optical paths from the light-emitting sides of the multiple resonant cavities to the coupling system are the same, and the reference plane is located between the laser unit and the beam combining system.

2. The multi-channel laser device according to claim 1, characterized in that: The multiple resonant cavities are holmium laser resonant cavities.

3. The multi-channel laser device according to claim 1, characterized in that: The plurality of optical paths include: A central optical path has at least one bracket, and each bracket has a first reflector at one end; At least one peripheral optical path has a second reflector for reflecting the laser light to the first reflector, wherein the laser light is reflected by the second reflector to the first reflector, and then reflected by the first reflector and propagates forward along the optical axis of the central optical path.

4. The multi-channel laser device as claimed in claim 3, characterized in that: It also includes at least one motor for driving the at least one bracket to rotate, each bracket also has a hollow part, and each motor is used to drive the corresponding bracket to rotate, so that the first reflector and the hollow part are alternately located on the optical axis of the central light path.

5. The multi-channel laser device as claimed in claim 4, characterized in that: The first reflector and the hollow portion are respectively located at two ends of the bracket, and the bracket adopts a counterweight balance design.

6. The multi-channel laser device according to claim 1, characterized in that: Each resonant cavity has a xenon lamp and a crystal, and two ends of each resonant cavity are respectively provided with a water inlet and a water outlet for guiding a cooling fluid to flow through the interior of each resonant cavity.

7. The multi-channel laser device according to claim 6, characterized in that: It also includes a temperature control system connected to the water inlet and the water outlet for supplying the cooling fluid.

8. The multi-channel laser device according to claim 6, characterized in that: The multiple resonant cavities have the same structure.

9. The multi-channel laser according to claim 1 or 3, characterized in that: The plurality of resonant cavities extend in a horizontal direction and are arranged in parallel and spaced apart.

10. The multi-channel laser device according to claim 1, characterized in that: The number of the multiple resonant cavities and the multiple optical paths is three.

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