Laser equipment, and laser treatment device

Abstract

To provide laser equipment including a resonator which is not reduced in performance and has little failure risk relating to a mirror, and to provide a laser treatment device.SOLUTION: A laser equipment 30 comprises: a columnar solid laser rod 31; a resonator including a first reflection film provided on a first end face of the solid laser rod 31 and a second reflection film provided on a second end face of the solid laser rod 31 on an opposite side of the first end face; and a flash lamp 32 which excites the solid laser rod 31. The first reflection film and the second reflection film are ion beam spluttering coat films capable of preventing infiltration of moisture from outside air. Reflectance of the first reflection film is lower than that of the second reflection film.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a laser device and a laser treatment device. [Background technology]

[0002] In recent years, laser light has been used in the dental field for treatments such as caries removal, tartar removal, and gum incision. For example, a laser treatment device capable of emitting an Er:YAG (Erbium / Yttrium Aluminum Garnet) laser with a wavelength of 2.94 μm is used for such treatments. A laser treatment device that emits an Er:YAG laser has a built-in laser device equipped with a resonator that includes a solid-state laser rod.

[0003] In the case of a resonator including such a solid-state laser rod, a total reflection mirror and an output mirror are placed on both ends of the solid-state laser rod. However, because infrared light with wavelengths of 2 μm or longer is highly absorbed by the OH groups contained in water, if moisture in the air is adsorbed onto the total reflection mirror or output mirror of the resonator, the adsorbed moisture will absorb the infrared light and generate heat, damaging the total reflection mirror or output mirror and reducing the performance of the resonator.

[0004] In the laser device disclosed in Japanese Patent Laid-Open No. 08-316552 (Patent Document 1), beam tubes are provided on both ends of a solid-state laser rod to prevent moisture from being adsorbed on the total reflection mirror and output mirror of the resonator. The beam tubes are filled with a liquid that has the property of transmitting infrared light, such as fluorine-based oil, and are structured so that the total reflection mirror and output mirror of the resonator are not exposed to the air. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 08-316552 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the beam tubes installed at both ends of the solid-state laser rod must employ a structure for sealing the liquid, and managing the sealed liquid is difficult, resulting in high manufacturing and maintenance costs. Furthermore, the laser device disclosed in Patent Document 1 has a risk of failure, in which the liquid sealing structure breaks and the sealed liquid leaks.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a laser device and a laser treatment device having a resonator that does not degrade performance and has a low risk of mirror-related failure. [Means for solving the problem]

[0008] The laser device according to the present disclosure has an absorption coefficient of 20 cm -1 A laser device that emits laser light of the above wavelength includes a cylindrical solid-state laser rod, a resonator including a first reflective film provided on a first end face of the solid-state laser rod, and a second reflective film provided on a second end face opposite the first end face of the solid-state laser rod, and a flash lamp that excites the solid-state laser rod. The first reflective film and the second reflective film are ion beam sputtering coated films that can prevent moisture from entering from the outside air. The reflectivity of the first reflective film is lower than that of the second reflective film.

[0009] A laser treatment device according to the present disclosure is a laser treatment device that treats an affected area using laser light, and includes the above-described laser device that emits laser light. [Effects of the Invention]

[0010] The present disclosure provides a resonator including a solid-state laser rod, a first reflective film provided on a first end face of the solid-state laser rod, and a second reflective film provided on a second end face of the solid-state laser rod, thereby realizing a resonator with no degradation in performance and low risk of mirror failure. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing the appearance of a laser treatment device according to an embodiment; [Figure 2] 1 is a diagram showing the appearance of a laser treatment device according to an embodiment; [Figure 3] 1A and 1B are diagrams for explaining a structure of a laser device according to an embodiment. [Figure 4] 1A and 1B are diagrams illustrating the appearance of a solid-state laser rod according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and description thereof will not be repeated.

[0013] [Configuration of laser treatment device] The main configuration of a laser treatment device 1 according to an embodiment will be described with reference to Figures 1 and 2. The laser treatment device 1 according to the embodiment is used, for example, in dental treatment to treat teeth in a patient's oral cavity. The laser treatment device 1 according to the embodiment can also be applied in fields other than dentistry, such as orthopedics, otolaryngology, surgery, urology, dermatology, and ophthalmology.

[0014] 1 and 2 are diagrams showing the appearance of a laser treatment device 1 according to an embodiment. As shown in FIGS. 1 and 2, the laser treatment device 1 includes a housing 10. The housing 10 is formed as a rectangular parallelepiped or approximately rectangular parallelepiped including a top surface 10A, a bottom surface 10B, a front surface 10C, a rear surface 10D, a right side surface 10E, and a left side surface 10F, and houses various components of the laser treatment device 1. In the following, the laser treatment device 1 will be described assuming that, when the laser treatment device 1 is installed on an installation surface, an axis along the horizontal direction of the housing 10 (the direction of the short sides of the front surface 10C and the rear surface 10D) is set as the X-axis, an axis along the vertical direction of the housing 10 (the direction of the short sides of the right side surface 10E and the left side surface 10F) is set as the Y-axis, and an axis along the height direction of the housing 10 (the direction of the long sides of the front surface 10C, the rear surface 10D, the right side surface 10E, and the left side surface 10F) is set as the Z-axis.

[0015] The laser treatment device 1 comprises a connection portion 11 , a waveguide 12 , a handpiece 13 , a holding portion 14 , a connection portion 15 , at least one leg portion 17 , a handle 18 , a display 19 , and a tray 20 .

[0016] The connecting part 11 is provided on the upper surface 10A of the housing 10 and has a pole along which the waveguide 12 is aligned. The connecting part 11 is configured so that the user can move the flexible waveguide 12 to a desired position by aligning the flexible waveguide 12 along the pole, and changes in accordance with the movement of the waveguide 12. The waveguide 12 extends flexibly and transmits laser light transmitted from a laser device (see FIG. 3) provided inside the housing 10 to the handpiece 13. The handpiece 13 emits the laser light transmitted via the waveguide 12 to the outside.

[0017] Holding unit 14 is provided on top surface 10A of housing 10 and is rotatable along the XY plane on top surface 10A. Holding unit 14 holds handpiece 13 at its tip, thereby fixing handpiece 13 to housing 10.

[0018] Connection unit 15 is provided on top surface 10A of housing 10 and is connected to top surface 10A of waveguide 12. Connection unit 15 connects a laser device provided inside housing 10 to waveguide 12, and also connects a water channel (not shown) provided along waveguide 12 to a tube pump (not shown) provided inside housing 10. The water channel supplies cleaning water supplied from the tube pump provided inside housing 10 to handpiece 13. Handpiece 13 emits the cleaning water supplied via the water channel to the outside.

[0019] At least one leg 17 is provided on the bottom surface 10B of the housing 10, creating a gap between the bottom surface 10B and the installation surface on which the housing 10 is placed. Specifically, each of the at least one leg 17 includes at least one wheel 170. The housing 10 is in contact with the installation surface via the at least one wheel 170 provided on the bottom surface 10B, and the at least one wheel 170 creates a gap between the bottom surface 10B and the installation surface.

[0020] In the laser treatment device 1 according to the embodiment, four legs 17A, 17B, 17C, and 17D are provided on the bottom surface 10B of the housing 10. Each of the four legs 17A, 17B, 17C, and 17D includes four wheels 170A, 170B, 170C, and 170D. Hereinafter, the four legs 17A, 17B, 17C, and 17D will be collectively referred to simply as "legs 17." The four wheels 170A, 170B, 170C, and 170D will be collectively referred to simply as "wheels 170." The wheels 170 rotate on the installation surface of the laser treatment device 1, allowing the laser treatment device 1 to move on the installation surface. This allows, for example, a user to move the laser treatment device 1 to a location where a patient is present when using the laser treatment device 1, and to move the laser treatment device 1 to a storage location when not using the laser treatment device 1. The at least one leg 17 may not include the at least one wheel 170, but may simply fix the housing 10 to the installation surface.

[0021] The handle 18 is a part that the user holds when moving the laser treatment device 1. The display 19 displays various information related to the treatment of a patient using the laser treatment device 1. The tray 20 holds treatment instruments and the like that are required when the user treats a patient using the laser treatment device 1.

[0022] Although the mounting position is not shown in FIGS. 1 and 2, the laser treatment device 1 is equipped with a laser device (see FIG. 3) that includes a resonator (oscillator) for generating laser light. As will be described later, the resonator includes a solid-state laser rod and a flash lamp (light source). The solid-state laser rod is, for example, a YAG crystal doped with Er as an active element. The solid-state laser rod is excited by irradiation with excitation light from the flash lamp, and emits laser light by amplifying spontaneously emitted light in the resonator.

[0023] The solid-state laser rod included in the oscillator is not limited to an Er:YAG rod, which is a YAG crystal doped with Er as an active element, but may be, for example, a YAG crystal doped with either Er or Ho as an active element. Furthermore, the solid-state laser rod is not limited to a YAG crystal, and may be any solid-state laser medium doped with a lanthanoid rare earth element. The solid-state laser rod may be, for example, an Er;Cr:YSGG crystal, a Ho:YAG crystal, or the like.

[0024] According to the laser treatment device 1 configured as described above, the user can extend the waveguide 12 while holding the handpiece 13, thereby positioning the tip of the handpiece 13 near the affected area of ​​the patient, and directing the laser light and cleansing water emitted from the tip of the handpiece 13 onto the affected area. This allows the user to treat the affected area using the laser light emitted by the laser treatment device 1.

[0025] [Laser device configuration] 3 is a diagram illustrating the structure of a laser device 30 according to an embodiment. The laser device 30 includes a resonator having a cylindrical solid-state laser rod 31 and a flash lamp 32 that excites the solid-state laser rod 31. The laser device 30 further includes a support member 33 that holds the solid-state laser rod 31 and fixes it to the housing 10 of the laser treatment device 1, a detection device 34 that detects laser light, and a control board 35 that controls the output of the flash lamp 32 based on the detected laser light.

[0026] In a laser treatment device 1 used in the medical field such as dental treatment, laser light irradiated to the affected area is absorbed by water and hydroxyapatite, which are the main components of the affected biological tissue, enabling treatment with incision, hemostasis, coagulation, and evaporation. In treatment, laser light with a high absorption rate locally on the affected area must be used to minimize the impact of transmitted light on surrounding healthy tissue. For this reason, laser light with a high absorption rate of water (absorption coefficient 20 cm) is used. -1 Laser light of wavelengths above 1000 nm is preferred, which differs from wavelengths commonly used in industrial applications.

[0027] For example, when the laser device 30 uses a Ho:YAG crystal for the solid laser rod 31, the absorption coefficient of water for the laser light emitted by the laser device 30 is 32 cm -1 In addition, when the laser device 30 uses Er:YAG crystal or Er;Cr:YSGG crystal for the solid laser rod 31, the water absorption coefficient of the laser light emitted by the laser device 30 is 12000 cm -1 , 5000cm -1 (Reference: DJ Segelstein, "The complex refractive index of water," University of Missouri-Kansas City (1981).) In addition, in the laser treatment device 1 used in the medical field such as dental treatment, the laser light emitted by the laser device 30 is preferably a pulsed laser light to reduce the thermal effects on surrounding healthy tissue during incision and vaporization. Specifically, the laser light emitted by the laser device 30 is preferably a pulsed laser light with a pulse width of 10 μs to 1000 μs.

[0028] The solid-state laser rod 31 is excited by irradiation with excitation light from the flash lamp 32, and a resonator must be configured to amplify the spontaneously emitted light. In a typical laser device, the resonator is configured by placing an output mirror (partially reflecting mirror) at a predetermined distance from one end of the solid-state laser rod, and placing a total reflecting mirror at a predetermined distance from the other end of the solid-state laser rod.

[0029] However, the absorption coefficient of water is 20 cm -1 Infrared light of the above wavelengths is highly absorbed by the OH groups contained in water, etc., and when moisture in the air is adsorbed onto the total reflection mirror or output mirror of the resonator, the adsorbed moisture absorbs the infrared light, generating heat and potentially damaging the total reflection mirror or output mirror.

[0030] Therefore, in the laser device 30 according to this embodiment, instead of providing a total reflection mirror and an output mirror separately from the solid-state laser rod 31, a reflection film formed by ion beam sputtering coating that can prevent moisture from entering from the outside air is directly formed on the end face of the solid-state laser rod 31. Figure 4 is a diagram showing the appearance of the solid-state laser rod 31 according to this embodiment.

[0031] 4, the solid-state laser rod 31 has a first reflective film 31a on one end face (first end face) and a second reflective film 31b on the other end face (second end face) to form a resonator 40 and generate laser oscillation. In other words, the first reflective film 31a and the second reflective film 31b are directly coated on the end faces of the solid-state laser rod 31 so that the reflective surfaces that form the mirrors of the resonator 40 are not exposed to the outside air. Therefore, the laser device 30 does not need to provide a total reflection mirror or an output mirror, and a resonator 40 can be realized that does not degrade performance and does not have a risk of mirror failure.

[0032] The first reflective film 31a and the second reflective film 31b are ion beam sputtering coated films. Ion beam sputtering coated films are highly dense films that can prevent moisture from penetrating to the reflective surfaces of the first reflective film 31a and the second reflective film 31b. The first reflective film 31a and the second reflective film 31b are not limited to ion beam sputtering coated films and may be formed by other methods as long as they are highly dense films.

[0033] Specifically, the first reflective film 31a and the second reflective film 31b are made of AlO 3、 Ta2O 5、Alternatively, the first reflective film 31a and the second reflective film 31b are preferably made of a multilayer film, at least one of which is made of Ta2O5. Of course, the first reflective film 31a and the second reflective film 31b may be made of Al2O5 or other suitable materials as long as the necessary reflectance can be ensured. 3、 Ta2O 5、 Also, it is not limited to SiO2.

[0034] First reflective film 31a corresponds to an output mirror and reflects light emitted from a laser crystal excited by excitation light from flash lamp 32, and can also emit the amplified light as laser light. On the other hand, second reflective film 31b corresponds to a total reflection mirror and reflects light emitted from a laser crystal excited by excitation light from flash lamp 32. Therefore, the reflectance of first reflective film 31a is lower than the reflectance of second reflective film 31b.

[0035] For example, the reflectance of the first reflective film 31a is about 92%, and the reflectance of the second reflective film 31b is about 99.4%. The reflectance of the second reflective film 31b may be set to 100% to function as a total reflection mirror, but in the laser device 30 according to this embodiment, the laser light transmitted through the second reflective film 31b is used to monitor and control the laser light emitted from the end face on which the first reflective film 31a is provided.

[0036] Specifically, the laser device 30 detects laser light transmitted through the second reflective film 31b using a detector 34. The detector 34 includes a detector 34a that detects laser light transmitted through the second reflective film 31b, and an optical filter 34b that blocks visible light between the detector 34a and the end face on which the second reflective film 31b is provided. The detector 34a is, for example, a pyroelectric element made of lithium tantalate (LiTaO3) or lead zirconate titanate (PZT). Note that the detector 34a is not limited to the above configuration as long as it can detect infrared light with a wavelength of 2 μm or more.

[0037] The optical filter 34b is a visible light cut filter and is made of, for example, silicon (Si) or germanium (Ge). By providing the optical filter 34b, stray light (especially excitation light from the flash lamp 32) other than the laser light that passes through the second reflective film 31b can be removed, and the detector 34a can accurately detect the laser light that passes through the second reflective film 31b. Of course, if no countermeasure against stray light is required for the detector 34a, the optical filter 34b need not be provided.

[0038] The control board 35 monitors the intensity of the laser light emitted from the end face provided with the first reflective film 31 a based on the intensity of the laser light detected by the detector 34 a. Furthermore, the control board 35 can also control the output of the flash lamp 32 based on the intensity of the laser light detected by the detector 34 a, and control the intensity of the laser light emitted from the end face provided with the first reflective film 31 a to a set value.

[0039] The control board 35 has a processor and a memory (not shown). The processor executes various programs stored in the memory to control the intensity of the laser light emitted from the end face on which the first reflective film 31a is provided, based on the setting values ​​received by the input unit.

[0040] A processor is comprised of a CPU, a GPU, etc., and can read and execute programs (such as an OS and a control program) stored in memory. The processor executes various programs read from memory. The memory is comprised of, for example, a non-volatile storage device such as a ROM or flash memory. The memory stores the OS for realizing basic functions as well as the control program.

[0041] The input unit is not limited to a specific device, but may be, for example, a touch panel superimposed on the display 19. Some or all of the functions provided by the processor executing a program may be implemented using a dedicated hardware circuit (for example, an ASIC or FPGA).

[0042] One method for monitoring the laser light emitted from the end face provided with the first reflective film 31a is to spectrally separate a portion of the laser light emitted from the end face provided with the first reflective film 31a and detect the separated laser light. This method requires the provision of a spectral optical system, which increases the size of the device. Furthermore, the spectral optical system spectrally separates the laser light emitted from the end face provided with the first reflective film 31a, and therefore requires optical elements with high resistance to the laser light intensity.

[0043] Therefore, the laser device 30 according to this embodiment achieves miniaturization by slightly reducing the reflectance of the second reflective film 31b, which functions as a total reflection mirror, from 100% to transmit the laser light and providing a function for detection by the detection device 34. Of course, the laser device 30 may be configured to include a spectroscopic optical system that disperses part of the laser light emitted from the end face provided with the first reflective film 31a.

[0044] Furthermore, in the laser device 30 according to this embodiment, by providing the first reflective film 31a and the second reflective film 31b on the end face of the solid-state laser rod 31, it is not necessary to provide separate components such as a total reflection mirror or an output mirror, thereby enabling the device to be made smaller and reducing component costs. Furthermore, by providing the first reflective film 31a and the second reflective film 31b on the end face of the solid-state laser rod 31 that has been processed to achieve parallelism with high precision, it is possible to reduce the costs associated with configuring precise mechanical components and adjusting them to achieve parallelism between the total reflection mirror and the output mirror.

[0045] In addition, the first reflective film 31a and the second reflective film 31b provided on the end faces of the solid-state laser rod 31 are formed of a highly dense ion beam sputtering coating film, which significantly reduces the risk of damage caused by moisture absorption, as occurs with total reflection mirrors and output mirrors. Furthermore, the solid-state laser rod 31 having the first reflective film 31a and the second reflective film 31b provided on the end faces constitutes the resonator 40, which prevents problems such as dust getting into the resonator 40 and improves the reliability of the laser device 30.

[0046] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0047] 1 Laser treatment device, 10 Housing, 10A Top, 10B Bottom, 10C Front, 10D Rear, 10E Right side, 10F Left side, 11, 15 Connection part, 12 Waveguide, 13 Handpiece, 14 Holding part, 17, 17A, 17B, 17C, 17D Leg, 18 Handle, 19 Display, 20 Tray, 21, 21A, 21B Air inlet, 30 Laser device, 31 Solid laser rod, 31a First reflective film, 31b Second reflective film, 32 Flash lamp, 33 Support member, 34 Detection device, 34a Detector, 34b Optical filter, 35 Control board, 40 Resonator.

Claims

1. The absorption coefficient of water is 20 cm －１ A laser device that emits laser light having a wavelength of at least a resonator including a columnar solid-state laser rod, a first reflective film provided on a first end face of the solid-state laser rod, and a second reflective film provided on a second end face of the solid-state laser rod opposite to the first end face; a flash lamp for exciting the solid-state laser rod; the first reflective film and the second reflective film are ion beam sputtering coated films that can prevent moisture from entering from the outside air, A laser device, wherein the reflectance of the first reflective film is lower than the reflectance of the second reflective film.

2. 2. The laser device according to claim 1, wherein the solid-state laser rod is a YAG crystal or a YSGG crystal doped with at least one of Er, Ho, and Cr as an active element.

3. 2. The laser device according to claim 1, wherein the laser light emitted by said laser device is a pulsed laser light having a pulse width of 10 μs to 1000 μs.

4. The first reflective film and the second reflective film are made of Al ２ O ３、 Ta ２ O ５、 or SiO ２ The laser device according to claim 1 , comprising:

5. The first reflective film and the second reflective film are multilayer films, and at least one film of the multilayer films is Ta. ２ O ５ 10. The laser device of claim 1, comprising a film made of:

6. The laser device according to claim 1 , further comprising a detector that detects the laser light transmitted through the second reflective film.

7. 7. The laser device according to claim 6, further comprising an optical filter for blocking visible light between the detector and the second end face on which the second reflective film is provided.

8. The laser device according to claim 7 , wherein the optical filter is made of silicon or germanium.

9. 7. The laser device according to claim 6, further comprising a control board that controls an output of the flash lamp based on the laser light detected by the detector.

10. A laser treatment device for treating an affected area using laser light, A laser treatment device comprising the laser device according to any one of claims 1 to 9, which emits laser light.

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