Reflection-type acousto-optic Q switch and Q-switched laser

Abstract

The utility model discloses a reflective acousto-optic Q switch and a Q-switched laser, and belongs to the technical field of optical devices. The reflective acousto-optic Q switch comprises a packaging metal shell; the optical fiber collimator is arranged on the first side wall of the packaging metal shell; the acousto-optic crystal is located in the packaging metal shell, and the electroacoustic transducer is arranged on the surface of the acousto-optic crystal; the space reflection unit is located in the packaging metal shell and comprises a first reflection piece, a second reflection piece and a third reflection piece, the first reflection piece is arranged in the light emitting direction of the optical fiber collimator and located on one side of the acousto-optic crystal, and the second reflection piece is arranged and located on the other side, provided with the reflection face, of the acousto-optic crystal; the third reflecting part is located on the side, close to the first side wall, of the second reflecting part and used for receiving light reflected by the second reflecting part and reflecting the light back to the second reflecting part. According to the utility model, the volume of the acousto-optic Q switch can be reduced, and miniaturization of equipment is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of optical device technology, and in particular to a reflective acousto-optic Q-switch and a Q-switched laser. Background Technology

[0002] As a key component within a laser cavity, the acousto-optic Q-switch operates by introducing controlled variable losses to regulate the laser's output state. This regulation mechanism allows the originally continuous laser power to be converted into laser pulses with high peak power, thus meeting various application requirements. In laser ranging, high peak power laser pulses enable more accurate distance measurement; in communications, they improve signal transmission efficiency and anti-interference capabilities; in precision machining, high peak power laser pulses achieve finer processing results; and in medical devices, they enable more precise laser treatment. Therefore, reflective acousto-optic Q-switches play a crucial role in multiple fields.

[0003] However, existing technologies have the following problems in implementation: Most acousto-optic Q-switches on the market currently adopt a dual-fiber collimator structure, which is relatively large. This structure requires the laser to consider the fiber routing positions on both sides and the overall structural footprint during design, increasing the length of the acousto-optic Q-switch. This results in the laser's overall structure requiring more space, which is not conducive to the miniaturization of the device.

[0004] This section provides background information related to this application, which is not necessarily prior art. Utility Model Content

[0005] The purpose of this invention is to provide a reflective acousto-optic Q-switch and a Q-switched laser, which can reduce the number of fiber collimators used and contribute to the miniaturization of the equipment.

[0006] To achieve the above objectives, the following technical solution is provided:

[0007] Reflective acousto-optic Q-switch, including:

[0008] Encapsulated metal casing;

[0009] An optical fiber collimator is disposed on the first sidewall of the encapsulated metal shell;

[0010] An acousto-optic crystal is located inside the encapsulated metal shell, and an electroacoustic transducer is disposed on the surface of the acousto-optic crystal.

[0011] A spatial reflection unit is located within the encapsulated metal shell. The spatial reflection unit includes a first reflector, a second reflector, and a third reflector. The first reflector is disposed in the light-emitting direction of the fiber optic collimator and located on one side of the acousto-optic crystal, so that the incident light passes through the acousto-optic crystal, and is used to receive and reflect the incident light. The second reflector is disposed on the other side of the acousto-optic crystal and is used to receive and reflect first-order diffracted light. The third reflector is located on one side of the second reflector and is used to receive the light reflected by the second reflector and reflect it back to the second reflector along the same path.

[0012] As an alternative to the reflective acousto-optic Q-switch, the first reflector, the second reflector, and the third reflector are mirrors coated with a total reflection film.

[0013] As an alternative to the reflective acousto-optic Q-switch, the second reflector is a plane mirror, with the reflecting surface forming an angle of 45°±5° with the emission direction of the first-order diffraction light from the acousto-optic crystal.

[0014] As an alternative to the reflective acousto-optic Q-switch, the reflective acousto-optic Q-switch further includes a lead wire and an RF connector. The first end of the lead wire passes through the first sidewall of the encapsulated metal shell and is connected to the electroacoustic transducer. The second end of the lead wire is connected to the RF connector. The diameter of the lead wire is smaller than the diameter of the RF connector.

[0015] As an alternative to a reflective acousto-optic Q-switch, the lead includes a conductor and an insulating protective layer, the insulating protective layer being wrapped around the surface of the conductor.

[0016] As an alternative to the reflective acousto-optic Q-switch, the insulating protective layer is made of plastic or rubber.

[0017] As an alternative to the reflective acousto-optic Q-switch, the fiber collimator is provided with a beam-expanding fiber, the diameter of which is 100μm-110μm.

[0018] As an alternative to the reflective acousto-optic Q-switch, a fixing tube is provided at the position where the fiber optic collimator is installed in the encapsulated metal shell, and the fiber optic collimator is inserted into the fixing tube.

[0019] As an alternative to the reflective acousto-optic Q-switch, the fixed tube is made of a low-expansion-coefficient alloy.

[0020] As an alternative to the reflective acousto-optic Q-switch, the encapsulated metal shell is provided with several connection holes, through which fasteners can be connected to external fixed objects.

[0021] As an alternative to the reflective acousto-optic Q-switch, the encapsulated metal shell is provided with heat dissipation fins or heat-conducting pillars.

[0022] A Q-switched laser includes an RF drive power supply and a reflective acousto-optic Q-switch as described in any of the preceding claims, wherein the electroacoustic transducer of the reflective acousto-optic Q-switch is connected to the output of the RF drive power supply.

[0023] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0024] The reflective acousto-optic Q-switch provided by this utility model includes a metal housing, an optical fiber collimator, an acousto-optic crystal, an electroacoustic transducer, and a spatial reflection unit. The optical fiber collimator is disposed outside the metal housing and located on the first side wall. The acousto-optic crystal, electroacoustic transducer, and spatial reflection unit are all located inside the metal housing. By placing the first reflector in the light-emitting direction of the optical fiber collimator and on one side of the acousto-optic crystal, the second reflector on the other side of the acousto-optic crystal, and the third reflector at the end of the second reflector near the first side wall, the original optical path can be spatially folded using the spatial reflection unit. This fully and effectively utilizes the internal space of the metal housing, shortening the length of the metal housing and further reducing the spatial structure of the acousto-optic Q-switch. The acousto-optic Q-switch provided by this utility model, combined with the spatial reflection unit and using a single-sided optical fiber collimator coupling method, can reduce the number of optical fiber collimators used and reduce the overall structural area occupied by the acousto-optic Q-switch.

[0025] The Q-switched laser provided by this invention uses a radio frequency drive power supply to transmit a high-frequency signal through a radio frequency connector and leads to an electroacoustic transducer, ensuring stable operation. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of this utility model and these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the assembly of the acousto-optic Q-switch in an embodiment of this utility model;

[0028] Figure 2 This is a top view of the acousto-optic Q-switch in an embodiment of this utility model;

[0029] Figure 3 This is a schematic diagram of the aperture structure in an embodiment of the present invention;

[0030] Figure 4 This is a perspective view of the structure of the acousto-optic Q-switch in an embodiment of the present invention;

[0031] Figure 5 This is a working optical path diagram of the acousto-optic Q-switch in the embodiment of the present invention, in which incident light is diffracted by the first reflector and then sequentially directed to the second and third reflectors.

[0032] Figure 6 This is a working optical path diagram of the acousto-optic Q-switch in this embodiment of the invention, in which the first-order diffracted light returns through the third reflector, the second reflector, and the first reflector when the electroacoustic transducer is energized.

[0033] Figure 7 This is the optical path diagram of the zero-order light in the light entry path of the acousto-optic Q-switch in the state where the electroacoustic transducer is not powered, according to an embodiment of this utility model.

[0034] Figure 8 This is the optical path diagram of the zero-order light in the optical return path of the acousto-optic Q-switch in the state where the electroacoustic transducer is not powered, according to an embodiment of this utility model.

[0035] Figure label:

[0036] 100, Encapsulated metal shell; 1001, First sidewall; 1002, Connecting hole; 200, Fiber optic collimator; 300, Acousto-optic crystal; 400, Electroacoustic transducer; 500, First reflector; 600, Second reflector; 700, Third reflector; 800, Lead wire; 900, RF connector; 1000, Fixing tube; 1100, Aperture. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] In the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are used only for the convenience of describing this utility model and for 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 this utility model. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0039] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" 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. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown 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 are only used to explain this utility model, and should not be construed as limiting this utility model.

[0041] Figure 1 This is a schematic diagram of the assembly of the acousto-optic Q-switch in an embodiment of this utility model; Figure 2 This is a top view of the acousto-optic Q-switch in an embodiment of this utility model; Figure 3 This is a schematic diagram of the aperture structure in an embodiment of the present invention; Figure 4 This is a perspective view of the structure of the acousto-optic Q-switch in an embodiment of the present invention; Figure 5 This is a working optical path diagram of the acousto-optic Q-switch in the embodiment of the present invention, in which incident light is diffracted by the first reflector and then sequentially directed to the second and third reflectors. Figure 6 This is a working optical path diagram of the acousto-optic Q-switch in this embodiment of the invention, in which the first-order diffracted light returns through the third reflector, the second reflector, and the first reflector when the electroacoustic transducer is energized. Figure 7 This is the optical path diagram of the zero-order light in the light entry path of the acousto-optic Q-switch in the state where the electroacoustic transducer is not powered, according to an embodiment of this utility model. Figure 8 This is the optical path diagram of the zero-order light in the optical return path of the acousto-optic Q-switch in the state where the electroacoustic transducer is not powered, according to an embodiment of this utility model.

[0042] To reduce the number of fiber collimators used and facilitate device miniaturization, this embodiment provides a reflective acousto-optic Q-switch and a Q-switched laser, which are described below in conjunction with... Figures 1 to 8 The specific content of this embodiment will be described in detail.

[0043] It should be noted that the first-order diffracted light mentioned in this embodiment refers to the first-order diffracted light generated after the light wave interacts with the sound wave in the acousto-optic crystal. It is a relatively significant type of diffracted light in the acousto-optic effect, and its propagation direction and energy distribution are significantly different from the zero-order light. The principle of first-order diffracted light generation: When a light wave and a sound wave meet in an acousto-optic crystal, the light wave is scattered by the periodic change in refractive index caused by the sound wave. According to the Bragg diffraction condition, light waves meeting specific conditions will diffract, generating first-order diffracted light. The generation of first-order diffracted light is the result of energy and momentum exchange between the light wave and the sound wave.

[0044] The zero-order light mentioned in this embodiment, also known as non-diffractive light or direct-transmitting light, refers to light that is directly transmitted through an acousto-optic crystal without being modulated by acoustic waves. Simply put, this light maintains its original propagation path and characteristics as if it hadn't encountered any acoustic interference. The principle behind zero-order light generation: When light waves enter an acousto-optic crystal, the acoustic waves cause periodic changes in the refractive index of the medium, forming a grating-like structure. However, zero-order light corresponds to light waves that do not effectively interact with this periodic refractive index change; they "bypass" the modulation caused by the acoustic waves and pass directly through the crystal.

[0045] The reflective acousto-optic Q-switch in this embodiment includes a metal housing 100, an optical fiber collimator 200, an electroacoustic transducer 400, an acousto-optic crystal 300, and a spatial reflection unit. The optical fiber collimator 200 is disposed on the first sidewall 1001 of the metal housing 100. The acousto-optic crystal 300 is located inside the metal housing 100, and the electroacoustic transducer 400 is disposed on the surface of the acousto-optic crystal 300. The incident surface of the acousto-optic crystal 300 is not opposite to the emitting surface of the optical fiber collimator 200. The acousto-optic crystal 300 is the core functional component of the reflective acousto-optic Q-switch. It utilizes the acousto-optic effect; ultrasonic waves generated by the electroacoustic transducer 400 propagate through the crystal, causing periodic changes in the crystal's refractive index, thereby modulating the laser beam passing through the crystal and achieving rapid switching control of the laser. The metal housing 100 has a receiving cavity, and both the acousto-optic crystal 300 and the electroacoustic transducer 400 are disposed within the metal housing 100. The enclosure formed by the metal shell 100 provides a sealed and stable environment for the acousto-optic crystal 300 and the electroacoustic transducer 400, effectively preventing external dust, moisture, chemicals, and other contaminants from corroding and damaging the internal sensitive components, ensuring their long-term stable operation. The metal shell 100 provides robust mechanical support for the acousto-optic crystal 300 and the electroacoustic transducer 400, ensuring they maintain a stable position and orientation during installation and use, preventing component displacement or damage due to vibration, impact, or other factors. The metal shell 100 also provides a certain degree of shielding for electromagnetic signals, reducing the impact of external electromagnetic interference on the normal operation of the acousto-optic crystal 300 and the electroacoustic transducer 400, and improving the stability and accuracy of signal transmission. The spatial reflection unit is located inside the encapsulated metal shell 100. The spatial reflection unit includes a first reflector 500, a second reflector 600, and a third reflector 700. The first reflector 500 is disposed in the light-emitting direction of the fiber collimator 200 and is located on one side of the acousto-optic crystal 300, so that the incident light passes through the acousto-optic crystal 300, and is used to receive and reflect the incident light. The second reflector 600 is disposed on the other side of the acousto-optic crystal 300 and is used to receive and reflect the first-order diffracted light. The third reflector 700 is located on one side of the second reflector 600 and is used to receive the light reflected by the second reflector 600 and reflect it back to the second reflector 600 along the same path.

[0046] For example, combined Figure 5 and Figure 6 As shown, the light path in this embodiment where diffraction occurs is: the light entry path and the light return path.

[0047] like Figure 5As shown, the light entry path is as follows: fiber collimator 200 (incident light enters the Q switch through fiber collimator 200) → first reflector 500 (incident light is reflected by the first reflector 500 and then strikes the acousto-optic crystal 300) → acousto-optic crystal 300 (according to the Bragg diffraction condition, the incident light is diffracted into first-order diffracted light and then strikes the second reflector 600 from the acousto-optic crystal 300) → second reflector 600 (reflects the first-order diffracted light and strikes the third reflector 700) → third reflector 700 (the first-order diffracted light is reflected by the third reflector 700 and then returns to the second reflector 600 along the original path)

[0048] like Figure 6 As shown, the light enters through the following path: third reflector 700 → second reflector 600 → acousto-optic crystal 300 (the first-order diffracted light is diffracted again and then directed toward the first reflector 500) → first reflector 500 → fiber collimator 200 (the last-order diffracted light is input into the Q switch through the fiber collimator 200).

[0049] Furthermore, since zero-order light and diffracted light alternate, a reflector is needed to separate them. (Refer to...) Figure 7 As shown, for example, when zero-order light is generated in the light entry path: with acousto-optic crystal 300 (light does not diffract), the zero-order light is not reflected by the second reflector 600. (Refer to...) Figure 8 As shown, for example, when zero-order light is generated in the light return path: the acousto-optic crystal 300 (light does not diffract) does not reflect the zero-order light by the first reflector 500, ensuring that the fiber collimator 200 outputs first-order diffracted light but cannot output zero-order light.

[0050] In summary, the reflective acousto-optic Q-switch provided in this embodiment has an optical fiber collimator 200 disposed outside the encapsulated metal shell 100 and located on the first sidewall 1001. The acousto-optic crystal 300, electroacoustic transducer 400, and spatial reflection unit are all located inside the encapsulated metal shell 100. Since the incident surface of the acousto-optic crystal 300 and the light-emitting surface of the optical fiber collimator 200 are not opposite each other, by setting the first reflector 500 in the light-emitting direction of the optical fiber collimator 200 and at the end of the acousto-optic crystal 300 with the incident surface, setting the second reflector 600 and at the end of the acousto-optic crystal 300 with the reflective surface, and setting the third reflector 700 at the end of the second reflector 600 near the first sidewall 1001, the original optical path can be spatially folded using the spatial reflection unit. This fully and effectively utilizes the internal space of the encapsulated metal shell 100, thereby shortening the length of the encapsulated metal shell 100 and further reducing the spatial structure of the reflective acousto-optic Q-switch. The reflective acousto-optic Q-switch provided in this embodiment combines a spatial reflection unit with a single-sided fiber optic collimator 200 coupling method, which reduces the number of fiber optic collimators 200 used and decreases the overall footprint of the reflective acousto-optic Q-switch. Figure 5 and Figure 6 As shown, in this embodiment, the fiber optic collimator 200 serves as both an input port and an output port. One fiber optic collimator receives the optical signal from an external laser source, such as incident light, while the other outputs the modulated optical signal to a subsequent optical system, such as first-order diffracted light. Figure 7 As shown, the working optical path diagram of the reflective acousto-optic Q-switch in the state where the electroacoustic transducer 400 is not powered on is as follows: the incident light is diffracted, and the zero-order light is directly transmitted from the acousto-optic crystal 300 and does not return from the fiber collimator 200.

[0051] Furthermore, the first reflector 500, the second reflector 600, and the third reflector 700 are reflectors coated with a total reflection film. The reflectors of this application have high reflectivity to laser light.

[0052] Furthermore, the second reflector 600 is a plane mirror, with its reflecting surface forming an angle of 45°±5° with the emission direction of the first-order diffracted light from the acousto-optic crystal 300. Limiting the angle between the reflecting surface of the second reflector and the first-order diffracted light within a certain range can improve the effect of shortening the optical path space, make reasonable use of the internal space of the acousto-optic Q-switch, and reduce the overall volume of the acousto-optic Q-switch.

[0053] Furthermore, such as Figure 1 As for Figure 4As shown, the reflective acousto-optic Q-switch also includes a lead 800 and an RF connector 900. The first end of the lead 800 passes through the first sidewall 1001 of the encapsulation metal shell 100 and connects to the electroacoustic transducer 400. The second end of the lead 800 connects to the RF connector 900. The diameter of the lead 800 is smaller than the diameter of the RF connector 900. The high-frequency signal from the RF drive power supply passes sequentially through the RF connector 900 and the lead 800 into the electroacoustic transducer 400. The electroacoustic transducer 400 converts the electrical signal into high-frequency sound waves (ultrasound) and couples them into the acousto-optic crystal 300. The sound waves propagate in the crystal, forming a dynamic grating that modulates the parameters of the incident light. Because the diameter of the lead 800 is smaller than the diameter of the RF connector 900, the larger RF connector 900 contacts the encapsulation metal shell 100 through the smaller diameter lead 800, allowing for a more miniaturized design of the encapsulation metal shell 100. Furthermore, by utilizing an insulating protective layer to ensure insulation between the lead 800 and the encapsulated metal shell 100, the RF connector 900 does not require an additional mica sheet, allowing it to fully contact the air and improving its heat dissipation. The fiber optic collimator 200 and the lead 800 are both located on the same side of the encapsulated metal shell 100. The fiber optic collimator 200 is used to collimate the laser beam in the fiber into parallel light and efficiently couple it into the acousto-optic crystal 300. Its co-side design with the lead 800 optimizes the optical path layout and reduces optical signal loss during transmission. For example, in a laser modulation system, the collimator ensures that the laser enters the acousto-optic crystal 300 at the optimal incident angle, improving modulation efficiency. Concentrating the fiber optic collimator 200 and the lead 800 on the same side of the encapsulated metal shell 100 reduces the overall size of the reflective acousto-optic Q-switch, facilitating integration into laser equipment. This co-side layout also facilitates modular packaging of the reflective acousto-optic Q-switch, simplifying equipment installation and maintenance. For example, during replacement or repair, the fiber optic interface and electrical signal connection point can be quickly located. The design of the fiber optic collimator 200 and lead wire 800 on the same side unifies the interface direction, facilitating the connection and debugging of optical and electrical paths by engineers. For example, during laser equipment assembly, the connection of fiber optics and electrical signals can be completed in one step, reducing operational steps. For example, in compact lasers, this design frees up more space for the layout of other optical components. Optionally, in this embodiment, the pigtail of the fiber optic collimator 200 is spirally coiled. The spirally coiled pigtail allows for flexible adjustment of the fiber length to adapt to different installation scenarios. By controlling the coiling radius (typically greater than the minimum bending radius of the fiber), optical signal attenuation due to excessive bending is avoided.

[0054] Exemplarily, the fiber optic collimator 200 is precisely positioned from a pigtail and a self-focusing lens, used to convert transmitted light within the fiber into collimated light (parallel light), or to couple external parallel (approximately parallel) light into the single-mode fiber. In this embodiment of the invention, the fiber optic collimator 200 is a single-clad fiber optic collimator. The fiber optic collimator 200 includes a fiber optic head (not shown), a glass tube (not shown), and a lens (not shown). The fiber optic head receives light, the glass tube is fitted over the fiber optic head, and the lens is positioned on the light-emitting surface of the fiber optic collimator 200. Optionally, as... Figure 3 As shown, a small-sized aperture 1100 is used and mounted on the lens of the fiber optic collimator 200. Its function is to block the zero-order light from entering, and the through-hole position of the aperture 1100 is located by a CCD and a beam analyzer to avoid light obstruction. The surface of the aperture 1100 is sandblasted to diffuse the zero-order light and allow it to pass through the glass tube, thus preventing the aperture 1100 cap from overheating.

[0055] Furthermore, the lead 800 includes a conductor and an insulating protective layer, with the insulating protective layer covering the surface of the conductor. The conductor serves as a channel for electrical signal transmission, responsible for accurately and efficiently transmitting the electrical signals provided by the external circuit to the electroacoustic transducer 400, ensuring that the electroacoustic transducer 400 can receive a suitable operating signal to generate stable and accurate ultrasonic waves. The insulating protective layer covering the surface of the conductor primarily serves an electrical insulation function, preventing short circuits between the conductor and the surrounding environment or other metal components, ensuring the safety and reliability of electrical signal transmission. Simultaneously, the insulating protective layer also provides some mechanical protection to the conductor, reducing wear and damage during use. Since the conductor is made of metal, when the conductor is conductive and current flows through it, the surrounding electromagnetic field changes with the current, thus generating electromagnetic radiation. By wrapping the surface of the conductor with an insulating protective layer, electromagnetic radiation is effectively confined within the device. This is because insulating materials can block the propagation of electromagnetic waves, preventing electromagnetic radiation from penetrating into the external space (this can be verified through a radiation interference test. A radiation interference test measures the magnitude of the electromagnetic wave signal emitted by a device under normal operating conditions, thus determining the degree of interference it causes to surrounding electronic equipment. This test is typically conducted in a specific testing environment, such as an anechoic chamber, using a receiving antenna to receive the radiated interference signal emitted from the device under test and comparing it with standard limits).

[0056] Furthermore, the insulating protective layer is made of plastic or rubber. Both plastic and rubber are excellent insulating materials, effectively preventing the wires from contacting the encapsulated metal housing or other conductive components, thus avoiding the risk of short circuits. For example, inside a reflective Q-switch, the wires need to pass through the encapsulated metal housing 100 to connect to the electroacoustic transducer 400; the insulating protective layer ensures insulation between the wires and the encapsulated metal housing 100. During installation, use, or transportation, the wires of the reflective Q-switch may be subjected to friction or compression. The plastic or rubber insulating protective layer provides cushioning, reducing wear on the wire's insulation. For example, during equipment vibration or movement, the insulating protective layer prevents the wires from breaking due to friction. Plastic and rubber have a certain degree of resistance to moisture and chemicals, protecting the internal metal conductors of the wires from corrosion and extending their service life. The soft and flexible nature of plastic and rubber materials facilitates wiring in confined spaces or curved paths within the reflective Q-switch, reducing installation difficulty. For example, when wiring inside the encapsulated metal housing 100, the insulating protective layer can be flexibly bent to adapt to structural constraints. A stable electrical connection can prevent performance degradation caused by signal interruption or interference during continuous laser operation.

[0057] Furthermore, an expanding fiber is disposed within the fiber collimator 200, the diameter of which is 100µm-110µm. In this embodiment, the diameter of the expanding fiber is larger than that of conventionally used optical fibers. By adding the expanding fiber inside the fiber collimator 200, the laser power density is reduced, preventing the coating layer from being burned off and improving the long-term operational stability of the product. For example, the diameter of the expanding fiber is 105µm. In this embodiment, the diameter of the lead 2 is 3mm-8mm. For example, the diameter of the lead 2 can be, but is not limited to, 3mm, 4mm, 5mm, 6mm, 7mm, or 8mm, etc., without further limitation.

[0058] Furthermore, a fixing tube 1000 is provided at the location where the fiber optic collimator 200 is installed in the encapsulated metal shell 100, and the fiber optic collimator 200 is inserted into the fixing tube 1000. The fixing tube 1000 provides physical support for the fiber optic collimator 200, preventing it from shifting under conditions such as vibration, impact, or thermal expansion and contraction, ensuring optical path stability, and preventing misalignment. The inner diameter of the fixing tube 1000 matches the outer diameter of the collimator, enabling precise installation of the collimator, reducing the risk of beam misalignment, and facilitating accurate positioning.

[0059] Furthermore, the fixing tube 1000 is made of a low-expansion-coefficient alloy. For example, the fixing tube 1000 is made of 4J29 alloy. The coefficient of thermal expansion of 4J29 alloy is 4.6-5.5 × 10⁻⁶ within the range of 20-450°C. -6The 4J29 alloy (at / ℃) is highly compatible with sealing materials such as glass and ceramics, effectively reducing thermal stress caused by temperature changes and preventing cracks or loosening between the fiber collimator 200 and the encapsulation metal shell 100. In laser equipment, temperature fluctuations can cause optical path deviations; the compatibility of the 4J29 alloy ensures optical path stability. The 4J29 alloy maintains structural stability at low temperatures, avoiding dimensional changes due to phase transformations, making it suitable for extreme temperature environments. The 4J29 alloy exhibits excellent corrosion resistance to atmosphere, water vapor, and various chemical media, preventing oxidation or corrosion in humid or corrosive environments and extending equipment lifespan. In industrial laser equipment, it prevents performance degradation caused by corrosion.

[0060] Furthermore, the encapsulated metal shell 100 is provided with several connection holes 1002, through which fasteners can pass to connect to external fixed objects. By firmly connecting the encapsulated shell to the equipment base using fasteners (such as bolts and screws), mechanical stresses such as vibration and impact can be effectively resisted, preventing displacement or loosening of the reflective acousto-optic Q-switch and ensuring stable optical path coupling efficiency. The connection holes 1002, in conjunction with standard fasteners, facilitate the installation, disassembly, and replacement of the reflective acousto-optic Q-switch, reducing maintenance costs. During laser equipment maintenance, the reflective acousto-optic Q-switch can be quickly removed for inspection by loosening the bolts, without the need to recalibrate the optical path. In practical use, different mounting platforms can be adapted by adjusting the position and number of connection holes 1002. The fasteners can also serve as heat conduction paths, transferring heat from the reflective acousto-optic Q-switch to the mounting base (if the base is made of a high thermal conductivity material, such as aluminum or copper), enhancing heat dissipation efficiency.

[0061] Furthermore, heat dissipation fins or heat-conducting pillars are added to the encapsulated metal casing 100. The heat from the internal heating element of the reflective acousto-optic Q-switch is rapidly conducted to the encapsulated metal casing 100. By adding heat dissipation fins or heat-conducting pillars to the outer surface of the encapsulated metal casing 100, the heat dissipation surface area of ​​the metal casing is increased, accelerating the transfer of heat to the surrounding environment and ensuring that the acousto-optic crystal 300 operates within a safe temperature range. Similar to a computer CPU heatsink, increasing the heat dissipation area improves heat dissipation efficiency.

[0062] This embodiment also provides a Q-switched laser, which includes an RF drive power supply and the aforementioned reflective acousto-optic Q-switch. The electroacoustic transducer 400 of the reflective acousto-optic Q-switch is connected to the output terminal of the RF drive power supply.

[0063] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Many other equivalent embodiments may be included without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A reflective acousto-optic Q-switch, characterized in that, include: Encapsulated metal casing (100); An optical fiber collimator (200) is disposed on the first sidewall (1001) of the encapsulated metal shell (100); An acousto-optic crystal (300) is located inside the encapsulated metal shell (100), and an electroacoustic transducer (400) is disposed on the acousto-optic crystal (300); A spatial reflection unit is located inside the encapsulated metal shell (100). The spatial reflection unit includes a first reflector (500), a second reflector (600), and a third reflector (700). The first reflector (500) is disposed in the light-emitting direction of the fiber collimator (200) and located on one side of the acousto-optic crystal (300), and is used to receive and reflect incident light so that the incident light passes through the acousto-optic crystal (300). The second reflector (600) is disposed on the other side of the acousto-optic crystal (300) and is used to receive and reflect first-order diffracted light. The third reflector (700) is located on one side of the second reflector (600) and is used to receive the light reflected by the second reflector (600) and reflect it back to the second reflector (600) along the same path.

2. The reflective acousto-optic Q-switch according to claim 1, characterized in that, The first reflector (500), the second reflector (600) and the third reflector (700) are reflective mirrors coated with a total reflection film.

3. The reflective acousto-optic Q-switch according to claim 1, characterized in that, The second reflector (600) is a plane mirror, and the reflecting surface forms an angle of 45°±5° with the first-order diffraction light emission direction of the acousto-optic crystal (300).

4. The reflective acousto-optic Q-switch according to claim 1, characterized in that, The reflective acousto-optic Q-switch further includes a lead wire (800) and an RF connector (900). The first end of the lead wire (800) passes through the first sidewall (1001) of the encapsulation metal shell (100) and is connected to the electroacoustic transducer (400). The second end of the lead wire (800) is connected to the RF connector (900). The diameter of the lead wire (800) is smaller than the diameter of the RF connector (900).

5. The reflective acousto-optic Q-switch according to claim 4, characterized in that, The lead (800) includes a conductor and an insulating protective layer, the insulating protective layer being wrapped around the surface of the conductor.

6. The reflective acousto-optic Q-switch according to claim 1, characterized in that, The fiber collimator (200) is provided with a beam-expanding fiber, the diameter of which is 100μm-110μm.

7. The reflective acousto-optic Q-switch according to claim 1, characterized in that, A fixing tube (1000) is provided at the position where the fiber collimator (200) is installed on the encapsulated metal shell (100), and the fiber collimator (200) is inserted into the fixing tube (1000).

8. The reflective acousto-optic Q-switch according to claim 7, characterized in that, The fixed tube (1000) is made of a low expansion coefficient alloy.

9. The reflective acousto-optic Q-switch according to claim 1, characterized in that, The encapsulated metal shell (100) is provided with a plurality of connection holes (1002), through which fasteners can pass to connect with external fixed objects.

10. A Q-switched laser, characterized in that, It includes a radio frequency driving power supply and a reflective acousto-optic Q-switch as described in any one of claims 1-9, wherein the electroacoustic transducer (400) of the reflective acousto-optic Q-switch is connected to the output terminal of the radio frequency driving power supply.

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