A hermetically sealed lithium niobate modulation device

Abstract

The present invention discloses an airtightly packaged lithium niobate modulator device, specifically relating to the technical field of lithium niobate modulators, including an outer shell box, a base, a heat sink, a lithium niobate chip, and an optical fiber assembly based on the electro-optical effect of lithium niobate crystals. The present invention utilizes the coordinated cooperation of a sealing mechanism, a driving mechanism, and an internal sealing mechanism. The internal sealing mechanism is linked by an insulating ring belt, a ratchet, and a counterweight block to form a dynamic wrapping seal that adapts to thermal deformation at the optical fiber passageway. Combined with the traditional glass solder outer seal, it forms a double-layer protection to reduce the risk of air leakage. The driving mechanism's limiting frame and docking card form multi-directional support through a connecting plate assembly, guiding the molten solder to expand the contact area and inhibiting weld cracking and component loosening. The gas cavity enclosed by the sealing mechanism releases inert gas when the solder shrinks, and forms a stable protective atmosphere with the shell air, effectively delaying oxidation and extending its service life.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium niobate modulators, in particular to an airtightly packaged lithium niobate modulator device. Background Art

[0002] Lithium niobate (LNbO) modulation devices are core optical communication components based on the electro-optical effect of LNbO crystals. They control the phase or intensity of light waves via voltage signals, achieving high-speed, low-loss optical signal modulation. They are widely used in fiber-optic communications, sensing, and microwave photonics. The packaging process used in their production directly impacts device performance and reliability, requiring precise assembly and airtight packaging to ensure long-term stability.

[0003] Patent publication number CN106483683B discloses an airtightly packaged lithium niobate modulation device, comprising: a tube shell, a lithium niobate wafer, a heat sink, an optical fiber spacer, glass solder, a Kovar tube, a stress tube, a side plate with a tail tube, a tube shell cover, glue, an optical fiber, and solder. The optical fiber passes through the Kovar tube, and is sealed to the Kovar tube using glass solder. A metal tube is placed on the other end of the Kovar tube and fixed using glue. The front end of the optical fiber is fixed to the optical fiber spacer using glue to form an optical fiber assembly. The optical fiber assembly is coupled to the lithium niobate wafer and then fixed using glue. The coupled lithium niobate wafer is glued to the inner bottom of the tube shell and fixed. The side plates with a tail tube are placed on both sides of the tube shell, and the gap between the side plates with a tail tube and the tube shell is sealed using laser welding. The Kovar tube on the optical fiber assembly and the tail tube of the side plates with a tail tube are then sealed using solder. Finally, the tube shell cover is sealed to the tube shell using parallel seam welding to complete the airtight packaging of the lithium niobate modulation device. This packaging method eliminates the leakage problem caused by using adhesive.

[0004] The above-mentioned existing hermetic packaging of lithium niobate modulators involves mounting the lithium niobate chip on a heat sink, then mounting the optical fiber, and then passing the optical fiber through a Kovar tube to connect to the outside. Glass solder is then used to seal the gap between the optical fiber and the Kovar tube, and finally a top cover is added and welded to complete the hermetic packaging of the lithium niobate modulator. However, there are the following problems:

[0005] First, relying solely on glass solder for a single-layer seal after the optical fiber passes through the Kovar tube lacks a dynamic compensation mechanism. Under temperature fluctuations, differences in the thermal expansion coefficients of the materials can easily lead to sealing gaps, posing a significant risk of air leakage and reducing the reliability of the airtightness.

[0006] Secondly, during packaging, the lithium niobate chip is still in an air environment, resulting in some air remaining in the housing after packaging, which in turn oxidizes the device. Traditional packaging relies on passive sealing through gluing and welding, which cannot actively create a stable atmosphere and shortens the life of the device.

[0007] Finally, traditional packaging relies on local welding, which has limited contact area and is not combined with mechanical limit design. Under thermal cycles or external force impact, the welds are prone to cracking, causing components to loosen, optical path deviation, and even seal failure.

[0008] Therefore, this solution provides a hermetically packaged lithium niobate modulation device to solve the above problems. Summary of the Invention

[0009] The purpose of the present invention is to provide an airtight packaged lithium niobate modulation device to solve the problems in the prior art such as the risk of air leakage under temperature changes, the aging of the device caused by residual air during packaging, and the insufficient welding contact area leading to weld cracking and component loosening.

[0010] In order to solve the above technical problems, the basic technical solutions proposed by the present invention are:

[0011] A hermetically sealed lithium niobate modulation device includes a housing box based on the electro-optical effect of lithium niobate crystal, a base, a heat sink, a lithium niobate chip and an optical fiber assembly. The inner side wall of the housing box is provided with a tube body connected to the outside, the periphery of the tube body is provided with an inner sealing mechanism, a driving mechanism is provided below the tube body, and a blocking mechanism is provided below the driving mechanism. The inner side of the housing box located above the tube body is fixedly connected to a support frame; the blocking mechanism includes a top cover, a solder ring and a bottom plate fixedly connected in sequence from top to bottom, a docking card plate is fixedly connected above the periphery of the top cover, and the periphery of the docking card plate is fixedly connected uniformly. The connecting plate 1 is distributed around, and the inner side of the top cover is fixedly connected to the inner side plate; the driving mechanism includes a limiting horizontal plate and a limiting vertical plate that constitute a support frame, as well as a sliding bar slidably connected to the inner side of the limiting vertical plate and an inclined guide rail fixedly connected to the top of the limiting horizontal plate, one side of the inclined guide rail is slidably connected to a counterweight block, and the peripheries of the limiting horizontal plate and the limiting vertical plate are fixedly connected to the inner wall of the outer shell box; the inner sealing mechanism includes an inner rotating ring rotatably sleeved on the outer periphery of the tube body, the inner side of the inner rotating ring is fixedly connected to an insulating ring belt, the other end of the insulating ring belt is fixedly connected to the inner wall of the tube body, and one side of the inner rotating ring is fixedly connected to a ratchet.

[0012] Preferably: the base is installed above the heat sink by bolts, the two ends of the lithium niobate chip are coupled to the optical fiber assembly, the lithium niobate chip is bonded to the top of the heat sink, and the end of the optical fiber assembly away from the lithium niobate chip passes through the insulating ring and the tube body and is connected to the outside of the outer shell box, the inner side plate is located on the periphery of the heat sink, the top of the docking card fits under the limiting horizontal plate and the limiting vertical plate, and two centrally symmetrical support columns are fixedly connected to the top of the top cover, and the top of the support column and the counterweight block are in contact with the inner top of the outer shell box.

[0013] Preferably: the inner side of the bottom plate is slidably connected to the periphery of the inner plate, the top of the bottom plate is fixedly connected to a piston rod that is evenly distributed, the top of the piston rod is fixedly connected to a piston head, the upper and lower ends of the top cover are fixedly connected to an injection tube and a protective tube that are evenly distributed, the piston rod is inserted into the inside of the injection tube, and the piston head blocks the port of the injection tube.

[0014] Preferably, the top cover, the inner plate, the bottom plate and the solder ring together form a gas cavity, the interior of the gas cavity is filled with inert gas, and the protective tube is located inside the gas cavity.

[0015] Preferably: the periphery of the docking card is provided with grooves that are evenly distributed around it, the grooves and the connecting plate 1 are vertically staggered with each other, and the connecting plate 2 is fixedly connected to the bottom of the limiting horizontal plate and the limiting vertical plate. The connecting plate 2 is inserted into the inside of the groove and is located between the two connecting plates 1. The outer sides of the connecting plate 1 and the connecting plate 2 are both in contact with the inner wall of the outer shell box.

[0016] Preferably: one end of the sliding bar is fixedly connected to a connecting rope, the other end of the connecting rope is fixedly connected to one end of the counterweight block, one side of the sliding bar is fixedly connected to a ratchet bar, the ratchet bar is fitted under the ratchet wheel, and a rectangular through groove is opened at one end of the sliding bar close to the counterweight block.

[0017] Preferably, one side of the counterweight is fixedly connected to a guide wheel and a limiting protrusion distributed up and down, and the guide wheel and the limiting protrusion are respectively slidably connected to two grooves of the inclined guide rail.

[0018] Preferably, a positioning notch is provided at one end of the counterweight block, a positioning plugboard is slidably connected to the upper inner wall of the positioning notch, a spring piece 1 is fixedly connected above the positioning plugboard, the positioning notch fits the cross section of the sliding bar, and the positioning plugboard fits the rectangular through slot.

[0019] Preferably: a pressing plate is provided below the support frame, and upper and lower ends of the pressing plate are respectively fixedly connected to a limit rod and evenly distributed ratchet blocks, and a second spring is fixedly connected between the pressing plate and the support frame.

[0020] Preferably, the base is welded to the bottom of the outer shell box, and the optical fiber assembly passes through the hole tube at the outer shell box and is sealed by glass solder.

[0021] The beneficial effects of the present invention are:

[0022] The present invention realizes dynamic wrapping sealing when the optical fiber component passes through the tube body through the provided sealing mechanism, the mutual cooperation of the driving mechanism and the internal sealing mechanism, and the linkage design of the insulating ring belt and the ratchet, sliding bar and counterweight block in the internal sealing mechanism. When the external temperature changes, after the traditional glass solder is deformed, the insulating ring belt can adaptively twist with thermal expansion / contraction to compensate for the material deformation difference, significantly reduce the leakage risk of the traditional single-layer glass solder seal, improve the long-term airtightness reliability, and cooperate with the traditional outer glass solder seal to achieve internal and external double-layer sealing, thereby enhancing airtightness.

[0023] The present invention provides a blocking mechanism, and the mutual cooperation between the driving mechanism and the internal sealing mechanism. The supporting plate composed of the limiting horizontal plate and the limiting vertical plate in the driving mechanism and the connecting plate 2 at the bottom cooperate with the connecting plate 1 on the periphery of the docking card. As a result, after the solder ring melts and flows, the contact area between the solder ring and the inner wall of the outer shell box and the outer wall of the docking card can be increased, thereby making the welding more stable and suppressing the cracking of the weld under the impact of external force, thereby avoiding the optical path deviation or sealing failure caused by loose components.

[0024] The present invention provides a blocking mechanism, and the driving mechanism cooperates with the inner sealing mechanism. The top cover, inner side plate, bottom plate and solder ring of the blocking mechanism jointly form a gas cavity, so that after the solder ring is melted, the distance between the top cover and the bottom plate is reduced, thereby opening the air injection pipe, allowing the inert gas (nitrogen) in the gas cavity to merge with the air in the outer shell box, thereby reducing the air concentration in the outer shell box, forming a stable inert atmosphere, slowing down the oxidation of the outer shell box, and extending the life of the device.

[0025] The present invention provides a blocking mechanism, and the driving mechanism cooperates with the inner sealing mechanism. During packaging, the counterweight block is moved and the sliding bar is pulled to slide by flipping twice, so that the ratchet bar can drive the inner rotating ring and the ratchet wheel to rotate, thereby realizing automatic torsional sealing. After flipping again, the positions of the counterweight block and the sliding bar can be restricted at the same time to ensure that the ratchet wheel can no longer rotate, thereby reducing manual intervention and improving packaging efficiency and consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is an overall three-dimensional diagram of embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the overall internal structure of the first embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the internal structure of the first embodiment of the present invention after being turned over as a whole;

[0029] Figure 4 This is a structural diagram of a blocking mechanism according to a first embodiment of the present invention;

[0030] Figure 5This is a schematic structural diagram of the blocking mechanism according to the first embodiment of the present invention before it is disassembled and flipped;

[0031] Figure 6 This is a schematic diagram of the structure of the blocking mechanism after it is disassembled and flipped over according to the first embodiment of the present invention;

[0032] Figure 7 For the embodiment of the present invention Figure 6 The structural diagram of the middle part;

[0033] Figure 8 For the embodiment of the present invention Figure 6 Side view of the middle docking card plate;

[0034] Figure 9 Schematic diagram of the overall structure of the driving mechanism and the inner sealing mechanism of the first embodiment of the present invention;

[0035] Figure 10 This is a schematic structural diagram of the inner sealing mechanism of the first embodiment of the present invention;

[0036] Figure 11 Schematic diagram of the structure of the driving mechanism of the first embodiment of the present invention;

[0037] Figure 12 For the embodiment of the present invention Figure 11 The structural diagram of the middle part;

[0038] Figure 13 This is a schematic diagram of the internal structure of the counterweight block of Example 1 of the present invention.

[0039] Description of reference numerals:

[0040] 1. Housing box; 11. Tube body; 12. Support frame; 2. Base; 3. Heat sink; 4. Lithium niobate chip; 5. Optical fiber assembly; 6. Gas chamber;

[0041] 7. Sealing mechanism; 71. Top cover; 711. Air jet pipe; 712. Protective tube; 72. Inner plate; 73. Bottom plate; 731. Piston rod; 732. Piston head; 74. Docking plate; 741. Groove; 75. Solder ring; 76. Connecting plate 1; 77. Support column;

[0042] 8. Driving mechanism; 81. Limiting horizontal plate; 82. Limiting vertical plate; 83. Connecting plate 2; 84. Inclined guide rail;

[0043] 85. Sliding bar; 851. Ratchet bar; 852. Rectangular through slot; 86. Connecting rope;

[0044] 87. Counterweight; 871. Guide wheel; 872. Positioning protrusion; 873. Positioning notch; 874. Positioning insert; 875. Shrapnel 1;

[0045] 9. Inner sealing mechanism; 91. Inner rotating ring; 92. Ratchet; 93. Pressure plate; 94. Ratchet block; 95. Limit rod; 96. Second spring piece; 97. Insulating ring belt. DETAILED DESCRIPTION

[0046] Please refer to the following Figures 1 to 13 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0047] It should be noted that if there are any directions involved in the embodiments of the present invention, they shall be based on the directions shown in the drawings, such as front and back. Figure 1 The specific Figure 1 The left side is the front, Figure 1 The right side is the back; at the same time Figure 2 As shown in the figure, the left-right direction is roughly the horizontal direction, and the up-down direction shown in the figure is the vertical direction. If a specific posture changes, the directional indication will also change accordingly.

[0048] The present invention provides an airtightly packaged lithium niobate modulation device, comprising an outer shell 1 based on the electro-optical effect of a lithium niobate crystal, a base 2, a heat sink 3, a lithium niobate chip 4, and an optical fiber assembly 5. The inner sidewall of the outer shell 1 is provided with a tube 11 communicating with the outside, an inner sealing mechanism 9 is provided on the periphery of the tube 11, a driving mechanism 8 is provided below the tube 11, and a blocking mechanism 7 is provided below the driving mechanism 8. A support frame 12 is fixedly connected to the inner side of the outer shell 1 located above the tube 11.

[0049] The sealing mechanism 7 includes a top cover 71, a solder ring 75, and a bottom plate 73, which are fixedly connected in sequence from top to bottom. A docking plate 74 is fixedly connected to the upper periphery of the top cover 71. The periphery of the docking plate 74 is fixedly connected to connecting plates 76 evenly distributed around it. The inner side of the top cover 71 is fixedly connected to the inner side plate 72.

[0050] The driving mechanism 8 includes a limiting horizontal plate 81 and a limiting vertical plate 82 constituting a support frame, a sliding bar 85 slidably connected to the inner side of the limiting vertical plate 82, and an inclined guide rail 84 fixedly connected to the upper side of the limiting horizontal plate 81. A counterweight 87 is slidably connected to one side of the inclined guide rail 84. The peripheries of the limiting horizontal plate 81 and the limiting vertical plate 82 are fixedly connected to the inner wall of the outer shell box 1.

[0051] The inner sealing mechanism 9 includes an inner ring 91 that is rotatably sleeved on the outer periphery of the tube body 11. An insulating ring 97 is fixedly connected to the inner side of the inner ring 91. The other end of the insulating ring 97 is fixedly connected to the inner wall of the tube body 11. A ratchet 92 is fixedly connected to one side of the inner ring 91.

[0052] The outer shell box 1, tube body 11, base 2, heat sink 3, lithium niobate chip 4 and optical fiber assembly 5 constitute a lithium niobate electro-optical modulator based on the electro-optical effect of lithium niobate crystal. The phase or intensity of the light wave is controlled by a voltage signal to achieve high-speed, low-loss optical signal modulation. During assembly, the lithium niobate chip 4 and the optical fiber assembly 5 are first coupled and installed, and then the lithium niobate chip 4 is bonded to the top of the heat sink 3. The optical fiber assembly 5 is then passed through the inner rotating ring 91, the insulating ring 97 and the inside of the tube body 11 to connect to the outside. After that, the package is performed. During the package, it is first inverted, and then the solder ring 75 is melted by an electric soldering iron. Then, the base 2 is covered and the base 2 and the heat sink 3 are connected by bolts. Finally, the base 2 and the outer shell box 1 are welded.

[0053] The support frame composed of the limiting horizontal plate 81 and the limiting vertical plate 82 cooperates with the inclined guide rail 84 and the support column 77 to ensure that the top cover 71 and the like will not move downward after being flipped. In addition, the inclined guide rail 84 and the sliding bar 85 are symmetrical about the center point of the support frame.

[0054] In a further embodiment, the base 2 is installed above the heat sink 3 by bolts, the two ends of the lithium niobate chip 4 are coupled to the optical fiber assembly 5, the lithium niobate chip 4 is bonded to the top of the heat sink 3, and the end of the optical fiber assembly 5 away from the lithium niobate chip 4 passes through the insulating ring band 97 and the tube body 11, and is connected to the outside of the outer shell box 1. The inner plate 72 is located on the periphery of the heat sink 3, and the top of the docking card 74 fits under the limiting horizontal plate 81 and the limiting vertical plate 82. Two centrally symmetrical support columns 77 are fixedly connected to the top of the top cover 71, and the tops of the support columns 77 and the counterweight block 87 both contact the inner top of the outer shell box 1.

[0055] In this embodiment, the lithium niobate chip 4 is a lithium niobate chip in a lithium niobate electro-optical modulator. The lithium niobate chip uses lithium niobate crystal as the core material and is an optical device with both excellent electro-optical performance and physical stability. Through titanium diffusion or proton exchange process, it can form an optical waveguide structure on the surface of the lithium niobate crystal, thereby limiting the light field to the micron scale and realizing efficient electro-optical modulation. This is the existing technology; the tube body 11 is a metal tube made of Kovar alloy, which is used for the optical fiber to pass through the outer shell box 1.

[0056] In a further embodiment, the inner side of the bottom plate 73 is slidably connected to the outer periphery of the inner plate 72, and the top of the bottom plate 73 is fixedly connected to the piston rods 731 that are evenly distributed, and the top of the piston rods 731 is fixedly connected to the piston head 732. The upper and lower ends of the top cover 71 are fixedly connected to the injection tubes 711 and the protective tubes 712 that are evenly distributed, and the piston rod 731 is inserted into the inside of the injection tube 711, and the piston head 732 blocks the port of the injection tube 711.

[0057] In this embodiment, a rubber sealing gasket is provided between the inner side of the bottom plate 73 and the inner plate 72; the solder ring 75 on the outer periphery of the bottom plate 73 has a certain thickness, which is also the distance that the bottom plate 73 can move downward. However, after the solder ring 75 melts, a worker needs to assist in pressing down the bottom plate 73. This not only opens the port of the air injection pipe 711, but also accelerates the flow of the melted solder ring 75 to the outer periphery of the docking card 74 and contacts the connecting plate 2 83 and the connecting plate 1 76; the protective tube 712 is used to prevent the melted solder ring 75 from clogging The inside of the jet tube 711 is protected, and after the bottom plate 73 moves down, there is a gap between the protective tube 712 and the bottom plate 73, which facilitates the inert gas in the gas chamber 6 to enter the periphery of the lithium niobate chip 4; the solder ring 75 is made of SnAg solder as the core, and the surfaces of the docking card 74, the connecting plate 1 76 and the connecting plate 2 83 are nickel-plated or silver-plated. Therefore, after the solder ring 75 is melted by the electric soldering iron, it has a certain wettability with the surfaces of the docking card 74, the connecting plate 1 76 and the connecting plate 2 83, so it can flow.

[0058] In a further embodiment, the top cover 71 , the inner plate 72 , the bottom plate 73 and the solder ring 75 together form a gas cavity 6 , the interior of the gas cavity 6 is filled with inert gas, and the protective tube 712 is located inside the gas cavity 6 .

[0059] In this embodiment, the interior of the gas chamber 6 is filled with high-purity nitrogen, which balances cost, inertness and practicality, and there are two one-way holes at the upper end of the bottom plate 73, which can first extract the air in the gas chamber 6 and then inject high-purity nitrogen; the cross-section of the top cover 71 is a rectangular funnel-shaped, which on the one hand can avoid hindering the sliding of the upper counterweight block 87 and the sliding bar 85, and on the other hand can provide certain support and buffering for the periphery of the heat sink 3; there is a protrusion on the inner wall of the inner plate 72, which is used to prevent the heat sink 3 from moving downward when inverted.

[0060] In a further embodiment, the periphery of the docking card 74 is provided with grooves 741 that are evenly distributed around the periphery. The grooves 741 and the connecting plate 1 76 are vertically staggered with each other. Connecting plate 2 83 is fixedly connected to the bottom of the limiting horizontal plate 81 and the limiting vertical plate 82. Connecting plate 2 83 is inserted into the inside of the groove 741 and is located between the two connecting plates 1 76. The outer sides of connecting plate 1 76 and connecting plate 2 83 are both in contact with the inner wall of the outer shell box 1.

[0061] In this embodiment, the side cross-section of the docking card 74 after inversion is T-shaped, and the other side of its connecting plate 1 76 and connecting plate 2 83 does not contact the outer side wall of the docking card 74, leaving a gap, so that the melted solder ring 75 can fully enter the gap between connecting plate 1 76 and connecting plate 2 83.

[0062] In a further embodiment, one end of the sliding bar 85 is fixedly connected to a connecting rope 86, the other end of the connecting rope 86 is fixedly connected to one end of the counterweight block 87, one side of the sliding bar 85 is fixedly connected to a ratchet bar 851, the ratchet bar 851 is fitted under the ratchet 92, and a rectangular through groove 852 is provided at one end of the sliding bar 85 close to the counterweight block 87.

[0063] In this embodiment, the sliding bar 85 and the counterweight block 87 are connected to the connecting rope 86 with a winding ring, thereby connecting them. In addition, after the sliding bar 85 is displaced due to the sliding of the counterweight block 87, the connecting rope 86 can no longer be used to return the sliding bar 85 to its initial position, and at this time, some teeth of the ratchet bar 851 will maintain a clamping relationship with the ratchet 92, so that the rotated ratchet 92 can no longer rotate in the opposite direction.

[0064] In a further embodiment, one side of the counterweight block 87 is fixedly connected to a guide wheel 871 and a limiting protrusion 872 distributed up and down, and the guide wheel 871 and the limiting protrusion 872 are respectively slidably connected in two grooves of the inclined guide rail 84.

[0065] In this embodiment, the inclined guide rail 84 is divided into two upper and lower guide grooves, thereby separating the guide wheel 871 and the limiting protrusion 872, and the lower part of the counterweight block 87 is slightly wider than the upper part, thereby ensuring that the counterweight block 87 can always be perpendicular to the ground, so the positioning notch 873 is always facing the sliding bar 85.

[0066] In a further embodiment, a positioning notch 873 is provided at one end of the counterweight block 87, and a positioning plug plate 874 is slidably connected to the upper inner wall of the positioning notch 873, and a spring piece 875 is fixedly connected above the positioning plug plate 874. The positioning notch 873 fits the cross-section of the sliding bar 85, and the positioning plug plate 874 fits the rectangular through groove 852.

[0067] In this embodiment, the bottom end of the positioning plate 874 has a beveled surface, so that when the counterweight block 87 moves downward, one side of the sliding bar 85 is forced to lift the positioning plate 874. When the positioning plate 874 reaches the rectangular through groove 852, the sliding bar 85 and the counterweight block 87 can be positioned relative to each other. Therefore, after the packaging is completed, moving the modulator cannot cause the counterweight block 87 and the sliding bar 85 to move.

[0068] In a further embodiment, a pressure plate 93 is provided below the support frame 12 , and the upper and lower ends of the pressure plate 93 are respectively fixedly connected to a limit rod 95 and evenly arranged ratchet blocks 94 , and a spring piece 96 is fixedly connected between the pressure plate 93 and the support frame 12 .

[0069] In this embodiment, the ratchet block 94 allows the inner rotating ring 91 and the ratchet wheel 92 to rotate clockwise, thereby twisting the insulating ring belt 97 to wrap the passing optical fiber assembly 5 and perform internal sealing. In addition, the insulating ring belt 97 is polyimide, which has high insulation, temperature resistance and chemical stability, so that dynamic sealing can be performed after twisting.

[0070] In a further embodiment, the base 2 is welded to the bottom of the housing box 1 , and the optical fiber assembly 5 passes through the hole tube at the housing box 1 and is sealed by glass solder.

[0071] In this embodiment, both ends of the outer side of the outer shell box 1 also have tube bodies 11 , and the tube bodies 11 are communicated with the tube body 11 on the inner side of the outer shell box 1 .

[0072] The working principle of the present invention is as follows:

[0073] First, after the lithium niobate chip 4 is installed on top of the heat sink 3, the sealing mechanism 7 is sleeved onto the periphery of the heat sink 3 from above. Then, the optical fiber assembly 5 is installed on both sides of the lithium niobate chip 4. After installation, the other end of the optical fiber assembly 5 is passed through the inner sealing mechanism 9 and the tube body 11, so that one end of the optical fiber assembly 5 can reach the outside of the outer shell box 1. The outer shell box 1 is then covered with the sealing mechanism 7. At this time, the support column 77 will contact the inside of the outer shell box 1, the docking card plate 74 will be located below the limiting horizontal plate 81 and the limiting vertical plate 82, and the second connecting plate 83 will be inserted into the inside of the groove 741.

[0074] Secondly, it is turned 180 degrees, so that the limiting horizontal plate 81 and the limiting vertical plate 82 lift the docking card plate 74, and the counterweight block 87 will move downward along the guide of the inclined guide rail 84, thereby pulling the sliding bar 85 to move through the connecting rope 86, and then the ratchet bar 851 drives the ratchet 92 and the inner rotating ring 91 to rotate, and then one end of the insulating ring belt 97 also rotates. However, since the other end of the insulating ring belt 97 is fixed to the inner side of the tube body 11, the insulating ring belt 97 will be twisted, thereby wrapping the passing optical fiber assembly 5, thereby internally sealing the gap between the optical fiber assembly 5 when it passes through the inner sealing mechanism 9 and the tube body 11, and then externally sealing the gap between the optical fiber assembly 5 when it passes through the tube body 11 by glass solder, so that the airtightness inside the outer shell box 1 can be increased by double sealing;

[0075] In addition, after the inside and outside of the tube body 11 are sealed, the solder ring 75 can be heated along the periphery of the bottom plate 73 by an electric soldering iron, so that part of the solder ring 75 flows downward along the periphery of the docking card plate 74, thereby reaching the periphery of the connecting plate 1 76 and the connecting plate 2 83. Since the limiting horizontal plate 81 and the limiting vertical plate 82 are fixed to the inner wall of the outer shell box 1, and the connecting plate 2 83 is fixedly connected below the limiting horizontal plate 81 and the limiting vertical plate 82, the contact surface between the inner wall of the outer shell box 1 and the outer wall of the docking card plate 74 can be increased, thereby making the connection more secure. The other part of the solder ring 75 will flow to the inner side of the top cover 71 and be blocked by the protective tube 712.

[0076] At the same time, the melting of the docking clamp 74 causes the distance between the periphery of the bottom plate 73 and the top cover 71 to decrease, thereby moving the bottom plate 73 downward. This causes the piston rod 731 and the piston head 732 to move downward, thereby allowing the piston head 732 to open the air injection pipe 711 and release the inert gas in the gas chamber 6, allowing the gas to be reset inside the outer shell box 1, thereby protecting the lithium niobate chip 4 and extending its service life.

[0077] Finally, cover the base 2, weld the outer shell box 1 and the base 2 first, then connect the base 2 and the heat sink 3 with bolts, and then flip the outer shell box 1 over again, so that the base 2 is facing downward, so the counterweight 87 will move down again, so that the ratchet 851 passively pushes the positioning plug 874 and enters the inner side of the positioning notch 873, and under the rebound of the spring piece 875, the positioning plug 874 will be inserted into the rectangular through groove 852, thereby simultaneously limiting the displacement of the sliding bar 85 and the counterweight 87, and avoiding the sliding of the sliding bar 85 and the counterweight 87 during use to affect the normal use of the modulator, and maintaining the positional relationship between the ratchet 851 and the ratchet 92, and cooperating with the ratchet block 94 above the ratchet 92 so that the rotation state of the inner rotating ring 91 is maintained after flipping, that is, the torsion state of the insulating ring belt 97 is guaranteed, thereby avoiding the loosening of the insulating ring belt 97, thereby further improving the sealing of the insulating ring belt 97.

[0078] Based on the disclosure and teachings of the above description, those skilled in the art may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and modifications and variations of the present invention should also fall within the scope of protection of the claims of the present invention. In addition, although certain specific terms are used in this description, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. An airtight packaged lithium niobate modulation device, comprising a housing box (1), a base (2), a heat sink (3), a lithium niobate chip (4) and an optical fiber assembly (5) based on the electro-optical effect of a lithium niobate crystal, characterized in that: The inner side wall of the outer shell box (1) is provided with a tube body (11) communicating with the outside, an inner sealing mechanism (9) is provided on the outer periphery of the tube body (11), a driving mechanism (8) is provided below the tube body (11), a blocking mechanism (7) is provided below the driving mechanism (8), and a support frame (12) is fixedly connected to the inner side of the outer shell box (1) located above the tube body (11); The blocking mechanism (7) comprises a top cover (71), a solder ring (75) and a bottom plate (73) which are fixedly connected in sequence from top to bottom; a docking card (74) is fixedly connected above the periphery of the top cover (71); the periphery of the docking card (74) is fixedly connected to a connecting plate (76) which is evenly distributed around the periphery; and an inner side plate (72) is fixedly connected to the inner side of the top cover (71); The driving mechanism (8) includes a limiting transverse plate (81) and a limiting longitudinal plate (82) constituting a support frame, a sliding bar (85) slidably connected to the inner side of the limiting longitudinal plate (82), and an inclined guide rail (84) fixedly connected to the upper side of the limiting transverse plate (81), a counterweight (87) being slidably connected to one side of the inclined guide rail (84), and the peripheries of the limiting transverse plate (81) and the limiting longitudinal plate (82) are fixedly connected to the inner wall of the outer shell box (1); The inner sealing mechanism (9) comprises an inner rotating ring (91) rotatably sleeved on the outer periphery of the tube body (11), an insulating ring belt (97) is fixedly connected to the inner side of the inner rotating ring (91), the other end of the insulating ring belt (97) is fixedly connected to the inner wall of the tube body (11), and a ratchet (92) is fixedly connected to one side of the inner rotating ring (91).

2. The hermetically packaged lithium niobate modulation device according to claim 1, characterized in that: The base (2) is mounted on the top of the heat sink (3) by bolts, and the two ends of the lithium niobate chip (4) are coupled to the optical fiber assembly (5). The lithium niobate chip (4) is bonded to the top of the heat sink (3). The end of the optical fiber assembly (5) away from the lithium niobate chip (4) passes through the insulating ring belt (97) and the tube body (11) and is connected to the outside of the outer shell box (1). The inner side plate (72) is located on the periphery of the heat sink (3). The top of the docking card plate (74) fits under the limiting horizontal plate (81) and the limiting vertical plate (82). Two centrally symmetrical support columns (77) are fixedly connected to the top of the top cover (71). The tops of the support columns (77) and the counterweight (87) are in contact with the inner top of the outer shell box (1).

3. The hermetically packaged lithium niobate modulation device according to claim 1, characterized in that: The inner side of the bottom plate (73) is slidably connected to the outer periphery of the inner plate (72); piston rods (731) are fixedly connected to the top of the bottom plate (73), and the top of the piston rods (731) is fixedly connected to the piston head (732); the upper and lower ends of the top cover (71) are fixedly connected to the injection tubes (711) and the protective tubes (712) which are evenly arranged; the piston rods (731) are inserted into the interior of the injection tubes (711), and the piston heads (732) block the ports of the injection tubes (711).

4. The hermetically packaged lithium niobate modulation device according to claim 1, characterized in that: The top cover (71), the inner plate (72), the bottom plate (73) and the solder ring (75) together form a gas cavity (6). The interior of the gas cavity (6) is filled with an inert gas, and the protective tube (712) is located inside the gas cavity (6).

5. The hermetically packaged lithium niobate modulation device according to claim 1, characterized in that: The outer periphery of the docking card plate (74) is provided with grooves (741) distributed uniformly around the periphery. The grooves (741) and the connecting plate 1 (76) are vertically staggered with each other. The lower parts of the limiting horizontal plate (81) and the limiting vertical plate (82) are fixedly connected with the connecting plate 2 (83). The connecting plate 2 (83) is inserted into the interior of the groove (741) and is located between the two connecting plates 1 (76). The outer sides of the connecting plate 1 (76) and the connecting plate 2 (83) are both in contact with the inner wall of the outer shell box (1).

6. The hermetically packaged lithium niobate modulation device according to claim 1, characterized in that: One end of the sliding bar (85) is fixedly connected to a connecting rope (86), and the other end of the connecting rope (86) is fixedly connected to one end of the counterweight (87). One side of the sliding bar (85) is fixedly connected to a ratchet (851), and the ratchet (851) is fitted below the ratchet (92). A rectangular through slot (852) is provided at one end of the sliding bar (85) close to the counterweight (87).

7. The hermetically packaged lithium niobate modulation device according to claim 1, characterized in that: One side of the counterweight (87) is fixedly connected to a guide wheel (871) and a limiting protrusion (872) distributed up and down, and the guide wheel (871) and the limiting protrusion (872) are respectively slidably connected in two grooves of the inclined guide rail (84).

8. The hermetically packaged lithium niobate modulation device according to claim 1, characterized in that: One end of the counterweight block (87) is provided with a positioning notch (873), the upper inner wall of the positioning notch (873) is slidably connected to a positioning plug plate (874), and the upper part of the positioning plug plate (874) is fixedly connected to a spring piece (875), the positioning notch (873) fits the cross section of the sliding bar (85), and the positioning plug plate (874) fits the rectangular through groove (852).

9. The hermetically packaged lithium niobate modulation device according to claim 1, characterized in that: A pressure plate (93) is provided below the support frame (12), and the upper and lower ends of the pressure plate (93) are respectively fixedly connected to a limit rod (95) and evenly distributed ratchet blocks (94), and a second spring piece (96) is fixedly connected between the pressure plate (93) and the support frame (12).

10. The hermetically packaged lithium niobate modulation device according to claim 1, characterized in that: The base (2) is welded to the bottom of the outer shell box (1), and the optical fiber assembly (5) passes through the hole tube at the outer shell box (1) and is sealed by glass solder.

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