Electro-optic modulator and optical communication system

Abstract

This utility model discloses an electro-optic modulator and an optical communication system. The electro-optic modulator includes: a housing, a cover plate, a modulator chip, an optical input port, an optical output port, an RF signal input, and an internal component. The housing has a cavity and an opening, and the cover plate is used to seal the opening. The modulator chip is disposed within the cavity. The optical input port and the optical output port are both connected to the modulator chip. The RF signal input is connected to the modulator chip. The internal component is disposed within the cavity and connected to the housing. The modulator chip is disposed between the housing and the internal component. By placing the internal component within the cavity of the electro-optic modulator housing and placing the modulator chip between the housing and the internal component, the space around the modulator chip can be significantly reduced, signal resonance can be reduced, return loss can be lowered, and the bandwidth of the electro-optic modulator can be increased.

Description

Technical Field

[0001] This utility model relates to the field of integrated photonics, and in particular to an electro-optic modulator and an optical communication system. Background Technology

[0002] Electro-optic modulators are modulators made using the electro-optic effect of certain electro-optic crystals, such as lithium niobate (LiNbO3), gallium arsenide (GaAs), and lithium tantalate (LiTaO3). The electro-optic effect occurs when a voltage is applied to an electro-optic crystal, causing a change in its refractive index. This change alters the optical wave characteristics passing through the crystal, thereby modulating the phase, amplitude, intensity, and polarization state of the optical signal.

[0003] With the rapid development of optical communication and laser technology, electro-optic modulators are increasingly widely used in high-frequency signal modulation and photoelectric conversion. In these applications, the packaging technology of electro-optic modulators plays a crucial role in their performance, especially in high-speed data transmission and laser pulse modulation environments. Effective packaging design not only protects internal electronic and optical components but also reduces losses and improves the overall system efficiency.

[0004] Currently, electro-optic modulators typically use metal housings for encapsulation. While metal housings provide good mechanical protection, they can also cause high-frequency signals to resonate within the housing. This is especially true when accommodating external high-frequency connectors, which often leads to resonance within the metal housing during signal transmission. This increases return loss, reduces the modulator's bandwidth, and ultimately affects its overall performance. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the above-mentioned defects of the metal shell of the electro-optic modulator in the prior art, which is prone to resonance effect, and to provide an electro-optic modulator and an optical communication system.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] An electro-optic modulator includes: a housing, a cover plate, a modulator chip, a light incident port, a light exit port, a radio frequency signal inlet, and an internal component. The housing has a cavity and an opening, and the cover plate is used to seal the opening. The modulator chip is disposed within the cavity. The light incident port and the light exit port are both connected to the modulator chip. The radio frequency signal inlet is connected to the modulator chip. The internal component is disposed within the cavity and connected to the housing. The modulator chip is disposed between the housing and the internal component.

[0008] In this solution, by adopting the above structure, by placing the built-in component in the accommodating cavity inside the electro-optic modulator housing and placing the modulator chip between the housing and the built-in component, the space around the modulator chip can be significantly reduced, signal resonance can be reduced, return loss can be reduced, and the bandwidth of the electro-optic modulator can be improved.

[0009] Optionally, the built-in component is disposed between the modulator chip and the cover plate, and the built-in component is disposed adjacent to the modulator chip.

[0010] In this solution, by adopting the above structure, the built-in component is placed between the modulator chip and the cover plate, and is adjacent to the modulator chip. This facilitates the installation of the built-in component, reduces the gap between the modulator chip and the cover plate, reduces signal resonance, lowers return loss, and increases the bandwidth of the electro-optic modulator.

[0011] Optionally, the outer periphery of the built-in component forms a sealed space with the housing, and the modulator chip is disposed within the sealed space.

[0012] In this solution, by adopting the above structure, the built-in component and the housing form a sealed cavity, and the modulator chip is placed in the sealed cavity. This can significantly reduce the space around the modulator chip, reduce signal resonance, reduce return loss, and improve the bandwidth of the electro-optic modulator.

[0013] Optionally, the inner side of the housing is provided with a support surface, and the built-in component is covered on the support surface.

[0014] In this solution, by adopting the above structure, the built-in component is covered on the support surface, which can better seal the space between the built-in component and the modulator chip, and also improve the stability of the built-in component.

[0015] Optionally, the electro-optic modulator further includes a boss on the inner peripheral surface of the housing, and the built-in component covers the side of the boss facing the cover plate.

[0016] In this design, by adopting the above structure, the boss can be easily set on the inner circumferential surface of the shell, which facilitates processing and manufacturing.

[0017] Optionally, the housing has multiple support surfaces, and each support surface is provided with the built-in component.

[0018] In this solution, by adopting the above structure, multiple support surfaces and multiple corresponding built-in components, resonance phenomena within the accommodating cavity can be better avoided, signal resonance can be reduced, return loss can be lowered, and the bandwidth of the electro-optic modulator can be increased.

[0019] Optionally, the outer peripheral surface of the cover plate is fitted with the inner peripheral surface of the housing.

[0020] Optionally, the built-in component has an absorption layer disposed on the side of the built-in component facing the modulator chip, the absorption layer being used to absorb electromagnetic waves.

[0021] In this scheme, by adopting the above structure and using the absorption layer to absorb electromagnetic waves, the resonance phenomenon in the cavity can be further reduced, signal resonance can be reduced, return loss can be reduced, and the bandwidth of the electro-optic modulator can be improved.

[0022] Optionally, the built-in component is plate-shaped, and the absorbent layer is attached to the side of the built-in component.

[0023] In this solution, by adopting the above structure, the plate-shaped built-in component facilitates the application of the absorbent layer and also makes it easy to install into the accommodating cavity.

[0024] An optical communication system comprising the electro-optic modulator described above.

[0025] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this utility model.

[0026] The positive and progressive effects of this utility model are as follows:

[0027] This invention significantly reduces the space around the modulator chip by placing the built-in component in the cavity inside the electro-optic modulator housing and placing the modulator chip between the housing and the built-in component. This reduces signal resonance, lowers return loss, and increases the bandwidth of the electro-optic modulator. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the electro-optic modulator according to an embodiment of the present invention.

[0029] Figure 2 for Figure 1 A schematic diagram of the electro-optic modulator from another perspective.

[0030] Figure 3 A comparison of the return loss performance of electro-optic modulators with single-layer and double-layer housings.

[0031] Explanation of reference numerals in the attached figures:

[0032] Electro-optic modulator 100

[0033] Casing 11

[0034] 12 Container

[0035] Modulator chip 13

[0036] Light input port 14

[0037] Light emission port 15

[0038] RF signal input 16

[0039] Built-in component 17

[0040] Support surface 18

[0041] 19 convex surfaces

[0042] Absorbing layer 20 Detailed Implementation

[0043] The present invention will be described more clearly and completely below by way of embodiments and in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the embodiments.

[0044] like Figures 1 to 3 As shown, this embodiment includes an electro-optic modulator 100 and an optical communication system. The optical communication system includes the electro-optic modulator 100 as described below.

[0045] Optical communication systems typically use light as a carrier wave and optical fibers as the transmission medium, transmitting information via photoelectric conversion. Specifically, they may include a data source, an optical transmitter, an optical channel, and an optical receiver. The data source can include any signal source, specifically voice, image, and data signals encoded from source codes. The optical transmitter converts the signal into an optical signal suitable for transmission over the optical fiber. The optical channel includes basic optical fiber and may also include repeater amplifiers (EDFAs). The optical receiver receives the optical signal, extracts information, converts it into an electrical signal, and finally obtains the corresponding voice, image, and data information. The electro-optic modulator 100 is the "core converter" of the optical communication system, responsible for efficiently and accurately encoding electrical signals onto optical waves; its performance directly determines the transmission capacity, distance, and flexibility of the optical communication system.

[0046] Combination Figure 1 and Figure 2 The electro-optic modulator 100 includes: a housing 11, a cover plate, a modulator chip 13, a light input port 14, a light output port 15, an RF signal input 16, and a built-in component 17. The housing 11 has a cavity 12 and an opening, and the cover plate is used to seal the opening. The modulator chip 13 is disposed within the cavity 12. Both the light input port 14 and the light output port 15 are connected to the modulator chip 13. The RF signal input 16 is connected to the modulator chip 13. The built-in component 17 is disposed within the cavity 12 and connected to the housing 11. The modulator chip 13 is disposed between the housing 11 and the built-in component 17. By placing the built-in component 17 within the cavity 12 of the housing 11 of the electro-optic modulator 100 and placing the modulator chip 13 between the housing 11 and the built-in component 17, the space around the modulator chip 13 can be significantly reduced, signal resonance can be reduced, return loss can be lowered, and the bandwidth of the electro-optic modulator 100 can be improved.

[0047] The housing 11 contains electromagnetic wave resonance. The larger the housing 11, the easier it is for resonance to occur within the operating bandwidth of the electro-optic modulator 100, affecting its return loss and reducing its modulation performance. By adding the built-in component 17, the space formed by the built-in component 17 and the housing 11 becomes smaller. The modulator chip 13 is located within this space, meaning the space around the modulator chip 13 is smaller. This shifts the resonant point of the electro-optic modulator 100 outside its operating bandwidth, thereby reducing its return loss and improving its modulation performance.

[0048] In this example, the built-in component 17 is positioned above the modulator chip 13, thereby reducing the volume around the modulator chip 13. In other examples, the built-in component 17 can also be positioned in other directions of the modulator chip 13 to reduce the volume and achieve the same effect. Specifically, the built-in component 17 can be positioned on the left, right, front, rear, or bottom of the modulator chip 13, or it can be positioned in multiple locations simultaneously.

[0049] In one implementation, the outer periphery of the built-in component 17 forms a sealed space with the housing 11, within which the modulator chip 13 is located. By placing the built-in component 17 in the accommodating cavity 12 within the housing 11 of the electro-optic modulator 100, the built-in component 17 and the housing 11 form a sealed cavity, and the modulator chip 13 is placed within the sealed cavity. This significantly reduces the space around the modulator chip 13, reduces signal resonance, lowers return loss, and increases the bandwidth of the electro-optic modulator 100.

[0050] In one implementation, the light input port 14 and the light output port 15 can both be located on the housing 11, and they can be located on different sides of the housing 11, such as two opposite or adjacent sides; or they can be on the same side of the housing 11. The light input port 14 can be understood as including components for transmitting optical signals to the modulator chip 13. The light output port 15 can be understood as including components for transmitting optical signals from the modulator chip 13 to the outside. In this example, the laser is located outside the housing 11, and the laser can act as a light source to generate laser light, which enters the optical modulator chip 13 through the light input port 14. In other examples, the laser can also be integrated into the housing 11, and the laser light can enter the optical modulator chip 13 through the optical waveguide and the light input port 14.

[0051] The radio frequency (RF) signal input 16 can be located in the housing 11. The RF signal input 16 is typically a standard component with a relatively fixed cross-sectional diameter. Since the RF signal input 16 needs to be inserted into the side of the housing 11, the height of the housing 11 must be greater than the diameter of the RF signal input 16, resulting in a larger internal space within the housing 11. By adding an internal component 17, the internal space of the housing 11 can be separated. The internal component 17 fits snugly against the housing 11, forming a sealed cavity. The modulator chip 13 is placed within this sealed cavity, thus surrounding the modulator chip 13. This significantly reduces the space around the modulator chip 13, reduces signal resonance, lowers return loss, and improves the bandwidth of the electro-optic modulator 100.

[0052] In one implementation, the modulator chip 13 can be understood as a chip capable of modulating parameters such as the phase, amplitude, intensity, and polarization state of an optical signal. The input optical fiber passes through the optical input port 14 and connects to the modulator chip 13. The output optical fiber passes through the optical output port 15 and connects to the modulator chip 13. The radio frequency (RF) signal input 16 is connected to the modulator chip 13. The optical signal travels along the input optical fiber through the optical input port 14 and enters the modulator chip 13, while the RF signal travels through the RF signal input 16 and enters the modulator chip 13, thus modulating the optical signal. The modulated optical signal then passes through the optical output port 15 and exits along the output optical fiber.

[0053] In this example, the housing 11 can be a hollow cuboid with an internal cavity 12 and an opening on one side to facilitate the insertion of the modulator chip 13, internal components 17, etc. The housing 11 can be made of metal, specifically copper, iron, and various metal alloys. In other examples, the housing 11 can also be other shapes, such as cylindrical or spherical. The opening can be understood as an opening in the housing 11, used to insert components such as the modulator chip 13 into the housing. The opening can be located on any side of the housing 11; in this example, the opening is located on the side with the larger area of ​​the housing 11. In other examples, the opening can be located on other sides of the housing 11.

[0054] The outer peripheral surface of the cover plate fits against the inner peripheral surface of the housing 11. The cover plate is not shown in the figure. Figure 1 It is understood that the cover plate can be rectangular and capable of sealing the opening of the housing 11. The material of the cover plate can be the same as that of the housing 11. As one implementation method, the cover plate and housing 11 can be detachable, specifically connected by bolts, riveting, or snap-fit ​​connections; alternatively, they can be fixed, such as the cover plate being welded to the housing 11. The cover plate and housing 11 can also be integrally formed, for example, by using 3D printing.

[0055] The built-in component 17 can effectively reduce the space of the cavity 12 inside the housing 11, avoid resonance phenomenon in the cavity 12, reduce signal resonance, reduce return loss, and improve the bandwidth of the electro-optic modulator 100.

[0056] The built-in component 17 can be understood as a component disposed inside the accommodating cavity 12 and capable of forming a sealed cavity with the housing 11. In this example, the built-in component 17 is a rectangular plate-shaped object. In other examples, the built-in component 17 can be configured as a strip, mesh, or volumetric shape in combination with the shape of the housing 11. Specifically, the strip-shaped built-in component 17 can include components with a circular, triangular, or quadrilateral cross-section, and multiple strip-shaped built-in components 17 can be spaced apart. The mesh-shaped built-in component 17 can be in the shape of a fishing net, and multiple fishing net-shaped built-in components 17 can also be stacked. The volumetric built-in component 17 can specifically be a hexahedral block, a cylinder, or an irregular shape that matches the cross-section of the housing 11. The material of the built-in component 17 can include copper, iron, or various metal alloys.

[0057] The built-in component 17 can be positioned close to the modulator chip 13, thereby reducing the size of the sealed cavity. A smaller sealed cavity reduces signal resonance, lowers return loss, and increases the bandwidth of the electro-optic modulator 100. The distance between the built-in component 17 and the bottom of the accommodating cavity 12 can be controlled within 6 mm. The distance between the built-in component 17 and the modulator chip 13 should be minimized, specifically controlled within 3 mm. The distance between the built-in component 17 and the cover plate can range from 3 mm to 10 mm.

[0058] In one embodiment, the built-in component 17 can be disposed between the modulator chip 13 and the cover plate, with the built-in component 17 disposed adjacent to the modulator chip 13. The placement and proximity of the built-in component 17 between the modulator chip 13 and the cover plate facilitates its installation and reduces the gap between the modulator chip 13 and the cover plate. The built-in component 17 can reduce signal resonance, lower return loss, and improve the bandwidth of the electro-optic modulator 100.

[0059] The inner side of the housing 11 is provided with a support surface 18, and the built-in component 17 is covered on the support surface 18. The built-in component 17 covering the support surface 18 can better seal the space between the built-in component 17 and the modulator chip 13, and can also improve the stability of the built-in component 17. The support surface 18 can be understood as including a surface that can support or fix the built-in component 17, and can be a plane or a curved surface, a continuous surface, or include multiple spaced surfaces.

[0060] In one specific implementation, the electro-optic modulator 100 further includes a boss 19 on the inner peripheral surface of the housing 11, with the built-in member 17 covering the side of the boss 19 facing the cover plate. The boss 19 is conveniently located on the inner peripheral surface of the housing 11, facilitating manufacturing. The support surface 18 is the upper side of the boss 19. In other examples, the boss 19 may be spaced apart. In this example, the cross-section of the boss 19 is quadrilateral; in other examples, the cross-section of the boss 19 may be other shapes, such as triangles.

[0061] In other examples, a groove may be provided on the side wall of the housing 11, and the support surface 18 may be the side of the groove. As one embodiment, the support surface 18 may also be the inner side of the housing 11, and the built-in member 17 may be directly connected to the inner side of the housing 11.

[0062] The built-in component 17 is connected to the housing 11, which can be understood as a fixed or detachable connection of the built-in component 17 to the housing 11. In this example, the built-in component 17 is covered and bonded to the support surface 18. Bonding the built-in component 17 to the support surface 18 facilitates the installation of the built-in component 17 and also allows the built-in component 17 to better seal the modulator chip 13. In other examples, the built-in component 17 can also be installed using methods such as snap-fit, welding, or screw fixing.

[0063] In this example, the electro-optic modulator 100 includes a correspondingly arranged support surface 18 and an internal component 17. In other embodiments, the housing 11 may also have multiple support surfaces 18, each with an internal component 17. Multiple support surfaces 18 and multiple correspondingly arranged internal components 17 can better prevent resonance within the accommodating cavity 12, reduce signal resonance, lower return loss, and increase the bandwidth of the electro-optic modulator 100. The multiple support surfaces 18 can be arranged at intervals from top to bottom, or they can be disposed on other inner peripheral surfaces of the housing 11.

[0064] In one embodiment, the built-in component 17 has an absorption layer 20, which is disposed on the side of the built-in component 17 facing the modulator chip 13. The absorption layer 20 is used to absorb electromagnetic waves. By using the absorption layer 20 to absorb electromagnetic waves, the resonance phenomenon within the accommodating cavity 12 can be further reduced, signal resonance can be reduced, return loss can be lowered, and the bandwidth of the electro-optic modulator 100 can be increased. The absorption layer 20 can be bonded to the built-in component 17, or it can be tightly attached to the upper part of the support surface 18 by bonding or other methods, both of which can reduce the resonance distance of the housing 11 and absorb resonance energy.

[0065] The material of the absorption layer 20 can include traditional microwave absorbing materials such as ferrite, barium titanate, metal micropowder, graphite, silicon carbide, and conductive fibers, as well as novel microwave absorbing materials such as nanomaterials, chiral materials, conductive polymers, polycrystalline iron fibers, and circuit simulation microwave absorbing materials. Specifically, the material of the absorption layer 20 can be selected from materials suitable for high-frequency operation, while also possessing good microwave absorption performance and the ability to operate stably for extended periods.

[0066] In this example, the built-in component 17 is plate-shaped, and the absorbent layer 20 is attached to the side of the built-in component 17. The plate-shaped built-in component 17 facilitates the application of the absorbent layer 20 and also facilitates installation into the receiving cavity 12.

[0067] Combination Figure 3 The figure shows a comparison of the reporting loss performance of a conventional modulator and the electro-optic modulator 100 in this example under different frequency radio frequency signals.

[0068] In this example, the metal housing 11 of the electro-optic modulator 100 has three holes for connecting the light input port 14, the light output port 15, and the radio frequency signal input 16. In this example, the radio frequency signal input 16 is a high-frequency connector. The input fiber and the output fiber are connected to the light input port and the light output port, respectively, and the internal modulator chip 13 is aligned with optical components such as lenses. Then, the high-frequency connector is connected to the housing 11, and the electro-optic modulator 100 is connected to the external circuit by methods such as soldering to ensure accurate transmission of electrical signals. After completing the optical and electrical packaging, the basic structure and electrical connections of the electro-optic modulator 100 are ready, and the subsequent housing 11 packaging can be performed.

[0069] Specifically, an absorption layer 20 can be attached to the underside of the built-in component 17 and tightly bonded to the upper part of the support surface 18 using methods such as adhesive bonding. This reduces the resonant distance of the housing 11 and absorbs resonant energy. Finally, the outermost housing 11 is encapsulated by attaching the outermost cover plate to the housing 11 using screws, clips, or welding to ensure the mechanical strength of the encapsulation and the stability of signal transmission. This completes the encapsulation of the electro-optic modulator 100 in this example.

[0070] Compared to the electro-optic modulator 100 in this example, the ordinary modulator is basically the same except that it does not have the built-in component 17.

[0071] exist Figure 3In the graph, the horizontal axis represents the frequency of the RF signal input at RF signal inlet 16, and the vertical axis represents the return loss of the electro-optic modulator 100. Dark, discontinuous lines represent the performance curves of this example electro-optic modulator 100, while light, continuous curves represent the performance curves of a typical modulator. Compared to a typical modulator, it can be seen that the return loss of this example electro-optic modulator 100 remains almost consistently at a lower level, especially in the 53-63 GHz frequency range. This means that at these frequencies, this example electro-optic modulator 100 can reduce return loss and increase its bandwidth.

[0072] When a modulator receives an input RF signal, a return loss greater than -10dB typically indicates poor performance and is unacceptable. In contrast, the electro-optic modulator 100 in this example maintains a return loss below -10dB when the input RF signal frequency is within 63GHz, resulting in a wider bandwidth. Ordinary modulators, when controlling the return loss below -10dB, can only handle input RF signal frequencies up to 58GHz. The bandwidth of the electro-optic modulator 100 corresponds to its return loss; a lower return loss results in a higher bandwidth. In other words, the electro-optic modulator 100 in this example can improve bandwidth.

[0073] In other embodiments, the input radio frequency signal frequency band ranges from 0 to 20 GHz. In this example, the electro-optic modulator 100 can reduce signal resonance, reduce return loss, and increase the bandwidth of the electro-optic modulator 100.

[0074] The electro-optic modulator 100 in this example, by adopting a multi-layer housing 11 encapsulation scheme, can effectively suppress the resonance phenomenon generated by the metal housing 11, while being compatible with the size requirements of external high-frequency connectors.

[0075] Specifically, by incorporating the built-in component 17, metal cavity resonance can be reduced, thereby significantly reducing return loss and improving the signal stability and transmission efficiency of the electro-optic modulator 100. Simultaneously, it avoids electromagnetic resonance problems caused by the excessive size of the entire housing 11 due to compatibility with high-frequency connectors, ensuring the stability and compatibility of the electro-optic modulator 100 in high-speed, high-frequency applications. Furthermore, the absorbing material attached to the lower side of the built-in component 17 further suppresses resonance generated within the housing 11. The electro-optic modulator 100 of this example effectively resolves the contradiction between high-frequency resonance and high-frequency interface compatibility in traditional packaging solutions, improving the performance of the electro-optic modulator 100 in high-frequency environments, and possesses significant technical advantages and application value.

[0076] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. An electro-optic modulator, characterized by The electro-optic modulator includes: A housing and a cover plate, the housing having a receiving cavity and an opening, and the cover plate being used to seal the opening; A modulator chip, wherein the modulator chip is disposed within the accommodating cavity; The light input port and the light output port are both connected to the modulator chip. Radio frequency signal input, which is connected to the modulator chip; An internal component is disposed in the accommodating cavity and connected to the housing. The modulator chip is disposed between the housing and the internal component.

2. The electro-optic modulator of claim 1, wherein, The built-in component is disposed between the modulator chip and the cover plate, and the built-in component is disposed adjacent to the modulator chip.

3. The electro-optic modulator of claim 1, wherein, The outer periphery of the built-in component forms a sealed space with the housing, and the modulator chip is disposed within the sealed space.

4. The electro-optic modulator of claim 1, wherein, The inner side of the housing is provided with a support surface, and the built-in component is covered on the support surface.

5. The electro-optic modulator of claim 4, wherein, The electro-optic modulator also includes a boss on the inner circumferential surface of the housing, and the built-in component covers the side of the boss facing the cover plate.

6. The electro-optic modulator of claim 4, wherein, The housing has multiple support surfaces, and each support surface is provided with the built-in component.

7. The electro-optic modulator of claim 1, wherein, The outer peripheral surface of the cover plate is in contact with the inner peripheral surface of the housing.

8. The electro-optic modulator of claim 1, wherein, The built-in component has an absorption layer disposed on the side of the built-in component facing the modulator chip, and the absorption layer is used to absorb electromagnetic waves.

9. The electro-optic modulator of claim 8, wherein, The built-in component is plate-shaped, and the absorbent layer is attached to the side of the built-in component.

10. An optical communication system, characterized by, The optical communication system includes an electro-optic modulator as described in any one of claims 1-9.

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