Directly modulated integrated light source, preparation method thereof and heterogeneous integrated optical module

Abstract

This invention relates to the field of optical communication technology, and discloses a directly modulated integrated light source and its fabrication method, as well as a heterogeneous integrated optical module. The directly modulated integrated light source includes: a substrate, an electrode structure, and a light-emitting structure. A first surface of the substrate is adapted to form an optical coupler. The electrode structure is disposed on the substrate and spaced apart from the optical coupler in a first direction, adapted to connect a driver to receive different electrical signals. One end of the light-emitting structure is electrically connected to the electrode structure, and the other end abuts against the substrate, with the light-emitting surface facing the first surface. It is adapted to receive different electrical signals transmitted by the electrode structure and convert them into modulated optical signals for emission to the optical coupler. The varying electrical signals provided by the driver only need to pass through the electrode structure to be directly transmitted to the light-emitting structure and converted into modulated optical signals. The structure is simple, highly integrated, and has low loss on the transmission line, effectively ensuring the integrity and speed of signal transmission.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, specifically to a direct-modulation integrated light source and its fabrication method, and a heterogeneous integrated optical module. Background Technology

[0002] With the rapid development of high-speed communication and data centers, optical communication systems are increasingly demanding higher bandwidth from radio frequency (RF) devices to ensure signal integrity during high-speed signal transmission. Optical modules play a crucial role in optical communication systems, converting optical signals into electrical signals to meet the ever-growing demands for data transmission rates and bandwidth. Optical modules often employ heterogeneous integration technology to integrate optoelectronic devices with different functions or manufacturing processes, thereby improving integration and performance, reducing size and power consumption, and supporting higher signal bandwidth.

[0003] Optical modules obtained through heterogeneous integration technology typically include various optoelectronic devices such as a light source, modulator, optical amplifier, optical waveguide, and detector. Their basic working principle is that the light source emits light continuously under stimulation. The emitted light passes through the modulator to form a modulated optical signal carrying communication information, which is then emitted. This modulated optical signal is further processed and transmitted through components such as optical amplifiers and optical waveguides, ultimately being output from the optical port or, after passing through the detector, from the electrical port, achieving high-speed and stable transmission of the optical signal. (Reference) Figure 13 As shown. However, such optical modules contain many optoelectronic devices, have complex structures, and complex energy transmission links. They not only have poor integration but also suffer from high energy loss, ultimately making it difficult to guarantee the integrity and efficiency of signal transmission. Summary of the Invention

[0004] In view of this, the present invention provides a direct-modulation integrated light source and its fabrication method, as well as a heterogeneous integrated optical module, to solve the problems of complex structure, large energy transmission loss, and difficulty in ensuring signal transmission integrity and transmission efficiency of existing optical modules.

[0005] In a first aspect, the present invention provides a direct-modulation integrated light source, comprising: a substrate, an electrode structure, and a light-emitting structure; a first surface of the substrate is adapted to form an optical coupler; the electrode structure is disposed on the first surface of the substrate and spaced apart from the optical coupler in a first direction; the electrode structure is adapted to connect to a driver to receive different electrical signals; one end of the light-emitting structure is adapted to be electrically connected to the electrode structure, and the other end abuts against the first surface of the substrate; the light-emitting surface of the light-emitting structure faces the first surface; the light-emitting structure is adapted to receive different electrical signals transmitted by the electrode structure and convert them into modulated optical signals for emission to the optical coupler.

[0006] Beneficial effects: In this invention, the driver is used to provide a changing electrical signal, such as a changing voltage, to the directly modulated integrated light source. The signal can be directly transmitted to the light-emitting structure through the electrode structure, converting the changing electrical signal into a corresponding modulated optical signal. The fewer optoelectronic components and the simpler structure help improve the integration. At the same time, the energy transmission link is simple, and the electrode structure has good impedance matching characteristics on the transmission line, resulting in extremely low loss on this transmission line. The modulated optical signal can be formed without further processing by an external modulator, effectively ensuring the integrity and speed of signal transmission.

[0007] In one optional embodiment, the electrode structure includes a first electrode and a second electrode spaced apart in a second direction, the second direction forming a preset angle with the first direction; the first electrode and the second electrode are adapted to be connected to a driver.

[0008] Beneficial effects: The electrode structure includes a first electrode and a second electrode spaced apart in the second direction. The first electrode and the second electrode are connected to a driver through different leads. The driver inputs different non-zero levels to one of the first electrode and the second electrode, and grounds the other one. This makes the electrode structure and the light-emitting structure form a complete driving circuit. The electrode structure forms impedance matching the input and output terminals.

[0009] In one optional embodiment, the first electrode includes a first wire bonding area, a first transition area, and a first ball-planting area connected in sequence. The width of the first wire bonding area in the second direction is greater than the width of the first ball-planting area in the second direction. In the first direction, the width of the first transition area gradually decreases from one end of the first wire bonding area to the one end of the first ball-planting area.

[0010] The second electrode includes a second wire bonding area, a second transition area, and a second ball-planting area connected in sequence. The width of the second wire bonding area in the second direction is greater than the width of the second ball-planting area in the second direction. In the first direction, the width of the second transition area gradually decreases from one end of the second wire bonding area to the other end of the second ball-planting area.

[0011] The first and second hitting wire areas are adapted to be electrically connected to the driver, and the first and second ball-planting areas are adapted to be connected to the light-emitting structure.

[0012] Beneficial effects: Both the first and second electrodes have a structure where the width decreases from the input end to the output end. The wire bonding area has the largest width, which facilitates connection with the driver and maximizes the reception of electrical signals. The ball-planting area has the smallest width, which facilitates the reception and matching of soldered parts and achieves good and stable connection performance. The transition area realizes the performance transition from the wire bonding area to the ball-planting area, which facilitates the formation of good impedance matching characteristics of the electrode structure.

[0013] In one optional embodiment, the distance between the first electrode and the second electrode in the second direction ranges from 10 μm to 20 μm.

[0014] Beneficial effects: Setting the first electrode and the second electrode to have a spacing of 10μm to 20μm in the second direction, and combining the width dimensions of the first wire bonding area and the second wire bonding area in the second direction, together ensure that the two electrodes connected to the driver form a precise impedance match. If this limit is exceeded, the impedance value will deviate, thereby affecting the RF performance of the light output structure.

[0015] In one optional embodiment, the light-emitting structure is a surface-emitting laser, with a welding part and a light-emitting part provided on the light-emitting surface. The welding part is connected to the electrode structure, and the light-emitting part outputs a modulated light signal toward the optical coupler.

[0016] Beneficial effects: Surface-emitting lasers have higher integration, and a light-emitting space is formed between the light-emitting surface and the substrate. There is no need to perform complex encapsulation and filling of the light-emitting space, resulting in higher light-emitting stability. In addition, the angle between the modulated light signal emitted by the surface-emitting laser and the substrate normal is smaller, which means that the angle between the modulated light signal emitted by the surface-emitting laser and the surface normal of the optical coupler is smaller, resulting in higher optical coupling efficiency.

[0017] In one alternative embodiment, the angle between the direction of the modulated optical signal and the normal direction of the first surface of the substrate is less than 20°.

[0018] Beneficial effects: Within this range, the emitted modulated optical signal can form efficient coupling with the optical coupler, and after the modulated optical signal is coupled to the maximum extent, it is transmitted to subsequent devices such as optical waveguide structures, realizing efficient and complete transmission of the modulated optical signal.

[0019] In one optional embodiment, it further includes: a welding component disposed between one end of the electrode structure and the welding portion of the light-emitting structure, so that the light-emitting structure is disposed at an angle between the substrate and the electrode structure.

[0020] Beneficial effects: By setting a welding component with a certain height at one end of the electrode structure near the light-emitting structure, this invention enables the electrical signal in the electrode structure to be smoothly transmitted to the light-emitting structure. On the other hand, it also raises one side of the light-emitting structure, forming an angle between the light-emitting surface and the first surface of the substrate. The modulated light signal is obliquely emitted to the optical coupler, so that the modulated light signal obliquely emitted to the surface of the optical coupler will not be reflected back to the light-emitting structure. This avoids the impact of optical feedback on the stability of the light-emitting structure, such as temperature rise, damage to the light-emitting part, etc. It also avoids the problem of reduced integration caused by using an optical isolator to solve optical feedback.

[0021] In one optional embodiment, the weldment is configured as a welding ball with a height ranging from 60 μm to 100 μm; the length of the first and second welding ball areas in the first direction and the width in the second direction are both smaller than the diameter of the welding ball.

[0022] Beneficial effects: Solder balls enable soldering connections. Depending on the RF bandwidth requirements, solder balls coated with different materials can be used, resulting in higher soldering stability. The dimensions of the first and second solder ball placement areas are determined based on the size of the solder balls, slightly smaller than their diameter, to avoid excessive melting of the solder balls which could affect the optical coupling angle, and to prevent solder overflow from affecting the soldering connection performance and the performance of other structures.

[0023] In one alternative embodiment, it further includes: a solder resist layer disposed on the electrode structure and located on the outside of the weldment to limit the outflow of the weldment in the molten state.

[0024] Beneficial effects: The solder resist layer is set in the first transition area of ​​the first electrode and the second transition area of ​​the second electrode to prevent the melt flow of the welded parts located in the first ball-planting area and the second ball-planting area from flowing to the first and second wire bonding areas. This is because the first and second wire bonding areas are directly connected to the external driving structure and receive changing electrical signals. Their impedance matching is more critical. The solder resist layer effectively protects the performance of the electrode structure, especially the first and second wire bonding areas, thereby ensuring good impedance matching.

[0025] In a second aspect, the present invention also provides a method for preparing a direct-tuning integrated light source, comprising:

[0026] A substrate is provided, the substrate including a first surface on which an optical coupler is formed;

[0027] An electrode structure is formed on the first surface of the substrate. The electrode structure is spaced apart from the optical coupler in the first direction. The electrode structure is adapted to connect to a driving device to receive different electrical signals.

[0028] A light-emitting structure is placed on the first surface of the substrate. One end of the light-emitting structure is connected to the electrode structure, and the other end abuts against the first surface of the substrate. The light-emitting surface of the light-emitting structure faces the first surface and is suitable for receiving different electrical signals transmitted by the electrode structure and converting them into modulated optical signals for emission to the optical coupler.

[0029] Beneficial effects: In the preparation method of the direct-tuning integrated light source of the present invention, the impedance of each part of the transmission line is strictly set, including setting a gradually designed electrode structure, determining the light-emitting structure with a light coupling angle, and welding parts of appropriate size and material. At the same time, a solder resist layer is set to ensure the performance of the welding path, and finally a direct-tuning integrated light source with simple structure, high integration, smooth energy transmission link, low signal transmission loss, and high integrity is formed.

[0030] Thirdly, the present invention also provides a heterogeneous integrated optical module, comprising: the aforementioned direct-modulation integrated light source, driver, optical coupler, optical waveguide structure, and optical output component, wherein the driver is spaced apart from the substrate and wire-connected to the electrode structure of the direct-modulation integrated light source to output different electrical signals to the electrode structure; the optical coupler is formed on the first surface of the substrate and located on the side of the electrode structure relatively far from the driver, and the optical coupler is adapted to receive the modulated optical signal emitted by the direct-modulation integrated light source; the optical waveguide structure is disposed on the side of the optical coupler relatively far from the electrode structure and connected to the optical coupler to receive and transmit the modulated optical signal emitted by the optical coupler; the optical output component is disposed on the side of the optical waveguide structure relatively far from the optical coupler to receive the modulated optical signal transmitted by the optical waveguide structure and output it to an external structure.

[0031] Beneficial Effects: The heterogeneous integrated optical module of this invention first uses a driver chip to output high and low voltages of different magnitudes to the electrode structure of the directly modulated integrated light source. Then, through an impedance-matched electrode structure, this voltage output is efficiently transmitted to the light-emitting structure, which then outputs a modulated optical signal with a certain variation to the optical coupler. The optical coupler then couples the received modulated optical signal to the optical waveguide structure. The optical waveguide structure then transmits it to the optical output component. In this embodiment, the optical output component can have two paths: one is to first transmit to the detector and finally output to the external structure as an electrical signal; the other is to first transmit to the optical port and then transmit it as an optical signal to the optical fiber and output to the external structure. That is, different optoelectronic devices, including the directly modulated integrated light source, optical waveguide structure, and optical output component, are integrated on a two-dimensional planar substrate or on an optical chip with an optical coupler and optical waveguide structure. This results in a simple structure, high integration, which facilitates mass production. Furthermore, the energy transmission link is short, the RF bandwidth loss is low, and the optical module has high signal transmission integrity and high speed. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a front view schematic diagram of a direct-adjustment integrated light source according to an embodiment of the present invention;

[0034] Figure 2 This is a top view schematic diagram of a direct-adjustment integrated light source according to an embodiment of the present invention;

[0035] Figure 3 This is a top view schematic diagram of the electrode structure according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the transmission loss curve of the direct-modulation integrated light source according to an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the return loss curve of the direct-modulation integrated light source according to an embodiment of the present invention;

[0038] Figure 6 This is a schematic flowchart of the fabrication method of the direct-tuning integrated light source according to an embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of the substrate structure according to an embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of the structure after the optical coupler and optical waveguide structure are formed on the substrate according to an embodiment of the present invention;

[0041] Figure 9 This is a schematic diagram of the structure after the electrode structure is formed on the substrate according to an embodiment of the present invention;

[0042] Figure 10 This is a schematic diagram of the structure after a solder resist layer is formed on the electrode structure according to an embodiment of the present invention;

[0043] Figure 11 This is a schematic diagram of the structure after a weldment is formed on the electrode structure according to an embodiment of the present invention;

[0044] Figure 12 This is a schematic diagram of the temperature curve when the light-emitting structure is fixed to the welding part according to an embodiment of the present invention;

[0045] Figure 13 This is a structural block diagram of the optical module of the related technology;

[0046] Figure 14 This is a structural block diagram of a heterogeneous integrated optical module according to an embodiment of the present invention.

[0047] Explanation of reference numerals in the attached figures:

[0048] 100. Direct-modulation light source device; 200. Driver; 300. Optical coupler; 400. Optical waveguide structure; 401. First waveguide region; 402. Second waveguide region; 500. Optical output component;

[0049] 1. Substrate; 11. First surface;

[0050] 2. Electrode structure; 21. First electrode; 211. First stringing area; 212. First transition area; 213. First ball planting area; 22. Second electrode; 221. Second stringing area; 222. Second transition area; 223. Second ball planting area;

[0051] 3. Light-emitting structure; 31. Light-emitting surface; 32. Welding part; 33. Light-emitting part;

[0052] 4. Welded components;

[0053] 5. Solder resist layer. Detailed Implementation

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the drawings, not all structures. In the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concept of the invention. Various structural schematic diagrams according to embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, and some details are enlarged for clarity, and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from actual practices due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed. In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. Additionally, if one layer / component is "above" another layer / component in one orientation, then when the orientation is reversed, that layer / component can be "below" that other layer / component.

[0055] refer to Figures 1 to 5 This embodiment provides a direct-modulation integrated light source, including: a substrate 1, an electrode structure 2, and a light-emitting structure 3. The first surface 11 of the substrate 1 is adapted to form an optical coupler 300. The electrode structure 2 is disposed on the first surface 11 of the substrate 1 and spaced apart from the optical coupler 300 in a first direction. The electrode structure 2 is adapted to connect to a driver 200 to receive different electrical signals. One end of the light-emitting structure 3 is adapted to be electrically connected to the electrode structure 2, and the other end abuts against the first surface 11 of the substrate 1. The light-emitting surface 31 of the light-emitting structure 3 faces the first surface 11. The light-emitting structure 3 is adapted to receive different electrical signals transmitted by the electrode structure 2 and convert them into modulated light signals to be emitted to the optical coupler 300.

[0056] Specifically, in this embodiment, the substrate 1 is a passive substrate 1. The material of the substrate 1 is determined according to the different wavelengths of the light-emitting structure 3. The first surface 11 of the substrate 1, which is also the upper surface, can be used to process an optical coupler 300 for a specific light-emitting structure 3. For example, in this embodiment, a grating coupler is formed to receive the light beam from the light-emitting structure 3. An electrode structure 2 is also provided on the first surface 11 of the substrate 1. Specifically, it can be a metal electrode. One end of the metal electrode is connected to the driver 200 through a lead wire, and the other end is electrically connected to the light-emitting structure 3. In this embodiment, the driver 200 can be a driver chip. Compared to existing solutions that directly connect the optical structure 3 to a power source to continuously emit light, and then use the output light to form a modulated optical signal controlled by the driver 200, this embodiment allows the driver 200 to provide a variable electrical signal, such as varying voltages, which can be directly transmitted to the optical structure 3 via the electrode structure 2. This converts the variable electrical signal into a corresponding modulated optical signal. This approach reduces the number of optoelectronic components, simplifies the structure, and improves integration. Furthermore, the energy transmission link is simple, and the electrode structure 2 provides excellent impedance matching characteristics on this transmission line, resulting in extremely low losses. The modulated optical signal can be formed without further processing by an external modulator, effectively ensuring the integrity and speed of signal transmission.

[0057] The modulated optical signal here refers to light that is not continuously output, but rather exhibits different output patterns depending on the electrical signal. The light-emitting structure 3 directly outputs the modulated optical signal, exhibiting flexible output characteristics, i.e., good radio frequency performance. For example, when the driver 200 applies a large non-zero lasing voltage to the electrode structure 2, this voltage is transmitted through the electrode structure 2 to the light-emitting structure 3, and the light-emitting structure 3 outputs light, which can be understood as an output signal "1". When the driver 200 applies a weaker lasing voltage to the electrode structure 2, the light-emitting structure 3 outputs very weak light, which can be understood as an output signal "0". The output power corresponding to signal "0" is weaker than the output power corresponding to signal "1". In other words, the output power of the light-emitting structure 3 is directly controlled by the voltage applied by the driver 200 to the electrode structure 2.

[0058] like Figure 2 and Figure 3 As shown, the electrode structure 2 of this embodiment includes a first electrode 21 and a second electrode 22 spaced apart in a second direction, and the second direction forms a preset angle with the first direction (as above); the first electrode 21 and the second electrode 22 are adapted to be connected to the driver 200, one of them is connected to different lasing voltages through the driver 200 to generate high and low voltages, and the other of them is grounded through the driver 200 and does not generate voltage.

[0059] Specifically, in this embodiment, the second direction and the first direction are perpendicular to each other. The electrode structure 2 includes a first electrode 21 and a second electrode 22 spaced apart in the second direction. The first electrode 21 is connected to the driver 200 via a lead to supply different non-zero lasing voltages, and the second electrode 22 is connected to the driver 200 via a lead to ground, thereby forming a complete driving circuit between the electrode structure 2 and the light-emitting structure 3. In this embodiment, the first electrode 21 and the second electrode 22 are set to have identical structures to facilitate the matching of the input and output impedances of the electrode structure 2. For example, the input is typically a 50Ω impedance when the driver 200 outputs. To ensure the RF performance of the output, i.e., the light-emitting structure 3, the electrode structure 2 should correspondingly meet the 50Ω impedance matching requirement.

[0060] Specifically, such as Figure 3 As shown, the first electrode 21 includes a first bonding region 211, a first transition region 212, and a first ball-planting region 213 connected in sequence. The width H1 of the first bonding region 211 in the second direction is greater than the width H2 of the first ball-planting region 213 in the second direction. In the first direction, the width of the first transition region 212 gradually decreases from one end of the first bonding region 211 to the end of the first ball-planting region 213. That is, the first electrode 21 as a whole has a structure in which the width decreases from the input end to the output end. Furthermore, in this embodiment, the lengths of the first wire bonding area 211 (L1), the first transition area 212 (L2), and the first ball-planting area 213 (L3) are arranged in the first direction as follows: L1 > L2 > L3 (the size relationship is not fixed; the length of the transition area can also be very long, meaning L2 > L1 is also acceptable). That is, the first wire bonding area 211 has the largest area, which facilitates connection with the driver 200 and maximizes the reception of electrical signals. The first ball-planting area 213 has the smallest area, which facilitates the reception and matching of the soldering parts 4, achieving good and stable connection performance. The first transition area 212 realizes the performance transition from the first wire bonding area 211 to the first ball-planting area 213, which facilitates the formation of good impedance matching characteristics of the electrode structure 2.

[0061] Of course, the length L2 of the first transition zone 212 can also be greater than the length L1 of the first stringing zone 211, that is, L2>L1 is not excluded, so as to adjust the width of the first stringing zone 211 and the first ball planting zone 213 according to the needs.

[0062] Correspondingly, the second electrode 22 is exactly the same as the first electrode 21. The second electrode 22 includes a second bonding area 221, a second transition area 222, and a second ball-planting area 223 connected in sequence. The width of the second bonding area 221 in the second direction is greater than the width of the second ball-planting area 223 in the second direction. In the first direction, the width of the second transition area 222 gradually decreases from one end of the second bonding area 221 to the end of the second ball-planting area 223. That is, the second bonding area 221 and the first bonding area 211 are exactly the same size, the second transition area 222 and the first transition area 212 are exactly the same size, and the second ball-planting area 223 and the first ball-planting area 213 are exactly the same size. The first electrode 21 and the second electrode 22 together achieve impedance matching of the electrode structure 2 on the transmission line.

[0063] Specifically, in this embodiment, the length L1 of the first stringing area 211 and the second stringing area 221 in the first direction is ≥130μm, the length L2 of the first transition area 212 and the second transition area 222 in the first direction is ≥80μm, and the length L3 of the first ball-planting area 213 and the second ball-planting area 223 in the first direction is ≤50μm. The width H1 of the first stringing area 211 and the second stringing area 221 in the second direction ranges from 80μm to 120μm, and the width H2 of the first ball-planting area 213 and the second ball-planting area 223 in the second direction is ≤50μm.

[0064] The first bonding area 211 and the second bonding area 221 are adapted to be electrically connected to the driver 200. The driver 200 enables one of them to be connected to a different non-zero lasing voltage, while the other is grounded. The first ball-planting area 213 and the second ball-planting area 223 are adapted to be connected to the light-emitting structure 3.

[0065] like Figure 3 As shown, the distance D between the first electrode 21 and the second electrode 22 in the second direction ranges from 10 μm to 20 μm.

[0066] The first electrode 21 and the second electrode 22 are spaced 10μm to 20μm apart in the second direction. Combined with the width of the first wire bonding area 211 and the second wire bonding area 221 in the second direction, they together ensure that the two electrodes connected to the driver 200 form a precise impedance match. If this limit is exceeded, the impedance value will deviate, thereby affecting the radio frequency performance of the light output structure 3.

[0067] See Figure 1 In this embodiment, the light-emitting structure 3 is a surface-emitting laser. The light-emitting surface 31 is provided with a welding part 32 and a light-emitting part 33. The welding pad is connected to the electrode structure 2. The light-emitting part 33 outputs a modulated light signal toward the optical coupler 300.

[0068] Compared to edge-emitting lasers, the surface-emitting laser in this embodiment has higher integration. A light-emitting space is formed between the light-emitting surface 31 and the substrate 1, eliminating the need for complex encapsulation and filling of the light-emitting space. This results in higher light emission stability. Furthermore, the angle between the modulated light signal emitted by the surface-emitting laser and the normal to the substrate 1 (i.e., the surface normal of the optical coupler 300) is smaller, leading to higher optical coupling efficiency. This embodiment can use an existing surface-emitting laser, and its structure will not be described in detail here. The material of the substrate 1 is determined according to the different wavelengths of the surface-emitting laser, and its light-emitting portion 33 is typically formed as a light-emitting aperture.

[0069] In one embodiment, the angle between the direction of the modulated optical signal and the normal direction of the first surface 11 of the substrate 1 is less than 20°. Within this range, the emitted modulated optical signal can form efficient coupling with the optical coupler 300, and after the modulated optical signal is coupled to the maximum extent, it is transmitted to subsequent devices such as the optical waveguide structure 400, thereby realizing efficient and complete transmission of the modulated optical signal.

[0070] In one embodiment, such as Figure 1 and Figure 2 As shown, the above-mentioned direct-modulation integrated light source also includes: a welding component 4, which is disposed between one end of the electrode structure 2 and the welding part 32 of the light-emitting structure 3, so that the light-emitting structure 3 is inclinedly disposed between the substrate 1 and the electrode structure 2.

[0071] In this embodiment, by setting a welding component 4 with a certain height at one end of the electrode structure 2 near the light-emitting structure 3, the electrical signal in the electrode structure 2 can be smoothly transmitted to the light-emitting structure 3. On the other hand, it also raises one side of the light-emitting structure 3, forming an angle between the light-emitting surface 31 and the first surface 11 of the substrate 1. The modulated light signal is obliquely emitted to the optical coupler 300. In this way, the modulated light signal obliquely emitted to the surface of the optical coupler 300 will not be reflected back to the light-emitting structure 3, avoiding the impact of optical feedback on the stability of the light-emitting structure 3, such as temperature rise, damage to the light-emitting part 33, etc. It also avoids the problem of reduced integration caused by using an optical isolator to solve the problem of optical feedback.

[0072] Specifically, the aforementioned weldment 4 is configured as a welding ball, with the height of the welding ball ranging from 60μm to 100μm; the length of the first ball-planting area 213 and the second ball-planting area 223 in the first direction and the width in the second direction are both smaller than the diameter of the welding ball.

[0073] In this embodiment, solder balls are used to achieve the soldering connection. Based on different RF bandwidth requirements, gold solder balls, copper solder balls, or silver solder balls can be used, resulting in higher soldering stability. The dimensions of the first solder ball area 213 and the second solder ball area 223 are determined according to the size of the solder balls, and are slightly smaller than the diameter of the solder balls. In this embodiment, the diameter of the solder balls is between 60μm and 100μm, determined according to the light emission coupling angle of the light emission structure 3. For example, if the diameter is 60μm, then the first solder ball area 213 and the second solder ball area 223 are set as square structures with a side length slightly less than 50μm to avoid excessive melting of the solder balls, which would affect the light emission coupling angle, and to avoid solder overflow affecting the soldering connection performance and the performance of other structures.

[0074] Based on the above solutions, such as Figure 1 and Figure 2 As shown, the direct-modulation integrated light source of this embodiment also includes a solder resist layer 5, which is disposed on the electrode structure 2 and located on the outside of the weldment 4 to limit the outflow of the weldment 4 in the molten state.

[0075] Specifically, it is preferable to provide a solder resist layer 5 in the first transition region 212 of the first electrode 21 and the second transition region 222 of the second electrode 22 to prevent the welded parts 4 located in the first ball-planting region 213 and the second ball-planting region 223 from melting and flowing to the first wire bonding region 211 and the second wire bonding region 221. This is because the first wire bonding region 211 and the second wire bonding region 221 are directly connected to the external driving structure and receive changing electrical signals. Their impedance matching is more critical. Providing a solder resist layer 5 effectively protects the performance of the electrode structure 2, especially the first wire bonding region 211 and the second wire bonding region 221, thereby ensuring good impedance matching.

[0076] The direct-modulation integrated light source in this embodiment has good radio frequency performance. Figure 4 and Figure 5 A schematic diagram of the radio frequency electromagnetic simulation results is shown. Figure 4 This is a diagram illustrating transmission loss. Figure 5 This is a schematic diagram of return loss. Figure 4 and Figure 5 Therefore, for RF bandwidth regions of 30 GHz or less, the transmission loss of the direct-modulation integrated light source in this embodiment is within -0.3 dB, and the return loss is less than -30 dB. This means that the direct-modulation integrated light source with such a simple link in this embodiment has extremely low incident energy loss, which is basically about one-thousandth, and the integrity and efficiency of signal transmission are extremely high.

[0077] refer to Figures 1 to 12 This embodiment also provides a method for fabricating a direct-tuning integrated light source, used in the aforementioned direct-tuning integrated light source. Figure 6 The diagram below illustrates the process of this preparation method, which includes the following steps:

[0078] Step S601, a substrate 1 is provided, the substrate 1 including a first surface 11 on which an optocoupler 300 is formed.

[0079] refer to Figure 7 and Figure 8 For example, firstly, photoresist is spin-coated onto substrate 1, followed by exposure and development using photolithography to obtain the marking pattern of the optical coupler 300. Simultaneously, the optical waveguide structure 400 and position marking patterns are also obtained. These position markings are the first positioning marks in the photolithography process, defining reference points or regions to facilitate the determination of the forming areas of each structure on the first surface 11 of substrate 1. Then, dry etching is performed using an inductively coupled plasma etching machine to obtain the optical coupler 300, the optical waveguide structure 400, and the position marking structure. Finally, the photoresist is washed away with a resist remover, thus forming the final optical coupler 300, optical waveguide structure 400, and position marking structure.

[0080] In step S602, an electrode structure 2 is formed on the first surface 11 of the substrate 1. The electrode structure 2 is spaced apart from the optocoupler 300 in the first direction. The electrode structure 2 is adapted to connect to the driver 200 to receive different electrical signals.

[0081] refer to Figure 9 After etching the optical coupler 300, optical waveguide structure 400, and position marker structure, the electrode structure 2 is fabricated. Specifically, this includes: first, spin-coating photoresist onto the substrate 1; then, using photolithography, developing and removing the photoresist in the area where the electrode structure 2 is located; and finally, depositing multiple metal films, such as titanium / platinum / gold, using a metal deposition process, with the gold layer on top for wire bonding. Next, a lift-off process is used to remove the photoresist and the metal films attached to it, leaving only the metal film in the area where the target electrode structure is located. This metal film forms multiple appropriately sized metal pads, thus forming the electrode structure 2. The geometry of the metal pads affects the height of the implanted balls, which in turn affects the incident tilt angle of the light-emitting structure 3. In this embodiment, the electrode structure 2 preferably transitions gradually to the transmission line through a suitable gradient design to meet the impedance matching requirements of the transmission line.

[0082] The optical waveguide structure 400 includes a first waveguide region 401 directly connected to the optical coupler 300, and a second waveguide region 402 disposed on the other side of the first waveguide region 401. The first waveguide region 401 is configured as a width-tapered structure, with the smaller end connected to the second waveguide region 402.

[0083] In step S603, a light-emitting structure 3 is placed on the first surface 11 of the substrate 1. One end of the light-emitting structure 3 is connected to the electrode structure 2, and the other end abuts against the first surface 11 of the substrate 1. The light-emitting surface 31 of the light-emitting structure 3 faces the first surface 11 and is suitable for receiving different electrical signals transmitted by the electrode structure 2 and converting them into modulated light signals to be emitted to the optical coupler 300.

[0084] For example, a high-precision pick-and-place machine is used to align the light-emitting part 33 of the light-emitting structure 3 with the target position of the optical coupler 300 for placement. Simultaneously, a suction nozzle structure picks up the back side of the light-emitting structure 3. During placement, the suction nozzle structure performs appropriate temperature profile control on the light-emitting structure 3, such as... Figure 12 As shown, this results in a strong bond between the welded part 32 on the optical structure 3 and the welded part 4 on the electrode structure 2.

[0085] In one embodiment, between steps S602 and S603, the following further step is included:

[0086] refer to Figure 10 A solder resist layer 5 is formed on the electrode structure 2. Specifically, after forming the electrode structure 2, photoresist is spin-coated on the substrate 1, and the photoresist in the area where the solder resist layer 5 is located is removed by photolithography. Then, silicon oxide is prepared in the area where the solder resist layer 5 is located to form the solder resist layer 5. The solder resist layer 5 is specifically disposed on the transition region of the electrode structure 2 to block the flow of high-temperature solder balls during laser ball placement.

[0087] refer to Figure 11 Laser ball implantation is performed on electrode structure 2. For example, laser ball implantation technology is used to implant balls in the ball implantation area of ​​electrode structure 2. Specifically, the required diameter of the solder ball can be calculated using the working angle of the optical coupler 300 and the size of the light-emitting structure 3. The solder ball heated by the laser of the laser ball implantation machine can be ejected one by one and then attached to the ball implantation area of ​​electrode structure 2. A solder resist layer 5 is provided around the ball implantation area to prevent the solder ball from flowing to the surrounding area.

[0088] In the fabrication method of the direct-tuning integrated light source in this embodiment, the impedance of each part of the transmission line is strictly set, including setting a gradually designed electrode structure 2, a light-emitting structure 3 with a determined light coupling angle, and a welding part 4 of appropriate size and material. At the same time, a solder resist layer 5 is set to ensure the performance of the welding path, and finally a direct-tuning integrated light source with simple structure, high integration, smooth energy transmission link, low signal transmission loss, and high integrity is formed.

[0089] refer to Figure 14This embodiment also provides a heterogeneous integrated optical module, including: the aforementioned direct-modulation integrated light source, driver 200, optical coupler 300, optical waveguide structure 400, and optical output component 500. The driver 200 is disposed on the first surface 11 of the substrate 1 and connected to the electrode structure 2 of the direct-modulation integrated light source to output different electrical signals to the electrode structure 2. The optical coupler 300 is formed on the first surface 11 of the substrate 1 and located on the side of the electrode structure 2 relatively away from the driver 200. The optical coupler 300 is adapted to receive the modulated optical signal emitted by the direct-modulation integrated light source. The optical waveguide structure 400 is disposed on the side of the optical coupler 300 relatively away from the electrode structure 2 and connected to the optical coupler 300 to receive and transmit the modulated optical signal emitted by the optical coupler 300. The optical output component 500 is disposed on the side of the optical waveguide structure 400 relatively away from the optical coupler 300 to receive the modulated optical signal transmitted by the optical waveguide structure 400 and output it to an external structure.

[0090] Compared Figure 13 In the conventional scheme shown, the integrated light source or the feed light source is connected to an external power supply to continuously emit light. This light is modulated into a modulated optical signal by a modulator connected to the driver 200. A large amount of the optical signal is lost in this step. Therefore, it must then pass through an amplifier and other structures before it can enter the optical waveguide structure 400 and the subsequent optical output component 500. In this way, a large part of the light emitted by the light source is lost in the modulator stage. An additional optical amplifier structure is also required to ensure the optical output efficiency. The loss is large and the structure is complex.

[0091] In this embodiment, the driver 200 first uses a driver chip to output high and low voltages of different magnitudes to the electrode structure 2 of the directly modulated integrated light source. Then, the voltage output is efficiently transmitted to the light-emitting structure 3 via the impedance-matched electrode structure 2. The light-emitting structure 3 then outputs a modulated optical signal with a certain variation to the optical coupler 300. The optical coupler 300 then couples the received modulated optical signal to the optical waveguide structure 400. The optical waveguide structure 400 then transmits it to the optical output component 500. In this embodiment, the optical output component 500 can have two paths: one is to first transmit to the detector and finally output to the external structure in the form of an electrical signal; the other is to first transmit to the optical port, then transmit to the optical fiber in the form of an optical signal and finally output to the external structure. Figure 14 Optical coupler 300 is not shown in the diagram because optoelectronic devices of any different structure usually require optical coupling, so it is not specifically illustrated here.

[0092] In summary, the heterogeneous integrated optical module of this embodiment integrates different optoelectronic devices, including a direct-modulation integrated light source, an optical waveguide structure 400, and an optical output component 500, on a two-dimensional planar substrate 1 or on an optical chip with an optical coupler 300 and an optical waveguide structure 400. It has a simple structure, high integration, which is conducive to mass production. In addition, the energy transmission link is short, the radio frequency bandwidth loss is low, and the signal transmission integrity and speed of the optical module are high.

[0093] Further functional descriptions of the above structures are the same as those of the corresponding embodiments described above, and will not be repeated here.

[0094] The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0095] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A direct-modulation integrated light source, characterized in that, include: A substrate, the first surface of which is adapted to form an optical coupler; An electrode structure is disposed on a first surface of the substrate and spaced apart from the optocoupler in a first direction. The electrode structure includes a first electrode and a second electrode spaced apart in a second direction, the second direction forming a predetermined angle with the first direction. The first electrode and the second electrode are adapted to connect to a driver to receive different electrical signals. The spacing between the first electrode and the second electrode in the second direction ranges from 10 μm to 20 μm. The first electrode includes a first wire bonding area, a first transition area, and a first ball-planting area connected in sequence. The width of the first wire bonding area in the second direction is greater than the width of the first ball-planting area in the second direction. In the first direction, the width of the first transition area gradually decreases from one end of the first wire bonding area to one end of the first ball-planting area. The second electrode includes a second wire bonding area, a second transition area, and a second ball-planting area connected in sequence. The width of the second wire bonding area in the second direction is greater than the width of the second ball-planting area in the second direction. In the first direction, the width of the second transition area gradually decreases from one end of the second wire bonding area to one end of the second ball-planting area. The first wire bonding area and the second wire bonding area are adapted to be electrically connected to the driver. A light-emitting structure is provided, one end of which is adapted to be electrically connected to the electrode structure, and the other end abuts against a first surface of the substrate, with the light-emitting surface of the light-emitting structure facing the first surface; the light-emitting structure is adapted to receive different electrical signals transmitted by the electrode structure and convert them into modulated optical signals and emit them to the optical coupler. A welded component is disposed between the first ball-planting area and the second ball-planting area of ​​the electrode structure and the welded portion of the light-emitting structure, so that the light-emitting structure is inclined. A solder resist layer is disposed on the electrode structure and located on the outside of the weldment to limit the outflow of the weldment in the molten state.

2. The direct-adjustment integrated light source according to claim 1, characterized in that, The light-emitting structure is a surface-emitting laser. The light-emitting surface is provided with a welding part and a light-emitting part. The welding part is connected to the electrode structure, and the light-emitting part outputs a modulated light signal toward the optical coupler.

3. The direct-adjustment integrated light source according to claim 2, characterized in that, The angle between the direction of the modulated optical signal and the normal direction of the first surface of the substrate is less than 20°.

4. The direct-adjustment integrated light source according to claim 1, characterized in that, The welded component is configured as a welding ball, the height of which ranges from 60μm to 100μm; the length of the first and second welding ball areas in the first direction and the width in the second direction are both smaller than the diameter of the welding ball.

5. A method for fabricating a direct-tuning integrated light source, used to fabricate the direct-tuning integrated light source according to any one of claims 1-4, characterized in that, include: A substrate is provided, the substrate including a first surface on which an optical coupler is formed; An electrode structure is formed on a first surface of the substrate. The electrode structure is spaced apart from the optocoupler in a first direction. The electrode structure includes a first electrode and a second electrode spaced apart in a second direction, the second direction forming a predetermined angle with the first direction. The first electrode and the second electrode are adapted to connect to a driver to receive different electrical signals. The spacing between the first electrode and the second electrode in the second direction ranges from 10 μm to 20 μm. The first electrode includes a first wire bonding area, a first transition area, and a first ball-planting area connected in sequence. The width of the first wire bonding area in the second direction is greater than the width of the first ball-planting area in the second direction. In the first direction, the width of the first transition area gradually decreases from one end of the first wire bonding area to one end of the first ball-planting area. The second electrode includes a second wire bonding area, a second transition area, and a second ball-planting area connected in sequence. The width of the second wire bonding area in the second direction is greater than the width of the second ball-planting area in the second direction. In the first direction, the width of the second transition area gradually decreases from one end of the second wire bonding area to one end of the second ball-planting area. The first wire bonding area and the second wire bonding area are adapted to be electrically connected to the driver. A solder resist layer is formed on the first transition region and the second transition region of the electrode structure; A weldment is formed on the first and second ball-planting areas of the electrode structure; A light-emitting structure is placed on the first surface of the substrate. One end of the light-emitting structure is connected to the electrode structure through the welding member, and the other end abuts against the first surface of the substrate. The light-emitting surface of the light-emitting structure faces the first surface and is adapted to receive different electrical signals transmitted by the electrode structure and convert them into modulated optical signals for emission to the optical coupler.

6. A heterogeneous integrated optical module, characterized in that, include: The direct-adjustment integrated light source according to any one of claims 1-4; A driver is provided at a distance from the substrate and is wire-connected to the electrode structure of the direct-modulation integrated light source to output different electrical signals to the electrode structure. An optical coupler is formed on a first surface of the substrate and located on the side of the electrode structure relatively away from the driver, the optical coupler being adapted to receive a modulated light signal emitted by the direct-modulation integrated light source; An optical waveguide structure is disposed on the side of the optical coupler that is relatively far from the electrode structure and is connected to the optical coupler to receive and transmit the modulated optical signal coupled into the optical coupler; An optical output component is disposed on the side of the optical waveguide structure that is relatively far from the optical coupler, so as to receive the modulated optical signal transmitted by the optical waveguide structure and output it to an external structure.

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