Direct adjustment type integrated light source, preparation method thereof and heterogeneous integrated light module

Abstract

The invention relates to the technical field of optical communication, and discloses a direct adjustment type integrated light source, a preparation method thereof and a heterogeneous integrated optical module. The direct adjustment type integrated light source comprises a substrate, an electrode structure and a light emitting structure, wherein a first surface of the substrate is suitable for forming an optical coupler; the electrode structure is arranged on the substrate, is spaced from the optical coupler in the first direction, and is suitable for being connected with a driver to receive different electric signals; one end of the light-emitting structure is electrically connected with the electrode structure, the other end of the light-emitting structure abuts against the substrate, and the light-emitting surface faces the first surface and is suitable for receiving different electric signals transmitted by the electrode structure, converting the electric signals into modulated light signals and emitting the modulated light signals to the optical coupler. The variable electric signal provided by the driver can be directly transmitted to the light emitting structure only through the electrode structure to be converted into the modulated light signal, the structure is simple, the integration degree is high, the loss on a transmission line is low, and the integrity and the rate of signal transmission are effectively ensured.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technologies, and particularly to a directly modulated integrated light source, a preparation method thereof, and a heterogeneous integrated optical module. Background Art

[0002] With the rapid development of high-speed communication and data centers, the bandwidth requirements of optical communication systems for radio frequency devices are continuously increasing in order to pursue signal integrity in high-speed signal transmission. Optical modules play a key role in optical communication systems. By realizing the conversion between optical signals and electrical signals, they meet the growing data transmission rate and bandwidth requirements. Among them, optical modules use heterogeneous integration technology to integrate optoelectronic devices with different functions or different processes together, thereby improving the integration and performance of optical modules, reducing size and power consumption, and supporting higher signal bandwidths.

[0003] An optical module obtained by heterogeneous integration technology generally includes various optoelectronic devices such as a light source, a modulator, an optical amplifier, an optical waveguide, and a detector. Its basic working principle is that the light source is stimulated to continuously emit light. The emitted light forms a modulated optical signal carrying communication information after passing through the modulator and then emits. After that, the modulated optical signal is processed and transmitted through, such as an optical amplifier, an optical waveguide, etc., and finally outputs from the optical port or finally outputs from the electrical port through the detector, realizing the high-speed and stable transmission of optical signals. Refer to Figure 13 as shown. However, such an optical module has many optoelectronic devices, a complex structure, and a complex energy transmission link. It not only has poor integration but also large energy loss, ultimately resulting in difficulty in ensuring the integrity and transmission efficiency of signal transmission. Summary of the Invention

[0004] In view of this, the present invention provides a directly modulated integrated light source, a preparation method thereof, and a heterogeneous integrated optical module to solve the problems of the existing optical module having a complex structure, large energy transmission loss, and difficulty in ensuring the integrity and transmission efficiency of signal transmission.

[0005] In a first aspect, the present invention provides a directly modulated integrated light source, including: a substrate, an electrode structure, and a light output structure. The 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 is spaced 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 output 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 output surface of the light output structure faces the first surface; the light output structure is adapted to receive different electrical signals transmitted by the electrode structure and convert them into modulated optical signals for emitting to the optical coupler.

[0006] Beneficial effects: In the present invention, the driver is used to provide a varying electrical signal, such as a varying voltage, to the directly modulated integrated light source. It can be directly transmitted to the light output structure through the electrode structure, converting the varying electrical signal into a corresponding modulated optical signal. There are few optoelectronic devices, and the simple structure helps to improve the integration degree. At the same time, the energy transmission link is simple, and the configured electrode structure has good impedance matching characteristics on this transmission line, resulting in extremely low losses on this transmission line. A modulated optical signal can be formed without further processing by an external modulator, effectively ensuring the integrity and rate of signal transmission.

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

[0008] Beneficial effects: The electrode structure includes a first electrode and a second electrode spaced apart in a second direction. The first electrode and the second electrode are respectively connected to the 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, thereby forming a complete drive circuit between the electrode structure and the light output structure. The electrode structure forms the impedance matching of the input end and the output end.

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

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

[0011] The first wire bonding region and the second wire bonding region are adapted to be electrically connected to the driver, and the first ball bonding region and the second ball bonding region are adapted to be connected to the light output structure.

[0012] Beneficial effects: The overall first electrode and second electrode both present a structure with a decreasing width from the input end to the output end. The wire bonding region has the largest width, which is convenient for connecting to the driver to receive electrical signals to the greatest extent. The ball bonding region has the smallest width, which is convenient for receiving and matching the welded parts to achieve good and stable connection performance. The transition region realizes the performance transition from the wire bonding region to the ball bonding region, facilitating the formation of good impedance matching characteristics of the electrode structure.

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

[0014] Advantageous effects: By setting the spacing distance between the first electrode and the second electrode in the second direction to be 10 μm to 20 μm, and combining with the width dimensions of the first wire bonding area and the second wire bonding area in the second direction, it jointly ensures that the two electrodes connecting the driver form an accurate impedance match. Exceeding this limit range will cause the impedance value to deviate, thereby affecting the radio frequency performance of the light-emitting structure.

[0015] In an alternative embodiment, the light-emitting structure is a surface-emitting laser, and a welding part and a light-emitting part are arranged on the light-emitting surface. The welding part is connected to the electrode structure, and the light-emitting part outputs a modulated optical signal towards the optical coupler.

[0016] Advantageous effects: The surface-emitting laser has a higher integration level. An optical emission space is formed between the light-emitting surface and the substrate, eliminating the need for complex encapsulation and filling of the optical emission space, resulting in higher optical emission stability. Moreover, the angle between the modulated optical signal emitted by the surface-emitting laser and the normal direction of the substrate is smaller, that is, the angle between the modulated optical signal emitted by the surface-emitting laser and the surface normal of the optical coupler is smaller, and the optical coupling efficiency is higher.

[0017] In an 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] Advantageous effects: Within this range, the emitted modulated optical signal can form an efficient coupling with the optical coupler. After the modulated optical signal is maximally coupled, it is transmitted to subsequent devices such as optical waveguide structures, realizing the efficient and complete transmission of the modulated optical signal.

[0019] In an alternative embodiment, it further includes: a welding piece, arranged between one end of the electrode structure and the welding part of the light-emitting structure, so that the light-emitting structure is inclined and arranged between the substrate and the electrode structure.

[0020] Advantageous effects: In the present invention, by arranging a welding piece with a certain height at one end of the electrode structure close to the light-emitting structure, on the one hand, the electrical signal in the electrode structure is smoothly transmitted to the light-emitting structure, and on the other hand, one side of the light-emitting structure is raised, forming an angle between the light-emitting surface and the first surface of the substrate. The modulated optical signal is obliquely emitted to the optical coupler. In this way, the modulated optical signal obliquely emitted to the surface of the optical coupler will not be reflected back to the light-emitting structure, avoiding the influence of optical feedback on the stability of the light-emitting structure, such as increased temperature, damage to the light emission of the light-emitting part, etc., and also avoiding the problem of reduced integration caused by using an optical isolator to solve optical feedback.

[0021] In an alternative embodiment, the welded part is set as a solder ball, and the height range of the solder ball is 60μm to 100μm; the lengths of the first solder ball area and the second solder ball area in the first direction and the widths in the second direction are both smaller than the diameter of the solder ball.

[0022] Advantageous effects: The solder ball realizes the welded connection. Based on different radio frequency bandwidth requirements, the solder ball can be a tin ball coated with different materials, and the welding stability is higher. The sizes of the first solder ball area and the second solder ball area are determined according to the size of the solder ball, slightly smaller than the diameter of the solder ball, so as to avoid excessive melting of the solder ball and affecting the light output coupling angle, and to avoid solder overflow and affecting the welding connection performance and the performance of other structures.

[0023] In an alternative embodiment, it further includes: a solder mask layer, which is arranged on the electrode structure and located outside the welded part to limit the outflow of the welded part in the molten state.

[0024] Advantageous effects: The solder mask layer is arranged in the first transition area of the first electrode and the second transition area of the second electrode to prevent the welded parts located in the first solder ball area and the second solder ball area from melting and flowing to the first wire bonding area and the second wire bonding area. This is because the first wire bonding area and the second wire bonding area are directly connected to the external driving structure and receive the changing electrical signals, and their impedance matching is more critical. The solder mask layer effectively protects the performance of the electrode structure, especially the first wire bonding area and the second wire bonding area, so as to ensure good impedance matching.

[0025] In a second aspect, the present invention also provides a preparation method for a directly modulated integrated light source for preparing the directly modulated integrated light source as described above, including:

[0026] Providing a substrate, the substrate includes a first surface formed with an optical coupler;

[0027] Forming an electrode structure on the first surface of the substrate, the electrode structure is spaced from the optical coupler in the first direction, and the electrode structure is adapted to connect to a driving device to receive different electrical signals;

[0028] Placing a light output structure on the first surface of the substrate, one end of the light output structure is connected to the electrode structure, and the other end abuts against the first surface of the substrate; the light output surface of the light output 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 and emit them to the optical coupler.

[0029] Advantageous effects: In the preparation method of the directly modulated integrated light source of the present invention, the impedance conditions of each part on the transmission line are strictly set, including setting the electrode structure with a gradient design, the light output structure for determining the light output coupling angle, and the welded part with a suitable size and material. At the same time, a solder mask layer is set to ensure the performance of the welding path, and finally a directly modulated integrated light source with a simple structure, high integration, smooth energy transmission link, small signal transmission loss, and high integrity is formed.

[0030] In a third aspect, the present invention further provides a heterogeneous integrated optical module, comprising: the above-mentioned directly modulated integrated light source, driver, optical coupler, optical waveguide structure, and optical output component, wherein the driver is disposed at an interval from the substrate and is wire-connected to the electrode structure of the directly modulated 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 is located on a 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 directly modulated integrated light source; the optical waveguide structure is disposed on a side of the optical coupler relatively far from the electrode structure and is 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 a 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: In the heterogeneous integrated optical module of the present invention, first, the driver uses a driving chip to output high and low voltages of different magnitudes to the electrode structure of the directly modulated integrated light source; then, the voltage output situation is efficiently transmitted to the light-emitting structure through the impedance-matched electrode structure, and the light-emitting structure then outputs a modulated optical signal with certain variations to the optical coupler; then, the optical coupler couples and transmits the received modulated optical signal to the optical waveguide structure; then, the optical waveguide structure conveys it to the optical output component; the optical output component in this embodiment can have two paths. One is to first transmit to a detector and finally output to an external structure in the form of an electrical signal; the other is to first transmit to an optical port, and then transmit to an optical fiber in the form of an optical signal and then output to an external structure. That is, different optoelectronic devices, including a directly modulated integrated light source, an optical waveguide structure, and an optical output component, etc., are integrated on a two-dimensional planar substrate or an optical chip having an optical coupler and an optical waveguide structure. The structure is simple and has a high integration degree, which is conducive to mass production, and the energy transmission link is short, the radio frequency bandwidth loss is low, and the signal transmission integrity of the optical module is high and the speed is fast. Description of the Drawings

[0032] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 is a front view schematic diagram of the directly modulated integrated light source according to an embodiment of the present invention;

[0034] Figure 2 is a top view schematic diagram of the directly modulated integrated light source according to an embodiment of the present invention;

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

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

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

[0038] Figure 6 is a schematic flow chart of the manufacturing method of the directly modulated integrated light source according to an embodiment of the present invention;

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

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

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

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

[0043] Figure 11 is a schematic diagram of the structure after forming a welding part on the electrode structure according to an embodiment of the present invention;

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

[0045] Figure 13 is a structural block diagram of an optical module in the related art;

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

[0047] Description of the reference numerals:

[0048] 100, directly modulated 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 wire bonding area; 212. First transition area; 213. First ball mounting area; 22. Second electrode; 221. Second wire bonding area; 222. Second transition area; 223. Second ball mounting area;

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

[0052] 4. Welding piece;

[0053] 5. Solder mask layer. Detailed implementation manners

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention rather than all the structures are shown in the accompanying drawings. In the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concept of the present invention. Various structural schematic diagrams according to the embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, in which for the purpose of clear expression, some details are enlarged, and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are only exemplary, and may actually deviate due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs. In the context of the present invention, when a layer / component is referred to as being "on" another layer / component, the layer / component can be directly on the other layer / component, or there can be an intermediate layer / component between them. In addition, if a layer / component is "on" another layer / component in one orientation, then when the orientation is reversed, the layer / component can be "under" the other layer / component.

[0055] Refer to Figures 1 to 5 , this embodiment provides a directly modulated integrated light source, including: a substrate 1, an electrode structure 2, and a light output 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 is spaced from the optical coupler 300 in the first direction. The electrode structure 2 is adapted to connect to a driver 200 to receive different electrical signals; one end of the light output 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 output surface 31 of the light output structure 3 faces the first surface 11; the light output structure 3 is adapted to receive different electrical signals transmitted by the electrode structure 2 and convert them into modulated optical signals and emit them to the optical coupler 300.

[0056] Specifically, the substrate 1 of this embodiment is a passive substrate 1. The material of the substrate 1 is determined according to the different wavelength bands 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 the optical coupler 300 for the specific light-emitting structure 3. Exemplarily, in this embodiment, a grating coupler is formed to receive the light beam from the light-emitting structure 3. An electrode structure 2 is further provided on the first surface 11 of the substrate 1, which can specifically be a metal electrode. One end of the metal electrode is connected to the driver 200 through a lead, and the other end is electrically connected to the light-emitting structure 3. The driver 200 of this embodiment can be a driving chip. Compared with the existing solution where the light-emitting structure 3 is directly connected to a power supply to continuously emit light, and the output light then passes through a modulator controlled by the driver 200 to form a modulated optical signal, in this embodiment, the driver 200 provides a varying electrical signal, such as voltages of different magnitudes. This electrical signal only needs to pass through the electrode structure 2 and can be directly transmitted to the light-emitting structure 3, converting the varying electrical signal into a corresponding modulated optical signal. There are fewer optoelectronic devices, and the simple structure helps to improve the integration degree. At the same time, the energy transmission link is simple, and the configured electrode structure 2 has good impedance matching characteristics on this transmission line, resulting in extremely low losses on this transmission line. A modulated optical signal can be formed without the need for further processing by an external modulator, effectively ensuring the integrity and rate of signal transmission.

[0057] Here, the modulated optical signal means that the light is not continuously emitted, but rather shows different light-emitting situations according to different electrical signals. The light-emitting structure 3 directly outputs a modulated optical signal, presenting flexible light-emitting characteristics, that is, having good radio frequency performance. For example, when the driver 200 applies a relatively large non-zero lasing voltage to the electrode structure 2, after this voltage situation is transmitted to the light-emitting structure 3 through the electrode structure 2, the light-emitting structure 3 emits light, which can be understood as outputting a signal "1"; when the driver 200 applies a relatively weak lasing voltage to the electrode structure 2, the light-emitting structure 3 emits very weak light, which can be understood as outputting a signal "0". The optical power corresponding to the signal "0" is weaker than the optical power corresponding to the signal "1". That is, the light-emitting power of the light-emitting structure 3 is directly controlled according to the voltage applied by the driver 200 to the electrode structure 2.

[0058] As Figure 2 and Figure 3 shown, the electrode structure 2 of this embodiment includes a first electrode 21 and a second electrode 22 that are spaced apart in the second direction. The second direction forms a preset angle with the first direction (the same as above here); 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 is grounded through the driver 200 and does not generate a voltage.

[0059] Specifically, in this embodiment, the second direction is perpendicular to the first direction. The electrode structure 2 includes a first electrode 21 and a second electrode 22 that are spaced apart in the second direction. The first electrode 21 is connected to the driver 200 through a lead to apply different non-zero lasing voltages, and the second electrode 22 is connected to the driver 200 through a lead to be grounded. As a result, a complete drive circuit is formed 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 exactly the same structure, which facilitates the electrode structure 2 to form an impedance matching for the input end and the output end. Exemplarily, the input end usually has an impedance of 50Ω when the driver 200 outputs. To ensure the radio frequency performance of the output end, that is, the light-emitting structure 3, the electrode structure 2 should correspondingly meet the impedance matching of 50Ω.

[0060] Specifically, as Figure 3 shown, the first electrode 21 includes a first wire bonding area 211, a first transition area 212, and a first ball mounting area 213 that are connected in sequence. The width H1 of the first wire bonding area 211 in the second direction is greater than the width H2 of the first ball mounting area 213 in the second direction. In the first direction, the width of the first transition area 212 gradually decreases from one end of the first wire bonding area 211 to one end of the first ball mounting area 213. That is, the first electrode 21 as a whole presents a structure with a decreasing width from the input end to the output end. In addition, in this embodiment, it is also set that in the first direction, the relationship between the length L1 of the first wire bonding area 211, the length L2 of the first transition area 212, and the length L3 of the first ball mounting area 213 is: L1 > L2 > L3 (the size relationship is not necessarily like this, and the length of the transition area can also become very long, that is, L2 > L1 is also okay). That is, the first wire bonding area 211 has the largest area, which is convenient for connecting to the driver 200 to receive electrical signals to the greatest extent. The first ball mounting area 213 has the smallest area, which is convenient for receiving and matching the welded part 4 to achieve 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 mounting area 213, which is convenient for forming good impedance matching characteristics of the electrode structure 2.

[0061] Of course, the length L2 of the first transition area 212 can also be greater than the length L1 of the first wire bonding area 211, that is, L2 > L1 is not excluded, so as to adjust the widths of the first wire bonding area 211 and the first ball mounting area 213 according to requirements.

[0062] Correspondingly, the second electrode 22 and the first electrode 21 are exactly equal. The second electrode 22 includes a second wire bonding area 221, a second transition area 222, and a second ball mounting area 223 that are connected in sequence. The width of the second wire bonding area 221 in the second direction is greater than the width of the second ball mounting 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 wire bonding area 221 to one end of the second ball mounting area 223. That is, the sizes of the second wire bonding area 221 and the first wire bonding area 211 are exactly the same, the sizes of the second transition area 222 and the first transition area 212 are exactly the same, and the sizes of the second ball mounting area 223 and the first ball mounting area 213 are exactly the same. 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 lengths L1 of the first wire bonding area 211 and the second wire bonding area 221 in the first direction are ≥ 130 μm, the lengths L2 of the first transition area 212 and the second transition area 222 in the first direction are ≥ 80 μm, and the lengths L3 of the first ball mounting area 213 and the second ball mounting area 223 in the first direction are ≤ 50 μm. The range of the width H1 of the first wire bonding area 211 and the second wire bonding area 221 in the second direction is 80 μm to 120 μm, and the width H2 of the first ball mounting area 213 and the second ball mounting area 223 in the second direction is ≤ 50 μm.

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

[0065] As Figure 3 shown, the range of the interval distance D between the above-mentioned first electrode 21 and second electrode 22 in the second direction is 10 μm to 20 μm.

[0066] Setting the interval distance between the first electrode 21 and the second electrode 22 in the second direction to be 10 μm to 20 μm, and at the same time combining the width dimensions of the first wire bonding area 211 and the second wire bonding area 221 in the second direction, together ensure that the two electrodes connecting the driver 200 form precise impedance matching. Exceeding this limit range will cause the impedance value to deviate, thus affecting the radio frequency performance of the light emitting structure 3.

[0067] See Figure 1 , the light emitting structure 3 in this embodiment is a surface emitting laser. A welding part 32 and a light emitting part 33 are provided on the light emitting surface 31. The solder pad is connected to the electrode structure 2, and the light emitting part 33 outputs a modulated optical signal towards the optical coupler 300.

[0068] Compared with edge-emitting lasers, the surface-emitting laser in this embodiment has a higher integration level. An optical output space is formed between the optical output surface 31 and the substrate 1, eliminating the need for complex encapsulation and filling of the optical output space, resulting in higher optical output stability. Moreover, the angle between the modulated optical signal emitted by the surface-emitting laser and the normal direction of the substrate 1, i.e., the surface normal of the optical coupler 300, is smaller, leading to higher optical coupling efficiency. In this embodiment, an existing surface-emitting laser can be selected, and the related structure will not be elaborated here. The material of the substrate 1 is determined according to the different wavelength bands of the surface-emitting laser, and its optical output part 33 is usually formed as an optical output hole.

[0069] In one embodiment, the angle between the direction of the above-mentioned 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 an efficient coupling with the optical coupler 300. After the modulated optical signal is coupled to the maximum extent, it is transmitted to subsequent devices such as the optical waveguide structure 400, etc., realizing the efficient and complete transmission of the modulated optical signal.

[0070] In one embodiment, as Figure 1 and Figure 2 shown, the above-mentioned directly modulated integrated light source further includes: a welding member 4, arranged between one end of the electrode structure 2 and the welding portion 32 of the optical output structure 3, so that the optical output structure 3 is inclined and arranged between the substrate 1 and the electrode structure 2.

[0071] In this embodiment, by arranging a welding member 4 with a certain height at one end of the electrode structure 2 close to the optical output structure 3, on the one hand, the electrical signal in the electrode structure 2 is smoothly transmitted to the optical output structure 3, and on the other hand, one side of the optical output structure 3 is raised, forming an angle between the optical output surface 31 and the first surface 11 of the substrate 1. The modulated optical signal is obliquely emitted to the optical coupler 300. In this way, the modulated optical signal obliquely emitted to the surface of the optical coupler 300 will not be reflected back to the optical output structure 3, avoiding the influence of optical feedback on the stability of the optical output structure 3, such as increased temperature, damage to the optical output of the optical output part 33, etc., and also avoiding the problem of reduced integration level caused by using an optical isolator to solve optical feedback.

[0072] Specifically, the above-mentioned welding member 4 is set as a solder ball, and the height range of the solder ball is 60μm - 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 solder ball.

[0073] In this embodiment, solder balls are provided to achieve welding connection. Based on different radio frequency bandwidth requirements, the solder balls can be gold-tin balls, copper-tin balls or silver-tin balls, with higher welding stability. The sizes of the first solder ball area 213 and the second solder ball area 223 are determined according to the size of the solder balls, slightly smaller than the diameter of the solder balls. The diameter of the solder balls in this embodiment is between 60μm and 100μm, and is determined according to the light output coupling angle of the light output structure 3. For example, if the diameter is 60μm, the first solder ball area 213 and the second solder ball area 223 are set as square structures with side lengths slightly smaller than 50μm, so as to prevent the solder balls from excessive melting and affecting the light output coupling angle, and to prevent solder overflow from affecting the welding connection performance and the performance of other structures.

[0074] Based on the above solution, as Figure 1 and Figure 2 shown, the directly modulated integrated light source of this embodiment further includes a solder mask layer 5, which is arranged on the electrode structure 2 and outside the welded part 4 to limit the outflow of the welded part 4 in the molten state.

[0075] Specifically, it is preferably set that the solder mask layer 5 is in the first transition area 212 of the first electrode 21 and the second transition area 222 of the second electrode 22, so as to prevent the welded part 4 located in the first solder ball area 213 and the second solder ball area 223 from melting and flowing to the first wire bonding area 211 and the second wire bonding area 221. This is because the first wire bonding area 211 and the second wire bonding area 221 are directly connected to the external drive structure and receive changing electrical signals, and their impedance matching is more critical. Setting the solder mask layer 5 effectively protects the performance of the electrode structure 2, especially the first wire bonding area 211 and the second wire bonding area 221, thus ensuring good impedance matching.

[0076] The directly modulated integrated light source in this embodiment has good radio frequency performance, Figure 4 and Figure 5 show the schematic diagram of the radio frequency electromagnetic simulation results. Figure 4 is the schematic diagram of the transmission loss, Figure 5 is the schematic diagram of the return loss. From Figure 4 and Figure 5 it can be obtained that for the radio frequency bandwidth region less than or equal to 30GHz, the transmission loss of the directly modulated integrated light source of this embodiment is within -0.3dB, and the return loss is less than -30dB. This means that for the directly modulated integrated light source with a simple link like this embodiment, the loss of the incident energy is extremely small, basically about one-thousandth, and the integrity and efficiency of the signal transmission are extremely high.

[0077] Referring to Figures 1 to 12 , this embodiment also provides a preparation method for a directly modulated integrated light source, which is used for the directly modulated integrated light source described above. Figure 6 Fig. is the process schematic diagram of this preparation method. This preparation method includes the following steps:

[0078] Step S601 , providing a substrate 1 , wherein the substrate 1 comprises a first surface 11 on which an optical coupler 300 is formed.

[0079] refer to Figure 7 and Figure 8 , exemplarily, first, by spin coating photoresist on substrate 1, then using photolithography technology to expose on the photoresist and developing to obtain the marking pattern of optical coupler 300, at the same time, the optical waveguide structure 400 and the position marking pattern are also obtained, where the position mark is the first positioning mark of the photolithography process, and the reference point or reference area is determined to facilitate the determination of the molding area of ​​each structure on the first surface 11 of the substrate 1. Then, dry etching is performed using an inductively coupled plasma etcher to obtain the optical coupler 300, the optical waveguide structure 400 and the position marking structure. Finally, the photoresist is washed away using a degumming solution, and the final optical coupler 300, the optical waveguide structure 400 and the position marking structure are formed at this time.

[0080] Step S602 , forming an electrode structure 2 on the first surface 11 of the substrate 1 , wherein the electrode structure 2 is spaced apart from the optical coupler 300 in a first direction, and the electrode structure 2 is suitable for connecting to the driver 200 to receive different electrical signals.

[0081] refer to Figure 9 After the etching of the optical coupler 300, the optical waveguide structure 400 and the position mark structure is completed, the electrode structure 2 is formed and prepared. Specifically, it includes: first, spin-coating photoresist on the substrate 1, using photolithography technology to develop and remove the photoresist in the area where the electrode structure 2 is located, and using a metal deposition process to deposit multiple layers of metal films, such as titanium / platinum / gold, respectively, with the gold layer located on the top layer to achieve wire bonding. Afterwards, a stripping process is used to remove the photoresist and the metal film attached to the photoresist, leaving only the metal film in the area where the target electrode structure is located. The metal film is formed into a plurality of metal pads of appropriate sizes, that is, the electrode structure 2 is formed. The geometric size of the metal pad will affect the height of the implanted ball, and then affect the incident tilt angle of the light output structure 3. In this embodiment, the electrode structure 2 is preferably gradually transitioned to the transmission line through a suitable gradient design to meet the impedance matching 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 arranged on the other side of the first waveguide region 401 . The first waveguide region 401 is arranged as a tapered structure, and the smaller end is connected to the second waveguide region 402 .

[0083] Step S603, place the light-emitting structure 3 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 adapted to receive different electrical signals transmitted by the electrode structure 2 and convert them into modulated optical signals for emission to the optical coupler 300.

[0084] Exemplarily, align the light-emitting part 33 of the light-emitting structure 3 with the target position of the optical coupler 300 through a high-precision placement machine. At the same time, use a nozzle structure to suck the back surface of the light-emitting structure 3. During the placement, the nozzle structure performs appropriate temperature curve control on the light-emitting structure 3, such as Figure 12 as shown, so that the welding part 32 on the light-emitting structure 3 and the welding piece 4 on the electrode structure 2 are firmly combined.

[0085] In one embodiment, between the above step S602 and step S603, it further includes:

[0086] Refer to Figure 10 , form a solder mask layer 5 on the electrode structure 2. Specifically, after forming the electrode structure 2, continue to spin-coat a photoresist on the substrate 1, and use photolithography technology to develop and remove the photoresist in the area where the solder mask layer 5 is located; then use a coating process to prepare silicon oxide in the area where the solder mask layer 5 is located to form the solder mask layer 5. The solder mask layer 5 is specifically provided on the transition area of the electrode structure 2 to block the flow of high-temperature solder balls during laser ball implantation.

[0087] Refer to Figure 11 , perform laser ball implantation on the electrode structure 2. Exemplarily, use laser ball implantation technology to implant balls in the ball-implantation area of the electrode structure 2. Specifically, the diameter of the required solder balls can be calculated using the working angle of the above optical coupler 300 and the size of the light-emitting structure 3; the solder balls heated by the laser of the laser ball implantation machine can be ejected one by one and then adhered to the ball-implantation area of the electrode structure 2. The solder mask layer 5 is provided around the ball-implantation area to prevent the solder balls from flowing around the ball-implantation area.

[0088] In the preparation method of the directly modulated integrated light source in this embodiment, the impedance conditions of each part on the transmission line are strictly set, including setting the electrode structure 2 with a gradient design, the light-emitting structure 3 for determining the light-coupling angle, and the welding piece 4 with appropriate size and material. At the same time, the solder mask layer 5 is set to ensure the performance of the welding path, and finally a directly modulated integrated light source with a simple structure, high integration, smooth energy transmission link, small signal transmission loss, and high integrity is formed.

[0089] Refer to Figure 14, this embodiment also provides a heterogeneous integrated optical module, including: the above directly modulated 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 is connected to the electrode structure 2 of the directly modulated 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 is located on the side of the electrode structure 2 relatively far from the driver 200. The optical coupler 300 is adapted to receive the modulated optical signal emitted by the directly modulated integrated light source. The optical waveguide structure 400 is disposed on the side of the optical coupler 300 relatively far from the electrode structure 2 and is 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 far 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 with Figure 13 In the conventional scheme shown, first, the integrated light source or the fed light source is externally powered to continuously emit light. This part of the light forms a modulated optical signal through a modulator connected to the driver 200. A large amount of optical signals are lost in this step. Therefore, it is necessary to pass through structures such as an amplifier before entering 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, and an additional optical amplifier structure needs to be provided to ensure the optical output efficiency. The loss is large and the structure is complex.

[0091] In this embodiment, first, the driver 200 uses a driving chip to output different high and low voltages of different magnitudes to the electrode structure 2 of the directly modulated integrated light source. Subsequently, the voltage output situation is efficiently transmitted to the light-emitting structure 3 through the impedance-matched electrode structure 2. The light-emitting structure 3 then outputs a modulated optical signal with certain variations to the optical coupler 300. Then, the optical coupler 300 couples and transmits the received modulated optical signal to the optical waveguide structure 400. Then, the optical waveguide structure 400 conveys it to the optical output component 500. The optical output component 500 of this embodiment can have two paths. One is to first transmit to a detector and finally output to an external structure in the form of an electrical signal. The other is to first transmit to an optical port and then transmit to an optical fiber in the form of an optical signal and then output to an external structure. Figure 14 The optical coupler 300 is not shown because optical coupling is usually required for any optoelectronic devices with different structures, so no specific illustration is made here.

[0092] In summary, the heterogeneous integrated optical module of this embodiment integrates different optoelectronic devices on the substrate 1 in the two-dimensional plane or on the optical chip having the optical coupler 300 and the optical waveguide structure 400, including directly modulated integrated light sources, optical waveguide structures 400, optical output components 500, etc. It has a simple structure and high integration degree, which is conducive to mass production. Moreover, 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] The further functional descriptions of the above structures are the same as those in the corresponding embodiments above, and will not be elaborated here.

[0094] In the above description, technical details such as the layout and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. with the required shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not exactly the same as the methods described above. Additionally, although the above embodiments are described separately, this does not mean that the measures in each embodiment cannot be used in combination advantageously.

[0095] Although the embodiments of the present invention are 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 present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A direct-adjustment integrated light source, characterized in that, Comprising: A substrate, the first surface of the substrate being adapted to form an optical coupler; An electrode structure, disposed on the first surface of the substrate and spaced from the optical coupler in a first direction, the electrode structure being adapted to connect to a driver to receive different electrical signals; A light-emitting structure, one end of the light-emitting structure being adapted to be electrically connected to the electrode structure and the other end abutting against the first surface of the substrate, the light-emitting surface of the light-emitting structure facing the first surface; the light-emitting structure being adapted to receive different electrical signals transmitted by the electrode structure and convert them into modulated optical signals for emission to the optical coupler.

2. The directly adjustable integrated light source according to claim 1, wherein The electrode structure includes a first electrode and a second electrode spaced apart in a second direction, the second direction making a preset angle with the first direction; the first electrode and the second electrode are adapted to be connected to the driver.

3. The directly tunable integrated light source according to claim 2, characterized in that The first electrode includes a first wire bonding region, a first transition region, and a first ball bonding region connected in sequence, the width of the first wire bonding region in the second direction being greater than the width of the first ball bonding region in the second direction, and in the first direction, the width of the first transition region gradually decreases from one end of the first wire bonding region to one end of the first ball bonding region; The second electrode includes a second wire bonding region, a second transition region, and a second ball bonding region connected in sequence, the width of the second wire bonding region in the second direction being greater than the width of the second ball bonding region in the second direction, and in the first direction, the width of the second transition region gradually decreases from one end of the second wire bonding region to one end of the second ball bonding region; The first wire bonding region and the second wire bonding region are adapted to be electrically connected to the driver, and the first ball bonding region and the second ball bonding region are adapted to be connected to the light-emitting structure.

4. The directly adjustable integrated light source according to claim 3, wherein The spacing distance between the first electrode and the second electrode in the second direction ranges from 10 μm to 20 μm.

5. The directly tunable integrated light source according to claim 4, characterized in that, The light-emitting structure is a surface-emitting laser, and a welding portion and a light-emitting portion are provided on the light-emitting surface, the welding portion being connected to the electrode structure, and the light-emitting portion outputting a modulated optical signal toward the optical coupler.

6. The direct modulation integrated light source according to claim 5, 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°.

7. The direct modulation integrated light source according to claim 6, characterized in that Further comprising: A welding member, disposed between one end of the electrode structure and the welding portion of the light-emitting structure, so that the light-emitting structure is inclined and disposed between the substrate and the electrode structure.

8. The direct modulation integrated light source according to claim 7, characterized in that, The welding member is provided as a solder ball, the height range of the solder ball being 60 μm to 100 μm; the lengths of the first ball bonding region and the second ball bonding region in the first direction and the widths in the second direction are both smaller than the diameter of the solder ball.

9. The directly adjustable integrated light source according to claim 7 or 8, characterized in that, Further comprising: A solder mask layer, disposed on the electrode structure and outside the welding member, to limit the outflow of the welding member in a molten state.

10. A preparation method of a directly modulated integrated light source, for preparing the directly modulated integrated light source according to any one of claims 1-9, characterized in that, Comprising: Providing a substrate, the substrate including a first surface formed with an optical coupler; Forming an electrode structure on the first surface of the substrate, the electrode structure being spaced from the optical coupler in a first direction, the electrode structure being adapted to connect to a driving device to receive different electrical signals; An optical output structure is placed on the first surface of the substrate. One end of the optical output structure is connected to the electrode structure, and the other end abuts against the first surface of the substrate. The light output surface of the optical output 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 output to the optical coupler.

11. An heterogeneous integrated optical module, characterized in that, Comprising: The directly modulated integrated light source according to any one of claims 1-9; A driver, which is spaced apart from the substrate and is wire-bonded to the electrode structure of the directly modulated integrated light source to output different electrical signals to the electrode structure; An optical coupler, which is formed on the first surface of the substrate and is located on a side of the electrode structure relatively far from the driver. The optical coupler is adapted to receive the modulated optical signal emitted by the directly modulated integrated light source; An optical waveguide structure, which is arranged on a side of the optical coupler 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, which is arranged on a 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.

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