Optical emission assembly and optical network unit

Abstract

The invention provides an optical transmitting assembly and an optical network unit, and belongs to the technical field of optical communication. The light emitting assembly comprises a laser and a photoelectric detector, the photoelectric detector is located in the opposite direction of the emitting direction of the laser, a transmission film arranged at the receiving end of the photoelectric detector corresponds to a transmission peak, the position of the transmission peak is the center wavelength of the working wavelength range, and the laser comprises a laser body and a resistor. The resistor is attached to the DBR area in the laser body. Therefore, when the wavelength of the optical signal output by the laser deviates from the central wavelength, the power of the optical signal detected by the photoelectric detector is gradually reduced, so that the resistor attached to the DBR area in the laser body can be heated based on the power, the refractive index of the DBR area is changed, and the DBR area can output the optical signal close to the central wavelength. Therefore, under the condition that TEC does not exist, optical signals with high wavelength precision can be output.

Description

Technical Field

[0001] This application relates to the field of optical communication technology, and in particular to an optical emitting component and an optical network unit. Background Technology

[0002] In a passive optical network (PON), an optical network unit (ONU) includes an optical transmitter component, which outputs an optical signal. Fluctuations in ambient temperature can cause changes in the wavelength of the optical signal output by the transmitter component, potentially exceeding the wavelength range required for communication. Therefore, currently, a thermionic cooler is incorporated into the optical transmitter component.

[0003] The thermoelectric cooler (TEC) controls the temperature of the light-emitting component to ensure that it operates at a specified temperature, thereby maintaining a constant wavelength output by the light-emitting component. Summary of the Invention

[0004] This application provides an optical emitting component and an optical network unit, which can reduce the size of the optical emitting component. The technical solution adopted is as follows:

[0005] In a first aspect, this application provides an optical emitting component, which includes a photodetector and a laser. The photodetector is located in the opposite direction to the emission direction of the laser. The receiving end of the photodetector has a transmission film with a transmission peak and the maximum transmittance at the target wavelength. The target wavelength is the center wavelength of the first operating wavelength range of the optical emitting component. The laser includes a laser body and a resistor. The distributed Bragg reflector (DBR) region of the laser body is attached to the resistor. The photodetector is used to convert the light signal transmitted through the transmission film into an electrical signal. The resistor is used to transfer heat to the DBR region when energized. The amount of heat is related to the power of the electrical signal. The laser body is used to output a light signal with a wavelength belonging to the first operating wavelength range.

[0006] In the solution presented in this application, the photodetector in the optical emitting component is located in the opposite direction to the laser's emission direction. It monitors the optical power of the optical signal at the non-emission end of the laser. Although this optical power is small, it is proportional to the optical power of the optical signal output in the laser's emission direction. Furthermore, the transmission film at the receiving end of the photodetector has a transmission peak located at the center wavelength of the operating wavelength range. Thus, when the wavelength of the laser's output optical signal deviates from this center wavelength, the optical power of the transmitted signal decreases. Therefore, the resistance can be heated based on this optical power, thereby changing the refractive index of the DBR region. This allows the DBR region to output an optical signal close to the target wavelength, enabling the output of a high-wavelength-accuracy optical signal even without a TEC (Transmission Regulator). This provides an optical emitting component that does not require a TEC, simplifying the structure of the optical emitting component, reducing device design complexity, and lowering packaging costs.

[0007] In one alternative approach, the transmission film may include multiple layers stacked together, including layers with different refractive indices and layers with the same refractive index, so that the desired optical signal forms interference, thereby maximizing the transmittance at the desired wavelength position and causing a sharp drop in transmittance when the wavelength is deviated.

[0008] In one alternative approach, multiple film layers are arranged into multiple film layer groups. Each film layer group includes a film layer with a first refractive index and a film layer with a second refractive index. In each film layer group, the film layer with the first refractive index has the same thickness and / or the film layer with the second refractive index has the same thickness. In this way, a transmission film is obtained using film layers with two refractive indices, and the coating method is simple.

[0009] In one alternative approach, multiple film layers form multiple film layer groups. Each film layer group includes a film layer with a first refractive index and a film layer with a second refractive index. At least two film layer groups exist where the thicknesses of the film layers with the first refractive index and / or the thicknesses of the film layers with the second refractive index are different. This allows for the acquisition of a transmission film using film layers with two refractive indices, simplifying the coating process.

[0010] In one alternative approach, the material of the first refractive index film is silicon, and the material of the second refractive index film is silicon dioxide.

[0011] In one alternative approach, the laser body is a DBR laser, which has a DBR region, namely the first DBR region. The light source region and phase region of the laser body are located on the reflection direction of the first DBR region, and the photodetector is located on the transmission direction of the first DBR region. The light source region is used to generate an optical signal, the phase region is used to perform phase adjustment processing on the input optical signal, and the first DBR region is used to select an optical signal with a wavelength belonging to a first operating wavelength range for the laser body. Thus, since changing the temperature of the DBR region can change its refractive index, thereby changing the wavelength selected by the DBR region, using the DBR region in conjunction with resistive heating allows the optical emitting component to output an optical signal of a specified wavelength.

[0012] In one alternative approach, if the filtering capability of the first DBR region is insufficient, a second DBR region is also present in the laser body. The light source region and phase region of the laser body are located between the first and second DBR regions, and are situated in the reflection direction of the second DBR region. The second DBR region is used to select optical signals whose wavelengths belong to the first operating wavelength range for the laser body. In this way, by accumulating two DBR regions, the selected optical signal is made to be the single-mode light used by the optical emission component.

[0013] In one alternative approach, when the light signal generated in the light source area is a modulated light signal, the light source area integrates the signal modulation function, eliminating the need for a separate modulation area and reducing the size of the light emitting component.

[0014] In one alternative approach, when the optical signal generated in the light source region is an unmodulated optical signal, the modulation region of the laser body is located in the transmission direction of the second DBR region, and the modulation region modulates the input optical signal. In this way, since the modulation region is located outside the laser body, the laser body is not affected by the insertion loss of the modulation region.

[0015] In one alternative approach, the optical amplification region of the laser body is located in the emission direction of the modulation region. This amplification region amplifies the input optical signal. Thus, after the modulation region outputs a modulated optical signal, the optical amplification region amplifies this signal, resulting in a stronger output optical signal. Furthermore, since the end of the optical emitting component is typically a curved waveguide, the placement of the optical amplification region at the end is unaffected by the curved waveguide.

[0016] Secondly, this application provides an optical network unit, which includes a driving module and an optical emitting component as described in the first aspect or any optional method of the first aspect. The driving module is used to drive a laser body and a resistor to control the laser body to output an optical signal with a wavelength belonging to a first operating wavelength range, wherein the signal driving the laser body and the resistor is related to the power of the electrical signal.

[0017] In the solution shown in this application, integrating a TEC in the optical emitting component is difficult to package, which makes the device design more challenging. However, in this application, the optical emitting component does not need to have a TEC, so the packaging structure can be simplified, the device design difficulty can be reduced, and the packaging difficulty of the optical network unit can be reduced, thereby reducing the cost of the optical network unit.

[0018] In one alternative embodiment, the optical network unit has a first operating mode and a second operating mode, the first operating wavelength range being the wavelength range used by the optical network unit when it is in the first operating mode, and the driving module is further configured to drive the laser body so that the laser body outputs an optical signal with a wavelength belonging to the second operating wavelength range, the second operating wavelength range being the wavelength range used by the optical network unit when it is in the second operating mode.

[0019] In the solution presented in this application, the optical network unit has multiple operating modes. The optical emitting components for these multiple operating modes are combined into a single optical emitting component, reducing the number of optical emitting components and thus reducing the size of the optical network unit. Furthermore, since there is only one optical emitting component, only one driver module needs to be designed in the optical network unit to support multiple operating modes, thereby reducing the number of driver modules and further reducing the size of the optical network unit.

[0020] In one alternative approach, the endpoint difference of the first operating wavelength range is smaller than the endpoint difference of the second operating wavelength range. The driving module is also configured to stop driving the resistor when the optical network unit is in the second operating mode. This reduces the power consumption of the optical network unit by using resistor heating only in operating modes where high wavelength accuracy is required, and not using it in operating modes where low wavelength accuracy is required.

[0021] In one alternative embodiment, the driving module includes a first pin and a driving circuit. The first pin is electrically connected to a photodetector, and the driving circuit is used to acquire an electrical signal through the first pin and drive the laser body and resistor based on the electrical signal. In this way, the driving module can acquire an electrical signal from the photodetector and drive the laser body and resistor based on that signal, causing the laser body to output a light signal of a specified wavelength.

[0022] Optionally, the first working mode corresponds to 50G PON, and the second working mode corresponds to 10G PON. The driving module is the driving module in the first working mode. The driving module is a physical layer (PHY) chip. In the first working mode, the current driving the first DBR area is 0, which can reduce the power consumption in the first working mode.

[0023] In one alternative approach, when the optical network unit (ONU) switches operating modes, the optical line terminal (OLT) notifies the ONU. Within the ONU, the media access control (MAC) chip receives the operating mode switching message from the OLT and controls the drive module to drive the laser body to output an optical signal with a wavelength within the first operating wavelength range. This allows for remote control of the operating mode switching by the OLT, eliminating the need for on-site service and thus improving switching efficiency. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the system architecture of an optical communication system provided in an exemplary embodiment of this application;

[0025] Figure 2 This is a schematic diagram of a structure of a light emitting component provided in an exemplary embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the structure of a transmission film provided in an exemplary embodiment of this application;

[0027] Figure 4 This is a schematic diagram of the transmittance of the transmission film and the optical power detected by the photodetector provided in an exemplary embodiment of this application;

[0028] Figure 5 This is a schematic diagram of a temperature feedback mechanism provided in an exemplary embodiment of this application;

[0029] Figure 6 This is a schematic diagram of a direct-modulation optical network unit provided in an exemplary embodiment of this application;

[0030] Figure 7 This is a schematic diagram of another structure of a directly modulated optical network unit provided in an exemplary embodiment of this application;

[0031] Figure 8 This is another schematic diagram of a directly modulated optical network unit provided in an exemplary embodiment of this application;

[0032] Figure 9 This is a schematic diagram of a structure of an electroabsorption modulated optical network unit provided in an exemplary embodiment of this application;

[0033] Figure 10 This is a schematic diagram of another structure of an electroabsorption modulated optical network unit provided in an exemplary embodiment of this application;

[0034] Figure 11This is a schematic diagram illustrating the sending of a working mode switching message according to an exemplary embodiment of this application;

[0035] Figure 12 This is a schematic diagram illustrating the switching of working modes provided in an exemplary embodiment of this application;

[0036] Figure 13 This is a schematic diagram of a transceiver integrated optical network unit provided in an exemplary embodiment of this application.

[0037] Illustration

[0038] 1. Photodetector; 2. Laser; 3. Driver module; 4. Optical emission assembly; 5. MAC chip; 6. Optical receiving assembly; 7. Beam combiner; 8. Filter;

[0039] 11. Transmission film; 21. Laser body; 211. DBR region; 212. Light source region; 213. Phase region; 214. Modulation region; 215. Optical amplification region; 216. First film layer; 217. Second film layer; 22. Resistor; 221. First sub-resistor; 222. Second sub-resistor;

[0040] 31. Pin 1; 32. Driver circuit; 33. Pin 2; 34. Pin 3; 35. Pin 4; 36. Pin 5; 37. Pin 6; 38. Pin 7; 39. Pin 8; 310. Pin 9; 311. Pin 10. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0042] The following explains some terms and concepts involved in the embodiments of this application.

[0043] 1. Fiber to the Home (FTTH) is a fiber optic communication transmission method. Specifically, it refers to installing optical network units in a user's home or office. The significant technical features of FTTH are that it not only provides greater bandwidth but also enhances network transparency regarding data formats, rates, wavelengths, and protocols, relaxes requirements for environmental conditions and power supply, and simplifies maintenance and installation.

[0044] 2. Optical Network Unit (ONT): In FTTH, the optical modem installed in a user's home or office can also be understood as a gateway, used to connect to outdoor fiber optic cables to provide internet access. In this embodiment, the optical network unit is equivalent to an optical network terminal (ONT).

[0045] 3. The DBR region refers to a section of the laser containing a reflective cavity with a Bragg grating. Wavelength selection is achieved through the distributed reflection capability of the Bragg grating, and the selected wavelength is related to the grating period and the refractive index of the grating material. The selected wavelength is called the Bragg wavelength.

[0046] 4. Tunable, meaning that the wavelength of the laser can be continuously adjusted within a certain range.

[0047] 5. Simplex operation refers to an optical network unit transmitting signals at only one rate within the same time period.

[0048] 6. Differential drive refers to applying two electrical signals with opposite amplitudes to the positive and negative electrodes in the gain region of the laser to achieve differential drive.

[0049] 7. Single-mode output and multi-mode output: Single-mode output means that the laser output spectrum has only one peak, corresponding to one wavelength. Multi-mode output means that the laser output spectrum has multiple peaks, corresponding to multiple wavelengths.

[0050] 8. Optical PHY chip is an electrical chip used to provide direct current and high-speed modulation signals to lasers.

[0051] 9. Amplitude modulation refers to modulating the data to be transmitted in a PON system onto the pump current by changing the amplitude of the laser pump current. After the pump current is injected into the gain region of the laser, the intensity of the laser's output light signal also changes with the amplitude modulation of this current, thus modulating the transmitted data onto the laser.

[0052] 10. Monitor photodiode (MPD): Typically, an MPD is attached next to the laser in a light-emitting assembly. The MPD is usually placed on the back of the laser's output end, that is, in the opposite direction of the emission direction. The state of the laser is detected by detecting the weak light power at the non-output end on the back of the laser. This is because although the light power at the non-output end of the laser is very small, it is generally related to the light power at the output end on the front of the laser. Therefore, the light power at the output end can be indirectly detected by detecting the light power at the non-output end.

[0053] 11. A resistance temperature detector (RTD) is a resistor integrated into a laser. By applying current to the positive and negative terminals of the RTD, the resistor heats up, thereby heating the laser. This heats up the laser's refractive index, which in turn adjusts the laser's emission wavelength. Typically, heating increases the laser's refractive index, thus increasing the wavelength. Here, applying current to the RTD yields the opposite effect to applying current to the DBR region.

[0054] 12. 50G PON and 10G PON: These refer to 50G and 10G passive optical networks, respectively. The difference lies in the uplink transmission rate: 50G PON has an uplink transmission rate of 49.7664Gbps or 24.8832Gbps, while 10G PON has an uplink transmission rate of 9.9532Gbps or 2.488Gbps. Both 50G PON and 10G PON require the laser wavelength to be within a certain range. Typically, the wavelength requirement for 50G PON is stricter, approximately 1286±2nm, while the wavelength requirement for 10G PON is relatively more lenient, approximately 1270±10nm.

[0055] In current optical emission components, a temperature control device (TEC) is integrated into the laser to maintain a constant wavelength of the output light signal. This integration of the TEC increases the cost of the optical emission component and makes its structure more complex, resulting in higher packaging costs.

[0056] In this embodiment, the TEC is removed from the light emitting component, and a multi-layer coated photodetector is used to achieve fine wavelength adjustment, which simplifies the structure of the light emitting component and also reduces packaging costs.

[0057] The system architecture provided in the embodiments of this application is described below.

[0058] Figure 1 A system architecture diagram is provided. For example... Figure 1 As shown, optical network units are used in optical communication systems. These systems include optical line terminals (OLTs), optical distribution networks (ODNs), and optical network units. The OLTs are located in a central equipment room, while the optical network units are located in areas such as user homes or businesses. The OLTs connect to multiple optical network units via the ODN. Here, "user home" is a broad concept; any small area where optical network units are installed can be considered a user home.

[0059] An optical network unit (ONU) can support at least one operating mode. When supporting multiple operating modes, different operating modes correspond to different transmission rates and employ different wavelengths. For example, an ONU may support one operating mode, which could be either a first operating mode or a second operating mode. Alternatively, an ONU may support both a first and a second operating mode, where the uplink transmission rate corresponding to the first operating mode is higher than that corresponding to the second operating mode. The uplink transmission rate refers to the rate at which the ONU transmits signals to the optical line terminal (OLT). The first operating mode corresponds to 50G PON, and in the International Telecommunication Union (ITU) standard, the uplink transmission rate for the first operating mode is 49.7664 Gbps or 24.8832 Gbps, using a wavelength range of 1286 ± 2 nm. The second operating mode corresponds to 10G PON, and the uplink transmission rate for the second operating mode is 9.9532 Gbps or 2.488 Gbps, using a wavelength range of 1270 ± 10 nm.

[0060] The optical network unit includes a driver module 3 and an optical emitting component 4. The driver module 3 is used to drive the optical emitting component 4 to emit optical signals. The optical emitting component 4 will be described first below.

[0061] Figure 2 A schematic diagram of the structure of the light emitting component 4 is provided. For example... Figure 2 As shown, the light emitting assembly 4 includes a photodetector 1 and a laser 2. The photodetector 1 is used to convert the received optical signal into an electrical signal, and the laser 2 is used to output the optical signal. The photodetector 1 is located in the opposite direction to the emission direction of the laser 2, that is, at the non-emitting end of the laser 2.

[0062] The receiving end of photodetector 1 has a transmission film 11, which corresponds to a transmission peak and has the highest transmittance at the target wavelength. The target wavelength is the center wavelength of the first operating wavelength range, which is an operating wavelength range of the optical emitting component, corresponding to a working mode of the optical network unit. Laser 2 includes a laser body 21 and a resistor 22. The DBR region 211 of the laser body 21 is attached to the resistor 22. When current flows through the resistor 22, heat is transferred to the DBR region 211. Most of the optical signal from the laser body 21 is output from the emission direction, with a small portion output from the opposite direction. This small portion of the optical signal enters photodetector 1, which converts it into an electrical signal. The heat transferred by resistor 22 to the DBR region 211 is related to this electrical signal. This heat keeps the temperature of the laser body 21 suitable, allowing the laser body 21 to output an optical signal with a wavelength within the first operating wavelength range. In this way, we can use the electrical signal detected by photodetector 1 to adjust the heat transferred by resistor 22 to DBR region 211, find the light signal with the highest transmittance, and use the light signal with the highest transmittance, or the light signal close to the highest transmittance, as the output light signal of light emitting component 4. In this way, the light signal output by light emitting component 4 is close to the center wavelength of the working wavelength range.

[0063] Resistor 22 is used to heat the DBR region 211, therefore it can also be called a thermal resistor. Furthermore, because resistor 22 is relatively thin, it can also be called an on-chip resistor.

[0064] The photodetector 1 can be an MPD, and the receiving end of the MPD is coated with a transmission film 11.

[0065] It should be noted that resistor 22 only needs to be able to fit against DBR region 211. This embodiment does not limit the fitting position or fitting area. For example, resistor 22 can be placed flat next to the waveguide that implements DBR region 211.

[0066] Next, we will first describe the transmission membrane 11.

[0067] In one alternative approach, the thickness of the transmission film 11 is approximately 3 to 4 μm.

[0068] In one alternative embodiment, the transmission film 11 comprises a plurality of film layers stacked together, including film layers with different refractive indices and film layers with the same refractive index.

[0069] Optionally, the transmission film 11 can be made of a material with a high and low refractive index difference to enable interference of light signals of the desired wavelength. In one implementation, the multiple layers include a film layer with a first refractive index and a film layer with a second refractive index, wherein the first refractive index is greater than the second refractive index, and the difference between the first and second refractive indices is generally large, such as greater than a target value. In another implementation, the multiple layers include film layers with three or more refractive indices.

[0070] Optionally, the material of the first refractive index film is silicon, with a refractive index of 3.55, and the material of the second refractive index film is silicon dioxide, with a refractive index of 1.7.

[0071] Optionally, multiple film layers logically form multiple film layer groups. Each film layer group includes film layers with the same refractive index and film layers with different refractive indices, and the film layers with the same refractive index have the same thickness. For example, each film layer includes a film layer with a first refractive index and a film layer with a second refractive index, where the film layers with the first refractive index have the same thickness and the film layers with the second refractive index have the same thickness.

[0072] Optionally, each layer group includes a layer with a first refractive index and a layer with a second refractive index, arranged alternately. For example, in each layer group, the first layer is a layer with a first refractive index, the second layer is a layer with a second refractive index, the third layer is a layer with a first refractive index, and so on. Or, for another example, in each layer group, the first layer is a layer with a second refractive index, the second layer is a layer with a first refractive index, the third layer is a layer with a second refractive index, and so on.

[0073] It should be noted that, assuming the first and second film layers are adjacent, the refractive indices of the last film layer in the first film layer group and the last film layer in the second film layer group are generally different, although in some cases they may be the same.

[0074] Optionally, multiple film layer groups logically constitute multiple film layer groups, with at least two film layer groups containing films of the target refractive index, the thickness of which differs. For example, the multiple film layer groups include film layer groups (HL). 5 The film group (HL) is used, where H represents a high refractive index film and L represents a low refractive index film. 5 A film group (HL) consists of layers with refractive index H and refractive index L stacked five times, with alternating layers of refractive index H and refractive index L. 5 In the film layer group (HL), the thickness of the film layer with refractive index H is different, and / or the thickness of the film layer with refractive index L is different.

[0075] Optionally, in different film layer groups, the thickness of films with the same refractive index may differ. For example, as... Figure 3 As shown, the transmission film 11 is denoted as (HL). 5 (HL) 2 This indicates that the transmission film 11 has two film layer groups, in which the thickness of the film layer with refractive index H is different, and / or the thickness of the film layer with refractive index L is different.

[0076] Optionally, in different groups of films, the thicknesses of films with the same refractive index are not necessarily different. For example, transmission film 11 is denoted as (HL). 5 (HL)(HL) 5 (HL) 3 This indicates that the transmission film 11 has four film layer groups. In these four film layer groups, the thickness of the film layer with refractive index H is different, and the thickness of the film layer with refractive index L is also different.

[0077] Optionally, when setting the transmission film 11, after selecting the refractive index of the film layer and the wavelength at the transmission peak position, the number of film layers and the thickness of the film layer are calculated through simulation. It should be noted that for a certain film layer group, there may be consecutive film layers with the same refractive index in the simulation results. This is actually because the thickness of the film layer with the second refractive index between the film layers with the first refractive index is 0, which can be understood as the superposition of film layers with the same refractive index. For example, in the film layer group (HLL), there are consecutive film layers with the refractive index L. This is actually because the thickness of the film layer with the refractive index H between two film layers with the refractive index L is 0 in the simulation. When it was expressed above, it directly described the superposition of two film layers with the refractive index L. They are represented separately in Table 1. During coating, two adjacent film layers with the refractive index L can be coated together and can be understood as one film layer.

[0078] When using a silicon and silicon dioxide film system, details of the transmission film 11 are shown in Table 1.

[0079] Table 1

[0080] Membrane system Refractive index Transmission membrane 11 Total thickness Silicon and silicon dioxide 3.55 and 1.7 <![CDATA[(HL) 5 (HLL)(HL) 5 (HL) 3 ]]> 3.8μm

[0081] Transmittance simulation was performed on the film systems in Table 1, and the results were obtained. Figure 4The transmittance spectrum shown exhibits a narrow band transmission spectrum with a peak-like shape and a full width at half maximum (FWHM) of approximately 2 nm. This indicates that at wavelengths greater than the transmission peak, the transmittance of light signals of different wavelengths after passing through the transmission film 11 is not the same. Furthermore, at wavelengths less than the transmission peak, the transmittance of light signals of different wavelengths after passing through the film layer is also not the same, resulting in varying degrees of attenuation. Therefore, for this type of film-coated photodetector 1, changes in the wavelength of the laser 2 will cause changes in the optical power of the light signal received by the photodetector 1. This type of photodetector 1 is called a narrow-band coated MPD. Figure 4 As shown, the photodetector 1 receives the strongest light at a wavelength of 1286nm. As the wavelength shifts away from 1286nm, the received light gradually decreases, exhibiting a clear peak. Therefore, by tuning resistor 22 and adjusting the injection current in the DBR region of laser 2, the peak optical power can be found, maximizing the optical power of the signal received by photodetector 1. This ensures that the wavelength of the optical signal output by laser 2 corresponds to the peak position, which is the center wavelength of the operating wavelength range of the optical emitting component. For example, in the case of a 50G PON optical emitting component, the wavelength can be controlled to approximately 1286nm ± 2nm.

[0082] The wavelength control logic will be described next.

[0083] In response to Figure 4 In the description, the wavelength can be precisely controlled based on the optical power of the optical signal detected by photodetector 1. The selectable control logic is as follows:

[0084] The initial wavelength of DBR211 in the laser body 21 is designed to be 1286±2nm@50℃, so that the 1286nm wavelength can be precisely controlled in the full temperature range of -25 to 85℃ in conjunction with photodetector 1: 1. In the 50G PON working mode, the DBR region is tuned to 1286nm by heating through resistor 22 (normal power consumption <200mW@65℃, peak power consumption ~1W@-25℃). At high temperatures, the injection current of DBR region 211 can be adjusted; 2. In the 10G PON working mode, the wavelength is reduced by adjusting the injection current of DBR region 211 to achieve DBR region 211 tuning to 1270nm (power consumption of about 150mW). At low temperatures, the heating of resistor 22 can also be switched. Due to process errors, the wavelength of the DBR region 211 control usually fluctuates to a certain extent, typically ±2nm. Table 2 provides a possible control logic table, showing the scenario where the initial wavelength of the optical signal output by the DBR region 211 is 1284nm when the module temperature is 55℃, where the module temperature is the temperature of the optical network unit.

[0085] Table 2

[0086]

[0087] Table 3 provides another possible control logic table, showing the scenario where the initial wavelength of the optical signal output by the DBR region 211 is 1288nm at a temperature of 55°C for the laser body 21.

[0088] Table 3

[0089]

[0090] In Tables 2 and 3, the first column represents the temperature of the optical network unit. The second column, the initial wavelength of the DBR region 211, indicates the wavelength of the laser 2 at different module temperatures due to the lack of temperature control. Temperature changes lead to variations in refractive index, resulting in different wavelengths. The third column shows the increase in wavelength due to heating resistor 22 in 50G PON mode, and the fourth column shows the decrease in wavelength due to adding current to the DBR region 211 in 10G PON mode. For a module temperature of 55℃ and an initial wavelength of 1284nm, precise adjustment of the 1286nm wavelength can be achieved by heating the DBR region 211 with resistor 22. By changing the current in resistor 22 and combining it with a peak-finding strategy, the optical power detected by photodetector 1 is always at its peak, and the wavelength of laser 2 is also 1286nm. In Table 3, under 50G PON mode, at high temperatures, it may be necessary to switch to adding current to the DBR region to reduce the wavelength.

[0091] It should be noted that in Tables 2 and 3, under the 50G PON operating mode, in most cases, no current needs to be applied to the DBR region 211, which reduces power consumption. Under the 10G PON operating mode, there is no need to heat resistor 22. However, in another implementation, resistor 22 can be heated.

[0092] The peak finding strategy is as follows: When the wavelength of the output optical signal of laser 2 is less than 1286nm, current is applied to resistor 22 and gradually increased, causing resistor 22 to heat up, which in turn heats the DBR region 211, increasing the refractive index of the DBR region 211 and thus increasing the output wavelength of laser 2. At this time, due to the characteristics of photodetector 1, the optical power detected by photodetector 1 also gradually increases. After reaching the optical power corresponding to 1286nm, the optical power begins to decrease because it has passed the peak of the transmission spectrum. At this point, the current applied to resistor 22 is reduced to lower the temperature of the DBR region 211, making the refractive index of the DBR region 211 smaller, thereby reducing the output wavelength of laser 2. By repeatedly adjusting in this way, the wavelength can be precisely stabilized at 1286nm.

[0093] Furthermore, at low temperatures, the temperature rise caused by resistor 22 can appropriately compensate for the performance degradation of laser 2 caused by low temperatures, forming a temperature feedback mechanism. It is estimated that within the module temperature range of -25°C to 0°C, the temperature rise caused by resistor 22 will be approximately 100-70°C. Overall, due to the temperature compensation from heating resistor 22 on laser 2, the temperature of laser 2 can be controlled at around 50°C. Moreover, at the highest module temperature of 75°C, since the wavelength selected by DBR region 211 falls within the range of 1286±2nm, resistor 22 almost no longer needs heating, thus reducing chip power consumption at high temperatures (normal resistor 22 power consumption is 0.5W-1W). Figure 5 As shown.

[0094] It should be noted that the optical network unit may only support the 50G PON operating mode, thus enabling precise temperature control at 1286±2nm in this mode. Alternatively, the optical network unit may support both 50G PON and 10G PON operating modes, enabling precise temperature control at 1286±2nm in 50G PON mode and at 1270±10nm in 10G PON mode. This application does not limit the scope of the embodiments described.

[0095] This explanation uses 50G PON and 10G PON as examples, but it can also be applied to 50G PON and gigabit-capable PON (GPON) scenarios, or 10G PON and GPON scenarios, or 50G PON, 10G PON and GPON scenarios.

[0096] It should be noted that Tables 2 and 3 are only two possible control logics, and the embodiments of this application do not limit them.

[0097] The structure of the light emitting component 4 will be described next.

[0098] In one alternative embodiment, within the optical emitting assembly 4, the laser body 21 includes a DBR region 211, which is a first DBR region. The laser body 21 includes a light source region 212, a phase region 213, and the first DBR region. The first DBR region is attached to the resistor 22. The light source region 212 is located between the phase region 213 and the first DBR region, or the phase region 213 is located between the light source region 212 and the first DBR region. The light source region 212 generates an optical signal, the phase region 213 performs phase adjustment processing on the input optical signal, and the first DBR region selects an optical signal of a specified wavelength for the laser body 21. This specified wavelength is the wavelength of the optical signal that the optical emitting assembly 4 needs to output.

[0099] Optionally, in order to maximize the output of the optical signal generated by the laser 2 from the laser body 21 and minimize the optical signal transmitted from the first DBR region, the laser body 21 further includes a first film layer 216. The first film layer 216 is a high-reflectivity film, such as having a reflectivity greater than 90%. The first film layer 216 is located in the transmission direction of the first DBR region and in the incident direction of the photodetector 1.

[0100] In another alternative embodiment, the laser body 21 in the optical emitting assembly 4 includes two DBR regions 211, namely a first DBR region and a second DBR region. The laser body 21 also includes a light source region 212, a phase region 213, the first DBR region, and the second DBR region. The light source region 212 and the phase region 213 are located between the first and second DBR regions, situated along the reflection direction of both the first and second DBR regions. The photodetector 1 is located along the transmission direction of the first DBR region. For the optical signal output from the laser body 21, the transmittance of the first DBR region to that optical signal is less than that of the second DBR region, thus allowing most of the optical signal to be output from the second DBR region.

[0101] The light source region 212 generates an optical signal, the phase region 213 performs phase adjustment processing on the input optical signal, and the first DBR region and the second DBR region select a specified wavelength optical signal for the laser body 21. This specified wavelength is the wavelength of the optical signal that the optical emitting component 4 needs to output.

[0102] Optionally, in the presence of a first DBR region and a second DBR region, both the first DBR region and the second DBR region are attached to resistor 22. Alternatively, resistor 22 includes a first sub-resistor 221 and a second sub-resistor 222, with the first sub-resistor 221 attached to the first DBR region and the second sub-resistor 222 attached to the second DBR region. Driving module 3 is electrically connected to the first sub-resistor 221 to apply DC current to it, and driving module 3 is electrically connected to the second sub-resistor 222 to apply DC current to it.

[0103] Typically, the Bragg wavelength of the DBR region decreases as the current applied to the DBR region increases, and increases as the current applied to the bonding resistor 22 increases.

[0104] Optionally, the positions of the light source region 212 and the phase region 213 can be interchanged. That is, along the emission direction of the laser 2, the first DBR region, the light source region 212, the phase region 213 and the second DBR region are arranged in sequence, or along the emission direction of the laser 2, the first DBR region, the phase region 213, the light source region 212 and the second DBR region are arranged in sequence.

[0105] Optionally, to maximize the output of the optical signal generated by the laser 2 from the second DBR region, and to increase the output optical signal from the second DBR region, the laser body 21 further includes a first film layer 216 and a second film layer 217. The first film layer 216 is a high-reflection film, such as having a reflectivity greater than 90%. The first film layer 216 is located in the transmission direction of the first DBR region and in the incident direction of the photodetector 1. The second film layer 217 is an anti-reflection film, such as having a reflectivity less than 10%. The second film layer 217 is located in the transmission direction of the second DBR region.

[0106] Optionally, the light source region 212 can be called the gain region or the active region. The optical signal generated by the light source region 212 can be a modulated optical signal or an unmodulated optical signal. When the optical signal generated by the light source region 212 is an unmodulated optical signal, the optical signal output from the second DBR region is also an unmodulated optical signal. The laser body 21 also includes a modulation region 214, which is located in the transmission direction of the second DBR region. The modulation region 214 modulates the input optical signal and outputs a modulated optical signal.

[0107] Optionally, if the laser body 21 also includes a modulation region 214, in order to make the optical power of the optical signal output from the laser body 21 higher, the laser body 21 also includes an optical amplification region 215. The modulation region 214 outputs an optical signal to the optical amplification region 215, and the optical amplification region 215 performs signal amplification processing on the optical signal and outputs the amplified optical signal.

[0108] The optical network unit will be described next.

[0109] The optical network unit includes a driving module 3 and any of the optical emitting components 4 described above, with the driving module 3 connected to the optical emitting component 4. When the optical network unit is in a first operating mode, the driving module 3 applies current to the laser body 21 and the resistor 22 respectively, causing the laser body 21 to output an optical signal with a wavelength within the first operating wavelength range. When the optical network unit is in a second operating mode, the driving module 3 applies current to the laser body 21, causing the laser body 21 to output an optical signal with a wavelength within the second operating wavelength range.

[0110] Optionally, when the optical network unit is in the second operating mode, the driving module 3 drives the laser body 21 and stops driving the resistor 22, that is, stops heating the resistor 22, thereby reducing the power consumption of the optical emitting component 4. At the same time, the photodetector 1 can also stop working.

[0111] This is just one example. In another implementation, in different operating modes, the drive module 3 drives the resistor 22, but the applied current is different.

[0112] Optionally, since the temperature can be precisely controlled by combining the feedback of the photodetector 1 and the heating of the resistor 22, it is more suitable for applications with higher wavelength range requirements. Therefore, the difference between the endpoints of the first working wavelength range is smaller than the difference between the endpoints of the second working wavelength range.

[0113] Optionally, the optical signal generated in the light source region 212 may or may not be modulated, and the structure of the optical network unit will be different, which will be explained separately below.

[0114] 1. The optical signal generated by the light source region 212 is a modulated continuous optical signal. The laser body 21 is equivalent to a DBR laser.

[0115] In one alternative approach, Figure 6 A schematic diagram of an optical network unit is provided. For example... Figure 6 As shown, phase region 213 is located between light source region 212 and first DBR region. One end of the first DBR region is coated with a first film layer 216, and the other end is adjacent to phase region 213. Driving module 3 applies a continuous pump current to light source region 212, causing light source region 212 to generate an optical signal. The wavelength of this optical signal is multi-wavelength. Since the pump current is also superimposed with the amplitude modulation signal of the current operating mode (represented by a square wave shape in various figures, representing an AC modulation signal), data modulation on the optical signal can be achieved. After light source region 212 generates an optical signal, the optical signal is transmitted to phase region 213. Driving module 3 applies a DC current to phase region 213 to adjust the phase of the input optical signal. After phase adjustment, the input optical signal is output to the first DBR region. The driving module 3 applies a DC current to the first DBR region and to the first sub-resistor 221 to control the refractive index of the Bragg grating in the first DBR region. This allows the selection of a specified wavelength of light signal from the input light signal. This specified wavelength is the wavelength of the light signal in the current operating mode. After returning to the phase region 213 and the light source region 212, the light signal is output from the light source region 212 as the output of the light emitting component 4. Here, the phase of the light signal also changes when it passes through the phase region 213 again. In this way, different DC currents are applied to the first DBR region and the first sub-resistor 221 in different operating modes, so that the first DBR region can select a specified wavelength of light signal for output from the input light signal.

[0116] In another alternative approach, Figure 7 Another schematic diagram of an optical network unit structure is provided. For example... Figure 7 As shown, the light source region 212 is located between the phase region 213 and the first DBR region. One end of the first DBR region is coated with a first film layer 216, and the other end is adjacent to the light source region 212. The principle of the driving module 3 driving the laser body 21 to output a light signal of a specified wavelength is described in the section on... Figure 6The description will not be repeated here.

[0117] Optionally, the driving module 3 is an optical PHY chip, which includes a first pin 31, a driving circuit 32, a second pin 33, a third pin 34, a fourth pin 35, a fifth pin 36, a sixth pin 37, and a seventh pin 38. Each pin can also be referred to as a lead. The driving circuit 32 is electrically connected to each pin. The first pin 31 is electrically connected to the photodetector 1; the second pin 33 is electrically connected to the positive electrode of the light source region 212; the third pin 34 is electrically connected to the negative electrode of the light source region 212; the fourth pin 35 is electrically connected to the positive electrode of the phase region 213; and the fifth pin 36 is electrically connected to the positive electrode of the first DBR region. The sixth pin 37 is electrically connected to the positive electrode of the first sub-resistor 221, and the seventh pin 38 is electrically connected to the negative electrode of the first sub-resistor 221.

[0118] The driving circuit 32 acquires an electrical signal from the photodetector 1 via its first pin 31. The second pin 33 and the third pin 34 are a pair of pins for differential driving. The driving circuit 32 applies a pump current to the light source region 212 via the second pin 33 and the third pin 34 to differentially drive the light source region 212, thereby causing the light source region 212 to generate an optical signal. The driving circuit 32 applies a DC current to the phase region 213 via its fourth pin 35 to drive the phase region 213 to adjust the phase of the input optical signal. The driving circuit 32 applies a DC current to the first DBR region via its fifth pin 36 to drive the first DBR region to select an output optical signal of a specified wavelength from the input optical signal. Based on the electrical signal, the driving circuit 32 applies current to the resistor 22, causing the resistor 22 to transfer heat to the first DBR region.

[0119] Optionally, the light source region 212, the phase region 213, and the first DBR region share a negative electrode, all of which are electrically connected to the third pin 34. Alternatively, the phase region 213 and the first DBR region share a negative electrode, and the driving circuit 32 is connected to this negative electrode through another pin.

[0120] Optionally, if the filtering capability of the first DBR region is insufficient, Figure 8 Another schematic diagram of an optical network unit structure is provided. For example... Figure 8 As shown, the light emitting component 4 also includes a second DBR region, which is located in the light transmission direction. The light source region 212 and the phase region 213 are located between the second DBR region and the first DBR region, and the light source region 212 and the phase region 213 are located in the reflection direction of the second DBR region.

[0121] like Figure 8As shown, phase region 213 is located between light source region 212 and second DBR region. One end of the second DBR region is coated with a second film layer 217, and the other end is adjacent to phase region 213. Alternatively, the second DBR region may not be coated with the second film layer 217, and an anti-reflection film layer is naturally formed at the end of the second DBR region. After the optical signal returns from the first DBR region to phase region 213 and light source region 212, it reaches the second DBR region. Figure 6 Based on this, the driving module 3 applies a DC current to the second DBR region and to the second sub-resistor 222 to change the refractive index of the Bragg grating in the second DBR region, so that a part of the optical signal is output from the second DBR region as the output of the optical emitting component 4, and the other part of the optical signal returns to the light source region 212 to participate in the excitation.

[0122] In this way, different DC currents are applied to the second DBR region and the second sub-resistor 222 under different operating modes, so that the second DBR region can select a specified wavelength of optical signal for output from the input optical signal.

[0123] Alternatively, the light source region 212 is located between the phase region 213 and the second DBR region. One end of the second DBR region is coated with a second film layer 217, and the other end is adjacent to the light source region 212. Alternatively, the second DBR region may not be coated with a second film layer 217, and an anti-reflection film layer may naturally form at the end of the second DBR region. After the optical signal returns to the light source region 212 and the phase region 213 through the first DBR region, the phase region 213 changes the phase of the optical signal, and the phase-changed optical signal reaches the second DBR region. The driving module 3 applies a DC current to the second DBR region and applies a DC current to the second sub-resistor 222 to change the refractive index of the Bragg grating in the second DBR region, so that a portion of the optical signal is output from the second DBR region as the output of the light emitting component 4, while the other portion of the optical signal returns to the light source region 212 to participate in the excitation.

[0124] Optionally, the wavelengths of the optical signals selected by the first DBR region and the second DBR region are the same. The dimensions of the first DBR region and the second DBR region may be the same or different. The current applied to the first DBR region and the second DBR region, as well as the DC current applied to the first sub-resistor 221 and the second sub-resistor 222, are set according to the operating mode.

[0125] Optionally, if the optical emitting component 4 also includes a second DBR region, the second DBR region shares a fifth pin 36 with the first DBR region. The fifth pin 36 has two wires, which are connected to the first DBR region and the second DBR region respectively. The currents transmitted in the two wires may be the same or different. Alternatively, the second DBR region may use a separate pin.

[0126] Optionally, the drive module 3 further includes an eighth pin 39 and a ninth pin 310. The eighth pin 39 is electrically connected to the positive electrode of the second sub-resistor 222, and the ninth pin 310 is electrically connected to the negative electrode of the second sub-resistor 222, for applying current to the second sub-resistor 222.

[0127] Optionally, the light source region 212, the phase region 213, the first DBR region, and the second DBR region share a negative electrode and are all electrically connected to the third pin 34.

[0128] Optionally, for ease of management, the second to ninth pins can be arranged in a row on the side of the drive module 3. The arrangement includes, but is not limited to: the eighth pin 39 and the ninth pin 310 are adjacent, the eighth pin 39 is adjacent to the seventh pin 38, the seventh pin 38 is adjacent to the sixth pin 37, the sixth pin 37 is adjacent to the fourth pin 35, the fourth pin 35 is adjacent to the second pin 33, the second pin 33 is adjacent to the third pin 34, the third pin 34 is adjacent to the fifth pin 36, and the first pin 31 can be located on the bottom side of the drive module 3.

[0129] Optionally, the driving circuit 32 may include one circuit or multiple circuits. For example, the driving circuit 32 includes a light source driving circuit, a phase driving circuit, a DBR driving circuit, and a resistor driving circuit. The light source driving circuit is electrically connected to the second pin 33 and the third pin 34, the phase driving circuit is electrically connected to the fourth pin 35, the DBR driving circuit is electrically connected to the fifth pin 36, and the resistor driving circuit is electrically connected to the sixth pin 37 and the seventh pin 38.

[0130] 2. The optical signal output from the light source region 212 is an unmodulated continuous optical signal. The laser body 21 is equivalent to a DBR and electro-absorption modulated laser (EML) technology.

[0131] In one alternative embodiment, the optical network unit includes a driving module 3 and an optical emitting component 4. The optical emitting component 4 includes a photodetector 1 and a laser 2. The laser 2 includes a laser body 21 and a resistor 22. The laser body 21 includes a light source region 212, a phase region 213, a first DBR region, and a modulation region 214. The modulation region 214 employs an electro-absorption modulator (EAM). The modulation region 214 is located in the light reflection direction of the first DBR region and along the emission direction of the laser body 21. The light source region 212 is located between the phase region 213 and the modulation region 214, and the first DBR region is adjacent to the phase region 213. The driving module 3 applies a voltage signal to the modulation region 214. This voltage signal is superimposed with an amplitude modulation signal of the data in the current operating mode, which is an amplitude-modulated voltage signal. The modulation region 214 outputs a modulated optical signal.

[0132] When an EAM is used in modulation region 214, according to the quantum Stark effect of EAM, the absorption amplitude of the input optical signal by EAM will be different depending on the voltage applied to EAM. Therefore, when the optical signal output from light source region 212 passes through EAM, the light intensity will change with the change in voltage amplitude, thus realizing the signal modulation of the optical signal.

[0133] In another alternative, phase region 213 is located between light source region 212 and modulation region 214, and the first DBR region is adjacent to light source region 212.

[0134] In yet another alternative approach Figure 9 Another schematic diagram of an optical network unit structure is provided. For example... Figure 9 As shown, the laser body 21 includes a light source region 212, a phase region 213, a first DBR region, a second DBR region, and a modulation region 214. The light source region 212 is located between the phase region 213 and the first DBR region. The phase region 213 is located between the light source region 212 and the second DBR region. The modulation region 214 is located in the light transmission direction of the second DBR region. One end of the first DBR region is coated with a first film layer 216, and the other end is adjacent to the light source region 212. One end of the modulation region 214 is coated with a second film layer 217, and the other end is adjacent to the second DBR region. The driving module 3 applies a continuous pump current to the light source region 212, so that the optical signal output by the light source region 212 is an unmodulated continuous optical signal. This pump current is a direct current and does not contain a current signal with modulation amplitude. After the light source region 212 generates an optical signal, the optical signal is transmitted to the first DBR region. The driving module 3 applies a DC current to the first DBR region and to the first sub-resistor 221 to change the refractive index of the Bragg grating in the first DBR region, thereby changing the Bragg wavelength of the Bragg grating in the first DBR region. The optical signal output from the first DBR region returns to the light source region 212, and after passing through the light source region 212, it enters the phase region 213. The driving module 3 applies a DC current to the phase region 213 to adjust the phase of the input optical signal, and the input optical signal is output to the second DBR region after phase adjustment. The driving module 3 applies a DC current to the second DBR region and to the second sub-resistor 222 to change the refractive index of the Bragg grating in the second DBR region, thereby changing the Bragg wavelength of the Bragg grating in the second DBR region. The optical signal transmitted from the second DBR region enters the modulation region 214. The driving module 3 applies a voltage signal to the modulation region 214, and the modulation region 214 outputs a modulated optical signal. Here, a second film layer 217 is deposited at one end of the modulation region 214. The second film layer 217 is an anti-reflection film layer, which can reduce the optical signal returning to the modulation region 214, thereby reducing the impact on the modulation region 214.

[0135] Figure 9 and Figure 8 The difference is that, Figure 9 The optical signal generated in the light source region 212 is an unmodulated optical signal. Figure 8 The optical signal generated by the light source region 212 is a modulated optical signal.

[0136] In another alternative configuration, phase region 213 is located between light source region 212 and first DBR region.

[0137] Optionally, in order to achieve a relatively high optical power in the output optical signal of the laser body 21, the laser body 21 further includes an optical amplification region 215, such as... Figure 10 As shown ( Figure 10 (The connection lines between the pins and the laser body 21 are not shown in the diagram). The optical amplification region 215 is a semiconductor optical amplifier (SOA). The optical amplification region 215 is located in the emission direction of the modulation region 214. The driving module 3 applies a DC current to the optical amplification region 215, which amplifies the input optical signal and outputs it. Alternatively, the optical amplification region 215 can be set in the optical emitting assembly 4, which does not include the second DBR region. In this case, the laser body 21 does not include the second DBR region.

[0138] Optionally, the driving module 3 is an optical PHY chip, which includes a first pin 31 and a driving circuit 32, a second pin 33, a third pin 34, a fourth pin 35, a fifth pin 36, a sixth pin 37, a seventh pin 38, an eighth pin 39, a ninth pin 310, and a tenth pin 311. The driving circuit 32 is electrically connected to each of the pins. The first pin 31 is electrically connected to the photodetector 1; the second pin 33 is electrically connected to the positive electrode of the light source region 212; the third pin 34 is electrically connected to the positive electrode of the phase region 213; the fourth pin 35 is electrically connected to the positive electrodes of the first DBR region and the second DBR region; the fifth pin 36 is electrically connected to the positive electrode of the modulation region 214; the sixth pin 37 is electrically connected to the positive electrode of the optical amplification region 215; the seventh pin 38 and the eighth pin 39 are electrically connected to the positive and negative electrodes of the first sub-resistor 221, respectively; and the ninth pin 310 and the tenth pin 311 are electrically connected to the positive and negative electrodes of the second sub-resistor 222, respectively. Here, if the laser body 21 does not include the optical amplification region 215, the optical PHY chip may not include the sixth pin 37. This example uses the first and second DBR regions sharing one pin; the second DBR region can also use a separate pin, meaning the first DBR region is connected to one pin, and the second DBR region is connected to another pin.

[0139] The drive circuit 32 drives the connected devices through the aforementioned pins.

[0140] Optionally, the light source region 212, phase region 213, first DBR region, second DBR region, modulation region 214 and optical amplification region 215 share a common negative electrode. The optical PHY chip also includes an eleventh pin, and the driving circuit 32 is electrically connected to the eleventh pin, which is also electrically connected to the negative electrode.

[0141] Optionally, for ease of management, the second to eleventh pins can be arranged in a column. This application does not limit their arrangement order in its embodiments.

[0142] Optionally, the driving circuit 32 can be a single circuit or multiple circuits, with different circuits driving different parts.

[0143] It should be noted that the specific structure of the driving circuit 32 is not limited in the embodiments of this application. Any circuit that can be used to drive the laser body 21 can be applied to the embodiments of this application.

[0144] It should be noted that in the absence of a second DBR region, the optical emitting component 4 only includes the first DBR region. Setting the first DBR region to be relatively long may result in the selected optical signal being single-mode light. Furthermore, the output end of the laser body 21 is not coated with an anti-reflection film, and the output end is a natural reflective end face, which prevents all the optical signal from being output from the output end, thus allowing it to continue to return and participate in excitation.

[0145] Optionally, in Figures 6 to 10 In the optical network unit shown, in the optical transmission direction, the waveguide material of the light source region 212 is different from that of the phase region 213 and the first DBR region. The waveguide materials of the phase region 213 and the first DBR region may be the same or different, but both are materials that do not absorb the optical signal output by the optical network unit. The waveguide materials of the modulation region 214 and the optical amplification region 215 are different, and both are different from those of the light source region 212, the phase region 213, and the first DBR region. Figures 6 to 10 In this process, the materials of the first DBR region and the second DBR region may be the same or different.

[0146] exist Figures 6 to 10 In the optical network unit shown, in the laser body 21, the substrate material is indium phosphide, the waveguide material in the middle optical transmission direction is a quaternary compound, which is indium gallium arsenide phosphide or aluminum gallium indium arsenide, and the next layer is indium phosphide.

[0147] exist Figures 6 to 10The reason for setting phase region 213 in the optical network unit shown is that when applying DC current to the DBR region (the DBR region includes the first DBR region or the first DBR region and the second DBR region) to select the wavelength of the output optical signal, it may cause the output optical signal mode to be abnormal, such as changing from the original single-mode output to multi-mode output. The overall phase of the optical signal can be adjusted by adjusting the DC current applied to phase region 213, so that the optical emitting component 4 maintains single-mode output, that is, the output optical signal is a single-mode optical signal.

[0148] exist Figures 6 to 10 In the laser body 21 shown, the groove in the middle represents an electrical isolation region to prevent the currents in adjacent regions from affecting each other.

[0149] In one alternative approach, with the first operating mode corresponding to 50G PON and the second operating mode corresponding to 10G PON, according to the uplink wavelength range definitions in ITU standards G.987.3 and G.9804.3, the uplink wavelength range for 50G PON is 1286±2nm, and for 10G PON it is 1270±10nm. Therefore, the wavelength adjustment range of the first and second DBR regions must be at least 1280nm to 1286nm. Furthermore, considering the need to reserve a 2nm margin at the 1280nm and 1286nm edge wavelengths to accommodate wavelength errors introduced during chip manufacturing, the wavelength adjustment range of the first and second DBR regions is 10nm. Here, uplink refers to the transmission direction of optical network units sending optical signals to optical line terminals.

[0150] In one alternative approach, based on technical simulations, the current range driving the first and second DBR regions is 0 to 100 mA. The current range driving the phase region 213 is 0 to 10 mA.

[0151] In one alternative approach, Figures 6 to 10 The optical network unit shown also includes a MAC chip 5, such as... Figure 11As shown, MAC chip 5 is connected to driver module 3. During user operation of the optical network unit, if the operating mode needs to be changed, the optical line terminal (OLT) sends an operating mode switching message to the optical network unit. MAC chip 5 receives this operating mode switching message, determines the operating mode indicated by the message, and sends an instruction message to driver module 3, instructing driver module 3 to perform an operating mode switch. After receiving the instruction message, driver module 3 determines the current and other information to be applied to the laser body 21 based on the correspondence between the operating mode and control method. Driver circuit 32 drives laser body 21 according to this information and, based on the magnitude of the electrical signal obtained from photodetector 1, determines the DC current applied to resistor 22, so that laser body 21 outputs a target wavelength optical signal. This target wavelength is the wavelength of the optical signal in the operating mode indicated by the operating mode switching message. For example, as... Figure 12 As shown, the first working mode corresponds to 50G PON, and the second working mode corresponds to 10G PON. When the optical network unit is manufactured and shipped, it is set to the second working mode, automatically matching 10G PON service transmission and reception. When a user upgrades to the first working mode, the optical line terminal sends a working mode switching message to the optical network unit to instruct it to switch to the first working mode and match 50G PON service transmission and reception. This allows for automatic remote operation via the optical line terminal, avoiding secondary on-site visits and hardware replacements.

[0152] In one alternative approach, as users typically upgrade optical network units (ONUs) to higher transmission rates over time, to reduce the power consumption of the ONUs, the first drive current is lower than the second drive current. The first drive current is the current driving the first DBR region in the first operating mode, and the second drive current is the current driving the first DBR region in the second operating mode. This results in low power consumption for the ONUs after service upgrades.

[0153] Optionally, when the laser body 21 includes a second DBR region, the third driving current is lower than the fourth driving current. The third driving current is the current driving the second DBR region in the first operating mode, and the fourth driving current is the current driving the second DBR region in the second operating mode. This results in low power consumption for the optical network unit after service upgrades.

[0154] Optionally, when the operating mode is the second operating mode, the current of the driving module 3 driving resistor 22 can be 0, which is equivalent to stopping the driving of resistor 22 to save power consumption.

[0155] Optionally, when the operating mode is the second operating mode, the drive module 3 can instruct the photodetector 1 to stop working in order to save power consumption.

[0156] It should be noted that this explanation uses two operating modes as an example. When there are three or more operating modes, the DC current driving the first and second DBR regions can be set to the minimum under the most likely operating mode. For example, the DC current driving the first and / or second DBR regions can be set to 0.

[0157] In one alternative approach, the driver module 3 is an optical PHY chip, specifically a 50G PON optical PHY chip. In the second operating mode, this optical PHY chip operates at a reduced speed to match the 10G PON signal. In the first operating mode, the current driving the first DBR region and / or the second DBR region is turned off. For example, the DC current driving the first DBR region is 0, and the DC current driving the second DBR region is 0. Thus, in one operating mode, it is not necessary to drive the first and second DBR regions, which can reduce the power consumption of the optical network unit. Simulation results show that this can reduce power consumption by approximately 40mW.

[0158] In one alternative approach, such as Figure 13 As shown, the optical network unit also includes multiple optical receiving components 6, a beam combiner 7, and multiple filters 8. Each optical receiving component 6 corresponds to a specific operating mode, receiving optical signals from the optical line terminal under that mode. Different optical receiving components 6 are used to receive optical signals under different operating modes. The beam combiner 7 is located on the optical output path of the optical transmitting component 4 and on the optical incident direction of the multiple optical receiving components 6. Each optical receiving component 6 also has a filter 8 on its optical incident path. Except for the last optical receiving component 6, the filters 8 on the optical incident paths of the other optical receiving components 6 transmit the optical signals received by that optical receiving component 6 and also transmit the optical signals received by other optical receiving components 6. The filter 8 on the optical incident path of the last optical receiving component 6 reflects the optical signals received by that optical receiving component 6.

[0159] In this embodiment, the optical transmitter component does not require a TEC (Transmitter Engagement Device), thus simplifying its structure and reducing packaging costs. Furthermore, the optical transmitter component 4, driver module 3, MAC chip 5, and optical receiver component 6 can all be located on a single board. Since one optical transmitter component 4 and one driver module 3 support multiple operating modes, the board size can be reduced, and the wiring simplified, enabling miniaturized board design and facilitating the miniaturization of optical network units. Moreover, in the optical network unit, one optical PHY chip drives one optical transmitter component 4, enabling simplex operation and reducing chip costs. Furthermore, by setting the phase region 213, the optical transmitter component 4 can output a single-mode optical signal.

[0160] It should be noted that, during the fabrication of the optical network unit (ONU), the currents applied to the light source region 212, phase region 213, DBR region, and optical amplification region 16 can be configured within the ONU under different operating modes. Furthermore, the pump current applied to the light source region 212 can also be configured within the ONU, except without data modulation, and the voltage applied to the modulation region 214 can also be configured within the ONU, except without data modulation. The adjustment method for the DC current applied to resistor 22 can also be configured within the ONU. After the ONU switches to a certain operating mode, the current and other information corresponding to that operating mode are directly retrieved, driving the laser body 21 to output the optical signal under that operating mode. Alternatively, when the ONU is registered online, the optical line terminal (OLT) sends the aforementioned configuration parameters.

[0161] As mentioned earlier, the optical transmitting component is used in optical network units that support multiple operating modes, but it can also be used in optical network units that support only one operating mode. For example, the optical transmitting component is used in an optical network unit operating in a 50G PON standalone scenario to precisely control the wavelength of the uplink optical signal from 1340 to 1344 nm. Furthermore, the optical transmitting component can also be used in OLTs that require precise wavelength control, excluding TECs.

[0162] In this application, the terms "first" and "second," etc., are used to distinguish identical or similar items that have substantially the same function and purpose. It should be understood that there is no logical or temporal dependency between "first" and "second," nor does it limit the quantity or order of execution. It should also be understood that although the following description uses the terms "first" and "second," etc., to describe various elements, these elements should not be limited by the terms. These terms are merely used to distinguish one element from another. For example, without departing from the scope of various examples, a first pin can be referred to as a second pin, and similarly, a second pin can be referred to as a first pin. Both a first pin and a second pin can be pins, and in some cases, they can be separate and distinct pins.

[0163] In this application, the term "multiple" means two or more, and the term "and / or" includes three cases, for example, "A and / or B" includes three cases: A, B, and A and B.

[0164] The above description is merely an exemplary embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A light emitting component, characterized in that, It includes a photodetector (1) and a laser (2), wherein the photodetector (1) is located in the opposite direction to the emission direction of the laser (2); The receiving end of the photodetector (1) has a transmission film, which corresponds to a transmission peak and has the highest transmittance at the target wavelength. The target wavelength is the center wavelength of the first operating wavelength range of the light emitting component. The laser (2) includes a laser body (21) and a resistor (22). The distributed Bragg reflector (DBR) region (211) of the laser body (21) is attached to the resistor (22). The photodetector (1) is used to convert the light signal transmitted through the transmission film into an electrical signal; The resistor (22) is used to transfer heat to the DBR region (211) when energized, the amount of heat being related to the power of the electrical signal; The laser body (21) is used to output an optical signal whose wavelength belongs to the first working wavelength range.

2. The light emitting component according to claim 1, characterized in that, The transmission film comprises multiple layers stacked together, including layers with different refractive indices and layers with the same refractive index.

3. The optical emitting component according to claim 2, characterized in that, The plurality of film layers constitute a plurality of film layer groups, and each film layer group includes a film layer with a first refractive index and a film layer with a second refractive index. In each film layer group, the film layer with the first refractive index has the same thickness and / or the film layer with the second refractive index has the same thickness.

4. The light emitting component according to claim 2 or 3, characterized in that, The plurality of film layers constitute a plurality of film layer groups, each of the plurality of film layer groups includes a film layer with a first refractive index and a film layer with a second refractive index, and there are at least two film layer groups in the plurality of film layer groups, wherein the thickness of the film layer with the first refractive index is different and / or the thickness of the film layer with the second refractive index is different.

5. The light emitting component according to claim 3 or 4, characterized in that, The material of the first refractive index film is silicon, and the material of the second refractive index film is silicon dioxide.

6. The light emitting component according to any one of claims 1 to 5, characterized in that, The light source region (212) and phase region (213) of the laser body (21) are located in the reflection direction of the first DBR region of the laser body (21), and the photodetector (1) is located in the transmission direction of the first DBR region. The light source area (212) is used to generate light signals; The phase region (213) is used to perform phase adjustment processing on the input optical signal; The first DBR region is used to select an optical signal whose wavelength belongs to the first operating wavelength range for the laser body (21).

7. The light emitting component according to claim 6, characterized in that, The light source region (212) and phase region (213) of the laser body (21) are located between the first DBR region and the second DBR region of the laser body (21), and are located in the reflection direction of the second DBR region. The second DBR region is used to select an optical signal whose wavelength belongs to the first operating wavelength range for the laser body (21).

8. The light emitting component according to claim 6 or 7, characterized in that, The light signal generated by the light source area (212) is a modulated light signal.

9. The light emitting component according to claim 7, characterized in that, The light signal generated by the light source area (212) is an unmodulated light signal; The modulation region (214) of the laser body (21) is located in the transmission direction of the second DBR region; The modulation region (214) is used to perform signal modulation processing on the input optical signal.

10. The light emitting component according to claim 9, characterized in that, The optical amplification region (215) of the laser body (21) is located in the emission direction of the modulation region (214); The optical amplification area (215) is used to amplify the input optical signal.

11. An optical network unit, characterized in that, It includes a driving module (3) and a light emitting component (4) as described in any one of claims 1 to 10; The driving module (3) is used to drive the laser body (21) and the resistor (22) to control the laser body (21) to output an optical signal with a wavelength belonging to the first working wavelength range, wherein the signal driving the laser body (21) and the resistor (22) is related to the power of the electrical signal.

12. The optical network unit according to claim 11, characterized in that, The optical network unit has a first operating mode and a second operating mode, wherein the first operating wavelength range is the wavelength range used by the optical network unit when it is in the first operating mode; The driving module (3) is also used to drive the laser body (21) so that the laser body (21) outputs an optical signal with a wavelength belonging to the second working wavelength range, the second working wavelength range being the wavelength range used by the optical network unit when it is in the second working mode.

13. The optical network unit according to claim 12, characterized in that, The difference between the endpoints of the first operating wavelength range is smaller than the difference between the endpoints of the second operating wavelength range; The driving module (3) is also used to stop driving the resistor (22) when the optical network unit is in the second working mode.

14. The optical network unit according to any one of claims 11 to 13, characterized in that, The driving module (3) includes a first pin (31) and a driving circuit (32), wherein the first pin (31) is electrically connected to the photodetector (1); The driving circuit (32) is used to acquire the electrical signal through the first pin (31) and drive the laser body (21) and the resistor (22) based on the electrical signal.

15. The optical network unit according to any one of claims 11 to 14, characterized in that, The optical network unit also includes a media access control (MAC) chip (5); The MAC chip (5) is used to receive the working mode switching message sent by the optical line terminal and to control the driving module (3) to drive the laser body (21) to output an optical signal with a wavelength belonging to the first working wavelength range.

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