A three-receiving and three-transmitting combo pon optical device

Abstract

This application relates to a three-transmit, three-receive COMBO PON optical device. The device integrates a transmitting component and a receiving component, which are spatially aligned. The transmitting component contains three lasers and corresponding 45° filters. The receiving component contains a PBS prism, a quarter-wave plate, and multiple bandpass filters, used for beam splitting, polarization control, and selective filtering of downlink optical signals of different wavelengths. These signals are then received by corresponding detectors. By integrating the three transmitted and three received beams into the same device, efficient transmission and reception of COMBO PON optical signals is achieved. This application employs an optical path design of PBS prism + quarter-wave plate + filters + reflective glass, using dual receiving TOs (Transmit Tolerancing Units). This design saves one 1310nm receiving TO, reduces device thickness, and allows placement within SFP-DD and QSFP-DD optical module structures, resulting in a significant thickness reduction compared to previous designs.

Description

Technical Field

[0001] This application relates to the field of optical communication devices, and in particular to a three-transmit, three-receive COMBO PON optical device. Background Technology

[0002] With the development of Passive Optical Network (PON) technology, to meet the demand for high-speed access, the industry has gradually evolved from traditional GPON and XG-PON to ComboPON systems that support higher bandwidth and multi-service carrying capabilities. Combo PON technology supports multiple PON standards simultaneously within the same optical module, enabling multiplexing and wavelength division multiplexing of uplink and downlink signals. It offers advantages such as high bandwidth utilization, strong system compatibility, and low deployment costs. Currently, mainstream 50G Combo PON OLT optical devices typically employ a multi-wavelength combination structure with transmit wavelengths of 1342nm, 1490nm, and 1577nm, and receive wavelengths of 1310nm, 1296nm, and 1270nm to achieve multi-standard coexistence and high-speed data transmission.

[0003] The existing 50G combo PON OLT devices with three transmit and three receive functions mainly adopt the following design: a 1270nm detector is configured at the bottom and a 1286nm and 1310nm detector is configured at the top. This device design is too long and cannot be installed in an SFP-DD structure. Moreover, it is implemented internally using a pure filter solution, involving multiple 8° and 13° filters, which makes the optical path complex and the coupling process extremely difficult, making it difficult to achieve mass production.

[0004] The existing structure has obvious shortcomings in its implementation; refer to Figure 10 , Figure 11 The device is designed with a 1270nm detector at the bottom and 1286nm and 1310nm detectors at the top. This device design is too long to be installed in an SFP-DD structure. Moreover, it is implemented using a pure filter solution, which involves multiple 8° and 13° filters. The optical path is complex and the coupling process is extremely difficult, making it difficult to achieve mass production.

[0005] Based on the above difficulties, the applicant developed and improved a solution using a PBS prism to address the complex optical path problem and reduce the base size, referring to... Figure 12The main features are: a 1270nm detector 6010 at the bottom, a 1286nm detector 6020 at the top, and a 1310nm detector 6030 on the side. The internal optical path is achieved through a PBS prism 6040, adapter 6050, a quarter-wave plate, and filters 1 603, 2 604, 3 605, 4 606, 5 607, and 6 608. The process is simpler than before.

[0006] Regarding the aforementioned technologies, the inventors believe that the improved device has an excessive thickness due to the 1310nm laser on the side, and the overall structure is not symmetrical about the top and bottom TOs. It cannot be directly placed into SFP-DD and QSFP-DD structural components, and a reflective glass needs to be added to offset the optical path. This results in insufficient applicability. The internal receiving optical path requires multiple sets of filters and waveplates, and three receiving TOs are needed, making mass production difficult due to the high cost. Summary of the Invention

[0007] To overcome the aforementioned technical deficiencies, this application provides a three-transmit, three-receive COMBO PON optical device.

[0008] The COMBO PON optical device with three transmit and three receive capabilities provided in this application adopts the following technical solution: A three-transmit, three-receive COMBO PON optical device includes a device body, which includes a detector one, a detector two, an adapter with a converging lens, a transmitting component assembly, and a receiving component assembly. The adapter with a converging lens is located on one side of the receiving component assembly, the transmitting component assembly is located on the other side of the receiving component assembly, the second detector is located at the upper end of the receiving component assembly, the first detector is located at the lower end of the receiving component assembly, the adapter with a converging lens and the transmitting component assembly are correspondingly arranged on both sides of the receiving component assembly, and the second detector and the first detector are located at the upper and lower ends of the transmitting component assembly respectively. On one side of the main cavity of the transmitting component assembly, from top to bottom, are arranged three 45º filters: filter one, filter two, and filter three. All three filters are installed at the same angle and in the same position. On the other side of the main cavity, from top to bottom, are arranged three lasers: laser one, laser two, and laser three. All three lasers are installed at the same angle and in the same position. The receiving component includes a PBS prism one and a PBS prism two. The PBS prism two is stacked on top of the PBS prism one. The PBS prism two has quarter-wave plates on two corresponding sides. One of the quarter-wave plates on one side also has a quarter-wave plate at its lower end. Filter three and filter four are respectively arranged on the outer sides of the quarter-wave plates on the two corresponding sides of the PBS prism two. Filter two is arranged at the lower end of filter four. Reflective glass is arranged on the outer side of filter four. A quarter-wave plate is arranged at the lower end of the PBS prism. Filter one is arranged at the lower end of the quarter-wave plate. A quarter-wave plate is arranged at the upper end of the PBS prism two. Filter five is arranged at the upper end of this quarter-wave plate.

[0009] By adopting the above technical solution, efficient integrated transmission and reception of multi-wavelength optical signals are achieved within a single device. The transmitting component uses three sets of lasers and corresponding 45° filters to work in tandem, enabling uplink optical signals of different wavelengths to be combined and output along the same optical axis. This results in a compact structure and high optical path consistency. The receiving component utilizes superimposed PBS prisms, quarter-wave plates, and multi-stage filters to perform polarization separation, wavelength selection, and directional guidance on the incident downlink optical signal, achieving precise demultiplexing of three different wavelength signals, which are then transmitted to their respective detectors for reception and detection. The adapter with a converging lens effectively improves the coupling efficiency between the optical fiber and the internal optical path of the device, reducing insertion loss. The symmetrical spatial layout of the transmitting and receiving components makes the overall optical path more stable, reducing crosstalk and reflection interference, and improving the device's wavelength isolation, receiving sensitivity, and system stability. This meets the application requirements of high-speed, high-capacity COMBOPON access networks for high integration, low loss, and high reliability.

[0010] Optionally, the detector 3 is a dual receiver with 1286nm and 1310nm wavelengths.

[0011] By adopting the above technical solution, detector 2 uses a dual-wavelength receiving TO structure of 1286 nm and 1310 nm, which can realize the synchronous detection of two downlink signals in the same receiving channel, effectively reducing the number of receiving modules inside the device, reducing structural complexity and packaging volume, while improving the consistency and stability of multi-wavelength reception, which is conducive to improving the integration and receiving reliability of COMBO PON system.

[0012] Optionally, the detector 2 is a 1270nm receiver for receiving TO.

[0013] By adopting the above technical solution, high-sensitivity, low-noise photoelectric conversion can be achieved for specific downlink signals, ensuring stable reception of the corresponding service signals; at the same time, it forms a collaborative receiving architecture with the dual-wavelength receiving detector, which is conducive to the effective separation and reliable detection of multi-wavelength downlink signals, improving overall receiving performance and system compatibility.

[0014] Optionally, laser one, laser two, and laser three are respectively configured to correspond to filter one, filter two, and filter three, and are used to emit optical signals of different wavelengths to achieve multi-wavelength multiplexed transmission.

[0015] By adopting the above technical solutions, multiplexed output of multiple wavelengths can be achieved, and multiple channels of data can be transmitted in the same optical path. This makes the coupling efficiency of optical signals higher, reduces interference and power loss between wavelengths, improves the transmission capacity and spectrum utilization of the system, meets the needs of high-speed multi-wavelength communication in PON systems, and enhances the integration and stability of the overall device.

[0016] Optionally, both prism one and prism two are made of total internal reflection glass, and their reflective surfaces are coated to improve the light signal reflection efficiency and reduce signal loss.

[0017] By adopting the above technical solutions, the reflection efficiency and directional accuracy of optical signals are improved, the loss of optical energy during the reflection process is reduced, the transmission strength and stability of optical signals in the receiving optical path are enhanced, the consistency and high coupling efficiency of multi-wavelength signals in the wavelength division and guidance process are guaranteed, and optical transmission performance with low insertion loss and high signal-to-noise ratio is achieved.

[0018] Optionally, filter one, filter two, filter three, filter four, filter five and filter six are all bandpass filters, and their center wavelengths correspond one-to-one with the emission wavelength and the reception wavelength, used to selectively transmit or reflect optical signals of a specific wavelength band.

[0019] By adopting the above technical solution, six bandpass filters can achieve precise selective transmission or reflection of optical signals of different wavelengths, ensuring one-to-one correspondence between transmitted and received wavelengths, effectively reducing crosstalk between wavelengths, improving the accuracy of optical signal separation, and enabling independent transmission and stable reception of uplink and downlink multi-wavelength optical signals within the same device, thereby improving the transmission efficiency, signal-to-noise ratio, and overall system reliability of COMBO PON optical devices.

[0020] Optionally, the adapter is a standard SC / APC or LC / APC fiber optic interface, used for reliable connection with an external fiber optic communication network to achieve input and output coupling of optical signals.

[0021] By adopting the above technical solutions, reliable connection and efficient coupling between the device and the external optical fiber communication network can be achieved, ensuring stable input and output of uplink and downlink optical signals, reducing connection loss and reflection, improving the overall transmission efficiency and reliability of the system, and facilitating the rapid installation and maintenance of optical devices and compatibility with existing optical networks, thus meeting the high-density and compact application requirements of FTTx access networks.

[0022] Optionally, detector one, detector two, and detector three correspond to downlink received signals of different wavelengths, and preferably adopt an InGaAs PIN photodiode structure to improve receiving sensitivity.

[0023] By adopting the above technical solutions, efficient separation and reception of multi-wavelength optical signals can be achieved. The InGaAs PIN photodiode structure is used to improve photoelectric conversion efficiency and receiving sensitivity, reduce noise interference, ensure reliable signal reception under low power conditions, and work together to achieve accurate wavelength division of downlink signals, thereby improving the signal quality and communication stability of the PON system.

[0024] Optionally, the transmitting component assembly and the receiving component assembly are fixed by a coaxial alignment structure to control the optical axis overlap within ±0.1°, thereby ensuring high coupling efficiency and low insertion loss.

[0025] By adopting the above technical solutions, the coupling efficiency of optical signals is improved, optical loss is reduced, and efficient optical energy transmission is achieved. Precise alignment ensures the stability and reliability of multi-wavelength optical signals during multiplexing and wavelength division, reduces insertion loss and signal attenuation, and improves the transmission performance and system stability of the entire COMBO PON optical device.

[0026] Optionally, the outer shell of the device body is made of metal shielding material, and a heat conduction channel is set inside to reduce the operating temperature rise of the laser and improve the overall stability and lifespan of the device.

[0027] By adopting the above technical solutions, the heat generated by the laser is effectively dissipated, the operating temperature rise is reduced, the laser and optical components are kept operating at a stable temperature, and the overall thermal stability and performance reliability of the device are improved.

[0028] In summary, this application includes at least one of the following beneficial technical effects: By employing a top-to-bottom symmetrical arrangement of the receiving and transmitting optical paths within the same device body, the problem of excessive device thickness caused by the lateral arrangement of detectors or lasers in existing solutions is avoided. This makes the overall structure more compact and can be directly adapted to high-density packaging structures such as SFP-DD and QSFP-DD, significantly improving the structural applicability and versatility of the device.

[0029] By co-designing PBS prisms with quarter-wave plates and bandpass filters, the internal optical path structure is significantly simplified while ensuring effective separation and multiplexing of multi-wavelength signals. This reduces the number and installation complexity of large-angle (e.g., 8°, 13°) filters, lowers the difficulty of optical path coupling and assembly, and helps improve yield and achieve mass production.

[0030] By rationally configuring the number of receiver detectors and their corresponding wavelength combinations, the number of redundant optical components and receiver TOs is reduced while meeting the application requirements of the three-receiver, three-transmitter, multi-standard ComboPON system. This reduces the overall material cost and packaging complexity of the devices, while improving the optical path symmetry, stability, and long-term operational reliability, thus balancing performance and cost advantages. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of an embodiment of this application.

[0032] Figure 2 This is a schematic diagram of the launching component assembly according to an embodiment of this application.

[0033] Figure 3 This is a schematic diagram of the receiving component assembly according to an embodiment of this application.

[0034] Figure 4 This is the output optical path diagram of the 1342nm laser in Embodiment 1 of this application.

[0035] Figure 5 This is the output optical path diagram of the 1577nm laser in the embodiment of this application.

[0036] Figure 6 This is the output optical path diagram of the 1490nm laser in Embodiment 1 of this application.

[0037] Figure 7 This is a schematic diagram of the 1270nm laser receiving optical path in Embodiment 1 of this application.

[0038] Figure 8 This is a laser receiving optical path diagram of embodiment 1286nm of this application.

[0039] Figure 9 This is the optical path diagram of the 1310nm laser receiver in Embodiment 1 of this application.

[0040] Figure 10 This is a diagram of existing technology. Figure 1 .

[0041] Figure 11 This is a diagram of existing technology. Figure 2 .

[0042] Figure 12 This is a schematic diagram of the technological improvement. Figure 1 .

[0043] Explanation of reference numerals in the attached figures: 10. Device body; 1. Transmitting component assembly; 101. 45º filter one; 102. 45º filter two; 103. 45º filter three; 104. Laser one; 105. Laser two; 106. Laser three; 107. Main body; 2. Detector one; 3. Detector two; 5. Adapter with converging lens; 6. Receiving component assembly; 61. PBS prism one; 62. PBS prism two; 63. Quarter-wave plate; 64. Reflecting glass; 65. Filter Filter 1; 66. Filter 2; 67. Filter 3; 68. Filter 4; 69. 1270nm receiver TO; 71. Filter 5; 6010. 1270nm detector; 6020. 1286nm detector; 6030. 1310nm detector; 6040. PBS prism; 6050. Adapter 1; 603. Filter 1; 604. Filter 2; 605. Filter 3; 606. Filter 4; 607. Filter 5; 608. Filter 6. Detailed Implementation

[0044] The following is in conjunction with the appendix Figure 1-9 This application will be described in further detail.

[0045] This application discloses a three-transmit, three-receive COMBO PON optical device. (Refer to...) Figure 1 The device body 10 includes detector 1 2, detector 2 3, adapter with converging lens 5, transmitting component assembly 1, and receiving component assembly 6; Detector 2 is a dual TO receiver at 1286nm and 1310nm, while detector 1 is a TO receiver at 1270nm. The adapter with converging lens 5 is located on one side of the receiving component 6, the transmitting component 1 is located on the other side of the receiving component 6, the second detector 3 is located at the upper end of the receiving component 6, the first detector 2 is located at the lower end of the receiving component 6, the adapter with converging lens 5 and the transmitting component 1 are correspondingly arranged on both sides of the receiving component 6, and the second detector 3 and the first detector 2 are located at the upper and lower ends of the transmitting component 1 respectively. Reference Figure 2 On one side of the inner cavity of the main body 107 of the transmitting component assembly 1, three 45º filters—one 101, one 102, and one 103—are arranged from top to bottom. All three filters are installed at the same angle and in the same position. The 45º filter one 101 has a pass wavelength of 1342 nm and a block wavelength of 1577 nm and 1490 nm, respectively. The 45º filter two 102 has a pass wavelength of 1490 nm and a block wavelength of 1577 nm. 45-degree filter 3103: impedance is 1490nm. This filter can be replaced by reflective glass. On the other side of the inner cavity of the main body 107, laser 104, laser 2 105, and laser 3 106 are arranged from top to bottom. Laser 104, laser 2 105, and laser 3 106 are all installed at the same angle and position. Laser 104, laser 2 105, and laser 3 106 are respectively arranged to correspond to filter 101, filter 2 102, and filter 3 103, and are used to emit optical signals of different wavelengths to achieve multi-wavelength multiplexing transmission. Reference Figure 3 The receiving component 6 includes a PBS prism 1 61 and a PBS prism 2 62. The PBS prism 2 62 is stacked on top of the PBS prism 1 61. Quarter-wave plates 63 are respectively provided on two sides of the PBS prism 2 62. A quarter-wave plate 63 is also provided at the lower end of one of the quarter-wave plates 63 on one side. A filter 3 67 and a filter 4 68 are respectively provided on the outer sides of the quarter-wave plates 63 on the two sides of the PBS prism 2 62. A filter 2 66 is provided at the lower end of the filter 4 68. A reflective glass 64 is provided on the outer side of the filter 4 68. A quarter-wave plate 63 is provided at the lower end of the PBS prism 1 61. The PBS prism 62 has a first filter 65 at one end and a quarter-wave plate 63 at the upper end. A fifth filter 71 is located above the quarter-wave plate 63. The first filter 65 passes through 1270 nm and blocks 1286 and 1310 nm. The second filter 66 passes through 1342, 1577, and 1490 nm and blocks 1270, 1286, and 1310 nm. The third filter 67 blocks 1270, 1286, and 1310 nm (this filter can be replaced by reflective glass). The fourth filter 68 passes through 1310 nm and blocks 1270 and 1286 nm. The fifth filter 71 passes through 1286 nm and blocks 1270 and 1310 nm. The transmitting component 1 uses three sets of lasers and corresponding 45° filters to work together to achieve efficient multiplexing of uplink optical signals of different wavelengths on the same optical axis, ensuring the consistency and compactness of the transmitting optical path and reducing inter-wavelength crosstalk and coupling loss. The receiving component 6 adopts a PBS prism structure with superimposed vertical arrangement, combined with a quarter-wave plate and multi-stage filters, to perform polarization separation, wavelength selection and directional guidance on the incident downlink multi-wavelength optical signals, so that the 1270nm, 1286nm and 1310nm signals can be accurately demultiplexed and transmitted to the corresponding detectors for detection. This reduces the number of receiving TOs while improving receiving efficiency and stability. The adapter with a converging lens effectively improves the coupling efficiency between the optical fiber and the internal optical path of the device and reduces insertion loss. The overall transmitting and receiving components are arranged vertically and symmetrically, making the optical path structure more compact, which is conducive to reducing the length and thickness of the device and meeting the high-density packaging requirements of SFP-DD, QSFP-DD and other types of packaging.

[0046] Reference Figure 4 , Figure 4 The diagram shows the output optical path of a 1342nm laser. After the 1342nm laser diode emits laser light, it is collimated into parallel light by a collimating lens. This light passes directly through a 45-degree filter 1, which transmits 1342nm light and reflects light at wavelengths of 1577nm and 1490nm. The light exits from the center of the output port and is converted into linearly polarized light by an isolator. It then passes completely through a PBS prism 1 and is coupled to an adapter with a focusing C-lens.

[0047] Reference Figure 5 , Figure 5 The diagram shows the output optical path of a 1577nm laser. After the 1577nm laser diode emits laser light, it is collimated into parallel light by a collimating lens. The light is reflected at a 45-degree filter 2, which reflects 1577nm light and transmits 1490nm light. The laser light is then reflected by a 45-degree filter 1 and exits from the center of the isolator, becoming linearly polarized light. It is then completely transmitted through a PBS prism 1 and coupled to an adapter with a converging C-lens.

[0048] Reference Figure 6 , Figure 6 The diagram shows the output optical path of a 1490nm laser. After the 1490nm laser diode emits laser light, it is collimated into parallel light by a collimating lens. The light is reflected at 45-degree filter 3, which reflects 1490nm light. The laser light then passes upwards through 45-degree filter 2 and is reflected again at 45-degree filter 1. It exits from the center of the isolator, becomes linearly polarized, and is completely transmitted through PBS prism 1 before being coupled into an adapter with a converging C-lens.

[0049] Reference Figure 7 , Figure 7This is the optical path diagram for a 1270nm laser receiver. After the 1270nm laser is incident from the outside, it is converted into parallel light by the C-lens of the adapter. When it shines directly onto PBS prism 1, it is split into two mutually perpendicular polarized beams according to the polarization direction, namely transmitted light and reflected light. The transmitted light is reflected by filter 2, passes through a quarter-wave plate twice, changes its polarization direction by 90°, and then reaches PBS prism 1 again for reflection. It then passes downward through filter 1 and is received at detector 1. The reflected light enters PBS prism 2 upward. Since the polarization direction of PBS prism 2 is the same as that of PBS prism 1, it is reflected again. The reflected light enters filter 4 for reflection, passes through a quarter-wave plate twice, changes its polarization direction, passes through PBS prism 2 for transmission, and then is reflected at filter 3. The polarization direction changes again, and it is reflected upward at filter 5. The polarization direction changes again and becomes the same as that of PBS prism 2. It then passes vertically downward through PBS prism 1, PBS prism 2, and filter 1, and is received at the 1270nm receiving point TO.

[0050] Reference Figure 8 , Figure 8 The optical path diagram for receiving a 1286nm laser is as follows: After the 1286nm laser is incident on PBS prism 1, it is split into two beams. One beam passes through PBS prism 1, is reflected at filter 2, passes through two waveplates, and is reflected again at PBS prism 1. It then travels to filter 1 and is reflected again, changing its polarization direction. The laser polarization direction is the same as that of PBS prism 1. After passing through two PBS prisms with the same polarization direction, it is transmitted at filter 5 and enters the 1286 receiving surface of the 1286 / 1310 dual receiver TO. The other laser beam is reflected at PBS prism 1 and then reflected again at PBS prism 2. It is then reflected at filter 4, passes through PBS prism 2, is reflected at filter 3, and then reflected again at PBS prism 2. It then passes upward through filter 5 and enters the 1286 receiving surface of the 1286 / 1310 dual receiver TO to complete the reception.

[0051] Reference Figure 9 , Figure 9This is the optical path diagram for receiving a 1310nm laser. Before the PBS prism 2, the 1310nm laser follows the same optical path as the 1286nm laser. After incident on the PBS prism 2, the 1310nm laser splits into two polarized beams. One beam, after reflection, passes directly through filter 4, then is reflected at the 45-degree angle of the reflective glass, and enters the 1310nm receiving surface of the 1286nm / 1310nm dual-receiver TO to complete reception. The other beam is transmitted through the PBS prism 2, reflected again at filter 5, passes through two quarter-wave plates, experiences a 90-degree phase shift, and is reflected back to filter 3 at the PBS prism 2. Reflection occurs, the phase shifts again, and the polarization direction is the same as that of the PBS prism 2, resulting in transmission. It then directly transmits through filter 4, is reflected at the 45-degree angle of the reflective glass, and enters the 1310nm receiving surface of the 1286nm / 1310nm dual-receiver TO to complete reception.

[0052] Example 2 optimizes and adjusts the configuration of some filters and reflective elements in the receiving component to further simplify the device structure and reduce manufacturing costs; Reference Figure 3 and Figure 8 In this embodiment, the filter 67 used for wavelength division between 1270nm and 1286nm in the receiving component 6 is replaced by reflective glass. This reflective glass is installed at a 45° angle for total internal reflection of the target wavelength band optical signal. By using reflective glass instead of the bandpass filter, the dependence on high-precision multilayer filters can be reduced while ensuring that the optical path direction control function remains unchanged, thereby reducing the cost of optical components and improving assembly consistency. Meanwhile, the relative installation positions of PBS prism 1 61 and PBS prism 2 62 remain unchanged, with the structure of stacking them vertically. The quarter-wave plate 63 is still set on the corresponding side of the PBS prism to realize the conversion of polarization state, so that the light signal reflected by the reflective glass can be transmitted or reflected in a predetermined direction when it re-enters the PBS prism, and finally enters the corresponding receiver TO to complete signal detection. Through the above improvements, this embodiment further simplifies the internal optical structure without changing the overall optical path function and multi-wavelength demultiplexing capability, reduces device manufacturing costs and debugging difficulty, and is conducive to achieving mass production and engineering applications.

[0053] Example 3 This embodiment modifies the combination of filters in the transmitting component assembly to improve the device's adaptability to different PON emission wavelengths. Reference Figure 2 and Figures 4-6In this embodiment, the 45° filter three 103 in the transmitting component assembly 1 adopts a reflective glass structure to reflect 1490nm wavelength laser light, while other wavelength light signals are directly transmitted. Correspondingly, the 45° filter one 101 and the 45° filter two 102 still adopt bandpass filter structures, and are used to achieve selective transmission and reflection of wavelengths of 1342nm, 1490nm and 1577nm, respectively. By replacing one of the filters with reflective glass, the complexity of the transmitter's optical film system design can be reduced while ensuring multi-wavelength multiplexing functionality, and insertion loss and wavelength drift caused by film layer errors can be minimized. Furthermore, lasers 104, 105, and 106 remain installed at the same angle and along the same optical axis, enabling highly consistent multiplexing output of the three uplink optical signals within the main body 107. This embodiment is particularly suitable for COMBO PON systems that have flexible requirements for emission wavelength configuration. By changing the filter parameters or the angle of the reflective glass, it is possible to quickly adapt to different combinations of emission wavelengths, thereby improving the versatility and scalability of the device.

[0054] The implementation principle of a three-transmit, three-receive COMBO PON optical device according to an embodiment of this application is as follows: by integrating the transmitting and receiving optical paths within the same device body, and utilizing a combination of multi-wavelength laser multiplexing, polarization separation, and wavelength selection, the device achieves multiplexing of three uplink optical signals and demultiplexing of three downlink optical signals in a multi-standard PON system. On the transmitting side, multiple sets of lasers of different wavelengths are arranged along the same optical axis, and combined with the transmission and reflection characteristics of different wavelength optical signals using a 45° filter, the transmitting wavelengths are multiplied step by step within the device and finally coupled into the optical fiber along the same optical path, thereby achieving efficient multiplexing output of multi-wavelength uplink signals. On the receiving side, a PBS prism is used to separate the polarization of the incident downlink optical signal, and a quarter-wave plate is used to achieve controllable polarization state conversion, allowing optical signals with different polarization states to propagate along a predetermined path during multiple reflections and transmissions. Simultaneously, multi-stage filters selectively transmit or reflect different wavelengths, achieving step-by-step wavelength division and directional guidance of downlink optical signals at 1270nm, 1286nm, and 1310nm. After coordinated processing in both polarization and wavelength dimensions, each downlink optical signal is guided to its corresponding single-wavelength or dual-wavelength receiver (TO) to complete photoelectric conversion. While ensuring high-performance multi-wavelength transceiver operation, the internal optical path structure has been significantly simplified, reducing the number of receiver TOs and the use of complex filters. This makes the overall device structure more compact and symmetrical, and it can be adapted to high-density packaging forms such as SFP-DD and QSFP-DD. At the same time, it reduces the difficulty of assembly and adjustment and manufacturing costs, and improves the stability of the optical path, receiver sensitivity and system reliability, thereby meeting the engineering application requirements of high-speed, high-capacity COMBO PON access networks.

[0055] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A three-transmit, three-receive COMBO PON optical device, characterized in that: The device includes a device body (10), which includes a detector one (2), a detector two (3), an adapter with a converging lens (5), a transmitting component assembly (1), and a receiving component assembly (6). The adapter with converging lens (5) is located on one side of the receiving component (6), the transmitting component (1) is located on the other side of the receiving component (6), the second detector (3) is located at the upper end of the receiving component (6), the first detector (2) is located at the lower end of the receiving component (6), the adapter with converging lens (5) and the transmitting component (1) are correspondingly arranged on both sides of the receiving component (6), and the second detector (3) and the first detector (2) are located at the upper and lower ends of the transmitting component (1). The main body (107) of the transmitting component assembly (1) has three 45º filters (101, 102, and 103) arranged from top to bottom on one side of the inner cavity. The 45º filters are installed at the same angle and in the same position. The other side of the inner cavity of the main body (107) has three lasers (104, 105, and 106) arranged from top to bottom. The lasers are installed at the same angle and in the same position. The receiving component (6) includes a PBS prism one (61) and a PBS prism two (62). The PBS prism two (62) is stacked on the upper end of the PBS prism one (61). The PBS prism two (62) has quarter-wave plates (63) on its two sides respectively. One of the quarter-wave plates (63) on one side also has a quarter-wave plate (63) at its lower end. The PBS prism two (62) has filters three (67) and four (68) on its outer sides respectively. The filter four (68) has a filter two (66) at its lower end. The filter four (68) has a reflective glass (64) on its outer side. The PBS prism one (61) has a quarter-wave plate (63) at its lower end. The quarter-wave plate (63) has a filter one (65) at its lower end. The PBS prism two (62) has a quarter-wave plate (63) at its upper end. The quarter-wave plate (63) has a filter five (71) at its upper end.

2. The COMBO PON optical device with three transmit and three receive functions according to claim 1, characterized in that: The detector 2 (3) is a dual receiver TO with wavelengths of 1286 and 1310 nm.

3. The COMBO PON optical device with three transmit and three receive terminals according to claim 1, characterized in that: The detector 1 (2) is a 1270nm receiver for TO.

4. The optical device according to claim 1, characterized in that: The laser one (104), laser two (105) and laser three (106) are respectively arranged corresponding to the filter one (101), filter two (102) and filter three (103) to emit optical signals of different wavelengths to achieve multi-wavelength multiplexing transmission.

5. The optical device according to claim 1, characterized in that: Both prism one (601) and prism two (602) are made of total reflection glass, and their reflective surfaces are coated to improve the light signal reflection efficiency and reduce signal loss.

6. The optical device according to claim 1, characterized in that: The filters 1 (603), 2 (604), 3 (605), 4 (606), 5 (607) and 6 (608) are all bandpass filters, and their center wavelengths correspond one-to-one with the emission wavelength and the reception wavelength, and are used to selectively transmit or reflect optical signals of a specific wavelength band.

7. The optical device according to claim 1, characterized in that: The adapter (5) is a standard SC / APC or LC / APC fiber optic interface, used to reliably connect to an external fiber optic communication network and realize input and output coupling of optical signals.

8. The optical device according to claim 1, characterized in that: The detectors 1 (2), 2 (3) and 3 (4) correspond to downlink received signals of different wavelengths, and preferably adopt an InGaAs PIN photodiode structure to improve the receiving sensitivity.

9. The optical device according to claim 1, characterized in that: The transmitting component assembly (1) and the receiving component assembly (6) are fixed by a coaxial alignment structure, so that the optical axis overlap is controlled within ±0.1°, thereby ensuring high coupling efficiency and low insertion loss.

10. The optical device according to claim 1, characterized in that: The outer shell of the device body (10) is made of metal shielding material and has a heat conduction channel inside, which is used to reduce the operating temperature rise of the laser and improve the overall stability and lifespan of the device.

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