A single-transmit dual-receive wavelength 50G ONU optical device

Abstract

This invention discloses a single-transmit, dual-receive 50G ONU optical device, relating to the field of optical communication technology. It includes a housing with an optical channel inside. An optical receiving module is fixed to the upper side of the optical channel. A filtering component for dual-wavelength signal reception is fixed within the optical channel. The filtering component includes a reflective filter, a tilted filter, and a 0-degree filter. The reflective filter is fixed at a 37-degree angle to the vertical axis on the center line of the optical channel. The tilted filter is fixed below the optical receiving module at an 8-degree angle to the horizontal plane. The 0-degree filter is horizontally fixed directly below the optical receiving module. This optical device can achieve stable transmission of 1286±2nm optical signals and flexibly adapt to the reception of two wavelengths: 1342±2nm and 1366±2nm, solving the problem of high production costs caused by the use of dual bandpass filters in existing single-transmit, dual-receive 50G ONU optical devices.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, specifically to a single-transmit dual-receive wavelength 50G ONU optical device. Background Technology

[0002] With the rapid development of 50G-PON technology and the acceleration of its commercialization, the Optical Network Unit (ONU), as the core optical device on the user side of the 50G-PON system, plays a crucial role in optical signal interaction with the Optical Line Terminal (OLT) of the host computer. Its performance and functional adaptability directly determine the stability, flexibility, and cost controllability of the communication link.

[0003] Currently, conventional 50G ONU optical devices generally adopt a single-transmit, single-receive duplex structure. This means the transmitter (TX) outputs a 1286±2nm wavelength optical signal, and the receiver (RX) receives a 1342±2nm wavelength optical signal. This duplex optical device enables bidirectional communication with the OLT, meeting basic 50G high-speed communication requirements. However, in many commercial scenarios, the OLT requires multi-wavelength signal output. To achieve flexible adaptation between the ONU and OLT, an additional 1366±2nm wavelength receiving function needs to be added to the ONU. This function receives the 1366±2nm optical signal emitted by the OLT, enabling flexible reception of both 1342±2nm and 1366±2nm communication wavelengths and ensuring compatibility and flexibility of the communication link in different commercial scenarios.

[0004] Regarding the aforementioned functional requirement of single-transmit dual-receive (1 transmit, 2 receive), such as Figure 4 , 5 As shown, the conventional solution involves designing the 0-degree filter within a standard 50G ONU optical device as a dual-bandpass filter. In this dual-bandpass filter, the passband is defined as having a transmission loss of less than 1dB, with wavelengths ranging from 1340 to 1344 nm and 1364 to 1368 nm; the stopband is defined as having a transmission loss greater than or equal to 20dB, with wavelengths ranging from 1260 to 1335 nm, 1349 to 1359 nm, and 1373 to 1500 nm. The core function of this dual-bandpass filter is to simultaneously allow optical signals of both 1342±2 nm and 1366±2 nm wavelengths to pass through, while isolating other irrelevant wavelengths, thus ensuring the accuracy of optical signal transmission.

[0005] Furthermore, such as Figure 4As shown, the 1286±2nm wavelength optical signal output from the transmitter (TX) is almost completely transmitted through a 45-degree filter and then transmitted to the COM / OUT port (this port is the interface with the external optical fiber). The external dual-wavelength optical signals 1342±2nm and 1366±2nm are incident on the 45-degree filter through the COM / OUT port, where total internal reflection is achieved, and the optical signals are reflected and transmitted to the 0-degree dual bandpass filter. After being filtered by the dual bandpass filtering function of the 0-degree filter, the two independent optical signals RX 1342±2nm and 1366±2nm can be received.

[0006] However, after careful and in-depth industry research, it was found that the coating process of this type of dual-band filter is complex, and the cost of producing a single piece is very expensive, far exceeding the cost of the entire optical device itself.

[0007] Therefore, it is necessary to develop an alternative to reduce the cost of the filter. Summary of the Invention

[0008] To address the shortcomings and defects of the existing technologies, this invention proposes a single-transmit dual-receive wavelength 50G ONU optical device. This device, by setting multiple filters with specific angles and designs in the receiving circuit, can achieve stable transmission of 1286±2nm optical signals and flexibly adapt to the reception of two wavelengths, 1342±2nm and 1366±2nm. This solves the problem of high production costs caused by the use of dual bandpass filters in existing single-transmit dual-receive 50G ONU optical devices, realizes the core function of single-transmit dual-receive 50G ONU optical devices, and meets commercial requirements.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A single-transmitter, dual-receiver 50G ONU optical device includes a housing, within which an optical channel is provided. An optical transmitting module and an SC adapter are fixed at opposite ends of the optical channel, and an optical receiving module is fixed on the upper side of the optical channel. The optical transmitting module and the optical receiving module are arranged at a 90-degree angle. The device is characterized in that a filtering component for realizing dual-wavelength signal reception is also fixed within the optical channel. The filtering component includes a reflection filter, a tilt filter, and a 0-degree filter. The reflective filter is located on the left side of the optical receiving module and is fixed at an angle of 37 degrees to the center line of the optical channel. It is used to fully transmit the optical signal emitted by the optical transmitting module and fully reflect the optical signal received by the SC adapter. The tilted filter has a passband with a wavelength range of 1350~1360nm and a stopband with wavelength ranges of 1300~1344nm and 1364~1400nm. The tilted filter is located below the center line of the optical channel and is fixed below the optical receiving module at an angle of 8 degrees to the horizontal plane. It is used to allow the light signal that is totally reflected by the reflective filter to be incident on the tilted filter at an angle of 8 degrees, so that the light signal with a wavelength range of 1350~1360nm is completely transmitted, and the light signal with a wavelength range of 1300~1344nm and 1364~1400nm is totally reflected and vertically upward. The 0-degree filter has a passband with a wavelength range of 1340~1368nm and a stopband with wavelength ranges of 1300~1335nm and 1373~1400nm. The 0-degree filter is located above the center line of the optical channel and is horizontally fixed directly below the optical receiving module. It is used to allow the optical signal that is totally reflected by the tilted filter to be incident on the 0-degree filter at a 0-degree incident angle, and to allow the optical signals with wavelength ranges of 1342±2nm and 1366±2nm to be transmitted to the optical receiving module.

[0010] A groove is provided on the lower side of the optical channel. The bottom surface of the groove is inclined at 8 degrees relative to the horizontal plane, and the inclined filter is fixed on the bottom surface of the groove.

[0011] The upper part of the housing is provided with a mounting groove, which is connected to the optical channel through a through hole. The optical receiving module is fixed in the mounting groove, and the 0-degree filter is fixed in the through hole.

[0012] The reflective filter, tilt filter, and 0-degree filter are all fixed in the optical channel with adhesive.

[0013] An isolator and a TX collimating lens are fixed sequentially between the light emitting module and the reflective filter. The center lines of the light emitting module, the isolator, the TX collimating lens, and the SC adapter all coincide with the center line of the optical channel.

[0014] The SC adapter is equipped with a converging lens, the center line of which coincides with the center line of the optical channel.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: In this invention, the optical transmitting module and optical receiving module are arranged at a 90-degree angle, which is beneficial for meeting the access requirements of optical devices and 50G user-end optical modem PCB hardware. The reflective filter and the tilt filter are combined at 37 degrees and 8 degrees, respectively, totaling 45 degrees. This ensures that the received optical signal is deflected 90 degrees after passing through these two filters and reaches the 0-degree filter, thus guaranteeing effective reception and filtering of the optical signal. The tilt filter uses an 8-degree incident angle, resulting in a smaller incident angle for the optical signal, which is beneficial for achieving an isolation of over 30dB for optical signals in the stopband range. It should be noted that if a design greater than 8 degrees is used, the isolation performance will decrease to some extent; if a design less than 8 degrees is used, the placement distance between the reflective filter and the tilt filter will be too large, resulting in a larger optical device size, which is not conducive to connecting to hardware devices such as optical modems. Conversely, the angle of the reflective filter needs to be designed to be 37 degrees. A 0-degree filter is horizontally fixed directly below the optical receiving module. Since the received optical signal is reflected by the 37-degree and 8-degree filters, the light is already collinear with the center of the optical receiving module. Therefore, using a 0-degree filter ensures the optical signal is incident perpendicularly. This invention, by employing three filters with specific pass / stop band coating designs and arranged at a specific angle, not only achieves flexible adaptation to receiving wavelengths of 1342±2nm and 1366±2nm, but also effectively avoids interference from optical signals outside the 1342±2nm and 1366±2nm range at the receiving end, and ensures stable transmission of 1286±2nm optical signals. This improves the reliability and stability of the communication system while also reducing costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is the passband and stopband spectrum of the tilted filter in this invention; Figure 3 This is the passband and stopband spectrum of the 0-degree filter in this invention; Figure 4 Optical path diagram of an existing conventional 50G ONU; Figure 5 This is the dual bandpass spectrum of an existing 0-degree dual bandpass filter.

[0017] The following are labeled in the diagram: 1. Housing, 2. Optical channel, 3. Optical emitting module, 4. SC adapter, 5. Optical receiving module, 6. Reflective filter, 7. Tilt filter, 8. 0-degree filter, 9. Isolator, 10. TX collimating lens, 11. Converging lens. Detailed Implementation

[0018] like Figure 1As shown, this invention provides a single-transmit, dual-receive wavelength 50G ONU optical device, including a housing 1. An optical channel 2 is provided along the length of the housing 1. An optical transmitting module 3 and an SC adapter 4 are fixed at both ends of the optical channel 2, respectively. An optical receiving module 5 is fixed on the upper side of the optical channel 2. The optical transmitting module 3 and the SC adapter 4 are both located on the center line of the optical channel 2. The optical receiving module 5 is located between the optical transmitting module 3 and the SC adapter 4, and the optical transmitting module 3 and the optical receiving module 5 are arranged at a 90-degree angle. Crucially, a filtering component for realizing dual-wavelength signal reception is also fixed within the optical channel 2. This filtering component includes a reflective filter 6, a tilted filter 7, and a 0-degree filter 8, all fixed within the optical channel 2 by adhesive. like Figure 1 As shown, to achieve stable transmission of the transmitted optical signal and total reflection of the received optical signal to the tilted filter 7, a mounting structure for the reflective filter 6 is provided. Specifically, the reflective filter 6 is disposed on the left side of the optical receiving module 5 and fixed at an angle of 37 degrees to the center line of the optical channel 2. This allows the reflective filter 6 to achieve total transmission of the optical signal emitted by the optical transmitting module 3 and total reflection of the optical signal received by the SC adapter 4. Furthermore, it allows the total reflected optical signal to be incident on the tilted filter 7 at a smaller angle (8 degrees).

[0019] like Figure 1 , 2 As shown, to achieve filtering and reflection of optical signals between the reflective filter 6 and the 0-degree filter 8, a tilted filter 7 structure and mounting structure are further provided. Specifically, the tilted filter 7 has a filter passband with a wavelength range of 1350~1360nm and a filter stopband with wavelength ranges of 1300~1344nm and 1364~1400nm. The transmission loss of the filter passband is less than 1dB, and the isolation of the filter stopband is at least 30dB. The tilted filter 7 is located below the centerline of the optical channel 2 and is fixed below the optical receiving module 5 at an angle of 8 degrees to the horizontal plane. This tilted filter 7 enables the optical signal totally reflected by the reflective filter 6 to be incident on the tilted filter 7 at an 8-degree incident angle, and enables the optical signal with a wavelength range of 1350~1360nm to be completely transmitted, the optical signal with a wavelength range of 1300~1344nm and 1364~1400nm to be completely reflected, and the optical signal with a completely reflected wavelength to be perpendicularly incident on the 0-degree filter 8.

[0020] like Figure 1 , 3As shown, to achieve effective reception of the required dual-band optical signals, a 0-degree filter 8 structure and mounting structure are further provided. Specifically, the 0-degree filter 8 has a passband with a wavelength range of 1340~1368nm and a stopband with wavelength ranges of 1300~1335nm and 1373~1400nm. The transmission loss of the passband is less than 1dB, and the isolation of the stopband is at least 30dB. The 0-degree filter 8 is located above the centerline of the optical channel 2 and is horizontally fixed directly below the optical receiving module 5. This 0-degree filter 8 allows the optical signal totally reflected by the tilted filter 7 to be incident on the 0-degree filter 8 at a 0-degree incident angle, and allows optical signals in two wavelength ranges of 1342±2nm and 1366±2nm to be transmitted to the optical receiving module 5.

[0021] This invention essentially replaces the traditional filter assembly with a filter component consisting of a reflection filter 6, a tilt filter 7, and a 0-degree filter 8. Figure 4 The 45-degree filter and 0-degree dual-passband filter, through special design and layout of the reflection filter 6, tilt filter 7, and 0-degree filter 8, can achieve stable transmission of 1286±2nm optical signals and simultaneous flexible reception of optical signals of two wavelengths, 1342±2nm and 1366±2nm, while reducing costs. Specifically, actual manufacturing results show that the unit manufacturing cost of the reflection filter 6, tilt filter 7, and 0-degree filter 8 is only about 20 RMB, which is lower in production cost and more practical than existing dual-passband filters costing hundreds of US dollars.

[0022] like Figure 1 As shown, to improve the stability and reliability of the tilted filter 7 within the housing 1, a mounting structure for the tilted filter 7 is further provided. Specifically, a groove is provided on the lower side of the optical channel 2. This groove has a bottom surface of the same size as the tilted filter 7, and the bottom surface is tilted at an angle of 8 degrees relative to the horizontal plane. The tilted filter 7 is fixed precisely on the bottom surface of the groove, resulting in higher stability and reliability.

[0023] like Figure 1 As shown, in order to achieve stable installation of the optical receiving module 5 and the 0-degree filter 8, a mounting groove is further opened on the upper part of the housing 1. The mounting groove is connected to the optical channel 2 through a through hole. The optical receiving module 5 is fixed in the mounting groove and the 0-degree filter 8 is fixed in the through hole.

[0024] Furthermore, an RX converging lens is also provided directly below the 0-degree filter 8 to improve the reception quality of the optical signal.

[0025] like Figure 1As shown, an isolator 9 and a TX collimating lens 10 are fixed between the light emitting module 3 and the reflective filter 6 in sequence. The SC adapter 4 is equipped with a converging lens 11, and the center lines of the light emitting module 3, the isolator 9, the TX collimating lens 10, and the SC adapter 4 all coincide with the center line of the light channel 2. The center line of the converging lens 11 coincides with the center line of the light channel 2.

[0026] The transmitting and receiving principle of this invention is as follows: The optical emission module 3 emits a 1286±2nm optical signal, which is transmitted to the reflective filter 6 after passing through the isolator 9 and the TX collimating lens 10. After passing through the reflective filter 6, the signal is almost completely transmitted and then transmitted to the SC adapter 4. The SC adapter 4 transmits the signal with the external optical fiber, thus realizing the emission of the 1286±2nm optical signal.

[0027] Externally received optical signals are incident on reflective filter 6 via SC adapter 4. The optical signals undergo total internal reflection on reflective filter 6 and are then incident on tilted filter 7 at an 8-degree angle. Tilted filter 7 allows complete transmission of optical signals with wavelengths in the range of 1350–1360 nm, and allows total internal reflection of optical signals with wavelengths in the ranges of 1300–1344 nm and 1364–1400 nm, which are then incident vertically upwards onto 0-degree filter 8, achieving an isolation of 35 dB. After receiving the optical signal, 0-degree filter 8 filters out the remaining wavelength ranges, allowing only optical signals in the wavelength ranges of 1342±2 nm and 1366±2 nm to be transmitted to optical receiving module 5, thus enabling flexible reception of optical signals in these two wavelength ranges.

[0028] The above description is merely a specific embodiment of the present invention. Any feature disclosed in this specification may be replaced by other equivalent features unless otherwise specified. All features or steps in all methods or processes disclosed may be combined in any way, except for mutually exclusive features and / or steps.

Claims

1. A single-transmit, dual-receive wavelength 50G ONU optical device, comprising a housing (1), an optical channel (2) provided inside the housing (1), an optical transmitting module (3) and an SC adapter (4) respectively fixed at both ends of the optical channel (2), an optical receiving module (5) fixed on the upper side of the optical channel (2), and the optical transmitting module (3) and the optical receiving module (5) arranged at 90 degrees; characterized in that: The optical channel (2) is also equipped with a filter assembly for receiving dual-wavelength signals. The filter assembly includes a reflection filter (6), a tilt filter (7), and a 0-degree filter (8). The reflective filter (6) is located on the left side of the optical receiving module (5) and fixed at an angle of 37 degrees to the longitudinal axis on the center line of the optical channel (2). It is used to fully transmit the optical signal emitted by the optical transmitting module (3) and fully reflect the optical signal received by the SC adapter (4). The tilted filter (7) has a passband with a wavelength range of 1350~1360nm and a stopband with a wavelength range of 1300~1344nm and 1364~1400nm. The tilted filter (7) is located below the center line of the optical channel (2) and is fixed below the optical receiving module (5) at an angle of 8 degrees to the horizontal plane. It is used to make the light signal that is totally reflected by the reflective filter (6) enter the tilted filter (7) at an incident angle of 8 degrees, so that the light signal with a wavelength range of 1350~1360nm is fully transmitted, and the light signal with a wavelength range of 1300~1344nm and 1364~1400nm is totally reflected and vertically upward. The 0-degree filter (8) has a filter passband with a wavelength range of 1340~1368nm and a filter stopband with a wavelength range of 1300~1335nm and 1373~1400nm; the 0-degree filter (8) is located above the center line of the optical channel (2) and is horizontally fixed directly below the optical receiving module (5); the optical signal that is totally reflected by the tilted filter (7) is incident on the 0-degree filter (8) at a 0-degree incident angle, and the optical signals with wavelength ranges of 1342±2nm and 1366±2nm are transmitted to the optical receiving module (5).

2. The single-transmit dual-receive wavelength 50G ONU optical device according to claim 1, characterized in that: The lower side of the optical channel (2) is provided with a groove, the bottom surface of the groove is inclined at 8 degrees relative to the horizontal plane, and the inclined filter (7) is fixed on the bottom surface of the groove.

3. The single-transmit dual-receive wavelength 50G ONU optical device according to claim 1, characterized in that: The upper part of the housing (1) is provided with a mounting groove, which is connected to the optical channel (2) through a through hole. The optical receiving module (5) is fixed in the mounting groove, and the 0-degree filter (8) is fixed in the through hole.

4. A single-transmit dual-receive wavelength 50G ONU optical device according to any one of claims 1-3, characterized in that: The reflective filter (6), the tilted filter (7), and the 0-degree filter (8) are all fixed in the optical channel (2) with adhesive.

5. A single-transmit dual-receive wavelength 50G ONU optical device according to claim 1, characterized in that: An isolator (9) and a TX collimating lens (10) are fixed between the light emitting module (3) and the reflective filter (6) in sequence. The center lines of the light emitting module (3), the isolator (9), the TX collimating lens (10), and the SC adapter (4) all coincide with the center line of the optical channel (2).

6. The single-transmit dual-receive wavelength 50G ONU optical device according to claim 1, characterized in that: The SC adapter (4) is provided with a converging lens (11), the center line of which coincides with the center line of the optical channel (2).

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