50G PON (Passive Optical Network) optical device for improving partial wave isolation

Abstract

The invention discloses a 50G PON (Passive Optical Network) optical device for improving partial wave isolation, which relates to the technical field of optical devices and comprises a PLC (Programmable Logic Controller) chip provided with a total port and an RX partial wave unit; the RX wave division unit comprises an input slab waveguide, an array waveguide, an output slab waveguide, three fan-out waveguides and three output ports, and the input slab waveguide is used for enabling the composite optical signals to generate diffracted light beams and uniformly projecting the diffracted light beams into the array waveguide; the array waveguide is used for separating the light beam into optical signals with different wavelengths; the output slab waveguide is used for guiding the optical signals to the fan-out waveguides, and the fan-out waveguides are used for transmitting the optical signals with the corresponding wavelengths to the output ports with the isolation degree larger than 30 dB. According to the optical device, on the basis of reducing optical loss, the technical problem that the isolation degree between the optical signals is low after wave division processing is conducted on the composite optical signals through an existing 50G PON optical device is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical devices, and in particular to a 50G PON optical device with improved wavelength separation isolation. Background Art

[0002] At present, conventional 50G PON optical devices mainly use block components to realize the combination and demultiplexing of optical signals of different wavelengths, such as Figure 6 As shown, the Block element 27 has a main port 2 and three-way optical splitting and combining ports 28. In actual use, after the three optical signals enter the Block element 27 through the optical splitting and combining port 28, a composite optical signal can be output at the main port 2; conversely, the Block element 27 can be used to separate a composite optical signal input from the outside into three optical signals of different wavelengths at the main port 2 and output them through the optical splitting and combining port 28, thereby ultimately realizing the effective transmission of optical signals.

[0003] However, with the growing demand for higher bandwidth and the development of emerging applications such as 4K / 8K video, virtual reality (VR), augmented reality (AR), and the Internet of Things (IoT), higher requirements are also placed on optical devices. For example, in access network applications, new 50G PON optical devices are composed of three optical signals with emission wavelengths of TX 1577±5nm, TX 1490±10nm, and TX 1342±2nm, and three optical signals with receiving wavelengths of RX 1310±20nm, RX 1286±2nm, and RX 1270±10nm, and need to share a common port to transmit and receive optical signals. According to actual communication needs, when the above six wavelengths of optical signals are working, the isolation between the RX ports inside the optical device must be greater than 30dB to avoid interference between optical signals and affect communication stability. However, since the Block component achieves the wavelength combining / decombining function through coating, when it is used for combining / decombining the above six wavelength optical signals, its isolation can only reach 20dB, which makes it unable to meet the market demand for higher and higher transmission rates.

[0004] Therefore, it is urgent to develop a 50G PON optical device with higher isolation. Summary of the invention

[0005] In order to overcome the above-mentioned technical problems existing in the prior art, the present invention provides a 50G PON optical device with improved wavelength separation isolation. The optical device can solve the technical problem of low isolation between optical signals after the existing 50G PON optical device performs wavelength separation processing on the composite optical signal on the basis of reducing optical loss.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A 50G PON optical device with improved wavelength separation isolation, comprising a PLC chip, wherein the PLC chip is provided with a main port for receiving an external composite optical signal and an RX wavelength separation unit for separating the composite optical signal into three optical signals of different wavelengths and outputting the signals; The RX wave splitting unit includes an input slab waveguide, an array waveguide, an output slab waveguide, an RX1270 fan-out waveguide, an RX1286 fan-out waveguide, an RX1310 fan-out waveguide, a 1270 output port, a 1286 output port, and a 1310 output port. The input slab waveguide, the array waveguide, and the output slab waveguide are sequentially connected to the main port. The RX1270 fan-out waveguide, the RX1286 fan-out waveguide, and the RX1310 fan-out waveguide are all connected to the output slab waveguide. The 1270 output port, the 1286 output port, and the 1310 output port are respectively connected to the RX1270 fan-out waveguide, the RX1286 fan-out waveguide, and the RX1310 fan-out waveguide; wherein, The input slab waveguide is used to generate a diffracted light beam from the received composite optical signal and evenly project it into the array waveguide; the array waveguide is used to separate the light beam into different wavelengths based on the principle of diffraction and phase delay and project it into different output channels; the output slab waveguide is used to guide the optical signals of different wavelengths in each output channel to the RX1270 fan-out waveguide, RX1286 fan-out waveguide and RX1310 fan-out waveguide respectively; the RX1270 fan-out waveguide, RX1286 fan-out waveguide and RX1310 fan-out waveguide are used to transmit the optical signals of corresponding wavelengths to the 1270 output port, 1286 output port and 1310 output port respectively with an isolation greater than 30 dB.

[0007] The wavelength dispersion of the PLC chip is 0.2nm / um, the array waveguide is composed of 152 waveguides of equal length, there is a gap of 10um between the RX1270 fan-out waveguide and the RX1286 fan-out waveguide, there is a gap of 20um between the RX1286 fan-out waveguide and the RX1310 fan-out waveguide, the RX1286 fan-out waveguide includes 8 waveguides, the RX1270 fan-out waveguide includes 40 waveguides, the RX1310 fan-out waveguide includes 80 waveguides, and the spacing between adjacent waveguides in the RX1286 fan-out waveguide, the RX1270 fan-out waveguide and the RX1310 fan-out waveguide is 3um.

[0008] The 1270 output port, the 1286 output port and the 1310 output port are connected to the 1270 APD chip, the 1286 APD chip and the 1310 APD chip respectively through RX coupling lenses.

[0009] The PLC chip is also provided with a TX combining unit, which is used to combine three optical signals with different wavelengths into one composite optical signal and output it to the outside through the main port.

[0010] The TX combiner unit is an AWG combiner including a 1342 input port, a 1490 input port and a 1577 input port.

[0011] The 1342 input port is sequentially connected to a converging lens, an isolator, a collimating lens and a 1342 EML chip, and an optical signal with a wavelength of 1342 nm enters the 1342 input port sequentially through the 1342 EML chip, the collimating lens, the isolator and the converging lens.

[0012] The 1490 input port is sequentially connected to a converging lens, an isolator, a collimating lens and a 1490 DFB chip, and an optical signal with a wavelength of 1490 nm emitted by the 1490 DFB chip enters the 1490 input port sequentially through the collimating lens, the isolator and the converging lens.

[0013] The 1577 input port is connected to a converging lens, an isolator, a collimating lens and a 1577 EML chip in sequence, and an optical signal with a wavelength of 1577 nm emitted by the 1577 EML chip enters the 1577 input port via the collimating lens, the isolator and the converging lens in sequence.

[0014] The 50G PON optical device also includes a BOX shell for packaging the PLC chip.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention introduces a PLC chip, and the RX splitter unit including input flat waveguide, array waveguide, output flat waveguide, RX1270 fan-out waveguide, RX1286 fan-out waveguide, RX1310 fan-out waveguide, 1270 output port, 1286 output port and 1310 output port designed accordingly on the PLC chip, which can achieve the purpose of making the isolation between the optical signals greater than 30dB after the composite optical signal is split inside the optical device on the basis of reducing the optical loss. Compared with conventional 50G PON optical devices, it not only meets the communication needs, but also avoids the interference of optical signals with each other, thereby effectively improving the reliability and stability of the communication system.

[0016] 2. The receiving end of the present invention uses an APD chip, which can effectively improve the sensitivity of the receiving end. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the planar structure of the present invention; Figure 2 It is a schematic diagram of the planar structure of the PLC chip; Figure 3 It is a schematic diagram of the planar structure of the RX splitter unit; Figure 4It is a schematic diagram of the structure from the output slab waveguide to the fan-out waveguide in the RX wave splitting unit; Figure 5 The spectrum diagram of the optical signal transmitted by the PLC chip through the RX splitter unit; Figure 6 It is a schematic diagram of the planar structure of the existing Block component.

[0018] The markings in the figure are: 1. PLC chip, 2. main port, 3. RX splitter unit, 4. input planar waveguide, 5. array waveguide, 6. output planar waveguide, 7. RX1270 fan-out waveguide, 8. RX1286 fan-out waveguide, 9. RX1310 fan-out waveguide, 10. 1270 output port, 11. 1286 output port, 12. 1310 output port, 13. RX coupling lens, 14. 1270 APD chip, 15. 1286 APD chip, 16. 1310 APD chip, 17. TX combiner unit, 18. 1342 input port, 19. 1490 input port, 20. 1577 input port, 21. converging lens, 22. isolator, 23. collimating lens, 24. 1342 EML chip, 25. 1490 DFB chip, 26. 1577 EML chip, 27, Block component, 28, optical splitter and combiner port. DETAILED DESCRIPTION

[0019] The present invention provides a 50G PON optical device with improved wavelength separation isolation. The optical device introduces a PLC chip 1 based on silicon-based PLC planar waveguide technology. The optical device can realize wavelength combination processing of optical signals with three emission wavelengths of TX 1577±5nm, TX 1490±10nm, and TX 1342±2nm through the PLC chip 1, and realize high-isolation wavelength separation processing of optical signals with three receiving wavelengths of RX 1310±20nm, RX 1286±2nm, and RX 1270±10nm.

[0020] like Figure 1 , 2 As shown, the optical device includes a PLC chip 1, on which a main port 2, a TX combining unit 17 and an RX splitting unit 3 are provided. The TX combining unit 17 is used to combine three optical signals of different wavelengths into one composite optical signal. The main port 2 is used to output the composite optical signal combined by the TX combining unit 17 to the outside, and to receive a composite optical signal input from the outside; the RX splitting unit 3 is used to separate the composite optical signal into three optical signals of different wavelengths and output them.

[0021] like Figure 1-3As shown, specifically, the RX splitter unit 3 includes an input slab waveguide 4, an arrayed waveguide 5, an output slab waveguide 6, an RX1270 fan-out waveguide 7, an RX1286 fan-out waveguide 8, an RX1310 fan-out waveguide 9, a 1270 output port 10, a 1286 output port 11 and a 1310 output port 12. The input slab waveguide 4, the arrayed waveguide 5 and the output slab waveguide 6 are sequentially connected to the main port 2, the RX1270 fan-out waveguide 7, the RX1286 fan-out waveguide 8 and the RX1310 fan-out waveguide 9 are all connected to the output slab waveguide 6, and the 1270 output port 10, the 1286 output port 11 and the 1310 output port 12 are respectively connected to the RX1270 fan-out waveguide 7, the RX1286 fan-out waveguide 8 and the RX1310 fan-out waveguide 9. In addition, the 1270 output port 10, the 1286 output port 11 and the 1310 output port 12 are also connected to the 1270 APD chip 14, the 1286 APD chip 15 and the 1310 APD chip 16 through the RX coupling lens 13, respectively. The RX coupling lens 13 is used to couple the optical signal to each chip. The input planar waveguide 4 is used to generate a diffracted light beam from the received composite optical signal and evenly project it into the array waveguide 5, which can ensure that the optical signal has minimal loss during transmission and that the light field is evenly distributed; the array waveguide 5 is used to separate the light beam into different wavelengths based on the principle of diffraction and phase delay and project it into different output channels; the output planar waveguide 6 is used to guide the optical signals of different wavelengths in each output channel to the RX1270 fan-out waveguide 7, the RX1286 fan-out waveguide 8 and the RX1310 fan-out waveguide 9, respectively; the RX1270 fan-out waveguide 7, the RX1286 fan-out waveguide 8 and the RX1310 fan-out waveguide 9 are used to transmit the optical signals of corresponding wavelengths to the 1270 output port 10, the 1286 output port 11 and the 1310 output port 12 with an isolation greater than 30 dB; the 1270 APD chip 14 is used to couple the optical signal with a wavelength of 1270 nm through the RX coupling lens 13, and the 1286 fan-out waveguide 8 and the RX1310 fan-out waveguide 9 are used to transmit the optical signals with corresponding wavelengths to the 1270 output port 10, the 1286 output port 11 and the 1310 output port 12, respectively; the 1270 APD chip 14 is used to couple the optical signal with a wavelength of 1270 nm through the RX coupling lens 13, and the 1286 fan-out waveguide 8 and the RX1310 fan-out waveguide 9 are used to transmit the optical signal with corresponding wavelength to the 1270 output port 10, the 1286 output port 11 and the 1310 output port 12, respectively. The APD chip 15 is used to couple through the RX coupling lens 13 to achieve reception of optical signals with a wavelength of 1286 nm, and the 1310 APD chip 16 is used to couple through the RX coupling lens 13 to achieve reception of optical signals with a wavelength of 1310 nm.

[0022] like Figure 4As shown, preferably, the wavelength dispersion of the PLC chip 1 is 0.2nm / um, and the array waveguide 5 is composed of 152 waveguides of equal length, which can separate the optical signal into different wavelengths and project it into different output channels. The RX1286 fan-out waveguide 8 includes 8 waveguides, the RX1270 fan-out waveguide 7 includes 40 waveguides, and the RX1310 fan-out waveguide 9 includes 80 waveguides. The spacing between adjacent waveguides in the RX1286 fan-out waveguide 8, the RX1270 fan-out waveguide 7, and the RX1310 fan-out waveguide 9 is 3um. In this way, the RX1286 fan-out waveguide 8 can capture a total of 8x3x0.2=4.8nm wide spectrum, which is sufficient to completely extract the optical signal in the range of 1286±2nm to the 1286 output port 11. Similarly, the RX1270 fan-out waveguide 7 can capture a total spectrum of 40x3x0.2=24nm, which is sufficient to completely extract the optical signal in the range of 1270±10nm to the 1270 output port 10. The RX1310 fan-out waveguide 9 can capture a total spectrum of 80x3x0.2=48nm, which is sufficient to completely extract the optical signal in the range of 1310±20nm to the 1310 output port 12.

[0023] In addition, there is a gap of 10um between the RX1270 fan-out waveguide 7 and the RX1286 fan-out waveguide 8. The 10um gap has no corresponding fan-out waveguide for receiving the demultiplexed optical signal, which is equivalent to generating a stopband region with a width of 10x0.2=2nm, thereby achieving good isolation within a spectral interval of 2nm.

[0024] Similarly, there is a 20um gap between the RX1286 fan-out waveguide 8 and the RX1310 fan-out waveguide 9, and the 20um gap has no corresponding fan-out waveguide for receiving the demultiplexed optical signal, which is equivalent to generating a 20x0.2=4nm wide stopband region, thereby achieving good isolation within the 4nm spectral interval.

[0025] like Figure 1 As shown, in this embodiment, the TX combiner unit 17 is an AWG combiner including a 1342 input port 18, a 1490 input port 19 and a 1577 input port 20. The 1342 input port 18 is connected to a converging lens 21, an isolator 22, a collimating lens 23 and a 1342 EML chip 24 in sequence. The optical signal with a wavelength of 1342 nm emitted by the 1342 EML chip 24 enters the 1342 input port 18 in sequence through the collimating lens 23, the isolator 22 and the converging lens 21. The collimating lens 23 and the converging lens 21 both play the role of coupling optical signals, and the isolator 22 plays the role of isolating the reflected light of the link from entering the EML or DFB chip to avoid affecting the normal operation of the chip.

[0026] The 1490 input port 19 is connected to a converging lens 21 , an isolator 22 , a collimating lens 23 and a 1490 DFB chip 25 in sequence. An optical signal with a wavelength of 1490 nm emitted by the 1490 DFB chip 25 enters the 1490 input port 19 through the collimating lens 23 , the isolator 22 and the converging lens 21 in sequence.

[0027] The 1577 input port 20 is connected to a converging lens 21, an isolator 22, a collimating lens 23 and a 1577 EML chip 26 in sequence. The optical signal with a wavelength of 1577 nm emitted by the 1577 EML chip 26 enters the 1577 input port 20 through the collimating lens 23, the isolator 22 and the converging lens 21 in sequence.

[0028] After receiving three optical signals through the 1342 input port 18 , the 1490 input port 19 and the 1577 input port 20 , the PLC chip 1 combines the three optical signals into one composite optical signal and outputs it through the main port 2 .

[0029] like Figure 1 As shown, in this embodiment, the 50G PON optical device also includes a BOX shell, and the above-mentioned PLC chip 1 and other components are packaged in the BOX shell to form a complete 50G PON optical device.

[0030] like Figure 5 As shown, the present application provides a simulated transmission spectrum diagram of the optical device, observing the spectrum of the RX 1286±2nm window, that is, the black solid line, the loss in this window range is almost 0, the loss in the RX 1270±10nm window is -45dB (that is, there is 45dB isolation between the two ports), and the loss in the RX 1310±20nm window is -35dB (that is, there is 35dB isolation between the two ports). Since the isolation between ports is independent of the spectrum width of each port itself, the isolation between all RX ports is greater than 30dB, thereby effectively improving the isolation between the optical signals after the wavelength division processing.

[0031] The above description is only a specific implementation mode of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other alternative features that are equivalent or have similar purposes; all the disclosed features, or all the steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A 50G PON optical device for improving wavelength separation isolation, comprising a PLC chip (1), characterized in that: The PLC chip (1) is provided with a main port (2) for receiving an external composite optical signal and an RX wavelength splitting unit (3) for splitting the composite optical signal into three optical signals of different wavelengths and outputting the signals; The RX wave splitting unit (3) comprises an input planar waveguide (4), an array waveguide (5), an output planar waveguide (6), an RX1270 fan-out waveguide (7), an RX1286 fan-out waveguide (8), an RX1310 fan-out waveguide (9), a 1270 output port (10), a 1286 output port (11) and a 1310 output port (12), wherein the input planar waveguide (4), the array waveguide (5) and the output planar waveguide (6) are connected in sequence. On the main port (2), the RX1270 fan-out waveguide (7), the RX1286 fan-out waveguide (8) and the RX1310 fan-out waveguide (9) are all connected to the output slab waveguide (6), and the 1270 output port (10), the 1286 output port (11) and the 1310 output port (12) are respectively connected to the RX1270 fan-out waveguide (7), the RX1286 fan-out waveguide (8) and the RX1310 fan-out waveguide (9); wherein, The input planar waveguide (4) is used to generate a diffracted light beam from the received composite optical signal and uniformly project the light beam into the array waveguide (5); the array waveguide (5) is used to separate the light beam into different wavelengths based on the principle of diffraction and phase delay and project the light beam into different output channels; the output planar waveguide (6) is used to guide the optical signals of different wavelengths in each output channel to the RX1270 fan-out waveguide (7), the RX1286 fan-out waveguide (8) and the RX1310 fan-out waveguide (9), respectively; the RX1270 fan-out waveguide (7), the RX1286 fan-out waveguide (8) and the RX1310 fan-out waveguide (9) are used to transmit the optical signals of corresponding wavelengths to the 1270 output port (10), the 1286 output port (11) and the 1310 output port (12) respectively with an isolation greater than 30 dB.

2. A 50G PON optical device for improving wavelength separation isolation according to claim 1, characterized in that: The wavelength dispersion of the PLC chip (1) is 0.2 nm / um, the array waveguide (5) is composed of 152 waveguides of equal length, a gap of 10 um is provided between the RX1270 fan-out waveguide (7) and the RX1286 fan-out waveguide (8), a gap of 20 um is provided between the RX1286 fan-out waveguide (8) and the RX1310 fan-out waveguide (9), the RX1286 fan-out waveguide (8) includes 8 waveguides, the RX1270 fan-out waveguide (7) includes 40 waveguides, the RX1310 fan-out waveguide (9) includes 80 waveguides, and the spacing between adjacent waveguides in the RX1286 fan-out waveguide (8), the RX1270 fan-out waveguide (7) and the RX1310 fan-out waveguide (9) is 3 um.

3. The 50G PON optical device for improving wavelength separation isolation according to claim 1, characterized in that: The 1270 output port (10), the 1286 output port (11) and the 1310 output port (12) are respectively connected to the 1270 APD chip (14), the 1286 APD chip (15) and the 1310 APD chip (16) via the RX coupling lens (13).

4. A 50G PON optical device for improving wavelength separation isolation according to any one of claims 1 to 3, characterized in that: The PLC chip (1) is also provided with a TX combining unit (17), which is used to combine three optical signals of different wavelengths into one composite optical signal and output it to the outside through the main port (2).

5. A 50G PON optical device for improving wavelength separation isolation according to claim 4, characterized in that: The TX combiner unit (17) is an AWG combiner comprising a 1342 input port (18), a 1490 input port (19) and a 1577 input port (20).

6. A 50G PON optical device for improving wavelength separation isolation according to claim 5, characterized in that: The 1342 input port (18) is sequentially connected to a converging lens (21), an isolator (22), a collimating lens (23) and a 1342 EML chip (24); an optical signal with a wavelength of 1342 nm emitted by the 1342 EML chip (24) enters the 1342 input port (18) via the collimating lens (23), the isolator (22) and the converging lens (21) in sequence.

7. The 50G PON optical device for improving wavelength separation isolation according to claim 5, characterized in that: The 1490 input port (19) is sequentially connected to a converging lens (21), an isolator (22), a collimating lens (23) and a 1490 DFB chip (25); an optical signal with a wavelength of 1490 nm emitted by the 1490 DFB chip (25) enters the 1490 input port (19) via the collimating lens (23), the isolator (22) and the converging lens (21) in sequence.

8. The 50G PON optical device for improving wavelength separation isolation according to claim 5, characterized in that: The 1577 input port (20) is connected in sequence to a converging lens (21), an isolator (22), a collimating lens (23) and a 1577 EML chip (26); an optical signal with a wavelength of 1577 nm emitted by the 1577 EML chip (26) enters the 1577 input port (20) in sequence through the collimating lens (23), the isolator (22) and the converging lens (21).

9. The 50G PON optical device for improving wavelength separation isolation according to claim 1, characterized in that: The 50G PON optical device also includes a BOX shell for packaging the PLC chip (1).

Images