A low-cost 800G 2XFR4 silicon photonics engine

Abstract

This invention relates to a low-cost 800G 2XFR4 silicon photonics engine, comprising: four collimating lenses arranged side by side, each collimating lens having a laser chip coupled to its incident side; the output sides of the four collimating lenses being coupled together to a prism used to reduce the spacing between the four parallel collimated beams; the output side of the prism sequentially coupling an array converging lens, a polarization-independent optical isolator, and a silicon photonics chip along the light propagation direction, or vice versa. The advantages are: while meeting the same coupling tolerance requirements, the number of lenses is reduced, thus reducing the number of coupling operations and shortening coupling time; only one large polarization-independent optical isolator is needed, compared to the prior art using four separate polarization-independent optical isolators, allowing for a reduction in the overall size of the polarization-independent optical isolator, thereby reducing costs.

Description

Technical Field

[0001] This invention relates to the field of optical engine technology, specifically to a low-cost 800G 2XFR4 silicon photonics engine. Background Technology

[0002] The specific structure of a traditional 800G 2XFR4 silicon photonics engine is as follows: Figure 1 As shown, it includes: a silicon photonics chip and four laser chips arranged side by side. The silicon photonics chip has four input waveguides and two output waveguides. Two of the four input waveguides are coupled to one of the two output waveguides, and the other two input waveguides are coupled to the other of the two output waveguides. The two output waveguides of the silicon photonics chip are coupled to a dual-channel fiber array. The beam emitted by each laser chip is coupled into one of the input waveguides of the silicon photonics chip sequentially through a collimating lens, a polarization-independent optical isolator, and a converging lens. That is, it has four collimating lenses, four polarization-independent optical isolators, and four converging lenses. To improve the coupling tolerance, a dual-lens scheme is adopted, that is, the collimating lens first collimates the emitted light of the laser chip, and then the converging lens focuses the collimated light onto the silicon photonics chip. In the input waveguide of the chip, this scheme requires eight coupling steps due to the presence of four collimating lenses and four converging lenses, which is time-consuming. In addition, the dual-channel fiber array also requires one coupling step. Since the minimum size of the collimating lens is generally 0.6mm, an excess adhesive space must be reserved between two adjacent collimating lenses. This gap is usually 0.4mm, so the center-to-center distance between the optical axes of the laser chips in two adjacent channels is 1mm. There are four polarization-independent optical isolators, which are relatively expensive and require four placement steps. Since there is a magnetic repulsion problem between adjacent polarization-independent optical isolators, it significantly affects the placement efficiency. In addition, considering the excess adhesive of the collimating lenses, polarization-independent optical isolators, and converging lenses, the three materials must have appropriate gaps in the light propagation direction, resulting in a large overall space occupation and thus causing tight PCB layout space. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a low-cost 800G 2XFR4 silicon photonics engine to overcome the shortcomings of the prior art.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a low-cost 800G 2XFR4 silicon photonics engine, comprising: four collimating lenses arranged side by side, each collimating lens having a laser chip coupled to its incident light side, and the four collimating lenses having their output light sides coupled together to a prism used to reduce the spacing between the four parallel collimating beams; the output light side of the prism is coupled sequentially along the light propagation direction to an array converging lens, a polarization-independent optical isolator, and a silicon photonics chip, or the output light side of the prism is coupled sequentially along the light propagation direction to a polarization-independent optical isolator, an array converging lens, and a silicon photonics chip.

[0005] The beneficial effects of this invention are:

[0006] This invention features four collimating lenses and one array converging lens, totaling five lenses. While meeting the same coupling tolerance requirements, the reduced number of lenses decreases the number of coupling operations, shortens coupling time, and improves production efficiency. Because the spacing between the four parallel collimating beams is reduced, only one large polarization-independent isolator is needed. Compared to the existing technology using four separate polarization-independent isolators, the overall size of the isolator can be reduced, thus lowering costs. Furthermore, reducing the number of polarization-independent isolators from four to one eliminates the issues of four-stage bonding and magnetic repulsion between adjacent channels, thus not affecting bonding efficiency. Additionally, the issue of adhesive overflow from the polarization-independent isolator and array converging lens can be eliminated, reducing the overall space occupied by the isolator, collimating lens, and array converging lens, effectively alleviating the problem of limited PCB layout space. With the reduced spacing between the four parallel collimating beams, the spacing between the four parallel converging beams will also decrease, allowing for a reduction in the spacing between the four incident waveguides of the silicon photonics chip. This reduction in the spacing between the four incident waveguides of the silicon photonics chip allows for a smaller chip size, thereby reducing costs.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, the optical axis center spacing between two adjacent laser chips is 1mm, and the prism is used to reduce the spacing of the four parallel collimated beams from 1mm to 0.4mm to 0.55mm. The spacing between the four incident waveguides of the silicon photonics chip is 0.4mm to 0.55mm.

[0009] The further beneficial effects of adopting the above are as follows: Since the spacing is reduced to 0.4mm to 0.55mm, only one large polarization-independent optical isolator can be used. Compared with the existing technology that uses four separate polarization-independent optical isolators, the overall size of the polarization-independent optical isolator can be reduced, thereby reducing costs. In addition, the number of polarization-independent optical isolators is reduced from four to one, so there is no problem of four-stage patching and magnetic repulsion between adjacent channels. Since the spacing of the four incident waveguides of the silicon photonic chip is reduced from 1mm to 0.4mm to 0.55mm, the size of the silicon photonic chip can be reduced, thereby reducing costs.

[0010] Furthermore, the prism is used to reduce the spacing between the four parallel collimated beams from 1mm to 0.5mm, and the spacing between the four incident waveguides of the silicon photonics chip is 0.5mm.

[0011] Furthermore, the prism has parallel incident and exit surfaces. Inside the prism, there are sequentially a first reflecting surface, a second reflecting surface, a third reflecting surface, and a fourth reflecting surface. The first and second reflecting surfaces are parallel to each other, the third and fourth reflecting surfaces are parallel to each other, the second and third reflecting surfaces are arranged in a figure-eight shape and the beam end faces the exit surface. The four laser chips are sequentially the first laser chip, the second laser chip, the third laser chip, and the fourth laser chip.

[0012] The beam emitted by the first laser chip is incident on the incident surface between the first and second reflecting surfaces through a collimating lens, and is transmitted from the incident surface to the first reflecting surface. It is first turned 90° by the first reflecting surface and then reflected to the second reflecting surface, and then turned 90° by the second reflecting surface and then reflected to the exit surface.

[0013] The beam emitted by the second laser chip is collimated by a collimating lens and incident on the incident surface located between the second and third reflecting surfaces, and is transmitted from the incident surface to the exit surface.

[0014] The beam emitted by the third laser chip is collimated by a collimating lens and incident on the incident surface located between the third and fourth reflecting surfaces, and then transmitted from the incident surface to the exit surface.

[0015] The beam emitted by the fourth laser chip is collimated by a collimating lens and incident on the incident surface between the third and fourth reflecting surfaces. It is transmitted from the incident surface to the fourth reflecting surface, first turned 90° by the fourth reflecting surface and then reflected back to the third reflecting surface, and then turned 90° by the third reflecting surface and reflected back to the exit surface.

[0016] The further beneficial effect of adopting the above method is that it can effectively reduce the spacing between the four parallel collimated beams from 1mm to 0.5mm.

[0017] Furthermore, along the light propagation direction, the light-emitting side of the prism is coupled sequentially with an array converging lens, a polarization-independent light isolator, and a silicon photonic chip, with the polarization-independent light isolator fixed on the side of the silicon photonic chip.

[0018] Furthermore, along the light propagation direction, a polarization-independent optical isolator, an array converging lens, and a silicon photonic chip are sequentially coupled to the light-emitting side of the prism, with the polarization-independent optical isolator fixed on the light-emitting side of the prism.

[0019] Furthermore, the two output waveguides of the silicon photonics chip are coupled to a dual-channel fiber array.

[0020] Furthermore, each laser chip is fixed to a ceramic heat sink. Attached Figure Description

[0021] Figure 1 This is a structural diagram of an 800G 2XFR4 silicon photonics engine in the prior art;

[0022] Figure 2 This is a first structural diagram of the low-cost 800G 2XFR4 silicon photonics engine in this invention;

[0023] Figure 3 This is a second structural diagram of the low-cost 800G 2XFR4 silicon photonics engine in this invention;

[0024] Figure 4 This is a structural diagram of the prism in this invention.

[0025] The attached diagram lists the components represented by each number as follows:

[0026] 1. Collimating lens; 2. Laser chip; 3. Prism; 310. Incident surface; 320. Exit surface; 330. First reflecting surface; 340. Second reflecting surface; 350. Third reflecting surface; 360. Fourth reflecting surface; 4. Array converging lens; 5. Polarization-independent optical isolator; 6. Silicon photonic chip; 610. Entrance waveguide; 620. Exit waveguide; 7. Dual-channel fiber array; 8. Ceramic heat sink. Detailed Implementation

[0027] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0028] Example 1

[0029] like Figure 2 , Figure 3As shown, a low-cost 800G 2XFR4 silicon photonics engine includes: four collimating lenses 1 arranged side by side, and each collimating lens 1 has a laser chip 2 coupled to its incident light side, i.e., it has four laser chips 2. The output light sides of the four collimating lenses 1 are coupled to a prism 3 used to reduce the spacing between the four parallel collimating beams.

[0030] like Figure 2 As shown, on the light-emitting side of prism 3, an array converging lens 4, a polarization-independent light isolator 5, and a silicon photonic chip 6 are sequentially coupled along the light propagation direction. Specifically, this can be understood as follows:

[0031] The four parallel collimated beams emitted by the prism 3 are coupled into the same array converging lens 4. The array converging lens 4 converts the four parallel collimated beams into four parallel converged beams. Then, the four parallel converged beams are coupled into the four incident waveguides 610 of the silicon photonic chip 6 through the same polarization-independent light isolator 5.

[0032] Or, such as Figure 3 As shown, on the light-emitting side of prism 3, a polarization-independent optical isolator 5, an array converging lens 4, and a silicon photonic chip 6 are sequentially coupled along the light propagation direction. Specifically, this can be understood as follows:

[0033] The four parallel collimated beams emitted from the prism 3 are coupled into the same polarization-independent light isolator 5, and then coupled into the same array converging lens 4. The array converging lens 4 converts the four parallel collimated beams into four parallel converged beams, which are then coupled into the four incident waveguides 610 of the silicon photonic chip 6 respectively.

[0034] This invention comprises four collimating lenses 1 and one array converging lens 4, totaling five lenses. While meeting the same coupling tolerance requirements, the number of lenses is reduced, thereby reducing the number of coupling operations, shortening coupling time, and improving production efficiency. Because the spacing between the four parallel collimated beams is reduced, only one large polarization-independent optical isolator 5 is needed. Compared to the prior art which uses four separate polarization-independent optical isolators, the overall size of the polarization-independent optical isolator 5 can be reduced, thus lowering costs. Furthermore, since the number of polarization-independent optical isolators 5 is reduced from four to one, there is no need for four patching operations or adjacent channels. The magnetic repulsion issue does not affect the placement efficiency. In addition, the problem of adhesive overflow in the polarization-independent light isolator 5 and the array converging lens 4 can be eliminated, which reduces the overall space occupied by the polarization-independent light isolator 5, collimating lens 1 and array converging lens 4, effectively alleviating the problem of tight PCB layout space. With the reduced spacing of the four parallel collimating beams, the spacing of the four parallel converging beams will also be reduced, so the spacing of the four incident waveguides 610 of the silicon photonics chip 6 can also be reduced. Since the spacing of the four incident waveguides 610 of the silicon photonics chip 6 is reduced, the size of the silicon photonics chip 6 can be reduced, thereby reducing costs.

[0035] Example 2

[0036] like Figure 2 As shown, this embodiment is a further improvement on embodiment 1, as detailed below:

[0037] The optical axis center distance between two adjacent laser chips 2 is 1mm. Prism 3 is used to reduce the spacing of the four parallel collimated beams from 1mm to 0.4mm–0.55mm. Since the spot diameter is generally 0.4mm or larger, the reduced spacing of the four parallel collimated beams cannot be too small; therefore, 0.4mm–0.55mm is chosen. In this invention, the spacing of the four parallel collimated beams always satisfies a value greater than or equal to the spot diameter. If the reduction in size is not significant, the reduction in size for the polarization-independent isolator 5 will not be significant, thus the cost reduction effect will not be obvious. Since the spacing is reduced to 0.4mm–0.55mm… Therefore, only one large polarization-independent optical isolator 5 is needed. Compared with the existing technology that uses four separate polarization-independent optical isolators, the overall size of the polarization-independent optical isolator 5 can be reduced, thereby reducing costs. In addition, the number of polarization-independent optical isolators 5 is reduced from four to one, so there is no problem of four-stage patching and magnetic repulsion between adjacent channels. The spacing between the four incident waveguides 610 of the silicon photonic chip 6 is 0.4mm to 0.55mm. Since the spacing between the four incident waveguides 610 of the silicon photonic chip 6 is reduced from 1mm to 0.4mm to 0.55mm, the size of the silicon photonic chip 6 can be reduced, thereby reducing costs.

[0038] Furthermore: Prism 3 is used to reduce the spacing between the four parallel collimated beams from 1mm to 0.5mm, that is, to reduce the spacing by half. The spacing between the four incident waveguides 610 of the silicon photonic chip 6 is 0.5mm, that is, to reduce the spacing by half. Example 3

[0039] like Figure 2 , Figure 3 , Figure 4 As shown, this embodiment is a further improvement on embodiment 1 or 2, as detailed below:

[0040] The prism 3 has an incident surface 310 and an exit surface 320 that are parallel to each other. Inside the prism 3, there are a first reflecting surface 330, a second reflecting surface 340, a third reflecting surface 350 and a fourth reflecting surface 360 ​​in sequence. The first reflecting surface 330 and the second reflecting surface 340 are parallel to each other, the third reflecting surface 350 and the fourth reflecting surface 360 ​​are parallel to each other, and the second reflecting surface 340 and the third reflecting surface 350 are arranged in a figure-eight shape with the nozzle end facing the exit surface 320.

[0041] The four laser chips 2 are, in order, the first laser chip, the second laser chip, the third laser chip, and the fourth laser chip, according to... Figure 2 , Figure 3 The view shown, from bottom to top, shows the first laser chip, the second laser chip, the third laser chip, and the fourth laser chip;

[0042] The light beam emitted by the first laser chip is incident on the incident surface 310 between the first reflecting surface 330 and the second reflecting surface 340 through the collimating lens 1, and is transmitted from the incident surface 310 to the first reflecting surface 330. Then, it is first turned 90° from the first reflecting surface 330 and reflected to the second reflecting surface 340. Then, it is turned 90° from the second reflecting surface 340 and reflected to the exit surface 320. Finally, it is emitted through the exit surface 320.

[0043] The beam emitted by the second laser chip is incident on the incident surface 310 located between the second reflecting surface 340 and the third reflecting surface 350 through the collimating lens 1, and is transmitted from the incident surface 310 to the exit surface 320, and finally exits through the exit surface 320.

[0044] The beam emitted by the third laser chip is incident on the incident surface 310 located between the third reflecting surface 350 and the fourth reflecting surface 360 ​​through the collimating lens 1, and is transmitted from the incident surface 310 to the exit surface 320, and finally exits through the exit surface 320.

[0045] The beam emitted by the fourth laser chip is incident on the incident surface 310 between the third reflecting surface 350 and the fourth reflecting surface 360 ​​through the collimating lens 1, and is transmitted from the incident surface 310 to the fourth reflecting surface 360. Then, it is first turned 90° by the fourth reflecting surface 360 ​​and reflected back to the third reflecting surface 350. Then, it is turned 90° by the third reflecting surface 350 and reflected back to the exit surface 320. Finally, it is emitted out through the exit surface 320.

[0046] The above description can be understood as follows: the four parallel collimated beams emitted by the first laser chip, the second laser chip, the third laser chip, and the fourth laser chip, after passing through four collimating lenses 1, are respectively denoted as channel 1, channel 2, channel 3, and channel 4. Figure 2 , Figure 3 The view shown, from bottom to top, is channel 1, channel 2, channel 3 and channel 4. After two 90° turns, the light from channel 1 approaches the light from channel 2 and is 0.5mm away from the light from channel 2. After two 90° turns, the light from channel 4 enters the middle of the light from channel 2 and channel 3 and is 0.5mm away from both the light from channel 2 and channel 3.

[0047] In this embodiment, prism 3 is made of two parallelogram prisms and a trapezoidal prism glued together. The trapezoidal prism is located between the two parallelogram prisms. According to the perspective shown in the figure, from bottom to top, it can be understood as: the first parallelogram prism, the trapezoidal prism, and the second parallelogram prism.

[0048] Example 4

[0049] like Figure 2 As shown, this embodiment is a further improvement on any one of embodiments 1 to 3, as detailed below:

[0050] Along the light propagation direction, the light-emitting side of prism 3 is coupled with an array converging lens 4, a polarization-independent light isolator 5, and a silicon photonic chip 6. The polarization-independent light isolator 5 is fixed on the side of the silicon photonic chip 6.

[0051] Example 5

[0052] like Figure 3 As shown, this embodiment is a further improvement on any one of embodiments 1 to 3, as detailed below:

[0053] Along the light propagation direction, the light-emitting side of prism 3 is coupled with a polarization-independent light isolator 5, an array converging lens 4, and a silicon photonic chip 6. The polarization-independent light isolator 5 is fixed on the light-emitting side of prism 3.

[0054] Example 6

[0055] like Figure 2 , Figure 3 As shown, this embodiment is a further improvement on any one of embodiments 1 to 5, as detailed below:

[0056] The two output waveguides 620 of the silicon photonic chip 6 are coupled to a dual-channel fiber array 7. In addition, each laser chip 2 is fixed on a ceramic heat sink 8, that is, it has four ceramic heat sinks 8.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A low-cost 800G 2XFR4 silicon photonics engine, characterized in that, include: Four collimating lenses (1) are arranged side by side. Each collimating lens (1) has a laser chip (2) coupled to its incident light side. The light-emitting side of the four collimating lenses (1) is coupled to a prism (3) used to reduce the spacing between the four parallel collimating beams. The light-emitting side of the prism (3) is coupled in sequence along the light propagation direction to an array converging lens (4), a polarization-independent light isolator (5), and a silicon photonic chip (6). Alternatively, the light-emitting side of the prism (3) is coupled in sequence along the light propagation direction to a polarization-independent light isolator (5), an array converging lens (4), and a silicon photonic chip (6). The prism (3) has an incident surface (310) and an exit surface (320) that are parallel to each other. The prism (3) has a first reflecting surface (330), a second reflecting surface (340), a third reflecting surface (350) and a fourth reflecting surface (360) in sequence inside. The first reflecting surface (330) and the second reflecting surface (340) are parallel to each other. The third reflecting surface (350) and the fourth reflecting surface (360) are parallel to each other. The second reflecting surface (340) and the third reflecting surface (350) are arranged in a figure-eight shape and the beam end faces the exit surface (320). The four laser chips (2) are the first laser chip, the second laser chip, the third laser chip and the fourth laser chip in sequence. The light beam emitted by the first laser chip is incident on the incident surface (310) between the first reflecting surface (330) and the second reflecting surface (340) through the collimating lens (1), and is transmitted from the incident surface (310) to the first reflecting surface (330), first turning 90° from the first reflecting surface (330) and then reflected to the second reflecting surface (340), and then turning 90° from the second reflecting surface (340) and then reflected to the exit surface (320). The beam emitted by the second laser chip is incident on the incident surface (310) located between the second reflecting surface (340) and the third reflecting surface (350) through the collimating lens (1), and is transmitted from the incident surface (310) to the exit surface (320). The beam emitted by the third laser chip is incident on the incident surface (310) located between the third reflecting surface (350) and the fourth reflecting surface (360) through the collimating lens (1), and is transmitted from the incident surface (310) to the exit surface (320). The beam emitted by the fourth laser chip is incident on the incident surface (310) between the third reflecting surface (350) and the fourth reflecting surface (360) through the collimating lens (1), and is transmitted from the incident surface (310) to the fourth reflecting surface (360). It is first turned 90° by the fourth reflecting surface (360) and then reflected to the third reflecting surface (350), and then turned 90° by the third reflecting surface (350) and then reflected to the exit surface (320).

2. The low-cost 800G 2XFR4 silicon photonics engine according to claim 1, characterized in that, The optical axis center distance between two adjacent laser chips (2) is 1 mm. The prism (3) is used to reduce the distance between the four parallel collimated beams from 1 mm to 0.4 mm to 0.55 mm. The distance between the four incident waveguides (610) of the silicon photonic chip (6) is 0.4 mm to 0.55 mm.

3. A low-cost 800G 2XFR4 silicon photonics engine according to claim 1 or 2, characterized in that, The prism (3) is used to reduce the spacing between the four parallel collimated beams from 1 mm to 0.5 mm, and the spacing between the four incident waveguides (610) of the silicon photonic chip (6) is 0.5 mm.

4. A low-cost 800G 2XFR4 silicon photonics engine according to claim 1, characterized in that, The light-emitting side of the prism (3) is coupled sequentially with an array converging lens (4), a polarization-independent light isolator (5), and a silicon photonic chip (6) along the light propagation direction. The polarization-independent light isolator (5) is fixed on the side of the silicon photonic chip (6).

5. A low-cost 800G 2XFR4 silicon photonics engine according to claim 1, characterized in that, The light-emitting side of the prism (3) is coupled sequentially with a polarization-independent light isolator (5), an array converging lens (4), and a silicon photonic chip (6) along the light propagation direction. The polarization-independent light isolator (5) is fixed on the light-emitting side of the prism (3).

6. A low-cost 800G 2XFR4 silicon photonics engine according to claim 1, characterized in that, The two output waveguides (620) of the silicon photonic chip (6) are coupled to a dual-channel fiber array (7).

7. A low-cost 800G 2XFR4 silicon photonics engine according to claim 1, characterized in that, Each laser chip (2) is fixed on a ceramic heat sink (8).

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