A 400G DR4 silicon photonics chip, its optical engine, and coupling method

Abstract

This invention relates to a 400G DR4 silicon photonics chip, with two input waveguides arranged in a figure-eight pattern and the beam ends facing outwards. One input waveguide is tilted 8°±1° in the positive direction, and the other is tilted 8°±1° in the negative direction. Each input waveguide is coupled to four output waveguides. A 400G DR4 silicon photonics optical engine comprises an optical emitting component, an aspherical lens, an optical isolator, a prism, and the 400G DR4 silicon photonics chip, coupled sequentially along the light propagation direction. The optical axis center of the optical emitting component is located precisely in the middle of the two input waveguides in the 400G DR4 silicon photonics chip. The horizontally emitted light from the optical emitting component is deflected 8°±1° in either the positive or negative direction by the prism and then coupled into the input waveguide tilted 8°±1° in either the positive or negative direction. The advantages are: the laser chip in the optical emitting component does not need to be tilted 8°±1° during mounting, reducing mounting difficulty and improving optical power and yield.

Description

Technical Field

[0001] This invention relates to the field of optical engine technology, specifically to a 400G DR4 silicon photonic chip, an optical engine, and a coupling method. Background Technology

[0002] The specific structure of a traditional 400G DR4 silicon photonics engine is as follows: Figure 1 As shown, it includes: a 400G DR4 silicon photonics chip, an optical emitting component, an aspherical lens, an optical isolator, and a multi-channel fiber array. The 400G DR4 silicon photonics chip has one input waveguide and four output waveguides. To reduce light reflection, both the input and output waveguides are tilted forward by 8°±1°. The input waveguide is coupled to the four output waveguides. Specifically, the input waveguide is first split into two paths by a 1×2 equal-ratio coupler, and then split into four paths by two more 1×2 equal-ratio couplers. The emitted light from the optical emitting component is coupled into the input waveguide of the 400G DR4 silicon photonics chip after passing through the aspherical lens and the optical isolator. Because the input waveguide is tilted forward by 8°±1°, the optical emitting component, aspherical lens, and optical isolator are all arranged with a forward tilt of 8°±1°. However, the laser chip in the optical emitting component is tilted forward by 8°±1°, making mounting difficult. In addition, the quality of the input waveguide coupling end face is not high, and some 400G... The input waveguide insertion loss of the DR4 silicon photonics chip is about 1dB higher. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a 400G DR4 silicon photonics chip, an optical engine, and a coupling method 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 400G DR4 silicon photonics chip, which has two input waveguides and four output waveguides. The two input waveguides are arranged in a figure-eight shape with the beam ends facing outward. One of the two input waveguides is positively tilted at 8°±1° and the other input waveguide is negatively tilted at 8°±1°. Each input waveguide is coupled to the four output waveguides respectively, and all four output waveguides are positively tilted at 8°±1°.

[0005] The beneficial effects of this invention are as follows: The 400G DR4 silicon photonics chip is designed with two input waveguides, one of which is tilted positively by 8°±1° and the other by 8°±1° negatively. Each input waveguide is coupled to one of the four output waveguides. Therefore, any one of the two input waveguides can propagate light proportionally to the four output waveguides. When applied to a 400G DR4 silicon photonics engine, the optical axis center of the light emitting component is located in the middle of the two input waveguides in the 400G DR4 silicon photonics chip. First, a prism is coupled between the optical isolator and the 400G DR4 silicon photonics chip in a non-fixed manner. Then, an aspherical lens is coupled between the light emitting component and the optical isolator, and the coupled light power P1 is recorded. Then, the prism is flipped 180° and coupled between the optical isolator and the 400G DR4 silicon photonics chip in a non-fixed manner. Between the DR4 silicon photonics chips, an aspherical lens is coupled between the optical emitting component and the optical isolator, and the coupled optical power P2 is recorded. The magnitudes of the coupled optical power P1 and coupled optical power P2 are compared, and the prism is fixed in the direction of the one with the larger optical power. With this structure, the laser chip in the optical emitting component does not need to be tilted by 8°±1° for patching, which not only reduces the patching difficulty but also improves the optical power and yield. When one of the input waveguides is damaged or has a large insertion loss, the other input waveguide can be used, so that the 400G DR4 silicon photonics chip can still be used.

[0006] Based on the above technical solution, the present invention can be further improved as follows.

[0007] Furthermore, the two input waveguides are coupled to the two input terminals of a 2×2 equal ratio coupler, the two output terminals of the 2×2 equal ratio coupler are coupled to the input terminals of two 1×2 equal ratio couplers respectively, and the four output terminals of the two 1×2 equal ratio couplers are coupled to the four output waveguides respectively.

[0008] The further beneficial effect of adopting the above is that it can satisfy the requirement that each input waveguide propagates light to the four output waveguides in equal proportion.

[0009] Furthermore, the four output terminals of the two 1×2 equal-ratio couplers are each coupled to the four output waveguides via an MZM modulator.

[0010] Based on the above technical solution, the present invention also provides a 400G DR4 silicon photonics engine, comprising: an optical emitting component, an aspherical lens, an optical isolator, a prism, and a 400G DR4 silicon photonics chip. The optical emitting component, the aspherical lens, the optical isolator, the prism, and the 400G DR4 silicon photonics chip are coupled sequentially along the light propagation direction. The optical emitting component is arranged horizontally, and its optical axis center is located in the middle of the two input waveguides in the 400G DR4 silicon photonics chip. The horizontally emitted light from the optical emitting component is deflected by the prism at a forward or reverse angle of 8°±1° and then coupled into the input waveguide of the 400G DR4 silicon photonics chip, which is tilted at a forward or reverse angle of 8°±1°.

[0011] The further beneficial effects of the above-mentioned method are as follows: The optical axis center of the optical emitting component is located precisely in the middle of the two input waveguides in the 400G DR4 silicon photonics chip. First, a prism is coupled between the optical isolator and the 400G DR4 silicon photonics chip in a non-fixed manner. Then, an aspherical lens is coupled between the optical emitting component and the optical isolator, and the coupled optical power P1 is recorded. Next, the prism is rotated 180° and coupled between the optical isolator and the 400G DR4 silicon photonics chip in a non-fixed manner. Then, an aspherical lens is coupled between the optical emitting component and the optical isolator, and the coupled optical power P2 is recorded. The magnitudes of coupled optical power P1 and coupled optical power P2 are compared, and the prism is fixed in the direction of the larger optical power. With this structure, the laser chip in the optical emitting component does not need to be tilted by 8°±1° during mounting, which not only reduces the mounting difficulty but also improves optical power and yield. When one input waveguide is damaged or has high insertion loss, the other input waveguide can be used, allowing the 400G DR4 silicon photonics chip to continue to be used.

[0012] Furthermore, the input waveguide is made of silicon dioxide, the prism is made of silicon dioxide, the refractive index of silicon dioxide is 1.44 to 1.46, and the incident surface of the prism is tilted at 10.08° to 13.18°.

[0013] The further beneficial effects of adopting the above are: it can satisfy the requirement that the emitted light be deflected 8°±1° in the forward direction by the prism and then coupled into the input waveguide of the 400G DR4 silicon photonics chip with a forward tilt of 8°±1°, or that the emitted light be deflected 8°±1° in the reverse direction by the prism and then coupled into the input waveguide of the 400G DR4 silicon photonics chip with a reverse tilt of 8°±1°.

[0014] Furthermore, the light-reflecting surface of the prism is coated with an anti-reflective film.

[0015] The further beneficial effects of adopting the above are: reducing light reflection and improving coupling efficiency.

[0016] Furthermore, the prism is bonded to the 400G DR4 silicon photonic chip using adhesive with a refractive index of 1.4 to 1.45.

[0017] The further beneficial effects of the above are as follows: since the glue with a point refractive index of 1.4 to 1.45 is used between the prism and the 400G DR4 silicon photonic chip, the light reflection at the input waveguide end face of the 400G DR4 silicon photonic chip can be reduced, and the mode spot of the input waveguide can be increased to further improve the coupling efficiency.

[0018] Furthermore, the light emitting component includes a ceramic heat sink and a laser chip integrated on the ceramic heat sink.

[0019] Furthermore, the four output waveguides of the 400G DR4 silicon photonics chip are coupled to a multi-channel fiber array, with the end face of the multi-channel fiber array tilted at 8°±1°.

[0020] Based on the above technical solution, the present invention also provides a coupling method for a 400G DR4 silicon photonics engine, which is used to couple a 400G DR4 silicon photonics engine, comprising the following steps:

[0021] S1. Horizontally fix the optical emitting component, optical isolator and 400G DR4 silicon photonic chip in sequence along the optical propagation direction, and make the optical axis center of the optical emitting component located in the middle of the two input waveguides in the 400G DR4 silicon photonic chip;

[0022] S2. The prism is coupled between the optical isolator and the 400G DR4 silicon photonic chip in a non-fixed manner;

[0023] S3. Couple an aspherical lens between the optical emitting component and the optical isolator, and record the coupled optical power P1 of the 400G DR4 silicon photonic chip;

[0024] S4. Flip the prism 180° and couple it between the optical isolator and the 400G DR4 silicon photonic chip in a non-fixed manner;

[0025] S5. Couple an aspherical lens between the optical emitting component and the optical isolator, and record the coupled optical power P2 of the 400G DR4 silicon photonic chip;

[0026] S6. Compare the magnitudes of the coupled optical power P1 and the coupled optical power P2, and select the scheme with the larger coupled optical power. Then fix the prism according to the prism distribution in the scheme.

[0027] S7, Fixed aspherical lens. Attached Figure Description

[0028] Figure 1 This is a structural diagram of a 400G DR4 silicon photonics engine in the prior art;

[0029] Figure 2 This is a structural diagram of the 400G DR4 silicon photonics chip in this invention;

[0030] Figure 3 This is a first structural diagram of the 400G DR4 silicon photonics engine in this invention;

[0031] Figure 4 This is a second structural diagram of the 400G DR4 silicon photonics engine in this invention.

[0032] The attached diagram lists the components represented by each number as follows:

[0033] 1. 400G DR4 silicon photonics chip, 110. Input waveguide, 120. Output waveguide, 130. 2×2 equal ratio coupler, 140. 1×2 equal ratio coupler, 150. MZM modulator, 2. Optical emission component, 210. Ceramic heat sink, 220. Laser chip, 3. Aspherical lens, 4. Optical isolator, 5. Prism, 6. Multi-channel fiber array. Detailed Implementation

[0034] 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.

[0035] Example 1

[0036] like Figure 2 As shown, a 400G DR4 silicon photonics chip has two input waveguides 110 and four output waveguides 120. The two input waveguides 110 are arranged in a figure-eight shape, with the beam ends of the figure-eight facing outwards (i.e., towards the light emitting component 2). One of the two input waveguides 110 is tilted positively by 8°±1°, preferably 8°, and the other input waveguide 110 is tilted negatively by 8°±1°, preferably 8°. This can also be understood as the two input waveguides 110 being mirror images of each other. Each input waveguide 110 is coupled to one of the four output waveguides 120. Alternatively, one of the two input waveguides 110 is coupled to the other of the four output waveguides 120, and the other of the two input waveguides 110 is also coupled to the four output waveguides 120. All four output waveguides 120 are tilted positively by 8°±1°, preferably 8°.

[0037] The 400G DR4 silicon photonics chip 1 is designed with two input waveguides 110, one of which is tilted positively by 8°±1°, and the other is tilted negatively by 8°±1°. Each input waveguide 110 is coupled to four output waveguides 120. Therefore, any one of the two input waveguides 110 can propagate light proportionally to the four output waveguides 120. When applied in a 400G DR4 silicon photonics engine, the optical axis center of the light emitting component 2 is located at the exact midpoint between the two input waveguides 110 in the 400G DR4 silicon photonics chip 1. The prism 5 is first coupled to the optical isolator 4 and the 400G in a non-fixed manner. Between the DR4 silicon photonics chip 1, an aspherical lens 3 is coupled between the optical emitting component 2 and the optical isolator 4, and the coupled optical power P1 is recorded. Then, the prism 5 is rotated 180° and coupled between the optical isolator 4 and the 400G DR4 silicon photonics chip 1 in a non-fixed manner. Then, the aspherical lens 3 is coupled between the optical emitting component 2 and the optical isolator 4, and the coupled optical power P2 is recorded. The magnitudes of the coupled optical power P1 and the coupled optical power P2 are compared. The prism 5 is fixed in the direction of the one with the larger optical power. With this structure, the laser chip 220 in the optical emitting component 2 does not need to be tilted by 8°±1° for patching. This not only reduces the patching difficulty but also improves the optical power and yield. When one of the input waveguides 110 is damaged or has a large insertion loss, the other input waveguide 110 can be used, so that the 400G DR4 silicon photonics chip 1 can still be used.

[0038] Example 2

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

[0040] Two input waveguides 110 are coupled to the two input terminals of a 2×2 equal-ratio coupler 130. The two output terminals of the 2×2 equal-ratio coupler 130 are coupled to the input terminals of two 1×2 equal-ratio couplers 140, respectively. Since there are two 1×2 equal-ratio couplers 140, there are four output terminals. The four output terminals of the two 1×2 equal-ratio couplers 140 are coupled to four output waveguides 120, respectively. Taking one of the input waveguides 110 as an example, when the emitted light is coupled into the input waveguide 110, the initial emitted light will be split into two beams by the 2×2 equal ratio coupler 130 with a splitting ratio of 50:50, and will be propagated to two 1×2 equal ratio couplers 140 respectively. Each 1×2 equal ratio coupler 140 will then split the emitted light, which accounts for 50% of the initial emitted light, into two beams with a splitting ratio of 50:50, and will be propagated to the two output waveguides 120 they are coupled to respectively.

[0041] Furthermore, the four output terminals of the two 1×2 equal ratio couplers 140 are respectively coupled to the four output waveguides 120 via an MZM modulator 150, thus having four MZM modulators 150.

[0042] Example 3

[0043] like Figure 3 , Figure 4 As shown, a 400G DR4 silicon photonics engine includes: an optical emitting component 2, an aspherical lens 3, an optical isolator 4, a prism 5, and a 400G DR4 silicon photonics chip 1 as described in Embodiment 1 or 2. The optical emitting component 2, the aspherical lens 3, the optical isolator 4, the prism 5, and the 400G DR4 silicon photonics chip 1 are coupled sequentially along the light propagation direction, and the optical emitting component 2 is arranged horizontally with its optical axis center located at the exact middle of the two input waveguides 110 in the 400G DR4 silicon photonics chip 1.

[0044] The horizontally emitted light from the optical emitting component 2 is deflected by prism 5 at a forward angle of 8°±1° and then coupled into the input waveguide 110 of the 400G DR4 silicon photonics chip 1, which is tilted at a forward angle of 8°±1°. Figure 3 As shown;

[0045] Alternatively, the horizontally emitted light from the optical emitting component 2 is reversed by prism 5 by 8°±1° and then coupled into the input waveguide 110 of the 400G DR4 silicon photonic chip 1, which is tilted 8°±1° in the opposite direction. Figure 4 As shown.

[0046] Example 4

[0047] like Figure 3 , Figure 4 As shown, this embodiment is a further improvement on embodiment 3, as detailed below:

[0048] The material of prism 5 is preferably the same as that of the input waveguide 110, i.e., the same material. The material of the input waveguide 110 is usually silicon dioxide, so the material of prism 5 is silicon dioxide. The refractive index of silicon dioxide is 1.44 to 1.46. The incident surface of prism 5 is tilted at 10.08° to 13.18°. The specific tilt angle is calculated as follows:

[0049] Si n(a) × air refractive index = sin(b) × prism refractive index. Since prism 5 reverses the emitted light by 8° ± 1° or forwards by 8° ± 1°, then b = 8° ± 1°. The refractive index of silicon dioxide is 1.44 to 1.46, so the refractive index of the prism is also 1.44 to 1.46. Therefore, the incident surface of prism 5 is tilted vertically by 10.08° to 13.18°. In this embodiment, b is preferably 8°, and the refractive index of silicon dioxide is preferably 1.45. Therefore, the incident surface of prism 5 is tilted by 11.64°.

[0050] Example 5

[0051] like Figure 3 , Figure 4 As shown, this embodiment is a further improvement on embodiment 4, as detailed below:

[0052] The light-reflecting surface of prism 5 is coated with an anti-reflection film to reduce light reflection and improve coupling efficiency.

[0053] Example 6

[0054] like Figure 3 , Figure 4 As shown, this embodiment is a further improvement on embodiment 4 or 5, as detailed below:

[0055] The prism 5 is bonded to the 400G DR4 silicon photonic chip 1 using adhesive with a refractive index of 1.4 to 1.45. Since the adhesive with a point refractive index of 1.4 to 1.45 is used between the prism 5 and the 400G DR4 silicon photonic chip 1, the light reflection at the end face of the input waveguide 110 of the 400G DR4 silicon photonic chip 1 can be reduced, and the mode pattern of the input waveguide 110 can be improved to further enhance the coupling efficiency.

[0056] Example 7

[0057] like Figure 3 , Figure 4 As shown, this embodiment is a further improvement on any one of embodiments 3 to 6, as detailed below:

[0058] The light emitting component 2 includes a ceramic heat sink 210 and a laser chip 220 integrated on the ceramic heat sink 210.

[0059] Furthermore: the four output waveguides 120 of the 400G DR4 silicon photonics chip are coupled to the multi-channel fiber array 6, and the end face of the multi-channel fiber array 6 is tilted at 8°±1°, preferably 8°.

[0060] Example 8

[0061] A coupling method for a 400G DR4 silicon photonics engine, used to couple the aforementioned 400G DR4 silicon photonics engine, includes the following steps:

[0062] S1. Fix the optical emitting component 2, optical isolator 4 and 400G DR4 silicon photonic chip horizontally in sequence along the direction of light propagation, and make the optical axis center of the optical emitting component 2 located in the middle of the two input waveguides 110 in the 400G DR4 silicon photonic chip 1.

[0063] S2. The prism 5 is coupled between the optical isolator 4 and the 400G DR4 silicon photonic chip in a non-fixed manner;

[0064] S3. Couple the aspherical lens 3 between the optical emitting component 2 and the optical isolator 4, and record the coupled optical power P1;

[0065] S4. Flip the prism 5 180° and couple the prism 5 between the optical isolator 4 and the 400G DR4 silicon photonic chip 1 in a non-fixed manner;

[0066] S5. Couple the aspherical lens 3 between the optical emitting component 2 and the optical isolator 4, and record the coupled optical power P2;

[0067] S6. Compare the magnitudes of the coupled optical power P1 and the coupled optical power P2, and select the scheme with the larger coupled optical power. Then fix the prism 5 according to the distribution of the prism 5 in the scheme. That is to say, fix the prism 5 in the direction of the larger optical power.

[0068] S7, Fixed aspherical lens 3.

[0069] 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 400G DR4 silicon photonics engine, characterized in that, include: The light emitting component (2), the aspherical lens (3), the optical isolator (4), the prism (5), and the 400G DR4 silicon photonic chip (1); The 400G DR4 silicon photonics chip (1) has two input waveguides (110) and four output waveguides (120). The two input waveguides (110) are arranged in a figure-eight shape with the beam end facing outward. One of the two input waveguides (110) is tilted positively by 8°±1° and the other input waveguide (110) is tilted negatively by 8°±1°. Each input waveguide (110) is coupled to the four output waveguides (120). Any one of the two input waveguides (110) can propagate light to the four output waveguides (120). All four output waveguides (120) are tilted positively by 8°±1°. The optical emitting component (2), aspherical lens (3), optical isolator (4), prism (5), and 400G DR4 silicon photonic chip (1) are coupled sequentially along the light propagation direction. The optical emitting component (2) is arranged horizontally, and its optical axis center is located in the middle of the two input waveguides (110) in the 400G DR4 silicon photonic chip (1). The horizontally emitted light from the optical emitting component (2) is coupled into the input waveguide (110) of the 400G DR4 silicon photonic chip (1) after being bent 8°±1° in the positive direction by the prism (5); or, the horizontally emitted light from the optical emitting component (2) is coupled into the input waveguide (110) of the 400G DR4 silicon photonic chip (1) after being bent 8°±1° in the reverse direction by the prism (5). The coupling method is as follows: S1. Fix the optical emitting component (2), optical isolator (4) and 400G DR4 silicon photonic chip horizontally in sequence along the direction of light propagation, and make the optical axis center of the optical emitting component (2) located in the middle of the two input waveguides (110) in the 400G DR4 silicon photonic chip (1); S2. The prism (5) is coupled between the optical isolator (4) and the 400G DR4 silicon photonic chip (1) in a non-fixed manner; S3. Couple an aspherical lens (3) between the optical emitting component (2) and the optical isolator (4), and record the coupled optical power P1; S4. Flip the prism (5) 180° and couple the prism (5) between the optical isolator (4) and the 400G DR4 silicon photonic chip (1) in a non-fixed manner; S5. Couple an aspherical lens (3) between the optical emitting component (2) and the optical isolator (4), and record the coupled optical power P2; S6. Compare the magnitudes of the coupled optical power P1 and the coupled optical power P2, and select the scheme with the larger coupled optical power. Then fix the prism (5) according to the distribution pattern of the prism (5) in the scheme. S7. Fix the aspherical lens (3).

2. A 400G DR4 silicon photonics engine according to claim 1, characterized in that, Two input waveguides (110) are coupled to the two input ends of a 2×2 equal ratio coupler (130), the two output ends of the 2×2 equal ratio coupler (130) are coupled to the input ends of two 1×2 equal ratio couplers (140), and the four output ends of the two 1×2 equal ratio couplers (140) are coupled to four output waveguides (120).

3. A 400G DR4 silicon photonics engine according to claim 2, characterized in that, The four output terminals of the two 1×2 equal ratio couplers (140) are coupled to the four output waveguides (120) via an MZM modulator (150).

4. A 400G DR4 silicon photonics engine according to claim 1, characterized in that, The input waveguide (110) is made of silicon dioxide, the prism (5) is made of silicon dioxide, the refractive index of silicon dioxide is 1.44 to 1.46, and the incident surface of the prism (5) is tilted at 10.08° to 13.18°.

5. A 400G DR4 silicon photonics engine according to claim 1 or 4, characterized in that, The light-reflecting surface of the prism (5) is coated with an anti-reflective film.

6. A 400G DR4 silicon photonics engine according to claim 4, characterized in that, The prism (5) is bonded to the 400G DR4 silicon photonic chip (1) with an adhesive with a refractive index of 1.4 to 1.

45.

7. A 400G DR4 silicon photonics engine according to claim 1, characterized in that, The light emitting component (2) includes: a ceramic heat sink (210) and a laser chip (220) integrated on the ceramic heat sink (210).

8. A 400G DR4 silicon photonics engine according to claim 1, characterized in that, The four output waveguides (120) of the 400G DR4 silicon photonic chip are coupled to a multi-channel fiber array (6), and the end face of the multi-channel fiber array (6) is tilted at 8°±1°.

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