400G DR4 silicon optical chip, optical module and coupling method

Abstract

The invention relates to a 400G DR4 silicon optical chip, which is characterized in that one input end of a 2 * 2 coupler is coupled with an input waveguide, the other input end of the 2 * 2 coupler is coupled with one of four output waveguides, the output waveguide coupled by the 2 * 2 coupler reversely splits light to enter the 2 * 2 coupler, and the output waveguide is coupled with the other input end of the 2 * 2 coupler; light of each output end of the 2 * 2 coupler is divided into the two MZM modulators at equal ratio, and the four MZM modulators are respectively coupled with the four output waveguides. A 400G DR4 silicon optical module is characterized in that a light emitting end is coupled with an input waveguide of a 400G DR4 silicon optical chip through an aspheric lens and an optical isolator in sequence, and four output waveguides of the 400G DR4 silicon optical chip are coupled with a multi-channel optical fiber array. The beneficial effects are that even if the MPD and the MPD current amplification circuit are not provided, when the MPD current amplification circuit is applied to the optical module, the aspherical lens and the multi-channel optical fiber array can be coupled at the optimal position.

Description

Technical Field

[0001] The present invention relates to the technical field of optical modules, and in particular to a 400G DR4 silicon photonic chip, an optical module and a coupling method. Background Art

[0002] The structure of traditional 400G DR4 silicon photonic chip is as follows: Figure 1 As shown, it has an input waveguide, which divides less than or equal to 1% of the light into an MPD (detector), and the rest of the light (the remaining light greater than or equal to 99%) is divided into a first 1×2 equal ratio coupler, and the first 1×2 equal ratio coupler divides the light into two equal ratios, and couples them into two second 1×2 equal ratio couplers respectively, and each second 1×2 equal ratio coupler also divides the light into two equal ratios. Since there are two second 1×2 equal ratio couplers, the rest of the light will be divided into four equal ratios and coupled into four MZM modulators, and then the four MZM modulators are respectively coupled with four output waveguides. When the 400G DR4 silicon photonic chip is applied to 400G In the DR4 silicon photonics module, in order to couple the aspheric lens, the input side of the light source needs to distribute a portion of the input waveguide light to the MPD to monitor the optical power coupled to the input waveguide. Due to the large insertion loss of the silicon photonics chip, in order to ensure that sufficient optical power enters the MZM modulator, the light from the input waveguide distributed to the MPD is generally ≤1%, resulting in a very weak response circuit of the MPD. In particular, the aspheric lens needs to amplify the MPD current during the coupling and light-finding process to facilitate reading, thereby increasing the circuit complexity. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a 400G DR4 silicon photonic chip, an optical module and a coupling method to overcome the deficiencies in the above-mentioned prior art.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: a 400G DR4 silicon photonic chip, comprising: an input waveguide and a 2×2 coupler, an input end of the 2×2 coupler is coupled to the input waveguide, the other input end of the 2×2 coupler is coupled to one of the four output waveguides, the output waveguide coupled by the 2×2 coupler is reversely split and enters the 2×2 coupler, the light from each output end of the 2×2 coupler is equally divided into two MZM modulators, and the four MZM modulators are respectively coupled to the four output waveguides.

[0005] The beneficial effects of the present invention are:

[0006] After the emission light enters the input waveguide, the emission light in the input waveguide enters the 2×2 coupler, and then is equally divided into two paths, and each path is equally divided into two paths and enters two MZM modulators. At this time, there are four equal-ratio lights, and the lights in the four MZM modulators are then coupled into four output waveguides, and finally coupled into the multi-channel optical fiber array by the four output waveguides. In this scheme, since the output waveguide coupled by the 2×2 coupler is reversely split and enters the 2×2 coupler, the forward emission light cannot be coupled into the input waveguide through the output waveguide and the 2×2 coupler;

[0007] When determining the position of the multi-channel optical fiber array, the optical fiber used for coupling the reverse light splitting output waveguide in each channel of the multi-channel optical fiber array is connected to a high-power light source, and the optical fiber used for coupling other output waveguides is connected to a high-sensitivity optical power meter. The multi-channel optical fiber array is coupled with the output waveguide of the 400G DR4 silicon photonic chip. The test light emitted by the high-power light source is coupled into the reverse light splitting output waveguide through the optical fiber of the multi-channel optical fiber array. The test light is then coupled into the 2×2 coupler through the output waveguide and divided into two equal parts. Each of the two parts is then divided into two equal parts and enters two MZM modulators. The test light in the four MZM modulators is then coupled into four output waveguides, and then coupled into the optical fiber of the multi-channel optical fiber array by the four output waveguides, and finally coupled into three high-sensitivity optical power meters through the optical fiber. When the optical power collected by the high-sensitivity optical power meter of each channel is within the expected threshold range, the fixed position of the multi-channel optical fiber array can be determined.

[0008] When determining the position of the aspheric lens, connect the optical fiber of each channel of the multi-channel optical fiber array to a high-sensitivity optical power meter, turn on the optical transmitter and the high-sensitivity optical power meter, first couple the optical transmitter and the optical isolator with the input waveguide of the 400G DR4 silicon photonic chip, and then couple the aspheric lens in an unfixed manner. When the optical power collected by the high-sensitivity optical power meter of each channel is within the expected threshold range, the fixed position of the aspheric lens can be determined.

[0009] In this way, the coupling of the aspheric lens and the multi-channel optical fiber array in the 400G DR4 silicon photonics module is completed. Even if the 400G DR4 silicon photonics chip does not have MPD and complex MPD current amplification circuit, when it is used in the 400G DR4 silicon photonics module, the aspheric lens and the multi-channel optical fiber array can be coupled in the optimal position.

[0010] Based on the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, the output waveguide coupled by the 2×2 coupler has a reverse distribution of less than or equal to 1% of the light entering the 2×2 coupler.

[0012] Furthermore, a 1×2 coupler is integrated on the output waveguide coupled by the 2×2 coupler, and the 1×2 coupler is coupled with the 2×2 coupler and divides less than or equal to 1% of the light into the 2×2 coupler.

[0013] Furthermore, two output ends of the 2×2 coupler are respectively coupled to an input end of a 1×2 geometric ratio coupler, and four output ends of the two 1×2 geometric ratio couplers are respectively coupled to four MZM modulators.

[0014] Based on the above technical solution, the present invention also provides a 400G DR4 silicon photonic module, including: an optical transmitter, an aspheric lens, an optical isolator, a multi-channel optical fiber array and a 400G DR4 silicon photonic chip. The optical transmitter is sequentially coupled to the input waveguide of the 400G DR4 silicon photonic chip through the aspheric lens and the optical isolator, and the four output waveguides of the 400G DR4 silicon photonic chip are coupled to the multi-channel optical fiber array.

[0015] A further beneficial effect of the above is that even if the 400G DR4 silicon photonic chip does not have MPD and a complex MPD current amplification circuit, when it is used in a 400G DR4 silicon photonic module, the aspheric lens and the multi-channel optical fiber array can be coupled at the optimal position.

[0016] Furthermore, the multi-channel optical fiber array is a four-channel optical fiber array.

[0017] Furthermore, the light emitting end includes: a ceramic heat sink and a laser chip on the ceramic heat sink.

[0018] Based on the above technical solution, the present invention also provides a coupling method for a 400G DR4 silicon photonic module, comprising the following steps:

[0019] S1, connecting the optical fiber used for coupling the reverse splitting output waveguide in each channel of the multi-channel optical fiber array to an external high-power light source, and connecting the optical fiber used for coupling other output waveguides to an external high-sensitivity optical power meter;

[0020] S2, turning on the high-power light source and the high-sensitivity optical power meter, and then coupling the optical fibers connected to the high-power light source and the high-sensitivity optical power meter in the multi-channel optical fiber array with the four output waveguides of the 400GDR4 silicon photonic chip in an unfixed manner, and fixing the multi-channel optical fiber array when the optical power collected by the high-sensitivity optical power meter of each channel is within the expected threshold range;

[0021] S3, connecting the optical fiber of each channel of the multi-channel optical fiber array to a high-sensitivity optical power meter;

[0022] S4. Turn on the optical transmitter and the high-sensitivity optical power meter, first couple the optical transmitter and the optical isolator with the input waveguide of the 400GDR4 silicon photonic chip, then couple the aspheric lens in an unfixed manner, and fix the aspheric lens when the optical power collected by the high-sensitivity optical power meter of each channel is within the expected threshold range.

[0023] The further beneficial effect of adopting the above method is: the coupling of the aspheric lens and the multi-channel optical fiber array in the 400G DR4 silicon photonic module is completed in this way. Even if the 400G DR4 silicon photonic chip does not have MPD and a complex MPD current amplification circuit, when it is applied to the 400G DR4 silicon photonic module, the aspheric lens and the multi-channel optical fiber array can be coupled in the optimal position. Using a high-sensitivity optical power meter, even if the 400G DR4 silicon photonic chip does not have MPD and a complex MPD current amplification circuit, it is also convenient to find light for the aspheric lens.

[0024] Furthermore, the optical power of the high-power light source is greater than 20dbm.

[0025] Furthermore, the sensitivity of the high-sensitivity optical power meter is better than -50dBm. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a structural diagram of a 400G DR4 silicon photonic module in the prior art;

[0027] Figure 2 This is a structural diagram of the 400G DR4 silicon photonic chip in the present invention;

[0028] Figure 3 This is a structural diagram of the 400G DR4 silicon photonic module in the present invention;

[0029] Figure 4 This is a structural diagram of the 400G DR4 silicon photonics module coupled with a multi-channel optical fiber array in the present invention;

[0030] Figure 5 This is a structural diagram of the 400G DR4 silicon photonic module coupled with an aspheric lens in the present invention.

[0031] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0032] 1. 400G DR4 silicon photonic chip, 110. Input waveguide, 120. 2×2 coupler, 130. Output waveguide, 140. MZM modulator, 150. 1×2 coupler, 160. 1×2 ratio coupler, 2. Optical transmitter, 210. Ceramic heat sink, 220. Laser chip, 3. Aspheric lens, 4. Optical isolator, 5. Multi-channel optical fiber array, 6. High-power light source, 7. High-sensitivity optical power meter. DETAILED DESCRIPTION

[0033] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0034] Example 1

[0035] like Figure 2 As shown, a 400G DR4 silicon photonic chip includes: an input waveguide 110, a 2×2 coupler 120 and four output waveguides 130, one input end of the 2×2 coupler 120 is coupled to the input waveguide 110, and the other input end of the 2×2 coupler 120 is coupled to one of the four output waveguides 130. Usually, the output waveguide 130 closer to the input waveguide 110 is preferred for easy layout. The two output ends of the 2×2 coupler 120 are equal-ratio outputs, that is, the splitting ratio is 50%:50%. The output waveguide 130 coupled by the 2×2 coupler 120 is reversely split and enters the 2×2 coupler 120, and the light of each output end of the 2×2 coupler 120 is equally divided into two MZM modulators 140, and the four MZM modulators 140 are respectively coupled to the four output waveguides 130;

[0036] After the emission light enters the input waveguide 110, the emission light in the input waveguide 110 enters the 2×2 coupler 120, and then is equally divided into two paths, and each path is equally divided into two paths and enters two MZM modulators 140. At this time, there are four paths of equal ratio light, and the light in the four MZM modulators 140 is then coupled into the four output waveguides 130, and finally coupled into the multi-channel optical fiber array 5 by the four output waveguides 130. In this solution, since the output waveguide 130 coupled by the 2×2 coupler 120 is reversely split and enters the 2×2 coupler 120, the forward emission light cannot be coupled into the input waveguide 110 through the output waveguide 130 and the 2×2 coupler 120;

[0037] When determining the position of the multi-channel optical fiber array 5, the optical fiber used for coupling the reverse splitting output waveguide 130 in each channel of the multi-channel optical fiber array 5 is connected to a high-power light source 6, and the optical fiber used for coupling other output waveguides 130 is connected to a high-sensitivity optical power meter 7. The output waveguide 130 of the DR4 silicon photonic chip 1 is coupled, and the test light emitted by the high-power light source 6 is coupled into the reverse splitting output waveguide 130 through the optical fiber of the multi-channel optical fiber array 5. The test light is then coupled into the 2×2 coupler 120 through the output waveguide 130 and is equally divided into two paths. Each path is then equally divided into two paths and enters two MZM modulators 140. The test light in the four MZM modulators 140 is then coupled into the four output waveguides 130, and then coupled into the optical fiber of the multi-channel optical fiber array 5 by the four output waveguides 130, and finally coupled into three high-sensitivity optical power meters 7 through the optical fiber. When the optical power collected by the high-sensitivity optical power meter 7 of each channel is within the expected threshold range, the fixed position of the multi-channel optical fiber array 5 can be determined.

[0038] When determining the position of the aspheric lens 3, the optical fiber of each channel of the multi-channel optical fiber array 5 is externally connected to a high-sensitivity optical power meter 7, the optical transmitter 2 and the high-sensitivity optical power meter 7 are turned on, the optical transmitter 2 and the optical isolator 4 are first coupled with the input waveguide 110 of the 400G DR4 silicon photonic chip, and then the aspheric lens 3 is coupled in an unfixed manner, and when the optical power collected by the high-sensitivity optical power meter 7 of each channel is within the expected threshold range, the fixed position of the aspheric lens 3 can be determined;

[0039] In this way, the coupling of the aspheric lens and the multi-channel optical fiber array in the 400G DR4 silicon photonics module is completed. Even if the 400G DR4 silicon photonics chip does not have MPD and complex MPD current amplification circuit, when it is used in the 400G DR4 silicon photonics module, the aspheric lens and the multi-channel optical fiber array can be coupled in the optimal position.

[0040] Example 2

[0041] like Figure 2 As shown, this embodiment is a further improvement on the basis of embodiment 1, and the details are as follows:

[0042] The output waveguide 130 coupled by the 2×2 coupler 120 reversely divides less than or equal to 1% of the light into the 2×2 coupler 120 .

[0043] Furthermore, a 1×2 coupler 150 is integrated on the output waveguide 130 coupled by the 2×2 coupler 120 . The 1×2 coupler 150 is coupled to the 2×2 coupler 120 and divides less than or equal to 1% of the light into the 2×2 coupler 120 .

[0044] Example 3

[0045] like Figure 2 As shown, this embodiment is a further improvement on the basis of Embodiment 1 or 2, and the details are as follows:

[0046] The two output ends of the 2×2 coupler 120 are respectively coupled to the input end of a 1×2 geometric ratio coupler 160, and the four output ends of the two 1×2 geometric ratio couplers 160 are respectively coupled to the four MZM modulators 140. The 2×2 coupler 120 divides the light into two paths, and then each light path is coupled into a 1×2 geometric ratio coupler 160. Each 1×2 geometric ratio coupler 160 also divides the light into two paths. At this time, due to the presence of two 1×2 geometric ratio couplers 160, all the light is actually divided into four paths, and the four paths of light are respectively coupled into four MZM modulators 140.

[0047] Example 4

[0048] like Figure 3 As shown, a 400G DR4 silicon photonic module includes: a light emitting end 2, a non-spherical lens 3, an optical isolator 4, a multi-channel optical fiber array 5, and a 400G DR4 silicon photonic chip 1 as in any one of embodiments 1 to 3. The light emitting end 2 is sequentially coupled to the input waveguide 110 of the 400G DR4 silicon photonic chip 1 through the non-spherical lens 3 and the optical isolator 4, that is, the emission light emitted by the light emitting end 2 is sequentially coupled to the 400G DR4 silicon photonic chip 1 through the non-spherical lens 3 and the optical isolator 4. In the input waveguide 110 of the DR4 silicon photonic chip 1, the four output waveguides 130 of the 400GDR4 silicon photonic chip 1 are coupled with the multi-channel optical fiber array 5. When the emitted light enters the input waveguide 110, the emitted light in the input waveguide 110 enters the 2×2 coupler 120, and then is equally divided into two paths, and each path is further equally divided into two paths and enters two MZM modulators 140. At this time, there are four paths of equal-ratio light. The light in the four MZM modulators 140 is then coupled into the four output waveguides 130, and finally coupled into the multi-channel optical fiber array 5 by the four output waveguides 130.

[0049] Example 5

[0050] like Figure 3 As shown, this embodiment is a further improvement on the basis of embodiment 4, and the details are as follows:

[0051] The multi-channel optical fiber array 5 is a four-channel optical fiber array. In this solution, since there are only four output waveguides 130, the multi-channel optical fiber array 5 is preferably a four-channel optical fiber array.

[0052] Example 6

[0053] like Figure 3As shown, this embodiment is a further improvement on the basis of Embodiment 4 or 5, and the details are as follows:

[0054] The optical transmitting end 2 includes: a ceramic heat sink 210 and a laser chip 220 on the ceramic heat sink 210. The emission light emitted by the laser chip 220 is coupled into the input waveguide 110 of the 400G DR4 silicon photonic chip 1 after passing through the aspheric lens 3 and the optical isolator 4 in sequence.

[0055] Example 7

[0056] like Figure 4 , Figure 5 As shown, a coupling method of a 400G DR4 silicon photonic module includes the following steps:

[0057] S1. The optical fiber used for coupling the reverse splitting output waveguide 130 in each channel of the multi-channel optical fiber array 5 is connected to an external high-power light source 6. In the whole scheme, the high-power light source 6 has a built-in optical isolator to prevent the return light from interfering with the external high-power light source 6, and the optical fiber used for coupling other output waveguides 130 is connected to an external high-sensitivity optical power meter 7;

[0058] S2, turn on the high-power light source 6 and the high-sensitivity optical power meter 7, and then couple the multi-channel optical fiber array 5 with the 400G DR4 silicon photonic chip 1 in a manner of not fixing the multi-channel optical fiber array 5, specifically: let the optical fibers of the external high-power light source 6 and the high-sensitivity optical power meter 7 in the multi-channel optical fiber array 5 be coupled with the four output waveguides 130 of the 400G DR4 silicon photonic chip 1 respectively, and fix the multi-channel optical fiber array 5 when the optical powers collected by the high-sensitivity optical power meters 7 of the three channels are within the expected threshold range. The so-called expected threshold range can be understood as the optical powers collected by the high-sensitivity optical power meters 7 of each channel are at or near the maximum value, that is, the optimal position;

[0059] S3, connecting the optical fiber of each channel of the multi-channel optical fiber array 5 to a high-sensitivity optical power meter 7;

[0060] S4. Turn on the optical transmitter 2 and the high-sensitivity optical power meter 7. First, couple the optical transmitter 2 and the optical isolator 4 with the input waveguide 110 of the 400G DR4 silicon photonic chip. Then, couple the aspheric lens 3 in an unfixed manner. When the optical power collected by the high-sensitivity optical power meter 7 of each channel is within the expected threshold range, the aspheric lens 3 is fixed. The so-called expected threshold range can be understood as the optical power collected by the high-sensitivity optical power meter 7 of each channel is at the maximum value or near the maximum value, which is the optimal position.

[0061] Example 8

[0062] like Figure 4 , Figure 5As shown, this embodiment is a further improvement on the basis of Embodiment 7, and the details are as follows:

[0063] The optical power of the high-power light source 6 is greater than 20dbm. The high-power light source 6 is used to ensure that sufficient optical power enters the MZM modulator. The sensitivity of the high-sensitivity optical power meter 7 is better than -50dBm. The high-sensitivity optical power meter 7 is used. Even if the 400G DR4 silicon photonic chip 1 does not have MPD and a complex MPD current amplification circuit, it is also convenient for the aspheric lens 3 to find light.

[0064] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A 400G DR4 silicon photonic chip, characterized in that: include: An input waveguide (110) and a 2×2 coupler (120), wherein an input end of the 2×2 coupler (120) is coupled to the input waveguide (110), and another input end of the 2×2 coupler (120) is coupled to one of four output waveguides (130). The output waveguide (130) coupled by the 2×2 coupler (120) reversely splits light and enters the 2×2 coupler (120). Light from each output end of the 2×2 coupler (120) is equally divided into two MZM modulators (140). The four MZM modulators (140) are respectively coupled to the four output waveguides (130).

2. The 400G DR4 silicon photonic chip according to claim 1, characterized in that: The output waveguide (130) coupled by the 2×2 coupler (120) reversely divides less than or equal to 1% of the light into the 2×2 coupler (120).

3. A 400G DR4 silicon photonic chip according to claim 1 or 2, characterized in that: A 1×2 coupler (150) is integrated on the output waveguide (130) coupled by the 2×2 coupler (120), and the 1×2 coupler (150) is coupled with the 2×2 coupler (120) and divides less than or equal to 1% of the light into the 2×2 coupler (120).

4. A 400G DR4 silicon photonic chip according to claim 1, 2 or 3, characterized in that: The two output ends of the 2×2 coupler (120) are respectively coupled to the input end of a 1×2 geometric ratio coupler (160), and the four output ends of the two 1×2 geometric ratio couplers (160) are respectively coupled to four MZM modulators (140).

5. A 400G DR4 silicon photonic module, characterized in that: include: An optical transmitter (2), an aspheric lens (3), an optical isolator (4), a multi-channel optical fiber array (5), and a 400G DR4 silicon photonic chip (1) as described in any one of claims 1 to 4, wherein the optical transmitter (2) is coupled to the input waveguide (110) of the 400G DR4 silicon photonic chip (1) via the aspheric lens (3) and the optical isolator (4) in sequence, and the four output waveguides (130) of the 400G DR4 silicon photonic chip (1) are coupled to the multi-channel optical fiber array (5).

6. A 400G DR4 silicon photonic module according to claim 5, characterized in that: The multi-channel optical fiber array (5) is a four-channel optical fiber array.

7. The 400G DR4 silicon photonic module according to claim 5, characterized in that: The light emitting end (2) comprises: a ceramic heat sink (210) and a laser chip (220) located on the ceramic heat sink (210).

8. A coupling method for a 400G DR4 silicon photonic module according to any one of claims 5 to 7, characterized in that: The steps include: S1, connecting the optical fiber used for coupling the reverse splitting output waveguide (130) in each channel of the multi-channel optical fiber array (5) to an external high-power light source (6), and connecting the optical fiber used for coupling other output waveguides (130) to an external high-sensitivity optical power meter (7); S2, turning on the high-power light source (6) and the high-sensitivity optical power meter (7), and then coupling the optical fibers of the multi-channel optical fiber array (5) connected to the external high-power light source (6) and the high-sensitivity optical power meter (7) with the four output waveguides (130) of the 400G DR4 silicon photonic chip in a non-fixed manner, and fixing the multi-channel optical fiber array (5) when the optical power collected by the high-sensitivity optical power meter (7) of each channel is within the expected threshold range; S3, connecting the optical fiber of each channel of the multi-channel optical fiber array (5) to a high-sensitivity optical power meter (7); S4, turn on the optical transmitter (2) and the high-sensitivity optical power meter (7), first couple the optical transmitter (2) and the optical isolator (4) with the input waveguide (110) of the 400G DR4 silicon photonic chip, then couple the aspheric lens (3) in a non-fixed manner, and fix the aspheric lens (3) when the optical power collected by the high-sensitivity optical power meter (7) of each channel is within the expected threshold range.

9. The coupling method according to claim 8, characterized in that: The optical power of the high-power light source (6) is greater than 20dbm.

10. The coupling method according to claim 8, characterized in that: The sensitivity of the high-sensitivity optical power meter (7) is better than -50dBm.

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