Light receiving end, 1.6 T light engine and coupling method

Abstract

The invention relates to a light receiving end coupling method. A 0-degree light surface end of a light receiving optical fiber array clings to a cover plate of a multi-channel optical fiber array; the light receiving optical fiber array is moved downwards, the gap between the light receiving optical fiber array and the multi-channel optical fiber array is changed into 0.13 + / -0.01 mm, the obliquely downward emergent light of the multi-channel optical fiber array is coupled into the light receiving optical fiber array, and the light receiving optical fiber array stops moving when the reading of the optical power meter is maximum; the gap is enlarged; placing an array lens in the gap, moving the array lens, dispensing light-transmitting glue when the reading of the optical power meter is maximum, continuously moving the array lens, and solidifying the glue when the reading of the optical power meter is maximum again; a supporting block is fixed below the cover plate; a TIA chip is coupled on the PCB, and the array PD chip is reversely pasted on the TIA chip; under the active condition, the multi-channel optical fiber array is coupled with the array PD chip through the array lens, and the supporting block and the PCB are fixed. The beneficial effects are that the method is excellent in performance and return loss, and is high in yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light engine, in particular to a light receiving end, a 1.6T light engine and a coupling method. BACKGROUND

[0002] The traditional 1.6T light engine contains 8-way transmission and 8-way reception. The light-sensitive surface of the single-wave 200G array PD chip used in the 8-way reception is very small, generally only 8-10 um, and the array PD chip is generally inverted on the TIA chip. In order to ensure the yield, the light receiving end generally adopts the mode of array lens + multi-channel fiber array, and the specific structure is shown in Figure 1 The light receiving end includes a multi-channel fiber array, a pad, an array lens, an array PD chip, a TIA chip and a PCB board. The cover plate of the multi-channel fiber array is adhered to the PCB board. The pad is below the total reflection surface of the multi-channel fiber array and is fixed with the PCB board. The total reflection surface of the multi-channel fiber array has an inclination angle of 42.5°±0.5°, preferably 42.5°. The TIA chip is fixed on the PCB board. The array PD chip is inverted on the TIA chip. The array lens is between the array PD chip and the total reflection surface of the multi-channel fiber array and is fixed on the pad. The array PD chip is single-wave 200G and has a lens. The multi-channel fiber array has four channels. The conventional method of this kind of light receiving end is to align the array PD chip and the array lens by using passive patching. The defects of the scheme are as follows: 1) An expensive high-precision patching machine is required to patch the array lens, and the required precision is ±3 um and the angle is ±0.5°. 2) Since the array PD chip, the TIA chip, the pad, the array lens, the cover plate of the multi-channel fiber array and the substrate of the multi-channel fiber array all have thickness tolerances, generally with a tolerance of ±10 um, under extreme conditions, there is a cumulative tolerance, that is, the distance between the array PD chip, the array lens and the fiber core of the multi-channel fiber array may deviate from the optimal coupling distance, and the return loss difference (since the array lens and the lens of the array PD chip are passively patched, they cannot be adjusted in real time, and there are two more reflection surfaces between the array lens and the multi-channel fiber array), resulting in poor performance and low yield. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a light receiving end, a 1.6T light engine and a coupling method to overcome the shortcomings of the prior art.

[0004] The technical solution of the present application to solve the above technical problem is as follows: A light receiving end coupling method, comprising the following steps: S10, horizontally place a multi-channel fiber array with a full reflection surface inclined at an angle of 42.5°±0.5°, and let the 0° light surface end of a light receiving fiber array closely adhere to the cover plate of the multi-channel fiber array; S20, each channel of the multi-channel fiber array is externally connected to a light source, and each channel of the light receiving fiber array is externally connected to a light power meter; S30, move the light receiving fiber array downward, so that the gap between the multi-channel fiber array and the light receiving fiber array becomes 0.13mm±0.01mm, and the multi-channel fiber array is inclined downward to couple light into the light receiving fiber array, and stop moving when the light power meter reading is maximum, and the center of the fiber core in the multi-channel fiber array and the center of the fiber core in the light receiving fiber array have a transverse misalignment of 0.05mm±0.01mm; S40, continue to move the light receiving fiber array downward, and keep other parameters unchanged, only increase the gap; S50, place an array lens in the gap, and move the array lens, when the light power meter reading is maximum, point the transparent glue, and continue to move the array lens, when the light power meter reading is maximum again, solidify the glue, so as to fix the array lens and the cover plate; S60, fix a support block below the cover plate in the multi-channel fiber array; S70, couple a TIA chip on the PCB board, and inversely paste the array PD chip with the lens on the TIA chip; S80, in an active state, couple the multi-channel fiber array through the array lens and the array PD chip, and fix the support block and the PCB board.

[0005] The beneficial effects of the present application are: in the whole coupling process, the multi-channel fiber array and the array lens are actively coupled, and the array lens and the lens integrated in the array PD chip are also actively coupled, so that the performance and return loss can be optimized, thereby the yield is high, and the active coupling can be used without using a high-precision chip mounter, thereby reducing the cost.

[0006] On the basis of the above technical solution, the present application can be further improved as follows.

[0007] Further, the multi-channel fiber array comprises: a substrate and a cover plate, the cover plate is adhered below the substrate and fixes a plurality of optical fibers in V grooves on the substrate, the bare optical fibers of the optical fibers are adhered to the substrate and the cover plate by soft glue, the end of the substrate has a full reflection surface with an inclined angle of 42.5°±0.5°, and the end of the cover plate has an inclined surface coplanar with the full reflection surface.

[0008] Further, the end of the cover plate has a chamfer with a C0.1mm.

[0009] The further beneficial effect is that the chamfer can avoid the glue overflow and pollute the total reflection surface of 42.5°±0.5° when dispensing.

[0010] Further, the number of channels of the multi-channel fiber array is four.

[0011] Further, the gap between the multi-channel fiber array and the light-receiving fiber array is 0.13 mm in S30.

[0012] Further, the core center in the multi-channel fiber array and the core center in the light-receiving fiber array are 0.05 mm offset in the transverse direction in S30.

[0013] Further, the gap is 0.85 mm±0.01 mm in S40.

[0014] Further, S80 is specifically as follows: Each channel of the multi-channel fiber array is circumscribed by an output end of an optical circulator, the input end and the isolation end of each optical circulator are respectively circumscribed by an optical source and an optical power meter, the multi-channel fiber array is coupled with the array PD chip through the array lens, the optical power meter monitors the size of the reflected return loss light, and when the responsivity of the array PD chip and the return loss are qualified, the support block below the multi-channel fiber array is bonded and fixed with the PCB board by moving the relative position of the multi-channel fiber array and the array PD chip.

[0015] Based on the above technical solution, the application also provides an optical receiving end coupled by the optical receiving end coupling method.

[0016] The further beneficial effect is that the performance and return loss of the optical receiving end are optimal, and the yield is high.

[0017] Based on the above technical solution, the application also provides a 1.6T optical engine, which comprises an optical receiving end coupled by the optical receiving end coupling method.

[0018] The further beneficial effect is that the performance of the 1.6T optical engine is effectively improved, the yield is high, and the return loss is optimal. DETAILED DESCRIPTION

[0019] Figure 1 It is a structural diagram of the optical receiving end in the prior art; Figure 2 It is a structural diagram of the optical receiving end in the application; Figure 3 It is a coupling state diagram in S10 in the application; Figure 4 It is a coupling state diagram in S30 in the application; Figure 5is a coupling state diagram in S40 of the present invention; Figure 6 is a coupling state diagram in S50 of the present invention; Figure 7 is a coupling state diagram in S60 of the present invention; Figure 8 This is the main view of the coupling state in S80 of the present invention; Figure 9 It is a partial top view of the coupling state in S80 of the present invention; Figure 10 Graph showing the relationship between the offset and coupling efficiency of the light-receiving fiber array and the multi-channel fiber array in the present invention.

[0020] In the accompanying drawings, the components represented by the reference numerals are as follows: 1. Multi-channel fiber optic array, 110. Cover plate, 111. Chamfer, 120. Substrate, 130. Optical fiber, 140. Soft glue, 2. Array lens, 3. Support block, 4. TIA chip, 5. Array PD chip, 6. PCB board, 7. Receiver fiber array, 8. Light source, 9. Optical power meter, 10. Optical circulator. DETAILED DESCRIPTION

[0021] The principles and features of the present invention are described below with reference to 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.

[0022] Example 1 like Figures 2-9 As shown, a light receiving end coupling method includes the following steps: S10. Place a multi-channel optical fiber array 1 horizontally and a light-receiving optical fiber array 7 vertically below the multi-channel optical fiber array 1. The tilt angle of the total reflection surface of the multi-channel optical fiber array 1 is 42.5°±0.5°. The total reflection light of the 42.5°±0.5° total reflection surface has the characteristic of tilting downward. The optical surface end of the light-receiving optical fiber array 7 is a 0° surface. Then, the 0° optical surface end of the light-receiving optical fiber array 7 is placed in close contact with the cover plate 110 of the multi-channel optical fiber array 1. That is, the gap between the 0° optical surface end of the light-receiving optical fiber array 7 and the cover plate 110 of the multi-channel optical fiber array 1 is 0 mm. S20. Each channel of the multi-channel optical fiber array 1 is connected to an external light source 8, and each channel of the light-receiving optical fiber array 7 is connected to an external optical power meter 9. For example, if the multi-channel optical fiber array 1 has four channels, then four light sources 8 are connected, the light-receiving optical fiber array 7 also has four channels, and four optical power meters 9 are connected. S30, move the light receiving fiber array 7 downward, so that the gap between the light receiving fiber array 7 and the multi-channel fiber array 1 becomes 0.13mm±0.01mm, and the light receiving fiber array 7 is coupled by moving the light receiving fiber array 7, that is, the multi-channel fiber array 1 is inclined downward to couple into the light receiving fiber array 7, which can be understood as follows: the light in the core of the multi-channel fiber array 1 is inclined downward after the cover plate 110 and coupled into the core in the light receiving fiber array 7, and the optical power meter 9 will start to have a reading, and the moving of the light receiving fiber array 7 is stopped when the reading of the optical power meter 9 is maximum. At this time, the cores in the light receiving fiber array 7 and the cores in the multi-channel fiber array 1 are aligned, and the centers of the cores in the multi-channel fiber array 1 and the centers of the cores in the light receiving fiber array 7 have a 0.05mm±0.01mm misalignment in the transverse direction. For example, the misalignment refers to the misalignment in the left-right direction, not the front-back direction, and the misalignment of 0.05mm±0.01mm is the best misalignment point required for subsequent array lens 2 coupling. This step cannot be omitted because only when the gap is 0.13mm±0.01mm, the optical power meter 9 connected with the light receiving fiber array 7 has light display, and only after the light display, the subsequent coupling alignment can be performed. If the light receiving fiber array 7 cannot receive light, the subsequent steps cannot be performed; Figure 10 The figure shows the relationship between the offset of the light receiving fiber array and the multi-channel fiber array and the coupling efficiency in the application, wherein the abscissa is the offset of the light receiving fiber array and the multi-channel fiber array (unit: mm), and the ordinate is the coupling efficiency. The optical simulation shows that when the gap between the light receiving fiber array and the multi-channel fiber array is 0.13mm and the offset is 0.05mm, the coupling efficiency is best, thereby explaining the principle of active coupling: the offset of the light receiving fiber array and the multi-channel fiber array can be accurately controlled (the accuracy can reach ±0.3μm, which is one order of magnitude higher than passive patch); S40, continue to move the light receiving fiber array 7 downward, and other parameters remain unchanged, wherein the other parameters refer to the unchanged misalignment distance and the unchanged front, back, left and right positions of the cores in the light receiving fiber array 7, and only the gap is increased, which meets the requirement of subsequent array lens 2; S50, placing the array lens 2 in the gap, and then moving the array lens 2. Moving the array lens 2 means that the front, back, left, and right positions of the array lens 2 can be changed. When the optical power meter 9 reads the maximum, apply transparent glue between the array lens 2 and the multi-channel optical fiber array 1, and continue to move the array lens 2. Similarly, the front, back, left, and right positions of the array lens 2 are changed. When the optical power meter 9 reads the maximum again, the glue is cured. The curing of the glue can be achieved by irradiating UV light to fix the array lens 2 to the cover plate 110. At this time, the center line of the array lens 2 is actually misaligned with the center of the fiber core in the multi-channel optical fiber array 1. The coupling position of the array lens 2 is close to the optimal position for coupling with the subsequent array PD chip 5, with an error of ±0.3μm, which is one order of magnitude higher than that of the passive patch. S60: Fix the support block 3 below the cover plate 110 in the multi-channel optical fiber array 1. The support block 3 may be made of glass and may be fixed by bonding. S70, coupling the TIA chip 4 to the PCB board 6, and mounting the array PD chip 5 with a lens on the TIA chip 4. The array PD chip 5 is also a single-wavelength 200G chip, which is consistent with the existing technology. S80 , in an active state, couple the multi-channel optical fiber array 1 to the array PD chip 5 via the array lens 2 , and fix the support block 3 to the PCB board 6 .

[0023] Example 2 like Figure 2 As shown, this embodiment is a further improvement on the basis of embodiment 1, specifically as follows: The multi-channel optical fiber array 1 includes: a substrate 120 and a cover plate 110. The cover plate 110 is adhered to the bottom of the substrate 120 and fixes multiple optical fibers 130 in the V-grooves on the substrate 120. The bare optical fibers of the optical fibers 130 are bonded to the substrate 120 and the cover plate 110 using soft glue 140. The end of the substrate 120 has a total reflection surface with an inclination angle of 42.5°±0.5°, and the end of the cover plate 110 has an inclined surface coplanar with the total reflection surface.

[0024] Furthermore, the end of the cover plate 110 has a chamfer 111 of C0.1mm, which can prevent the glue from overflowing and contaminating the 42.5°±0.5° total reflection surface during dispensing.

[0025] In this embodiment, the number of channels of the multi-channel optical fiber array 1 is four, which is still consistent with the prior art.

[0026] Example 3 like Figure 4 As shown, this embodiment is a further improvement on the basis of embodiment 1 or 2, specifically as follows: In S30, the light receiving fiber array 7 is lowered to make the gap between the light receiving fiber array 7 and the multi-channel fiber array 1 become 0.13 mm. At this time, the center of the fiber core in the multi-channel fiber array 1 and the center of the fiber core in the light receiving fiber array 7 have a 0.05 mm misalignment in the lateral direction.

[0027] Embodiment 4 As shown in Figure 5 , this embodiment is a further improvement on the basis of Embodiment 1 or 2 or 3, and the specific implementation is as follows: In S40, the gap becomes 0.85 mm ± 0.01 mm. As a preferred solution, the gap becomes 0.85 mm. When the gap is increased from 0.13 mm ± 0.01 mm to 0.85 mm ± 0.01 mm, the light receiving fiber array 7 is dark, and only by coupling an array lens 2 can the light receiving fiber array 7 have light again.

[0028] Embodiment 5 As shown in Figure 8 , Figure 9 , this embodiment is a further improvement on the basis of Embodiment 1 or 2 or 3 or 4, and the specific implementation is as follows: S80 is as follows: An optical circulator 10 is connected to each channel of the multi-channel fiber array 1, and an optical source 8 and an optical power meter 9 are connected to the input end and the isolation end of each optical circulator 10, respectively. Then, the multi-channel fiber array 1 is coupled with the array PD chip 5 through the array lens 2, the optical power meter 9 monitors the size of the back loss light reflected back, and by moving the relative position of the multi-channel fiber array 1 and the array PD chip 5, when the responsivity of the array PD chip 5 and the back loss are qualified, the support block 3 below the multi-channel fiber array 1 is bonded and fixed to the PCB 6.

[0029] Embodiment 6 As shown in Figure 2 , an optical receiving end is coupled by using the optical receiving end coupling method of any one of Embodiments 1 to 5.

[0030] Embodiment 7 As shown in Figure 2 , a 1.6T optical engine includes an optical receiving end coupled by using the optical receiving end coupling method of any one of Embodiments 1 to 5.

[0031] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A light receiving end coupling method, characterized in that: The steps include: S10. Horizontally place a multi-channel optical fiber array with a total reflection surface tilted at an angle of 42.5°±0.5°, and place the 0° optical surface end of a light-receiving optical fiber array in close contact with the cover of the multi-channel optical fiber array. S20, each channel of the multi-channel optical fiber array is connected to an external light source, and each channel of the light-receiving optical fiber array is connected to an external optical power meter; S30, move the receiving fiber array downward so that the gap between it and the multi-channel fiber array becomes 0.13 mm ± 0.01 mm, and allow the light output from the multi-channel fiber array to be coupled downwardly into the receiving fiber array. When the optical power meter reading reaches the maximum, stop moving. The core centers of the multi-channel fiber array and the core centers of the receiving fiber array will be misaligned by 0.05 mm ± 0.01 mm in the horizontal direction. S40, continue to move the light receiving fiber array downward, keep other parameters unchanged, and only enlarge the gap; S50, placing the array lens in the gap, moving the array lens, and when the optical power meter reading reaches the maximum, applying transparent glue, and continuing to move the array lens, and when the optical power meter reading reaches the maximum again, curing the glue to fix the array lens to the cover plate; S60, fixing a support block below the cover plate in the multi-channel optical fiber array; S70, coupling the TIA chip on the PCB board, and flip-mounting the array PD chip with the lens on the TIA chip; S80. In an active state, the multi-channel optical fiber array is coupled to the array PD chip via the array lens, and the support block is fixed to the PCB board.

2. The optical receiving end coupling method according to claim 1, wherein: The multi-channel optical fiber array includes: a substrate and a cover plate, the cover plate is glued to the bottom of the substrate and fixes multiple optical fibers in the V-grooves on the substrate, the bare optical fibers of the optical fibers are bonded to the substrate and the cover plate using soft glue, the end of the substrate has a total reflection surface with an inclination angle of 42.5°±0.5°, and the end of the cover plate has an inclined surface coplanar with the total reflection surface.

3. The optical receiving end coupling method according to claim 2, wherein: The end of the cover plate has a chamfer of C0.1 mm.

4. The optical receiving end coupling method according to any one of claims 1 to 3, characterized in that: The multi-channel optical fiber array has four channels.

5. The optical receiving end coupling method according to claim 1, wherein: In S30, the light receiving fiber array is moved downward so that the gap between it and the multi-channel fiber array is reduced to 0.13mm.

6. The optical receiving end coupling method according to claim 5, characterized in that: In S30, the core centers of the multi-channel optical fiber array and the core centers of the light receiving optical fiber array are offset by 0.05 mm in the transverse direction.

7. The optical receiving end coupling method according to claim 1, wherein: In S40, the gap becomes 0.85 mm ± 0.01 mm.

8. The optical receiving end coupling method according to claim 1, wherein: S80 is as follows: Each channel of the multi-channel fiber array is connected to the output end of an optical circulator. The input and isolation ends of each optical circulator are respectively connected to a light source and an optical power meter. The multi-channel fiber array is then coupled to the array PD chip through an array lens. The optical power meter monitors the magnitude of the reflected return loss light. By moving the relative position of the multi-channel fiber array and the array PD chip, when both the array PD chip responsivity and return loss are qualified, the support block under the multi-channel fiber array is bonded and fixed to the PCB board.

9. An optical receiving end, characterized in that: The optical receiving end coupling method according to any one of claims 1 to 8 is used for coupling.

10. A 1.6T light engine, characterized in that: include: An optical receiving end coupled by the optical receiving end coupling method according to any one of claims 1 to 8.

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