Optical chip, optical module, and optical path alignment method

Abstract

The application provides an optical chip, an optical module and an optical path alignment method. The optical chip comprises a first optical interface, a second optical interface, a first waveguide, a second waveguide module, a first optical coupling device and a second optical coupling device. The first optical coupling device is connected to the first optical interface, the first waveguide and the second waveguide module respectively, and the second optical coupling device is connected to the second optical interface, the first waveguide and the second waveguide module respectively. The alignment optical signal passes through the first optical interface, the first optical coupling device, the first waveguide, the second optical coupling device and the second optical interface in sequence, thereby completing the alignment operation without adding a special optical interface to realize the optical path alignment. In addition, the optical fiber array used in packaging does not need to add an optical fiber corresponding to the special optical interface, thereby reducing the cost.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of optical communication, and in particular to an optical chip, an optical module and an optical path alignment method. BACKGROUND

[0002] For a silicon optical chip, the packaging volume of an optical module can be effectively reduced, but due to the external light source, the optical signal often needs to be coupled in and out of the chip through an optical fiber, so multiple optical inlets and outlets on the chip need to be arranged in a row with equal spacing corresponding to the optical fiber array for optical coupling. When the chip is packaged, the optical fiber array and the angle and position of the optical inlets and outlets of the chip need to be aligned, and for this purpose, an alignment optical path composed of waveguides is provided on the chip. The related art optical path alignment method needs to add two special optical interfaces connected to the alignment optical path outside the original optical inlets and outlets of the chip, and in order to transmit optical signals during alignment, two additional optical fibers are needed outside the original optical fiber array. Therefore, the method in the related art needs to use additional special optical interfaces and optical fibers, which will increase the cost. SUMMARY

[0003] The following is a summary of the subject matter of the detailed description herein. This summary is not intended to limit the scope of the claims.

[0004] Embodiments of the present application provide an optical chip, an optical module and an optical path alignment method, which can achieve optical path alignment without adding additional special optical interfaces and optical fibers.

[0005] In a first aspect, embodiments of the present application provide an optical chip, comprising:

[0006] a first optical interface;

[0007] a second optical interface;

[0008] a first waveguide for optical path alignment, the first waveguide being provided with an optical input end and an optical output end;

[0009] a second waveguide module for implementing optical signal processing of the optical chip, the second waveguide module being provided with a first optical port and a second optical port;

[0010] a first optical coupling device provided with a first interface end, a second interface end and a first coupling end, the first interface end being connected to the first optical interface, the second interface end being connected to the first optical port, the first coupling end being connected to the optical input end, the first optical coupling device being used for coupling an alignment optical signal from the first optical interface to the optical input end;

[0011] A second optical coupling device is provided with a third interface end, a fourth interface end and a second coupling end, the third interface end is connected with the second optical interface, the fourth interface end is connected with the second optical port, and the second coupling end is connected with the optical output end, and the second optical coupling device is used for coupling the alignment optical signal from the optical output end to the second optical interface.

[0012] In a second aspect, the embodiments of the present application further provide an optical module, comprising an optical fiber array and an optical chip as described in the first aspect, the optical fiber array comprises a first optical fiber and a second optical fiber, one end of the first optical fiber is connected with the first optical interface, and one end of the second optical fiber is connected with the second optical interface.

[0013] In a third aspect, the embodiments of the present application further provide an optical path alignment method, applied to the optical module as described in the second aspect, the optical path alignment method comprises:

[0014] sending an alignment optical signal to the first optical fiber, so that the alignment optical signal is sequentially output to the second optical fiber through the first optical interface, the first optical coupling device, the first waveguide, the second optical coupling device and the second optical interface;

[0015] receiving the alignment optical signal from the second optical fiber;

[0016] adjusting the position of the optical fiber array according to the alignment optical signal from the second optical fiber until the alignment optical signal from the second optical fiber meets an alignment condition.

[0017] The optical chip of the embodiment of the present application comprises a first optical interface, a second optical interface, a first waveguide, a second waveguide module, a first optical coupling device and a second optical coupling device, wherein the first waveguide is used for optical path alignment, and is provided with an optical input end and an optical output end; the second waveguide module is used for optical signal processing of the optical chip, and is provided with a first optical port and a second optical port; the first optical coupling device is provided with a first interface end, a second interface end and a first coupling end, the first interface end is connected with the first optical interface, the second interface end is connected with the first optical port, and the first coupling end is connected with the optical input end, and the first optical coupling device is used for coupling the alignment optical signal from the first optical interface to the optical input end; the second optical coupling device is provided with a third interface end, a fourth interface end and a second coupling end, the third interface end is connected with the second optical interface, the fourth interface end is connected with the second optical port, and the second coupling end is connected with the optical output end, and the second optical coupling device is used for coupling the alignment optical signal from the optical output end to the second optical interface. According to the technical scheme of the embodiment of the present application, by arranging the first optical coupling device and the second optical coupling device, and connecting the first optical coupling device to the first optical interface, the first waveguide and the second waveguide module respectively, and connecting the second optical coupling device to the second optical interface, the first waveguide and the second waveguide module respectively, when the optical path is aligned, the alignment optical signal can pass through the first optical interface, the first optical coupling device, the first waveguide, the second optical coupling device and the second optical interface in sequence, so that the alignment operation can be completed, and therefore, the embodiment of the present application can realize optical path alignment without increasing additional special optical interfaces; in addition, since no additional special optical interfaces are added, the fiber array also does not need to add additional optical fibers corresponding to the special optical interfaces, and therefore, the embodiment of the present application also does not increase additional optical fibers when realizing optical path alignment, thereby reducing the cost. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the technical scheme of the present application, and constitute a part of the specification, and are used to explain the technical scheme of the present application together with the embodiments of the present application, and do not constitute a limitation on the technical scheme of the present application.

[0019] Figure 1 is a structural schematic diagram of an optical module for realizing optical path alignment in the prior art;

[0020] Figure 2 is a structural schematic diagram of an optical chip provided by an embodiment of the present application;

[0021] Figure 3 is a structural schematic diagram of an optical chip provided by another embodiment of the present application;

[0022] Figure 4is a structural schematic diagram of an optical module provided by one embodiment of the present application;

[0023] Figure 5 is a structural schematic diagram of an optical module provided by another embodiment of the present application;

[0024] Figure 6 is a schematic diagram of loss of an alignment optical path adopted by various schemes provided by one embodiment of the present application;

[0025] Figure 7 is a flow chart of an optical path alignment method provided by one embodiment of the present application;

[0026] Figure 8 is a specific flow chart of adjusting a position of an optical fiber array according to an alignment optical signal from a second optical fiber in an optical path alignment method provided by one embodiment of the present application;

[0027] Figure 9 is a specific flow chart of adjusting a position of an optical fiber array according to an alignment optical signal from a second optical fiber in an optical path alignment method provided by another embodiment of the present application;

[0028] Figure 10 is a specific flow chart of adjusting a position of an optical fiber array in an optical path alignment method provided by one embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0030] It should be noted that although the functional modules are divided in the device schematic diagram, and the logical order is shown in the flow chart, in some cases, the steps shown or described can be executed in a manner different from the module division in the device or the order in the flow chart. The terms "first", "second", etc. in the specification, claims or above-described drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence.

[0031] In the related art, as shown in Figure 1 , Figure 1 is a structural schematic diagram of an optical module for implementing optical path alignment in the prior art. Figure 1The optical module in the prior art comprises a silicon optical chip 100 and an optical fiber array 200, wherein the silicon optical chip 100 is provided with a local oscillator light input port 110, a signal light input port 120 and a working waveguide module (not shown in the figure) for realizing optical signal processing of the optical chip, wherein the working waveguide module is connected with the local oscillator light input port 110 and the signal light input port 120 respectively; the optical fiber array 200 is provided with a local oscillator laser input optical fiber 210 and a signal light input optical fiber 220, wherein the local oscillator laser input optical fiber 210 is connected to the local oscillator light input port 110, and the signal light input optical fiber 220 is connected to the signal light input port 120. For the optical module shown in the prior art, in order to realize optical path alignment, an alignment waveguide 140 needs to be arranged in the silicon optical chip 100, and two special optical interfaces 130 for optical path alignment need to be additionally arranged outside the local oscillator light input port 110 and the signal light input port 120, wherein the special optical interfaces 130 are connected with the alignment waveguide 140, and correspondingly, the optical fiber array 200 also needs to additionally arrange two special optical fibers 230 for optical path alignment, therefore, the prior art needs to increase the special optical interfaces 130 and the special optical fibers 230, thereby causing the increase of cost and the increase of package size. Figure 1 For the optical module shown in the prior art, in order to realize optical path alignment, an alignment waveguide 140 needs to be arranged in the silicon optical chip 100, and two special optical interfaces 130 for optical path alignment need to be additionally arranged outside the local oscillator light input port 110 and the signal light input port 120, wherein the special optical interfaces 130 are connected with the alignment waveguide 140, and correspondingly, the optical fiber array 200 also needs to additionally arrange two special optical fibers 230 for optical path alignment, therefore, the prior art needs to increase the special optical interfaces 130 and the special optical fibers 230, thereby causing the increase of cost and the increase of package size.

[0032] Based on the above, the embodiment of the present application provides an optical chip, an optical module and an optical path alignment method, wherein the optical chip comprises a first optical interface, a second optical interface, a first waveguide, a second waveguide module, a first optical coupling device and a second optical coupling device, wherein the first waveguide is used for optical path alignment, and the first waveguide is provided with an optical input end and an optical output end; the second waveguide module is used for realizing optical signal processing of the optical chip, and the second waveguide module is provided with a first optical port and a second optical port; the first optical coupling device is provided with a first interface end, a second interface end and a first coupling end, the first interface end is connected with the first optical interface, the second interface end is connected with the first optical port, and the first coupling end is connected with the optical input end, and the first optical coupling device is used for coupling an alignment optical signal from the first optical interface to the optical input end; the second optical coupling device is provided with a third interface end, a fourth interface end and a second coupling end, the third interface end is connected with the second optical interface, the fourth interface end is connected with the second optical port, and the second coupling end is connected with the optical output end, and the second optical coupling device is used for coupling an alignment optical signal from the optical output end to the second optical interface. In addition, the optical module comprises an optical fiber array and the above optical chip, and the optical fiber array comprises a first optical fiber and a second optical fiber, one end of the first optical fiber is connected with the first optical interface, and one end of the second optical fiber is connected with the second optical interface. According to the technical scheme of the embodiment of the present application, by arranging the first optical coupling device and the second optical coupling device, and connecting the first optical coupling device to the first optical interface, the first waveguide and the second waveguide module respectively, and connecting the second optical coupling device to the second optical interface, the first waveguide and the second waveguide module respectively, when the optical path is aligned, the alignment optical signal can pass through the first optical interface, the first optical coupling device, the first waveguide, the second optical coupling device and the second optical interface in sequence, so that the alignment operation can be completed, and therefore, the embodiment of the present application can realize optical path alignment without increasing additional special optical interfaces, and the packaging size is reduced. In addition, since no additional special optical interfaces are added, the optical fiber array also does not need to add additional optical fibers corresponding to the special optical interfaces, and therefore, the embodiment of the present application does not increase additional optical fibers when realizing optical path alignment, and the cost is reduced and the packaging size is reduced.

[0033] The embodiment of the present application is further described below with reference to the drawings.

[0034] As Figure 2 shown, Figure 2is a structural schematic diagram of the optical chip 300 provided by an embodiment of the present application. The optical chip 300 comprises a first optical interface 310, a second optical interface 350, a first waveguide 330, a second waveguide module (not shown in the figure), a first optical coupling device 320 and a second optical coupling device 340. Specifically, the first waveguide 330 is used for optical path alignment, and the first waveguide 330 is provided with an optical input end and an optical output end; the second waveguide module is used for realizing optical signal processing of the optical chip 300, and the second waveguide module is provided with a first optical port and a second optical port; the first optical coupling device 320 is provided with a first interface end, a second interface end and a first coupling end, the first interface end is connected with the first optical interface 310, the second interface end is connected with the first optical port, and the first coupling end is connected with the optical input end, and the first optical coupling device 320 is used for coupling the alignment optical signal from the first optical interface 310 to the optical input end; the second optical coupling device 340 is provided with a third interface end, a fourth interface end and a second coupling end, the third interface end is connected with the second optical interface 350, the fourth interface end is connected with the second optical port, and the second coupling end is connected with the optical output end, and the second optical coupling device 340 is used for coupling the alignment optical signal from the optical output end to the second optical interface 350.

[0035] In an embodiment, the embodiment of the present application only needs to set the first optical coupling device 320 and the second optical coupling device 340, and the first optical coupling device 320 is connected to the first optical interface 310, the first waveguide 330 and the second waveguide module respectively, and the second optical coupling device 340 is connected to the second optical interface 350, the first waveguide 330 and the second waveguide module respectively, so that when the optical path is aligned, the alignment optical signal can pass through the first optical interface 310, the first optical coupling device 320, the first waveguide 330, the second optical coupling device 340 and the second optical interface 350 in turn, so that the alignment operation can be completed, and therefore, the embodiment of the present application can realize optical path alignment without increasing additional special optical interfaces; in addition, since no additional special optical interfaces are added, the fiber array 400 also does not need to add additional optical fibers corresponding to the special optical interfaces, and therefore, the embodiment of the present application also does not increase additional optical fibers when realizing optical path alignment, reduces the cost, and does not need to increase additional two special optical interfaces for optical path alignment, and reduces the packaging size of the optical module.

[0036] It is worth noting that when Figure 2 the optical chip 300 shown in the figure is an ICR (Integrated Coherent Receiver, integrated coherent receiver) chip, the first optical interface 310 can be a local oscillator light input port, the second optical interface 350 can be a signal light input port, the first optical coupling device 320 can be one of a polarization beam splitter, a polarization beam splitter rotator and a directional coupler, and the second optical coupling device 340 can be a directional coupler.

[0037] Exemplarily, for Figure 2 As shown in the optical chip 300, in the case that the first optical coupling device 320 is a polarization beam splitter and the second optical coupling device 340 is a directional coupler with TM coupling efficiency of 5%, when the optical chip 300 is packaged, optical alignment needs to be performed, the embodiment of the present application can input a TM polarized light signal to the first optical interface 310 from the external first optical fiber, then the TM polarized light signal enters the first waveguide 330 through the first coupling end of the polarization beam splitter, with a loss of less than 0.5 dB, and then the TM polarized light signal passes through the first waveguide 330 and enters the directional coupler through the second coupling end, and enters the second optical interface 350 from the third interface end, wherein 95% of the light signal is absorbed, and 5% of the coupled light is output to the outside through the second optical interface 350, so as to be received by the detector, and finally, when the input TM polarized light signal has the minimum loss by adjusting the angle and position of the external optical fiber array, that is, the optical path is aligned. When the optical chip 300 normally works, the embodiment of the present application can input a TE polarized light signal to the first optical interface 310 from the external first optical fiber, then the TE polarized light signal enters the second waveguide module through the second interface end of the polarization beam splitter, with a loss of less than 0.2 dB; at the same time, the embodiment of the present application also inputs TE and TM polarized light signals into the optical chip 300 from the external second optical fiber, the TE polarized light enters the second waveguide module through the fourth interface end of the directional coupler from the second optical interface 350 with a loss of less than 0.04 dB, and the TM polarized light enters the second waveguide module through the fourth interface end of the directional coupler from the second optical interface 350 with a loss of less than 0.22 dB, so that the optical chip 300 can normally work.

[0038] It should be noted that the polarization beam splitter is a 1x2 element, and the light input into the optical chip 300 from the external first optical fiber is input through the first interface end of the polarization beam splitter, when the polarization of the input light is TE polarization, it is output to the second waveguide module inside the optical chip 300 from the second interface end of the polarization beam splitter; when the polarization of the input light is TM polarization, it is output to the first waveguide 330 from the first coupling end of the polarization beam splitter. In addition, the directional coupler is a 2x2 element, and the asymmetry of the shape of the silicon optical chip waveguide cross section will cause the coupling efficiencies of the two polarizations to be different. Exemplarily, for a silicon waveguide with a length of 220 nm and a width of 500 nm, the TM polarization coupling efficiency is greater than the TE polarization coupling efficiency, so the directional coupler can be designed to have a coupling efficiency of 5% for the TM polarization with large coupling efficiency at the second coupling end, and a coupling efficiency of less than 1% for the TE polarization with small coupling efficiency.

[0039] It can be understood that if the TE polarization coupling efficiency of the directional coupler designed by the waveguide structure of the certain optical chip 300 is greater than the TM polarization coupling efficiency, the directional coupler as the second optical coupling device 340 can be replaced by a directional coupler with 5% coupling of TE polarization to the second coupling end. At the same time, the polarization beam splitter as the first optical coupling device 320 is replaced by a polarization beam splitter rotator, which further rotates the TM polarization to TE polarization when the TM polarized optical signal input in alignment from the first coupling end into the first waveguide 330, facilitating subsequent coupling from the second coupling end to the directional coupler with a larger efficiency, and output from the second optical interface 350 to the external second optical fiber.

[0040] In addition, it is worth noting that for the ICR optical chip, since only the local oscillator light is input in TE polarization when it is working in the first optical interface 310 and the second optical interface 350, only the first optical interface 310 can use the polarization beam splitter to connect the first waveguide 330.

[0041] As shown in Figure 3 , Figure 3 is a structural schematic diagram of an optical chip 300 provided by another embodiment of the present application. The optical chip 300 further includes a third optical interface 360 for inputting an optical signal, and the second waveguide module is provided with a third optical port, wherein the third optical interface 360 is connected with the third optical port.

[0042] It is worth noting that when Figure 3 the optical chip 300 shown is a non-coherent silicon optical transceiver chip, the first optical interface 310 can be a laser input port, the second optical interface 350 can be a modulated light output port, the first optical coupling device 320 can be one of a polarization beam splitter, a polarization beam splitter rotator and a directional coupler, and the second optical coupling device 340 can also be one of a polarization beam splitter, a polarization beam splitter rotator and a directional coupler.

[0043] Exemplarily, for Figure 3As shown in the optical chip 300, in the case that the first optical coupling device 320 and the second optical coupling device 340 are both polarization beam splitters, when the optical chip 300 is packaged, light alignment needs to be performed, and the embodiment of the present application can input a TM polarized light signal to the first optical interface 310 from the outside first optical fiber, then the TM polarized light signal enters the first waveguide 330 through the first coupling end of the polarization beam splitter corresponding to the first optical interface 310, and the loss is less than 0.5 dB, then the TM polarized light signal passes through the first waveguide 330 and enters the polarization beam splitter corresponding to the second optical interface 350 through the second coupling end, and enters the second optical interface 350 from the third interface end, and the loss is less than 0.5 dB, then the TM polarized light output from the second optical interface 350 is received by the detector, and finally when the angle and position of the external optical fiber array are adjusted so that the loss of the input TM polarized light signal is the smallest, the optical path alignment is completed. When the optical chip 300 is normally working, the embodiment of the present application can input a TE polarized light signal to the first optical interface 310 from the outside first optical fiber, then the TE polarized light signal enters the second waveguide module through the second interface end of the polarization beam splitter corresponding to the first optical interface 310, and the loss can be less than 0.2 dB, then the TE polarized light signal continues to enter other structures in the optical chip 300 from the second waveguide module, and the modulated light signal after the modulation of the optical chip 300 is output to the second optical fiber from the third interface end of the polarization beam splitter corresponding to the second optical interface 350, and the loss is less than 0.2 dB, so that the optical chip 300 can normally work.

[0044] In addition, it is worth noting that for a non-coherent silicon optical transceiver chip, when the laser and the optical chip 300 are aligned using an optical fiber array, in the working state, the laser needs to input a TE polarized light signal to the first optical interface 310 through the first optical fiber, and then output the TE polarized output after the chip modulation, so as long as the first optical interface 310 and the second optical interface 350 are arranged at both ends of the optical chip 300, as shown in Figure 3 , then the polarization beam splitter can be used to connect the first waveguide 330 at both ends without affecting the normal work of the optical chip 300, at this time, the loss of the TM polarized light in the alignment optical path is very small when the alignment packaging is completed.

[0045] It should be noted that, as shown in Figure 2 and Figure 3 , the optical chip 300 is also provided with a fuse structure 331 for fusing the first waveguide 330. In an embodiment, the first waveguide 330 is provided with a fuse structure 331 capable of being electrically heated and fused, and the first waveguide 330 is fused after the alignment packaging is completed, so that the optical signal will not be reversely input to the laser through the first waveguide 330 when the optical chip 300 normally works.

[0046] Specifically, the fuse structure 331 can be a resistor. The embodiment of the present application can set the resistor inside the optical chip 300 and close to the first waveguide 330, and lead two wires from both ends of the resistor respectively. After the alignment packaging is completed, the embodiment of the present application can pass current through the resistor through the two wires. Since the resistor will generate a large amount of heat during the current passing, and the heat generated by the resistor will be transferred to the first waveguide 330, so that the first waveguide 330 is fused due to high temperature, thereby achieving the fusing processing of the first waveguide 330.

[0047] In addition, in addition to the above-mentioned fusing of the first waveguide 330 by the fuse structure 331, the embodiment of the present application can also set a recess on the surface of the optical chip 300, and expose a part of the first waveguide 330 at the recess. After the alignment packaging is completed, the embodiment of the present application can use a small hard object such as tweezers to press the first waveguide 330 at the recess, so that the first waveguide 330 at the recess is crushed and damaged, thereby also achieving the cutting processing of the first waveguide 330.

[0048] As shown in FIG. 4, Figure 4 Figure 4 is a structural schematic diagram of an optical module provided by an embodiment of the present application. The optical module includes an optical fiber array 400 and the optical chip 300 as described above. The optical fiber array 400 includes a first optical fiber 410 and a second optical fiber 420. One end of the first optical fiber 410 is connected with the first optical interface 310, and one end of the second optical fiber 420 is connected with the second optical interface 350.

[0049] It is worth noting that the specific implementation and corresponding technical effects of the optical module of the embodiment of the present application can be correspondingly referred to the above-mentioned embodiment of the optical chip 300.

[0050] ​For example, when the ICR optical chip 300 is aligned during packaging, this embodiment of the invention can input a 1600nm wavelength TM polarized light signal from the first optical fiber 410, pass through a polarization beam splitter to enter the first waveguide 330 with a loss of less than 0.5dB, and then pass through a directional coupler to output from the second optical interface 350 into the second optical fiber 420 with a coupling efficiency of 5% (approximately -13dB). The angle and position of the fiber array 400, which includes the first and second optical fibers 410 and 420, are adjusted until the optical power of the light signal is maximized, indicating that the alignment position of the fiber array 400 with the ICR optical chip is optimal. At this time, the loss of the TM polarized light signal in the chip-to-optical loop includes the 5% coupling efficiency (approximately -13dB) of the directional coupler at 1600nm, the less than 0.5dB loss of the polarization beam splitter, and the approximately 1-2dB loss of the TM polarized light signal in the first waveguide 330, totaling approximately 14-16dB of loss. Therefore, the alignment optical path loss is minimal without the need to add more optical fibers. When the ICR optical chip is working normally, this embodiment of the invention can input a TE-polarized optical signal from the first optical fiber 410. At this time, the TE-polarized optical signal, after passing through a polarization beam splitter, is output from the second interface end to the second waveguide module with very little loss (approximately 0.2 dB), and continues to enter other structures in the optical chip 300. Simultaneously, signal light with both TE and TM polarizations is input from the second optical fiber 420. Since the TM-polarized optical signal input from the second optical fiber 420 has a wavelength less than 1600 nm, it experiences a coupling loss of approximately 3.5% at the directional coupler and continues to enter the optical chip 300 from the second waveguide module. Meanwhile, the TE-polarized optical signal input from the second optical fiber 420 experiences a loss of less than 1% at the directional coupler and continues to enter the optical chip 300 from the second waveguide module.

[0051] In contrast, if directional couplers are used for both the first optical coupling device 320 and the second optical coupling device 340, the alignment optical path experiences a loss of 13dB at both directional couplers, with a total on-chip loop loss of approximately 28dB. The measured loss is as follows: Figure 6 As shown in curve 1, the loss is relatively large and there are many oscillations. Furthermore, if a polarization beam splitter is used as the first optical coupling device 320, and a directional coupler is used as the second optical coupling device 340, the measured loss is as follows: Figure 6 As shown in curve 3, the loss is better than that in curve 1.

[0052] like Figure 5 As shown, Figure 5 This is a schematic diagram of the structure of an optical module provided in another embodiment of the present invention. The optical chip 300 in the optical module is also provided with a third optical interface 360, wherein the third optical interface 360 ​​is connected to the second waveguide module; at the same time, the fiber array 400 in the optical module also includes a third optical fiber 430, one end of which is connected to the third optical interface 360.

[0053] It is worth noting that the specific implementation of the optical module of the embodiments of the present application and the corresponding technical effects can be correspondingly referred to the above-mentioned embodiments of the optical chip 300.

[0054] Exemplarily, when the incoherent silicon optical transceiver chip is in package alignment, the embodiments of the present application can input the TM polarized light signal from the first optical fiber 410 to the first optical interface 310, enter the first waveguide 330 through the polarization beam splitter with a loss of less than 0.5 dB, use the polarization beam splitter at the other end to couple the TM polarized light signal in the first waveguide 330 to the second optical fiber 420 of the second optical interface 350 for output, and adjust the angle and position of the optical fiber array 400 until the optical power of the light signal is maximum, that is, the optical fiber array 400 is in the best alignment position with the optical chip 300. At this time, the alignment light signal loss is only about 1-2 dB, and the actual measurement loss is shown in the curve 2 of Figure 6 When the optical chip 300 is normally working, the laser is input from the corresponding first optical fiber 410 of the first optical interface 310, and the polarization is fixed as TE polarization. At this time, the input light is output from the second interface end with very small (less than 0.2 dB) loss after passing through the polarization beam splitter, and continues to enter other structures in the chip from the second waveguide module. The light after modulation in the chip enters the polarization beam splitter from the second interface end and is output to the second optical fiber 420 through the third interface end, wherein the loss of the polarization beam splitter is also very small (less than 0.2 dB), so that the chip can normally work.

[0055] It should be noted that for the incoherent silicon optical transceiver chip, in order to ensure the normal work of the chip, the first optical interface 310 and the second optical interface 350 are arranged at the positions of the two sides of the optical fiber array 400.

[0056] Based on the above-mentioned optical chip and optical module, the following respectively proposes various embodiments of the optical path alignment method of the present application.

[0057] As Figure 7 shown, Figure 7 is a flowchart of the optical path alignment method provided by an embodiment of the present application; the optical path alignment method can be applied to the above-mentioned optical module, and the optical path alignment method includes but is not limited to steps S100, S200 and S300.

[0058] Step S100, an alignment light signal is sent to a first optical fiber, so that the alignment light signal is output to a second optical fiber through a first optical interface, a first optical coupling device, a first waveguide, a second optical coupling device and a second optical interface in sequence;

[0059] Step S200, receiving the alignment light signal from the second optical fiber;

[0060] Step S300: Adjust the position of the fiber array according to the alignment optical signal from the second fiber until the alignment optical signal from the second fiber meets the alignment conditions.

[0061] In one embodiment, when the optical module described above is used for alignment, the optical chip contains a first optical coupling device and a second optical coupling device. The first optical coupling device is connected to a first optical interface, a first waveguide, and a second waveguide module, respectively, and the second optical coupling device is connected to a second optical interface, the first waveguide, and the second waveguide module, respectively. Therefore, when aligning the optical path, the alignment optical signal can sequentially pass through the first optical interface, the first optical coupling device, the first waveguide, the second optical coupling device, and the second optical interface to complete the alignment operation. Thus, the embodiment of the present invention can achieve optical path alignment without adding an additional dedicated optical interface. In addition, since no additional dedicated optical interface is added, the fiber array does not need to add additional optical fibers corresponding to the dedicated optical interface. Therefore, the embodiment of the present invention does not add additional optical fibers when achieving optical path alignment, reducing costs, and does not require adding two additional dedicated optical interfaces for optical path alignment, thus reducing the package size of the optical module.

[0062] like Figure 8 As shown, Figure 8 This is a flowchart illustrating the specific process of adjusting the position of the fiber array based on the alignment optical signal from the second fiber in an optical path alignment method provided by an embodiment of the present invention. When the alignment condition is maximum optical power, step S300 mentioned above includes, but is not limited to, steps S410 and S420.

[0063] Step S410: Obtain the optical power of the alignment optical signal from the second optical fiber;

[0064] Step S420: Adjust the position of the fiber optic array according to the optical power until the optical power reaches its maximum value.

[0065] In one embodiment, when the optical power of the alignment optical signal sent to the first optical fiber is fixed, the embodiment of the present invention can determine whether the optical fiber array is aligned with the optical chip based on the magnitude of the optical power of the alignment optical signal from the second optical fiber. When the optical power of the alignment optical signal from the second optical fiber is at its maximum, it indicates that the optical fiber array and the optical chip have been aligned.

[0066] like Figure 9 As shown, Figure 9 This is a flowchart of a specific process for adjusting the position of an optical fiber array based on an alignment optical signal from a second optical fiber in an optical path alignment method provided in another embodiment of the present invention. When the alignment condition is the lowest power loss, step S300 mentioned above includes, but is not limited to, steps S510 and S520.

[0067] Step S510: Obtain the first optical power of the alignment optical signal sent to the first optical fiber and the second optical power of the alignment optical signal from the second optical fiber;

[0068] Step S520: Adjust the position of the fiber array according to the first optical power and the second optical power until the power loss of the second optical power relative to the first optical power is the lowest.

[0069] In one embodiment, the present invention can determine whether the fiber array is aligned with the optical chip based on the loss value between the first optical power of the alignment optical signal sent to the first optical fiber and the second optical power of the alignment optical signal from the second optical fiber. When the difference between the first optical power and the second optical power is the smallest, that is, when the loss of the second optical power relative to the first optical power is the smallest, it indicates that the fiber array and the optical chip have been aligned.

[0070] like Figure 10 As shown, Figure 10 This is a flowchart of adjusting the position of the fiber array in an optical path alignment method provided by an embodiment of the present invention; the adjustment of the position of the fiber array in step S300 above includes, but is not limited to, step S600.

[0071] Step S600: Adjust the relative distance and / or relative direction between the fiber array and the first optical port and the second optical interface of the first optical interface, respectively.

[0072] In one embodiment, the present invention can align the fiber array with the optical chip by adjusting the angle and distance of the fiber array relative to the optical chip.

[0073] The above provides a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A photonic chip, comprising: a first optical interface; a second optical interface; a first waveguide for optical alignment, the first waveguide being provided with an optical input end and an optical output end; a second waveguide module for optical signal processing of the photonic chip, the second waveguide module being provided with a first optical port and a second optical port; a first optical coupling device provided with a first interface end, a second interface end and a first coupling end, the first interface end being connected with the first optical interface, the second interface end being connected with the first optical port, the first coupling end being connected with the optical input end, the first optical coupling device being configured to couple an alignment optical signal from the first optical interface to the optical input end; and a second optical coupling device provided with a third interface end, a fourth interface end and a second coupling end, the third interface end being connected with the second optical interface, the fourth interface end being connected with the second optical port, the second coupling end being connected with the optical output end, the second optical coupling device being configured to couple the alignment optical signal from the optical output end to the second optical interface; wherein, in a case that the photonic chip is an integrated coherent receiver chip, the first optical coupling device is one of a polarization beam splitter, a polarization beam splitter rotator and a directional coupler, and the second optical coupling device is a directional coupler; and in a case that the photonic chip is a non-coherent silicon optical transceiver chip, the first optical coupling device is one of a polarization beam splitter, a polarization beam splitter rotator and a directional coupler, and the second optical coupling device is one of a polarization beam splitter, a polarization beam splitter rotator and a directional coupler. The photonic chip further comprises a third optical interface for inputting an optical signal, and the second waveguide module is provided with a third optical port, and the third optical interface is connected with the third optical port. The photonic chip is further provided with a fusing structure for fusing the first waveguide. The optical module comprises a fiber array and the photonic chip according to any one of claims 1 to 3, the fiber array comprises a first optical fiber and a second optical fiber, the first optical fiber is connected with the first optical interface, and the second optical fiber is connected with the second optical interface. 5.An optical alignment method applied to the optical module according to claim 4, the optical alignment method comprising: transmitting an alignment optical signal to the first optical fiber, so that the alignment optical signal is sequentially output from the first optical interface, the first optical coupling device, the first waveguide, the second optical coupling device and the second optical interface to the second optical fiber; receiving the alignment optical signal from the second optical fiber; and adjusting a position of the fiber array according to the alignment optical signal from the second optical fiber until the alignment optical signal from the second optical fiber meets an alignment condition. The alignment condition is that an optical power is maximum, and the adjusting of the position of the fiber array according to the alignment optical signal from the second optical fiber until the alignment optical signal from the second optical fiber meets the alignment condition comprises: acquiring the optical power of the alignment optical signal from the second optical fiber; and adjusting the position of the fiber array according to the optical power until the optical power reaches a maximum value. ​ ​ ​ 2. The optical chip of claim 1, wherein: ​ 3. The optical chip of any of claims 1 to 2, wherein: ​ 4. An optical module characterized by comprising: ​ ​ ​ ​ ​ 6. The optical path alignment method of claim 5, wherein, ​ ​ ​ 7. The optical path alignment method of claim 5, wherein, The alignment condition is a minimum power loss, and the adjusting the position of the optical fiber array according to the alignment light signal from the second optical fiber until the alignment light signal from the second optical fiber meets the alignment condition comprises: obtaining a first optical power of the alignment light signal sent to the first optical fiber and a second optical power of the alignment light signal from the second optical fiber; adjusting the position of the optical fiber array according to the first optical power and the second optical power until the power loss of the second optical power relative to the first optical power is minimum.

8. A method of optical path alignment according to any one of claims 5 to 7, wherein, The adjusting the position of the optical fiber array comprises: adjusting the relative distance and / or the relative direction of the optical fiber array to the first optical interface and the second optical interface respectively. The alignment condition is a minimum power loss, and the adjusting the position of the optical fiber array according to the alignment light signal from the second optical fiber until the alignment light signal from the second optical fiber meets the alignment condition comprises: obtaining a first optical power of the alignment light signal sent to the first optical fiber and a second optical power of the alignment light signal from the second optical fiber; adjusting the position of the optical fiber array according to the first optical power and the second optical power until the power loss of the second optical power relative to the first optical power is minimum. The adjusting the position of the optical fiber array comprises: adjusting the relative distance and / or the relative direction of the optical fiber array to the first optical interface and the second optical interface respectively.

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