Coupling method of double lenses at input end of silicon optical chip and silicon optical device

Abstract

The invention relates to the technical field of optical communication, and provides a silicon optical chip input end double-lens coupling method comprising the following steps: S1, mounting an isolator between a CW laser and a silicon optical chip; s2, a converging lens to be coupled and a collimating lens to be coupled are taken, the converging lens is located between the silicon optical chip and the isolator, and the collimating lens is located between the CW laser and the isolator; s3, a single-lens coupling device is adopted to couple the collimating lens and the converging lens; and S4, curing the collimating lens and the converging lens to complete double-lens coupling. The invention also provides a silicon optical device which comprises a silicon optical chip, a converging lens and a collimating lens, and the converging lens and the collimating lens are coupled by adopting the method. According to the invention, a single-lens coupling device is used for coupling the converging lens and the collimating lens, a double-lens coupling device is not added, the coupling efficiency can be met, and the coupling time is reduced.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technologies, and specifically to a coupling method for a double-lens at the input end of a silicon photonic chip and a silicon photonic device. Background Art

[0002] Silicon photonic chips are an emerging chip technology, which refers to using a silicon wafer as a substrate, and fabricating many originally discrete electronic components and optical components into miniaturized chips through mature silicon wafer and semiconductor processes to replace traditional "optical transceiver modules" and achieve the collaborative processing of optical signals and electrical signals. Currently, silicon wafers are used in the industry to fabricate computing elements. If the "optical waveguide elements" for processing optical signals can be integrated onto the silicon wafer to enable the silicon wafer to simultaneously process the operation of electrical signals and the transmission of optical signals, silicon photonics technology is achieved.

[0003] For silicon photonic devices suitable for COB packaging, a focusing lens and a collimating lens need to be coupled and converged between a CW laser and a silicon photonic chip to converge the light emitted by the CW laser into the waveguide of the silicon photonic chip. Currently, in the industry, a six-axis coupling and co-alignment scheme for the focusing lens and the collimating lens simultaneously is generally used to maximize the coupling efficiency. However, this scheme requires a new double-lens coupling device, and the double lenses are coupled and co-aligned simultaneously, which takes a long time for coupling and requires a large investment in equipment, and is not suitable for mass production. Or, first, a spot coupling device is used for the spot coupling of the collimating lens, but the silicon photonic chip needs to be re-mounted, and then wire bonding is performed. During the curing and wire bonding processes, the collimating lens may be displaced and the spot may be deformed. Then, when performing the focusing lens coupling, there may be differences in the beam mode field matching, resulting in low coupling efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a coupling method for a double-lens at the input end of a silicon photonic chip and a silicon photonic device, which can at least solve some defects in the prior art.

[0005] To achieve the above purpose, an embodiment of the present invention provides the following technical solution: A coupling method for a double-lens at the input end of a silicon photonic chip, comprising the following steps:

[0006] S1, Mount an isolator between the CW laser and the silicon photonic chip;

[0007] S2, Take a focusing lens and a collimating lens to be coupled, wherein the focusing lens is located between the silicon photonic chip and the isolator, and the collimating lens is located between the CW laser and the isolator;

[0008] S3, Use a single-lens coupling device to couple the collimating lens and the focusing lens respectively;

[0009] S4, Cure the collimating lens and the focusing lens to complete the double-lens coupling.

[0010] Further, the method for coupling the converging lens is specifically as follows:

[0011] Move the converging lens between the silicon photonic chip and the isolator;

[0012] Adjust the position of the converging lens to perform X / Y-axis optical axis light seeking;

[0013] After finding the maximum backlight current, drive the converging lens to move one unit distance along the Z-axis optical axis direction towards the silicon photonic chip;

[0014] Repeat the light seeking until the backlight current meets the preset range, and then stop the light seeking.

[0015] Further, perform the light seeking action by reading the magnitude of the backlight current of the silicon photonic chip and performing weak light monitoring.

[0016] Further, the method for coupling the collimating lens is specifically as follows:

[0017] Move the collimating lens between the CW laser and the isolator;

[0018] Adjust the position of the collimating lens to perform X / Y-axis optical axis light seeking;

[0019] After finding the maximum backlight current, drive the collimating lens to move one unit distance along the Z-axis optical axis direction towards the CW laser;

[0020] Repeat the light seeking until the backlight current starts to decrease, and then stop the light seeking;

[0021] Then move the collimating lens back one unit distance and adjust the angle of the collimating lens to perform light seeking until the backlight current reaches the maximum value.

[0022] Further, perform the light seeking action by reading the magnitude of the incident light current of the silicon photonic chip.

[0023] Further, use a single-lens coupling device to complete the movement of the converging lens and the collimating lens, the acquisition of the incident light current of the silicon photonic chip, and the acquisition of the backlight current.

[0024] Further, the light seeking method adopts cross light seeking or spiral light seeking.

[0025] Further, before coupling, first drive the CW laser to emit light.

[0026] Further, the mounting in the S1 step is specifically as follows: Fix the silicon photonic chip on the carrier, then mount the optical waveguide of the CW laser with reference to the optical waveguide of the silicon photonic chip, and finally mount the isolator in the middle of the CW laser and the silicon photonic chip, leaving sufficient coupling space.

[0027] Another technical solution is provided in an embodiment of the present invention: a silicon photonics device, including a silicon photonics chip, a focusing lens, and a collimating lens, and coupling the focusing lens and the collimating lens by using the above method.

[0028] Compared with the prior art, the beneficial effect of the present invention is that: using a single-lens coupling device to couple the focusing lens and the collimating lens neither adds a double-lens coupling device nor increases the coupling time while meeting the coupling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of a silicon photonics chip, a CW laser, an isolator, a focusing lens, and a collimating lens of a silicon photonics device provided in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] Please refer to Figure 1 , an embodiment of the present invention provides a method for coupling a double lens at the input end of a silicon photonics chip, including the following steps: S1, mounting an isolator between a CW laser and a silicon photonics chip; S2, taking a focusing lens and a collimating lens to be coupled, where the focusing lens is located between the silicon photonics chip and the isolator, and the collimating lens is located between the CW laser and the isolator; S3, coupling the collimating lens and the focusing lens respectively by using a single-lens coupling device; S4, curing the collimating lens and the focusing lens to complete the double-lens coupling. In this embodiment, using a single-lens coupling device to couple the focusing lens and the collimating lens can ensure the coupling efficiency, shorten the double-lens coupling time, and reduce the investment in double-lens coupling devices compared with the prior art, thereby reducing the equipment cost.

[0032] As an optimized solution of the embodiment of the present invention, please refer to Figure 1, the method for coupling the converging lens is specifically as follows: Move the converging lens between the silicon photonics chip and the isolator; Adjust the position of the converging lens to perform X / Y-axis optical axis light search; When the maximum backlight current is found, drive the converging lens to move one unit distance along the Z-axis optical axis direction towards the silicon photonics chip; Repeat the light search until the backlight current meets the preset range and then stop the light search. Preferably, the light search operation is performed by reading the magnitude of the backlight current of the silicon photonics chip and performing weak light monitoring. In this embodiment, by supplying 200 mA current to the CW laser to make it emit light, the converging lens is moved to the middle of the isolator and the silicon photonics chip according to the focal length position. Therefore, moving one unit distance means moving one focal length position. By reading the magnitude of the backlight current of the silicon photonics chip and performing weak light monitoring, X / Y-axis cross or spiral light search is performed. After finding the maximum backlight current, move one step distance along the Z-axis optical axis direction towards the silicon photonics chip. Repeat the X / Y-axis cross or spiral light search steps until the backlight current meets 1.5 - 2.0 μA after moving in the Z-axis X / Y-axis cross or spiral light search and then stop, and then complete the dispensing and curing.

[0033] As an optimized solution of the embodiment of the present invention, please refer to Figure 1 , the method for coupling the collimating lens is specifically as follows: Move the collimating lens between the CW laser and the isolator; Adjust the position of the collimating lens to perform X / Y-axis optical axis light search; When the maximum backlight current is found, drive the collimating lens to move one unit distance along the Z-axis optical axis direction towards the CW laser; Repeat the light search until the backlight current starts to decrease and then stop the light search; Then move the collimating lens back to the previous unit distance and adjust the angle of the collimating lens to perform light search until the backlight current reaches the maximum value. Preferably, the light search operation is performed by reading the magnitude of the incident light current of the silicon photonics chip. In this embodiment, by supplying 200 mA current to the CW laser to make it emit light, the collimating lens is moved to the middle of the CW laser and the isolator according to the focal length position. By reading the magnitude of the incident light current of the silicon photonics chip, X / Y-axis cross or spiral light search is performed. After finding the maximum backlight current, move one step distance along the Z-axis optical axis direction towards the CW laser. This one step distance is one unit distance, that is, move one step of the focal length position. Repeat the X / Y-axis cross or spiral light search steps until the backlight current starts to decrease after moving in the Z-axis X / Y-axis cross or spiral light search and then stop. Stop the collimating lens at the focal length position of the previous step in the Z-axis direction, then adjust the angle to perform light search until the maximum value is reached, and complete the dispensing and curing.

[0034] As an optimized solution of the embodiment of the present invention, a single-lens coupling device is used to complete the movement of the converging lens and the collimating lens, the acquisition of the incident light current of the silicon photonic chip, and the acquisition of the backlight current. In this embodiment, by using a single-lens coupling device to complete the coupling of the converging lens and the collimating lens, the cost can be reduced, and the coupling time can also be reduced. In this embodiment, the coupling of the converging lens and the collimating lens is completed by a single-lens coupling device, including driving and current acquisition. The driving is realized by a single suction nozzle or a single gripper cooperating with a stepping motor and visual recognition and positioning, and the current is acquired by reading the value of the internal register of the MCU on the PCB board. The dual-lens coupling device mentioned in the above background technology adds a six-dimensional coupling module of a suction nozzle or a gripper on the basis of the single-lens coupling device, with higher cost and more cumbersome coupling steps.

[0035] As an optimized solution of the embodiment of the present invention, the light-seeking method adopts cross light-seeking or spiral light-seeking. In this embodiment, the cross light-seeking is to scan along the X / Y axis, and the spiral light-seeking is to scan spirally along the optical axis direction. Both can be used for light-seeking.

[0036] As an optimized solution of the embodiment of the present invention, the mounting in the S1 step is specifically as follows: fixing the silicon photonic chip on a carrier, then mounting the optical waveguide of the CW laser with reference to the optical waveguide of the silicon photonic chip, and finally mounting the isolator between the CW laser and the silicon photonic chip, leaving sufficient coupling space.

[0037] Please refer to Figure 1 , the embodiment of the present invention also provides a silicon photonic device, including a silicon photonic chip, a converging lens, and a collimating lens, and coupling the converging lens and the collimating lens by using the above method. The coupling efficiency of the silicon photonic device can be improved.

[0038] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A coupling method for a double-lens at the input end of a silicon photonic chip, characterized in that, It includes the following steps: S1. Mount the isolator between the CW laser and the silicon photonics chip; S2. Take the focusing lens and the collimating lens to be coupled, where the focusing lens is located between the silicon photonics chip and the isolator, and the collimating lens is located between the CW laser and the isolator; S3. Use a single-lens coupling device to couple the collimating lens and the focusing lens respectively; S4. Cure the collimating lens and the focusing lens to complete the double-lens coupling.

2. The coupling method of the double-lens at the input end of the silicon photonic chip according to claim 1, characterized in that, The method for coupling the focusing lens is specifically as follows: Move the focusing lens between the silicon photonics chip and the isolator; Adjust the position of the focusing lens to perform X / Y-axis optical axis light search; After finding the maximum backlight current, drive the focusing lens to move one unit distance along the Z-axis optical axis direction towards the silicon photonics chip; Repeat the light search until the backlight current meets the preset range and then stop the light search.

3. The coupling method of the double-lens at the input end of the silicon photonic chip according to claim 2, characterized in that: Perform the light search operation by reading the magnitude of the backlight current of the silicon photonics chip and performing weak light monitoring.

4. The coupling method of the double-lens at the input end of the silicon photonic chip according to claim 1, wherein: The method for coupling the collimating lens is specifically as follows: Move the collimating lens between the CW laser and the isolator; Adjust the position of the collimating lens to perform X / Y-axis optical axis light search; After finding the maximum backlight current, drive the collimating lens to move one unit distance along the Z-axis optical axis direction towards the CW laser; Repeat the light search until the backlight current starts to decrease and then stop the light search; Move the collimating lens back to the previous unit distance, and adjust the angle of the collimating lens to perform light search until the backlight current reaches the maximum value.

5. The coupling method of the double-lens at the input end of the silicon optical chip according to claim 4, characterized in that: Perform the light search operation by reading the magnitude of the incident light current of the silicon photonics chip.

6. The coupling method of the double-lens at the input end of the silicon optical chip according to claim 1, characterized in that: Use a single-lens coupling device to complete the movement of the focusing lens and the collimating lens, the acquisition of the incident light current of the silicon photonics chip, and the acquisition of the backlight current.

7. The coupling method of the double-lens at the input end of the silicon photonic chip according to claim 1, characterized in that: The light search method adopts cross light search or spiral light search.

8. The coupling method of the double-lens at the input end of the silicon optical chip according to claim 1, wherein: Before coupling, first drive the CW laser to emit light.

9. The coupling method of the double-lens at the input end of the silicon photonic chip according to claim 1, wherein The mounting in step S1 is specifically as follows: Fix the silicon photonics chip on the carrier, then mount the optical waveguide of the CW laser with reference to the optical waveguide of the silicon photonics chip, and finally mount the isolator in the middle of the CW laser and the silicon photonics chip, leaving sufficient coupling space.

10. A silicon photonics device, characterized in that: It includes a silicon photonics chip, a focusing lens, and a collimating lens, and the focusing lens and the collimating lens are coupled by using the method according to any one of claims 1-9.

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