CN215297763U

CN215297763U - Grating coupling CPO silicon light engine

Info

Publication number: CN215297763U
Application number: CN202121893556.XU
Authority: CN
Inventors: 李量; 杨恒毅; 杨建民; 许詹垒; 于泽晖; 冯雯雯; 尤炎炎
Original assignee: Hengtong Rockley Technology Co Ltd
Current assignee: Suzhou Zhuoyu Photon Technology Co ltd
Priority date: 2021-08-13
Filing date: 2021-08-13
Publication date: 2021-12-24
Anticipated expiration: 2031-08-13

Abstract

The utility model provides a grating coupling CPO silicon light engine, it includes: a circuit substrate and an optical unit; the optical unit includes: an electrical chip, a silicon optical chip, and an optical coupling assembly; the electric chip and the silicon optical chip are arranged on the top surface of the circuit substrate, and the electric chip is positioned on one side of the end face of one end of the silicon optical chip and is in signal transmission with the silicon optical chip; be provided with the grating window on the silicon optical chip, optical coupling subassembly includes: a coupling assembly body and an optical fiber; the bottom surface of the coupling component body comprises: the optical fiber is connected with the top surface of the silicon optical chip in an adhesive mode, the grating window is arranged on the top surface of the silicon optical chip, the optical fiber is connected with the grating window in a sealing mode, and the optical fiber extends to the outside from the inclined surface. The utility model discloses carry out the module design with each part, optical coupling subassembly's bottom surface has the plane that splices with the top surface of silicon optical chip and the inclined plane relative with the grating window. Therefore, the packaging reliability requirement can be met, and the reflection problem in optical signal transmission is also solved. And the polarization-independent grating is adopted, so that the external laser does not need a polarization-maintaining optical fiber.

Description

Grating coupling CPO silicon light engine

Technical Field

The utility model relates to an optical device encapsulates technical field, especially relates to a grating coupling CPO silicon photo engine.

Background

At present, the package of the CPO silicon optical engine generally adopts an external light source mode, and the optical engine has two optical path coupling modes:

the first is based on end-face coupling, which has the advantages of less coupling loss, lower cost of the horizontal fiber array, but higher requirement on coupling precision.

The second is vertical coupling based on a grating coupler, and the grating coupling mode has the advantages that the coupling precision requirement is not high, the grating preparation process is mature, but the difficult problem is how to give consideration to the reflected light influence and the packaging reliability caused by the vertical coupling end face, and meanwhile, the polarization-related loss can be caused when an external light source is transmitted into a silicon optical engine through a section of optical fiber.

Therefore, it is necessary to provide a further solution to the above problems.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a grating coupling CPO silicon light engine through a special design optic fibre (FA, Fiber Array) structure and polarization irrelevant type grating to overcome the not enough that exists among the prior art.

In order to solve the technical problem, the technical scheme of the utility model is that:

a grating-coupled CPO silicon light engine, comprising: a circuit substrate and an optical unit disposed on the circuit substrate;

the optical unit includes: an electrical chip, a silicon optical chip, and an optical coupling assembly;

the electric chip and the silicon optical chip are arranged on the top surface of the circuit substrate, and the electric chip is positioned on one side of the end face of one end of the silicon optical chip and is in signal transmission with the silicon optical chip;

still be provided with the grating window on the top surface of silicon optical chip other end, optical coupling subassembly includes: a coupling assembly body and an optical fiber; the bottom surface of the coupling assembly body includes: the optical fiber comprises a plane and an inclined plane, wherein the plane is bonded with the top surface of the silicon optical chip, the inclined plane is opposite to the grating window, one end of the optical fiber extends to the inclined plane, and the other end of the optical fiber extends to the outside of the coupling component body.

As an improvement of the grating-coupled CPO silicon photo engine of the present invention, the top surface of the circuit substrate is provided with a groove for accommodating the optical unit.

As the utility model discloses the improvement of grating coupling CPO silicon light engine, circuit substrate is PCBA, PCBA's bottom surface still is provided with the array shell fragment.

As the utility model discloses the improvement of grating coupling CPO silicon light engine, optical unit is a plurality of, a plurality of optical unit set up side by side in on the circuit substrate.

As the utility model discloses grating coupling CPO silicon light engine's improvement, the optical unit is four, and according to the array orientation this moment, four electric chips are Driver chip, TIA chip, Driver chip and TIA chip in proper order.

As the utility model discloses grating coupling CPO silicon light engine's improvement, the optical unit is four, and according to the array orientation this moment, four silicon optical chips are TX chip, RX chip, TX chip and RX chip in proper order.

As an improvement of the grating coupling CPO silicon optical engine of the present invention, the grating windows on the TX chip and the RX chip are polarization independent gratings formed by an etching process.

As an improvement of the grating-coupled CPO silicon optical engine of the present invention, the inclined plane is a chamfered surface between the side surface and the bottom surface of the coupling component body.

As an improvement of the grating-coupled CPO silicon optical engine of the present invention, the inclined plane has an inclination angle of 5-15 degrees with respect to the top surface of the silicon optical chip.

As the utility model discloses the improvement of grating coupling CPO silicon light engine, the optical coupling subassembly through optical matching glue with silicon optical chip splices mutually.

Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses carry out the module design with electric chip, silicon optical chip and optical coupling subassembly, optical coupling subassembly's bottom surface has the plane that splices mutually with silicon optical chip's top surface and the inclined plane relative with the grating window. Therefore, the packaging requirement is met, the reflection problem existing in optical signal transmission is solved, and effective conduction of optical signals is guaranteed; the bonding reliability of FA and the silicon optical chip is improved; in addition, the external laser does not need a polarization maintaining fiber by adopting the polarization-independent grating.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic perspective view of an embodiment of a grating-coupled CPO silicon optical engine according to the present invention;

FIG. 2 is a bottom view of the circuit substrate of FIG. 1;

fig. 3 is an enlarged schematic view of the optical coupling assembly in the grating-coupled CPO silicon optical engine of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1, an embodiment of the present invention provides a grating-coupled CPO silicon optical engine, which includes: a circuit substrate 10, and an optical unit 20 disposed on the circuit substrate 10.

As shown in fig. 2, the circuit substrate 10 is used as a carrier for packaging other devices. In one embodiment, the circuit substrate 10 may be a PCBA, i.e., a PCB board on which electronic components are mounted. The bottom surface of this PCBA board still is provided with array shell fragment 11. The array elastic sheet 11 can be used as an electric signal interface between the silicon photo engine and a main board of the switch, and the array elastic sheet 11 can be repeatedly used for many times, so that the silicon photo engine can be flexibly replaced.

The grating-coupled CPO silicon photo engine of the present embodiment modularly packages the electrical chip, the silicon photo chip and the optical coupling assembly.

Specifically, the optical unit 20 includes: an electrical chip 21, a silicon optical chip 22 and an optical coupling assembly 23.

The electric chip 21 and the silicon optical chip 22 are disposed on the top surface of the circuit substrate 10, and the electric chip 21 is located on one side of an end surface of one end of the silicon optical chip 22 and connected to the silicon optical chip 22 through wire bonding, so as to realize signal transmission between the electric chip 21 and the silicon optical chip 22. Accordingly, the top surface of the circuit board 10 is formed with a groove 12 for accommodating the optical unit 20, and the depth of the groove 12 is determined by the thickness difference between the electrical chip 21 and the silicon optical chip 22.

The optical unit 20 may be provided in plurality as needed, and the plurality of optical units 20 are disposed side by side on the circuit substrate 10. At this time, the plurality of optical units 20 may be collectively disposed in one groove of the circuit substrate 10 or individually disposed in respective grooves.

When the optical unit 20 is four, the electric chip 21 and the silicon optical chip 22 are also provided in four.

Specifically, in order to meet the processing requirements for the optical signal and the electrical modulation signal, the four electrical chips 21 are a Driver chip 211, a TIA chip 212, a Driver chip 211, and a TIA chip 212 in sequence according to the arrangement direction of the four optical units 20. The Driver chip 211 is configured to modulate an input external optical signal, and the TIA chip 212 is configured to perform transimpedance amplification on an electrical modulation signal output by the silicon optical chip (RX chip) to form a voltage signal.

Further, in order to realize the reception and transmission of the optical signal, the four silicon optical chips 22 are the TX chip 221, the RX chip 222, the TX chip 221, and the RX chip 222 in this order according to the arrangement direction of the four optical units 20. The TX chip 221 is configured to receive an external light source signal, load a modulation signal through the Driver chip 211, and output the modulation signal. The RX chip 222 is used to receive the modulated optical signal and then convert it into an electrical modulated signal to be input to the TIA chip 212.

As shown in fig. 3, in any optical unit, a grating window 220 is further disposed on the top surface of the other end of the silicon optical chip 22, and the optical coupling component 23 is directly coupled to the grating window 220. Specifically, the optical coupling assembly 23 includes: a coupling assembly body 231 and an optical fiber 232.

The grating windows 220 on the TX chip 221 and the RX chip 222 are polarization-independent gratings formed by an etching process. Thus, the external laser does not need the polarization maintaining fiber 232. And the light direction of the in-out grating supports two types of vertical and angle, and the angle of the chamfer surface of the optical fiber 232 is only required to be correspondingly matched.

The bottom surface of the coupling member body 231 includes: a plane 2310 glued to the top surface of the silicon photonic chip 22 and a slope 2311 opposite to the grating window 220, wherein one end of the optical fiber 232 extends to the slope 2311, and the other end extends to the outside of the coupling component body 231. Thus, the optical fiber 232 is bent and coupled to an external grating coupler.

This design is designed to take into account that if the bottom surface of the coupling component body 231 is directly coupled to the grating window 220, the optical signal is reflected due to the mismatch in angle, and the transmission of the optical signal is affected. Therefore, while the packaging requirement is considered, the surface of the optical coupling assembly 23 opposite to the grating window 220 is designed as the inclined surface 2311, which is beneficial to realizing angle matching, and further overcomes the reflection problem in optical signal transmission.

To form the aforementioned chamfer 2311, the chamfer 2311 may be a chamfered surface between the side and bottom surfaces of the coupling assembly body 231. In one embodiment, bevel 2311 is angled at 5-15 deg. relative to the top surface of silicon photonics chip 22. Preferably, bevel 2311 is at an angle of 10 ° relative to the top surface of silicon photonics chip 22.

The optical coupling assembly 23 is bonded to the silicon photonics chip 22 by an optical matching glue 24.

To sum up, the utility model discloses carry out the module design with electric chip, silicon optical chip and optical coupling subassembly, optical coupling subassembly's bottom surface has the plane that splices mutually with silicon optical chip's top surface and the inclined plane relative with the grating window. Therefore, the packaging requirement is met, the reflection problem existing in optical signal transmission is solved, and effective conduction of optical signals is guaranteed; the bonding reliability of FA and the silicon optical chip is improved; in addition, the external laser does not need a polarization maintaining fiber by adopting the polarization-independent grating.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A grating-coupled CPO silicon light engine, comprising: a circuit substrate and an optical unit disposed on the circuit substrate;

2. A grating-coupled CPO silicon light engine as claimed in claim 1, wherein the top surface of said circuit substrate defines a recess for receiving said optical unit.

3. A grating-coupled CPO silicon light engine as claimed in claim 1 or 2, wherein the circuit substrate is a PCBA, and an array spring is further disposed on a bottom surface of the PCBA.

4. A grating-coupled CPO silicon light engine as recited in claim 1, wherein said optical unit is a plurality of optical units disposed side-by-side on said circuit substrate.

5. A grating-coupled CPO silicon light engine as claimed in claim 4 wherein the number of said optical units is four, and then the four electrical chips are Driver chip, TIA chip, Driver chip and TIA chip in sequence according to the arrangement direction.

6. A grating-coupled CPO silicon optical engine as claimed in claim 4 or 5, wherein the number of the optical units is four, and the four silicon optical chips are sequentially a TX chip, an RX chip, a TX chip and an RX chip according to the arrangement direction.

7. A grating-coupled CPO silicon optical engine as described in claim 6, wherein said grating windows on the TX and RX chips are polarization-independent gratings formed by an etching process.

8. A grating-coupled CPO silicon light engine as claimed in claim 1, wherein said inclined surface is a chamfered surface between a side surface and a bottom surface of said coupling component body.

9. A grating-coupled CPO silicon light engine as claimed in claim 1 or 8 wherein the inclined plane has an inclination of 5-15 ° with respect to the top surface of the silicon light chip.

10. A grating-coupled CPO silicon light engine as described in claim 1, wherein said optical coupling component is bonded to said silicon photonics chip by an optical matching glue.