CN115407450A

CN115407450A - Optical waveguide and method for beam assisted alignment

Info

Publication number: CN115407450A
Application number: CN202110594680.4A
Authority: CN
Inventors: 马麟; 许奔波
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-11-29

Abstract

Optical waveguide and beam assisted alignment methods are disclosed. An optical waveguide includes a substrate, a cladding layer, and a core layer. The cladding layer is arranged on the substrate and covers the core layer; these three portions form an open recess. The groove comprises two oppositely-arranged surfaces. One of the surfaces of the core layer is a first inclined surface, and the other surface of the core layer is a second inclined surface. The first and second slopes are reflective surfaces. The core layer comprises a first core layer and a second core layer which are arranged on two sides of the groove, and the first core layer and the second core layer respectively comprise a first inclined plane and a second inclined plane. The first slope is used for changing a transmission path of the signal light or the continuous light in the optical waveguide to be output in the second direction or transmitted along the first core layer. The second inclined surface is used for changing the transmission path of the alignment assisting light in the optical waveguide to be output in the third direction or transmitted along the second core layer. The second direction and the third direction are toward the same side of the substrate. The optical waveguide enables fast and low-cost coupling alignment by assisting in aligning the optical transmission path of light.

Description

Optical waveguide and method for beam assisted alignment

Technical Field

The present invention relates to the field of optical devices, and more particularly to optical waveguides, optical transmission systems, and methods for beam assisted alignment.

Background

An optical waveguide is one of key components of an optical communication system for outputting an input optical beam to another optical communication system component. An optical waveguide, such as a vertical reflection waveguide, can achieve both the direction change of a light beam and the transmission of the light beam. In the research and commercial use of optical waveguides, it is an important research topic how to achieve alignment of light beams between an optical waveguide and its associated component, i.e. so that light beams transmitted through the optical waveguide can completely or largely enter another component with which it is associated.

Fig. 1 is a schematic diagram of a system including a conventional vertical reflective waveguide. As shown in fig. 1, the system includes a vertical reflective waveguide 100 and a light receiving device 200. The vertical reflection waveguide 100 includes a substrate 101, and a core layer 103 and a cladding layer 102 disposed on the substrate 101. The core layer 103 is used to transmit an optical beam (e.g., incident light in fig. 1). The core layer 103 and the cladding layer 102 form a groove as shown in fig. 1, one of the faces of which is used to reflect incident light so that the incident light is transmitted to the light-receiving device 200.

Before the optical beam transmission is performed by using the system shown in fig. 1, in order to ensure the alignment between the vertical reflective waveguide 100 and the light receiving device 200, that is, to ensure that the power of the input light receiving device 200 is large, it is necessary to adjust the relative positions of the two, and use an auxiliary instrument (e.g., a power meter or a power meter) to detect the power value of the input light receiving device 200. When the power value is large or reaches a preset threshold value, it is determined that the vertical reflection waveguide 100 and the light receiving device 200 are aligned and coupled. This method is called active alignment because it requires alignment by active devices. The method has long service life and high cost.

Disclosure of Invention

Example embodiments of the present application provide new optical waveguide and alignment coupling schemes to reduce the cost of coupling alignment and the time of coupling alignment.

In a first aspect, embodiments of the present application disclose an optical waveguide. The optical waveguide includes a substrate, a cladding layer, and a core layer. Wherein,

the core layer is arranged in the cladding layer, and the cladding layer is arranged on the substrate. The substrate, the cladding and the core layer form a groove with an opening facing a first direction, or the cladding and the core layer form a groove with an opening facing the first direction, and the first direction is a direction departing from the substrate facing the core layer or a direction departing from the cladding facing the substrate. The groove comprises a first surface and a second surface which are oppositely arranged, the first surface is a first inclined surface at the part of the core layer, the first inclined surface is used for changing the transmission direction of the signal light or the continuous light, the second surface is a second inclined surface at the part of the core layer, the second inclined surface is used for changing the transmission direction of the auxiliary alignment light, and the first inclined surface and the second inclined surface are reflecting surfaces. The core layer comprises a first core layer and a second core layer which are arranged on two sides of the groove. Wherein the first core layer includes the first slope for changing a transmission path of the signal light or the continuous light in the optical waveguide such that the signal light or the continuous light input into the optical waveguide along the first core layer is output in a second direction or such that the signal light or the continuous light input in a direction opposite to the second direction is transmitted along the first core layer. The second core layer includes the second inclined surface, and the second inclined surface is used for changing a transmission path of the alignment assisting light in the optical waveguide, so that the alignment assisting light input into the optical waveguide along the second core layer is output along a third direction or the alignment assisting light input along a reverse direction of the third direction is transmitted along the second core layer, and the second direction and the third direction are towards the same side of the substrate.

In one possible implementation, the cladding layer includes a first cladding layer and a second cladding layer, the first cladding layer and the second cladding layer are contiguous, and the core layer is disposed between the first cladding layer and the second cladding layer.

In one possible implementation, the first core layer and the second core layer are on the same plane. In so doing, the fabrication of the optical waveguide is simple.

In one possible implementation, the third direction and the second direction are parallel. This design makes the design of the coupling alignment marks of the device to be mated with the optical waveguide simple.

In one possible implementation, the third direction or the second direction is perpendicular to the substrate.

In one possible implementation, the first face and the second face are mirror symmetric.

In one possible implementation, the optical waveguide further comprises a dust-proof member adjoining the groove for dust-proof the groove. For example, the dust-proof member is a dust-proof cover, and the dust-proof cover is disposed on the substrate to seal the groove. For another example, the dust-proof component is a filling material, the filling material is filled in the groove and covers at least the first inclined surface and the second inclined surface, and the optical refractive index of the filling material is smaller than the optical refractive index of the core layer. For another example, the dust-proof component is a coated protective layer, and the coated protective layer at least covers the first inclined surface and the second inclined surface. It is understood that the dust-proof member can improve the coupling efficiency of the optical waveguide. The above-described dust-proof solutions may be used in combination.

In one possible implementation, the optical waveguide further comprises a photodetector, wherein the first slope is a slope that is partially reflective and partially refractive. The photoelectric detector is used for receiving the light refracted by the first inclined plane and monitoring the optical power of the signal light or the continuous light. It should be understood that the photodetector may also be placed outside of the optical waveguide for use with the optical waveguide.

In a second aspect, an optical transmission system is disclosed in an embodiment of the present application. The system comprises an optical waveguide as disclosed in the first aspect or any one of its implementations and a further optical waveguide. The another optical waveguide includes another substrate, another cladding layer, another core layer, and an alignment mark. Wherein the another core layer is disposed in the another cladding layer, the another cladding layer is disposed on the another substrate, the another optical waveguide includes a third surface, and a portion of the third surface on the another core layer is a third inclined surface. When the alignment mark of the another optical waveguide is on a transmission path of the alignment assisting light reflected by the second cross section of the optical waveguide, the third inclined surface is configured to change a transmission direction of the signal light or the continuous light output from the second direction so that the signal light or the continuous light is output along the another core layer, or the third inclined surface is configured to change a transmission direction of the signal light or the continuous light transmitted along the another core layer so that the signal light or the continuous light is input into the optical waveguide in a direction opposite to the second direction and is transmitted along the first core layer after being reflected by the first inclined surface.

In one possible implementation, the alignment mark is located within the other cladding layer; alternatively, the alignment mark is located within the core layer.

In one possible implementation, the optical waveguide and the further optical waveguide are coupled in a joint manner.

In a third aspect, a method for beam assisted alignment is disclosed. The method comprises several steps. First, the relative positions of the optical beam processing apparatus and the optical waveguide are adjusted using the transmission path of the alignment assisting light formed by the first core layer and the first inclined surface of the optical waveguide. The optical waveguide comprises a substrate, a cladding layer and a core layer, wherein the substrate, the cladding layer and the core layer form an open groove, or the cladding layer and the core layer form an open groove. The groove comprises a first face and a second face which are oppositely arranged, the first face is arranged on the core layer, the portion of the core layer is a second inclined face, the second inclined face is used for changing the transmission direction of signal light or continuous light, the second face is arranged on the core layer, the portion of the core layer is a first inclined face, the first inclined face is used for changing the transmission direction of auxiliary alignment light, the first inclined face and the second inclined face are reflecting faces, the core layer comprises a first core layer and a second core layer which are arranged on two sides of the groove, the first core layer comprises the first inclined face, and the second core layer comprises the second inclined face. The beam processing apparatus includes an alignment mark. Next, when it is determined that the alignment mark is on the transmission path of the auxiliary alignment light, it is determined that the signal light or the continuous light is transmitted to the optical beam processing device by the optical waveguide to be processed by the optical beam processing device, or the signal light or the continuous light is transmitted to the optical waveguide by the optical beam processing device to realize beam deflection transmission by the optical waveguide.

In one possible implementation, the beam processing device is a light transmission waveguide. Wherein a transmission direction of the signal light or the continuous light remains unchanged after being transmitted via the optical beam processing device and the optical waveguide. In another possible implementation, the beam processing device is a light transmission waveguide. Wherein a transmission direction of the signal light or the continuous light is changed by 180 degrees after being transmitted through the beam processing device and the optical waveguide.

In one possible implementation, the optical beam processing device is a light receiving device or a light transmitting device.

The optical waveguide disclosed herein can accomplish fast and low-cost alignment coupling by auxiliary alignment of the optical transmission paths with independent signal light or continuous light.

Drawings

FIG. 1 is a schematic diagram of a system including a conventional vertical reflective waveguide;

fig. 2 is a schematic structural diagram of a first optical waveguide provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of a second optical waveguide provided in an embodiment of the present application;

fig. 4 is a schematic structural diagram of a third optical waveguide provided in an embodiment of the present application;

fig. 5 is a schematic structural diagram of a fourth optical waveguide provided in an embodiment of the present application;

fig. 6 is a schematic structural diagram of a first optical transmission system according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a second optical transmission system according to an embodiment of the present application;

FIG. 8 is a schematic diagram illustrating alignment mark position calculation according to an embodiment of the present disclosure;

fig. 9 is a schematic structural diagram of a third optical transmission system according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a fifth optical waveguide provided in an embodiment of the present application;

fig. 11 is a flowchart illustrating a beam assisted alignment method according to an embodiment of the present disclosure.

Detailed Description

To address the problems of the prior art, the present application provides a new optical waveguide, system and method for beam assisted alignment.

Before describing the optical waveguide, system, and method of beam-assisted alignment in detail, this application provides some general explanation. The following summary description applies to all embodiments of the present application unless explicitly stated otherwise.

The device form and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present invention, and do not limit the technical solution provided in the embodiment of the present application. As can be known to those skilled in the art, with the evolution of device morphology and the appearance of new service scenarios, the technical solution provided in the embodiments of the present application is also applicable to similar technical problems.

The technical scheme provided by the application can be suitable for an optical communication system. Such as a data center network, an optical transmission network, an optical access network, or a data communication network, etc. Specifically, the technical solution provided by the present application can be used for any network corresponding to a portion that needs to perform beam deflection transmission. For example, a scenario for connecting two devices may be used. As another example, a scenario may be used to connect two components inside one device. The present application has no limitation on the length of the optical waveguide. For example, in the scenario of the aforementioned device interconnect, the optical waveguide may have a length of 20 mm to 30 cm.

It should be noted that the terms "first," "second," and the like in this application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are capable of operation in other sequences than described of illustrated herein. "and/or" is used to describe the association relationship of the associated objects, meaning that three relationships may exist. For example, a and/or B, may represent: a exists alone, A and B exist simultaneously, and B exists alone. The same or similar technical descriptions provided in the method embodiments may also be applied to the apparatus embodiments, unless otherwise specified. And vice versa.

Unless specifically stated otherwise, a specific description of some features in one embodiment may also be applied to explain that other embodiments refer to corresponding features. For example, the material example for the optical waveguide in one embodiment can be applied to the optical waveguide mentioned in the other embodiments. As another example, a description of the location of the alignment marks, etc. Further, to more clearly show the relationship of components in different embodiments, the same or similar reference numbers are used in this application to refer to components with the same or similar functions in different embodiments.

The active alignment method needs to determine whether the optical waveguide and its associated device are aligned by means of an instrument such as a power meter, and has the problems of long time consumption, high cost and the like. To this end, the present application provides a new optical waveguide and beam alignment method. The novel optical waveguide comprises an auxiliary alignment optical path, can realize beam alignment quickly and effectively and has low cost.

Fig. 2 is a schematic structural diagram of a first optical waveguide according to an embodiment of the present disclosure. As shown in fig. 2, the optical waveguide 300 includes a base layer, a core layer, and clad layers (301, 302, and 303), and a groove 304 formed by the base layer, the core layer, and the clad layers. The core layer includes one or more optical paths, each for a light beam. Specifically, the light beam includes a signal light or a continuous light, or a secondary alignment light. The signal light refers to a light beam loaded with data. Continuous light, in english Continuous Wave (CW), refers to a light beam that is not loaded with data. The cladding layer covers the core layer, which may also be referred to as a cladding layer or a cladding layer, and has a refractive index different from that of the core layer, and the difference between the refractive indices can play a role in that light is bound in the core layer for transmission. The base layer is disposed on a layer on one side of the cladding layer, which may also be referred to as a substrate, to provide mechanical strength and physical support.

It should be noted that the optical waveguide of fig. 2 does not distinguish the relative positional relationship between the base layer, the core layer, and the clad layer. That is, the opening direction of the groove 304 may be a direction toward the core layer away from the base layer or a direction toward the base layer away from the clad layer. For example, the opening of the groove shown in fig. 2 is an opening in the base layer, and the bottom of the groove is the cladding layer. For another example, the opening of the groove shown in fig. 2 is an opening on the cladding layer, and the bottom of the groove is the cladding layer or the core layer. That is, the three layers of the substrate, the cladding layer, and the core layer form an open groove; alternatively, the cladding layer and the core layer form an open recess. The present application is not limited thereto. For further examples, reference may be made to the embodiments of FIGS. 3-9.

As shown in fig. 2, the recess 304 includes two opposing faces (one face is 304a, and the face opposite the face 304a is not shown in fig. 2). Where the portion of face 304a in the core layer is referred to as a first chamfer (shown as 304a-a in fig. 2) and the portion of the core layer opposite face 304a is referred to as a second chamfer (not shown in fig. 2). Wherein the first inclined plane 304a-a is used to change the transmission direction of the signal light or the continuous light. The second slope is used to change the transmission direction of the secondary alignment light. The first and second angled surfaces 304a-a are reflective surfaces. In particular, if air is filled in the grooves, the refractive index difference between the first core layer and the air needs to be designed so that the first slope 304a-a and the second slope can achieve light reflection. It will be appreciated that if the grooves are filled with other materials, the refractive index of the other materials should be less than the refractive index of the core layer so that the difference in refractive index between the two is such as to enable light reflection on the two inclined surfaces.

It should be noted that the secondary alignment light may be natural light, or the secondary alignment light may be white light. For a description of the transmission paths of the alignment assisting light and the alignment assisting light, reference may be made to the following embodiments.

The core layer is divided into two parts by the groove. In particular, the core layer includes a first core layer and a second core layer. Wherein the first core layer is used for transmitting signal light or continuous light. The first core layer includes a first slope 304a-a. The first slope 304a-a is used to change a transmission path of the signal light or the continuous light in the optical waveguide 300 so that the signal light or the continuous light input to the optical waveguide 300 along the first core layer is output in the second direction or so that the signal light or the continuous light input in the opposite direction of the second direction is transmitted along the first core layer. The second core layer is for transmitting secondary alignment light and includes a second slope. The second inclined surface is used to change a transmission path of the secondary alignment light in the optical waveguide 300 so that the secondary alignment light input to the optical waveguide 300 by the second core layer is output in the third direction or so that the secondary alignment light input in a direction opposite to the third direction is transmitted along the second core layer. Wherein the second direction and the third direction are towards the same side of the substrate.

To more clearly describe the second and third directions, and the relationship of the three layers of the optical waveguide, further device embodiments are provided below.

Fig. 3 is a schematic structural diagram of a second optical waveguide according to an embodiment of the present application. It should be understood that fig. 3 provides an exemplary view ofbase:Sub>A cross-section of the device along the directionbase:Sub>A-base:Sub>A' shown in fig. 2. Specifically, the optical waveguide 300 shown in fig. 3 includes base and clad layers (301 and 303), core layers (302 a and 302 b), and a groove 304. It should be understood that the example shown in FIG. 3 does not distinguish between the relative positions of the base layer and the cladding layer; specifically, it may be that the base layer is located on top and the cladding layer is located under the base layer; alternatively, the base layer may be on the bottom and the cladding layer on the base layer. The bottom surface of the recess 304 may be clad or base when the base is at the bottom.

As shown in fig. 3, the core layers include a first core layer 302a and a second core layer 302b. The recess 304 includes two opposing faces, face 304a and face 304b. Where the portion of the face 304a on the first core layer 302a is referred to as a first bevel 304a-a and the portion of the face 304b on the second core layer is referred to as a second bevel 304b-b. Specifically, the first inclined surface 304a-a serves to reflect incident light incident from the left side end surface of the first core layer 302a, so that the incident light is transmitted toward the outgoing light shown in fig. 3. Alternatively, the first inclined plane 304a-a may also reflect light transmitted in the opposite direction of the outgoing light such that it is transmitted along the first core layer 302a and output from the left end face of the first core layer 302a, according to the principle that the optical path is reversible. Similarly, the first slope 304b-b serves to reflect light incident from the right-side end face of the second core layer 302b so that it is transmitted in the secondary alignment light exit light direction (vertical direction in fig. 3) shown in fig. 3. Alternatively, the second inclined surface 304b-b may also be used to reflect light transmitted by the light in the opposite direction of the secondary alignment light exit light, such that it is transmitted along the second core layer 302b and output from the right end surface of the second core layer 302b, according to the principle that the optical path is reversible. The exit light direction and the auxiliary alignment light exit direction as shown in fig. 3 are both directed in the same direction, i.e., perpendicular to the optical waveguide 300 and downward. It should be understood that in particular applications, the second and third directions shown in fig. 3 do not have to be oriented perpendicular to the optical waveguide. The present application only requires that both directions are towards the same side of the core layer. Such as the underside of the core layer in fig. 3. For further examples, reference may be made to fig. 5-7, etc., which are not described herein.

It should be noted that the cladding layer may be fabricated in two steps during the fabrication process. Specifically, a first cladding layer is applied to the base layer, followed by placement of one or more optical pathways (constituting the core layer), and then another cladding layer is applied to completely cover the core layer. Thus, the cladding in the present application may comprise a first cladding and a second cladding, the first and second cladding being contiguous. A core layer is disposed between the first cladding layer and the second cladding layer. The first cladding layer and the second cladding layer may also be referred to as an upper cladding layer and a lower cladding layer, respectively. It should be understood that the cladding layer may also be formed integrally, and then the core layer is processed in the middle of the cladding layer by a special process, so as to form a structure in which the same cladding layer fully wraps the core layer. For example: by a laser direct writing process. A single optical path may be used to transmit one or more wavelengths of light. It should be understood that in the example of fig. 3, the two portions of the core are at the same level. In the manufacturing process, the manufacturing can be completed by one-time manufacturing, and the process is simple.

It should be understood that in the present embodiment, the

surfaces

304a and 304b are mirror-symmetric, so that the direction of the outgoing light and the direction of the auxiliary alignment light are parallel, and the calibration function is relatively simple to implement.

It should be appreciated that in the present embodiment, the first and second inclined surfaces 304a-a and 304b-b are all fully reflective surfaces. In practical applications, the two inclined surfaces may also be partially reflective and partially refractive surfaces. Specifically, refer to the description of fig. 5, which is not repeated herein.

When the optical waveguide 300 is coupled and aligned with another device (e.g., another optical waveguide, an optical transmitter device or an optical receiver device), the optical waveguide 300 uses the second inclined surface 304b-b to transmit auxiliary alignment light, thereby performing auxiliary alignment to achieve rapid and low-cost coupling alignment.

It should be understood that references herein to coupling of two devices refer to the transfer of signal light or continuous light from one device to the other, either directly or indirectly. One of the two devices is referred to as an optical waveguide in the present application, and the other device is referred to as another device coupled to the optical waveguide. In particular, the further device may be a further optical waveguide, an optical transmitting device or an optical receiving device. Detailed description is given with reference to fig. 6-7 and 9, which are not repeated herein.

Alternatively, the two directions depicted in FIG. 3 may be in a parallel relationship, so that the position of the alignment marks of the device coupled to the optical waveguide may be determined more simply.

Fig. 4 is a schematic structural diagram of a third optical waveguide provided in an embodiment of the present application. It should be understood that fig. 4, like fig. 3, also provides a cross-sectional view of the optical waveguide. From fig. 4 and the perspective view example of fig. 1, a person skilled in the art can know the perspective view of the device corresponding to fig. 4 without inventive effort. As shown in fig. 4, the optical waveguide 400 includes a base layer 403, cladding layers 401 and core layers (302 a and 402 b), and grooves 404 formed by these three layers. Specifically, the functions of the base layer 403, the cladding layer 401 and the core layer can be referred to the descriptions of the corresponding objects shown in fig. 2-3, and are not described herein again. The present embodiment provides an optical waveguide 400 that differs from the devices shown in fig. 2-3 in several major respects.

First, the directions of incidence or emission of the two light beams, i.e., (1) the signal light or the continuous light and (2) the auxiliary alignment light, are located above the core layer. For example, the direction of the two beams incident from the substrate may also be described as being toward the same side of the substrate 403. As shown in fig. 4, the signal light or the continuous light is incident into the optical waveguide 400 from the upper side of the optical waveguide 400 through the base 403, is reflected by the first cross section 404a-a, is transmitted through the core layer 302a, and is output from the left end face of the core layer 302 a. Similarly, the alignment assisting light is incident into the optical waveguide 400 from the upper layer of the optical waveguide 400 via the base layer 403, and is output via the core layer 402b after being reflected via the second cross section 404 b-b. The above-described reverse direction is also possible according to the principle of reversible optical path.

In practical applications, the signal light or the continuous light may exit from the vertical direction in fig. 4, while the auxiliary alignment light enters in the vertical direction. It will be appreciated that in this application scenario, the relationship of the two beams may be described as still being above the core layer. Alternatively, if the opposite direction of the incident light direction shown in fig. 4 is taken as the first direction and the vertically downward direction of the alignment assisting light is taken as the second direction, the above application scenarios can also be described as the opposite direction of the first direction and the second direction facing the same side of the substrate.

Second, the

cores

302a and 402b are not located at the same horizontal level. That is, the core layer 302a for transmitting signal light or continuous light and the core layer 402b for transmitting auxiliary alignment light are separately fabricated to obtain two core layers of different levels as shown in fig. 4.

Third, the shape of the grooves is different. Accordingly, the signal light or the continuous light and the auxiliary alignment light are not in the same direction as the light waveguide 400 is input or output. Taking the example where both the incident light and the secondary alignment light are input from the core layer side, then in this embodiment, the input directions of both beams are toward the upper side of the base layer. Differently, in the example shown in fig. 3, the output directions of both beams are directed towards the lower side of the base layer.

In the example shown in fig. 4, by providing a transmission optical path of the auxiliary alignment light, the optical waveguide 400 determines that the optical waveguide 400 has completed coupling alignment with the device when the alignment mark of the device coupled with the optical waveguide 400 is seen by using the auxiliary alignment optical path. The coupling alignment is fast and low cost.

Fig. 5 is a schematic structural diagram of a fourth optical waveguide provided in an embodiment of the present application. It should be understood that fig. 5, like fig. 3, also provides a cross-sectional view of an optical waveguide. From fig. 5 and the perspective illustration of fig. 1, a person skilled in the art can learn the perspective illustration of the device corresponding to fig. 5 without inventive effort. As shown in fig. 5, optical waveguide 500 includes base and cladding layers (301 and 303) and core layers (302 a and 302 b), and grooves 504 formed by these three layers. Specifically, the functions of the base layer, the cladding layer and the core layer can be referred to the descriptions of the corresponding objects shown in fig. 2-3, and are not described in detail herein. The present embodiment provides an optical waveguide 500 that differs from the devices shown in fig. 2-3 in several major ways.

First, the two opposing faces of the groove are inclined to such an extent that the direction of the emergent light and the secondary alignment light is not perpendicular to the base layer or the cladding layer. The design can meet the requirements of different application scenarios. For example, due to the length limitation of the device for receiving the outgoing light, the alignment mark needs to be designed closer to the light receiving point. As another example, the apparatus for receiving the outgoing light supports only oblique reception and the like.

Second, cross section 504a-a is a partially reflective and partially refractive design. As shown in FIG. 5, cross-section 504a-a reflects a substantial portion of incident light away from the outgoing light direction as shown, and a small portion of incident light away from the refracted light direction as shown. The refracted light may be used with an optical monitoring device (e.g., a normal PD or APD, etc.). Because the percentage of the total incident light intensity that is refracted can be predetermined, monitoring the power of the refracted light using the light monitoring device can provide many inputs of device control judgment information, such as: the incident light power, the coupled light power intensity, etc. are used to monitor the power of the signal light or light beam. This can be done to determine the coupling efficiency. It is to be understood that this light monitoring device may be disposed within the recess 504; alternatively, the optical monitoring device can be placed separately and combined with the optical waveguide 500 to form a system for use.

In the example shown in fig. 5, optical waveguide 500 utilizes a transmission optical path that assists in aligning light to achieve fast and low cost coupling alignment. Alternatively, the optical waveguide 500 may also perform monitoring of the signal light by refracting part of it or the continuous light.

Fig. 6 is a schematic structural diagram of a first optical transmission system according to an embodiment of the present application. As shown in fig. 6, the optical transmission system includes an optical waveguide 300 and an optical waveguide 600. Of these, optical waveguide 300 is the example in fig. 2. It should be understood that the optical waveguide 300 may be replaced with either of fig. 4 or 5, or other variations described herein. The present application is not limited thereto. Optical waveguide 600 includes a core layer, cladding layers, and base layers (not distinguished in fig. 6), and alignment marks 601. The three layers of the optical waveguide 600 form a slope (hereinafter referred to as a third cross section) for deflecting the light beam at one end surface. The alignment mark 601 is used to achieve coupling alignment. As shown in fig. 6, when the alignment mark 601 of the optical waveguide 600 can be recognized by the auxiliary alignment transmission optical path, it can be determined that the signal light output from the optical waveguide 300 can be transmitted in the core layer of the optical waveguide 600 after being reflected by the third cross section; and vice versa. That is, the optical waveguide 300 and the optical waveguide 600 may constitute an optical transmission system to complete transmission of signal light. It should be understood that the signal light in the present embodiment may be replaced with a continuous light.

As shown in fig. 6, it is possible to judge whether or not the two devices are aligned by observing whether or not the auxiliary alignment mark is visible by natural light through the auxiliary alignment light transmission path. Alternatively, the light emitted by the white light source, for example, a white light source disposed below the auxiliary alignment mark of the optical waveguide 600, may be used, and the auxiliary alignment light may be viewed through the auxiliary alignment light transmission path. Alternatively, a light beam for alignment assistance may be actively transmitted through an observation port (located on the right end surface of the device 300 in fig. 6) of the optical transmission path of the alignment assistance light, and the light beam may be reflected by the optical waveguide 600 to determine whether or not the alignment assistance mark is observed. The accuracy is higher with the scheme of actively sending the beam. The corresponding scheme can be selected according to specific needs, and the application is not limited.

It should be noted that fig. 6-9 show test views of optical waveguides, where the positions of the core layer and/or the grooves in the optical waveguides are provided by dashed lines for clarity of the corresponding embodiments.

It should be noted that, in this embodiment, there is a certain interval between the two waveguides. In practical application, the two waveguides can be directly attached, so that the coupling efficiency is improved, and the optical path can be prevented from being polluted.

It should be understood that in the present embodiment, the alignment mark 601 is provided on a surface layer (base layer or clad layer) of the optical waveguide 600. In practical applications, the core layer may also be disposed, which is referred to the embodiment shown in fig. 7 and will not be described herein again.

Fig. 7 is a schematic structural diagram of a second optical transmission system according to an embodiment of the present application. As shown in fig. 7, the optical transmission system includes an optical waveguide 300 and an optical waveguide 700. Of these, optical waveguide 300 is the example in fig. 2. It should be understood that the optical waveguide 300 may be replaced with either of fig. 4 or 5, or other variations described herein. The present application is not limited thereto. Optical waveguide 700 includes a core layer, cladding and base layers (not distinguished in fig. 7), and alignment marks 701. The three layers of the optical waveguide 700 form a groove, wherein one side of the groove is a slope for deflecting the light beam (hereinafter referred to as a fourth cross section). Alignment marks 701 are provided on the core layer for achieving coupling alignment. As shown in fig. 7, when the alignment mark 701 of the optical waveguide 700 can be recognized through the auxiliary alignment transmission optical path of the optical waveguide 300, it can be determined that the signal light output from the optical waveguide 300 can be transmitted in the core layer of the optical waveguide 700 after being reflected by the fourth cross-section; and vice versa. That is, the optical waveguide 300 and the optical waveguide 700 may constitute an optical transmission system, and perform transmission of signal light.

It should be understood that the signal light in the present embodiment may be replaced with a continuous light. The position of the alignment mark 701 may be set at other positions as well, as in the embodiment shown in fig. 6.

In practical designs, the selection of the position of the alignment marks is related to a number of parameters of the two devices being coupled. For example, in fig. 6 and 7, the inclination angles of two sections for reflecting light beams in the groove of the optical waveguide 300, the distances of the sections of the groove at the core portion from the bottom corresponding to the groove, and the like. Furthermore, the coupling distance of the two devices may also need to be taken into account in the position setting of the alignment marks. The design of the alignment mark position is described below with reference to fig. 8.

Fig. 8 is a schematic diagram of alignment mark position calculation according to an embodiment of the present disclosure. In particular, FIG. 8 shows some parameters of the optical waveguide 300 and the optical waveguide 700 related to the design of the position of the alignment marks. It should be understood that not all component examples are given in fig. 8. Specifically, H2 and H1 denote the heights of the first core layer and the second core layer from the bottom, respectively; the distance between the two reflecting surfaces denoted by W1; the angles a and b respectively represent the included angles between the emergent directions of two light beams (1) auxiliary alignment light and (2) signal light or continuous light) and the vertical direction; d denotes the distance between the reflecting surface of the optical waveguide 700 and the alignment mark; h3 and the spacing of the two waveguides.

Using the above parameters, D = W1+ (H2 + H3) × tan (b) - (H1 + H3) × tan (a) can be found.

With this formula, after the corresponding parameters are obtained, the positions of the alignment marks can be known to design and produce the corresponding optical waveguide 700. Alternatively, the optical waveguide 700 may be designed and produced after it is designed (i.e., D is known) so that the parameters of the optical waveguide 300 satisfy the above formula to realize the optical transmission system shown in fig. 8.

It will be appreciated that the above formula is equally applicable if the alignment marks are not located within the optical waveguide or if the configuration of the two waveguides differs somewhat from the example shown in figure 8. Some parameters require some changes. For example, if the transmission directions of the signal light or the continuous light and the alignment assist light are parallel, D = W1. For another example, if the alignment mark is designed on the surface of the optical waveguide, D measures the distance between the position where the signal light or the continuous light is incident on or emitted from the surface of the optical waveguide and the alignment. For another example, the angles of the two beams can be calculated from the horizontal.

Fig. 9 is a schematic structural diagram of a third optical transmission system according to an embodiment of the present application. As shown in fig. 9, the optical transmission system includes an optical waveguide 300 and a light receiving or transmitting device 800. Of these, optical waveguide 300 is the example in fig. 2. It should be understood that the optical waveguide 300 may be replaced with the optical waveguide of fig. 4 or 5, or the optical waveguide described herein or other variations. The present application is not limited thereto. The light receiving or transmitting device 800 includes a light transmitting component or a light receiving component and an alignment mark 801. As shown in fig. 9, when the alignment mark 801 of the optical waveguide 800 can be recognized through the auxiliary alignment transmission optical path of the optical waveguide 300, it can be determined that the signal light output from the optical waveguide 300 can be received by the light receiving or transmitting device 800 or the signal light transmitted by the light receiving or transmitting device 800 can be transmitted at the optical waveguide 300 and output by the core layer. It will be appreciated that the identification alignment marks referred to above may be identified with the aid of an image recognition device or viewed directly through the transmission path of the auxiliary alignment light.

It should be understood that the alignment mark of the light receiving or transmitting device 800 may be designed according to the position of the alignment mark described in fig. 9, or may be aligned by using some external mark already existing in the light receiving or transmitting device 800. For example, according to the design principle related to fig. 9, the parameters of the optical deflection waveguide to be fitted therewith are designed by the number of the surface of the optical transmitting device or the optical receiving device. The present application is not limited thereto.

Fig. 10 is a schematic structural diagram of a fifth optical waveguide according to an embodiment of the present application. As shown in fig. 10, the optical waveguide 900 includes a dust-proof component in addition to the components of the optical waveguide 300 of fig. 2 (reference numerals for corresponding components are not provided in fig. 9, and fig. 2-3 may be referred to specifically). The dustproof component is used for preventing the inclined plane of the reflected or refracted light beam from being polluted by dust, water and the like, and the coupling efficiency is effectively ensured. In one specific design, the dust-proof component may be a cover plate, shown as 901 in fig. 10, which covers the opening of the recess. In another specific design, the dust-proof component may be a coated protective layer, such as portion 902 shown in FIG. 10, that covers at least the beveled portion of the reflected or refracted light beam. The coated protective layer may be referred to as a protective layer or a coating layer, etc., and the application is not limited thereto. In addition, the coating can also accurately control the reflectivity/refractive index so as to improve the reflection efficiency or the refraction efficiency. In yet another design, the dust-proof component is a filling material that fills at least the beveled portion covering the reflected or refracted light beam. Note that the optical refractive index of the filler material is smaller than that of the core layer, so as to achieve light reflection.

It should be understood that the various designs described above may also be combined to provide protection. As shown in fig. 10, a cover 901 and a coating 902 may be provided simultaneously. The coating may be used with the PD-containing embodiment of fig. 5 to achieve refraction for the monitoring wavelength of the signal light or the continuous wavelength of light and to reflect other portions of the signal light or the continuous wavelength of light to achieve efficient monitoring. The present application is not limited thereto.

In addition to enabling fast coupling alignment, the optical waveguide 900 shown in fig. 10 may also improve the reliability and ensure performance of the optical waveguide 900.

It will be appreciated that the material of the optical waveguide in the above device embodiments may be a polymer waveguide such as quartz, silicon nitride, etc. Alternatively, the material of the optical waveguide may be glass, silicon dioxide, silicon nitride, silicon oxynitride, lithium niobate, or the like. This is not limited in this application.

Fig. 11 is a schematic flowchart of a beam-assisted alignment method according to an embodiment of the present disclosure. Specifically, the beam assisted alignment method includes the following two steps.

In section 1501, the relative positions of the optical beam processing apparatus and the optical waveguide are adjusted using a transmission path of the alignment assisting light formed by the first core layer and the first inclined surface of the optical waveguide. The optical waveguide comprises a substrate, a cladding and a core layer, wherein the substrate, the cladding and the core layer form an open groove, the groove comprises a first surface and a second surface which are oppositely arranged, the first surface is arranged on the part of the core layer and is a second inclined surface, the second inclined surface is used for transmitting signal light or continuous light, the second surface is arranged on the part of the core layer and is a first inclined surface, the first inclined surface is used for transmitting auxiliary alignment light, the first inclined surface and the second inclined surface are reflecting surfaces, the core layer comprises a first core layer and a second core layer which are arranged on two sides of the groove, the first core layer comprises the first inclined surface, and the second core layer comprises the second inclined surface. The optical beam processing apparatus includes an alignment mark.

In particular, the optical waveguide may be a device as shown in any of fig. 2-3, 4-5 or 9. This embodiment is not limited to this.

In part 1502, when it is determined that the alignment mark is on the transmission path of the auxiliary alignment light, it is determined that the signal light or the continuous light is transmitted to the optical beam processing device by the optical waveguide to be processed by the optical beam processing device, or the signal light or the continuous light is transmitted to the optical waveguide by the optical beam processing device to be beam deflection-transmitted by the optical waveguide.

In particular, it may be determined that the coupling alignment of the two devices has been completed (i.e. effective transmission of the light beam between the two can be completed) by determining that the alignment mark is observed through the transmission path of the secondary alignment light.

In a specific implementation, the beam processing device is a light transmission waveguide. Wherein the transmission direction of the signal light or the continuous light is not changed after being transmitted through the light beam processing device and the optical waveguide. For example, a transmission path of signal light as shown in fig. 6.

In another specific implementation, the beam processing device is a light transmission waveguide. Wherein a transmission direction of the signal light or the continuous light is changed by 180 degrees after being transmitted through the beam processing device and the optical waveguide. For example, a transmission path of signal light as shown in fig. 7.

In yet another specific implementation, the optical beam processing apparatus is a light receiving device or a light transmitting device.

Finally, it should be noted that: the above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An optical waveguide comprising a substrate, a cladding layer and a core layer, wherein:

the core layer is arranged in the cladding layer, and the cladding layer is arranged on the substrate;

the substrate, the cladding layer and the core layer form a groove with an opening facing a first direction, or the cladding layer and the core layer form a groove with an opening facing the first direction, wherein the first direction is a direction facing away from the substrate towards the core layer or a direction facing away from the cladding layer towards the substrate;

the groove comprises a first surface and a second surface which are oppositely arranged, the first surface is a first inclined surface at the part of the core layer, the first inclined surface is used for changing the transmission direction of the signal light or the continuous light, the second surface is a second inclined surface at the part of the core layer, the second inclined surface is used for changing the transmission direction of the auxiliary alignment light, and the first inclined surface and the second inclined surface are reflecting surfaces;

the sandwich layer including set up in the first sandwich layer and the second sandwich layer of recess both sides, wherein:

the first core layer includes the first slope for changing a transmission path of the signal light or the continuous light in the optical waveguide such that the signal light or the continuous light input into the optical waveguide along the first core layer is output in a second direction or such that the signal light or the continuous light input in a reverse direction of the second direction is transmitted along the first core layer;

the second core layer includes the second inclined surface, and the second inclined surface is used for changing a transmission path of the alignment assisting light in the optical waveguide, so that the alignment assisting light input into the optical waveguide along the second core layer is output along a third direction or the alignment assisting light input along a reverse direction of the third direction is transmitted along the second core layer, and the second direction and the third direction are towards the same side of the substrate.

2. The optical waveguide of claim 1 wherein said cladding layers comprise a first cladding layer and a second cladding layer, said first cladding layer and said second cladding layer being contiguous, said core layer being disposed between said first cladding layer and said second cladding layer.

3. An optical waveguide as claimed in claim 1 or 2 wherein said first and second core layers are in the same plane.

4. An optical waveguide as claimed in any one of claims 1 to 3 wherein said third direction and said second direction are parallel.

5. The optical waveguide of any of claims 1-4, wherein the third direction or the second direction is perpendicular to the substrate.

6. The optical waveguide of any of claims 1-5, wherein said first face and said second face are mirror symmetric.

7. The optical waveguide of any of claims 1-6, further comprising a dust-proofing component adjacent to the groove for dust-proofing the groove.

8. The optical waveguide of claim 7, wherein the dust-proof member is a dust-proof cover provided on the substrate to seal the groove.

9. The optical waveguide of claim 7, wherein the dust-repellent member is a filler material filled in the groove and covering at least the first slope and the second slope, and an optical refractive index of the filler material is smaller than an optical refractive index of the core layer.

10. The optical waveguide of claim 7, wherein said dust-proof component is a coated protective layer covering at least said first slope and said second slope.

11. An optical waveguide according to any one of claims 1 to 10 wherein the material of the optical waveguide is polymer, glass or silicon.

12. The optical waveguide according to any of claims 1-11, wherein the optical waveguide has a length of between 20 mm and 30 cm.

13. Optical transmission system, characterized in that the system comprises an optical waveguide according to any of claims 1-12 and a further optical waveguide comprising a further substrate, a further cladding layer, a further core layer and alignment marks, wherein:

the other core layer is arranged in the other cladding layer, the other cladding layer is arranged on the other substrate, the other optical waveguide comprises a third surface, and the part of the third surface on the other core layer is a third inclined surface;

when the alignment mark of the other optical waveguide is on the transmission path of the auxiliary alignment light reflected by the second cross section of the optical waveguide, the third inclined surface is configured to change the transmission direction of the signal light or the continuous light output from the second direction so that the signal light or the continuous light is output along the other core layer, or the third inclined surface is configured to change the transmission direction of the signal light or the continuous light transmitted along the other core layer so that the signal light or the continuous light is input into the optical waveguide in the direction opposite to the second direction and is transmitted along the first core layer after being reflected by the first inclined surface.

14. The optical transmission system of claim 13, wherein the alignment mark is located within the other cladding; alternatively, the alignment mark is located within the core layer.

15. The optical transmission system according to claim 13 or 14, wherein the optical waveguide and the another optical waveguide are coupled by being bonded.

16. A method of beam assisted alignment, the method comprising:

adjusting the relative positions of the optical beam processing apparatus and the optical waveguide by using a transmission path of the alignment assisting light formed by the first core layer and the first inclined surface of the optical waveguide, wherein:

the optical waveguide comprises a substrate, a cladding layer and a core layer, wherein the substrate, the cladding layer and the core layer form an open groove, or the cladding layer and the core layer form an open groove;

the groove comprises a first surface and a second surface which are oppositely arranged, the first surface is a second inclined surface at the part of the core layer, the second inclined surface is used for changing the transmission direction of signal light or continuous light, the second surface is a first inclined surface at the part of the core layer, the first inclined surface is used for changing the transmission direction of the auxiliary alignment light, the first inclined surface and the second inclined surface are reflecting surfaces, the core layer comprises a first core layer and a second core layer which are arranged at two sides of the groove, the first core layer comprises the first inclined surface, and the second core layer comprises the second inclined surface;

the optical beam processing apparatus includes an alignment mark;

when it is determined that the alignment mark is on the transmission path of the auxiliary alignment light, it is determined that the signal light or the continuous light is transmitted from the optical waveguide to the beam processing device to be processed by the beam processing device, or the signal light or the continuous light is transmitted from the beam processing device to the optical waveguide to achieve beam deflection transmission by the optical waveguide.

17. The method of claim 16, wherein the beam processing device is a light transmission waveguide, wherein: after being transmitted through the optical beam processing device and the optical waveguide, the transmission direction of the signal light or the continuous light is kept unchanged.

18. The method of claim 16, wherein the beam processing device is a light transmission waveguide, wherein: after being transmitted through the beam processing device and the optical waveguide, the transmission direction of the signal light or the continuous light is changed by 180 degrees.

19. The method of any of claims 16-18, wherein the optical beam processing device is a light receiving device or a light transmitting device.