CN111045143A

CN111045143A - Optical waveguide and method for producing the same

Info

Publication number: CN111045143A
Application number: CN201911392616.7A
Authority: CN
Inventors: 郑宇�; 张中; 黎雄; 张正友
Original assignee: Tencent Technology Shenzhen Co Ltd
Current assignee: Tencent Technology Shenzhen Co Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-04-21
Anticipated expiration: 2039-12-30
Also published as: CN111045143B

Abstract

An embodiment of the present disclosure provides an optical waveguide and a method for manufacturing the same, the method including: providing a first space in a first direction through the first auxiliary layer and forming a first optical confinement layer in the first space; providing a second space in the first direction on the first optical confinement layer through a second auxiliary layer, and forming an optical transmission layer in the second space, wherein the second space is located inside an edge of the first space in the first direction; removing the second auxiliary layer; providing a third space in the first direction on the first auxiliary layer through a third auxiliary layer, and forming a second light confining layer in the third space, wherein the second space is located inside an edge of the third space in the first direction, and the first light confining layer and the second light confining layer wrap the light transmission layer, and refractive indexes of the first light confining layer and the second light confining layer are smaller than that of the light transmission layer. The method can flexibly adjust the thickness of the optical transmission layer, and the cost for preparing the optical waveguide by adopting the method is low.

Description

Optical waveguide and method for producing the same

Technical Field

Embodiments of the present disclosure relate to an optical waveguide and a method of manufacturing the same.

Background

The optical waveguide is a guide structure formed of an optically transparent medium for transmitting an electromagnetic wave of an optical frequency. The optical waveguide principle is that on the medium interfaces with different refractive indexes, the total reflection of electromagnetic waves is utilized to limit the light waves to propagate in the waveguide formed by the material layers with relatively high refractive indexes. The optical waveguide has the characteristics of small material consumption, high stability, easy integration and large-scale production, and is widely applied to the fields of optical communication, photoelectric integration and the like.

The optical waveguide has a typical structure of a buried type in which a high refractive index central layer is surrounded by a low refractive index cover layer, or a ridge type in which a high refractive index central layer is formed on a low refractive index lower cover layer and an air layer is used as an upper cover layer. Light incident on the central layer of the optical waveguide is reflected at an interface between the central layer and the cover layer, or an interface between the central layer and an air layer, while propagating in the central layer.

Disclosure of Invention

At least one embodiment of the present disclosure provides a method for manufacturing an optical waveguide, including: providing a first space in a first direction through a first auxiliary layer and forming a first optical confinement layer in the first space; providing a second space in the first direction on the first optical confinement layer through a second auxiliary layer, and forming an optical transmission layer in the second space, wherein the second space is located inside an edge of the first space in the first direction; removing the second auxiliary layer; providing a third gap in the first direction on the first auxiliary layer through a third auxiliary layer, and forming a second light confining layer in the third gap, wherein in the first direction, the second gap is located inside an edge of the third gap, and the first light confining layer and the second light confining layer wrap the light transmission layer, wherein a refractive index of the first light confining layer and the second light confining layer is smaller than a refractive index of the light transmission layer.

For example, in a manufacturing method provided in at least one embodiment of the present disclosure, the first space, the second space, and the third space each have a bar shape extending in a second direction perpendicular to the first direction.

For example, in a manufacturing method provided in at least one embodiment of the present disclosure, a length of the first space in the second direction is greater than or equal to a length of the second space in the second direction, and a length of the second space in the second direction is less than or equal to a length of the third space in the second direction.

For example, in a manufacturing method provided in at least one embodiment of the present disclosure, forming the first optical confinement layer in the first space of the first auxiliary layer includes: applying a first optical limiting layer material in the first interval, and carrying out curing treatment on the first optical limiting layer material to form the first optical limiting layer; forming the light transmission layer in the second space of the second auxiliary layer includes: and applying a light transmission layer material in the second interval, and carrying out curing treatment on the light transmission layer material to form the light transmission layer.

For example, in the manufacturing method provided by at least one embodiment of the present disclosure, before the curing treatment is performed on the first optical confinement layer material, a vacuum pumping treatment is further performed on the first optical confinement layer material; before the curing treatment is carried out on the light transmission layer material, the method also comprises the step of carrying out vacuum pumping treatment on the light transmission layer material.

For example, in at least one embodiment of the present disclosure, there is provided a manufacturing method, wherein along the second direction, the first light confinement layer material and the light transmission layer material each include a first end and a second end opposite to each other, and the vacuuming process includes: creating a negative pressure to the first end of the first optical confinement layer material to draw bubbles in the first optical confinement layer material and applying additional first optical confinement layer material at the second end of the first optical confinement layer material; applying a negative pressure to said first end of said light transmitting layer material to extract air bubbles from said light transmitting layer material, applying additional light transmitting layer material at said second end of said light transmitting layer material.

For example, in a manufacturing method provided by at least one embodiment of the present disclosure, before performing the curing treatment on the light transmission layer material and after performing the vacuum pumping treatment, forming the light transmission layer further includes: a light introduction part is formed at the first end of the light transmission layer material and a light discharge part is formed at the second end of the light transmission layer material.

For example, in a manufacturing method provided in at least one embodiment of the present disclosure, forming the second optical confinement layer in the third interval of the third auxiliary layer includes: and applying a second light limiting layer material in the third interval, and carrying out curing treatment on the second light limiting layer material to form the second light limiting layer.

For example, in at least one embodiment of the present disclosure, before the curing process is performed on the second optical confinement layer material, a negative pressure is formed at an exposed surface of the second optical confinement layer material to extract air bubbles in the second optical confinement layer material, and additional second optical confinement layer material is applied at two ends of the second optical confinement layer material along the second direction.

For example, in a manufacturing method provided in at least one embodiment of the present disclosure, the first optical confinement layer fills all regions of the first space, the optical transmission layer fills all regions of the second space, the second optical confinement layer fills all regions of the third space, and in a direction perpendicular to a plane where the first direction and the second direction are located, a thickness of the first optical confinement layer is the same as a thickness of the first auxiliary layer, a thickness of the optical transmission layer is the same as a thickness of the second auxiliary layer, and a maximum thickness of the second optical confinement layer is the same as a thickness of the third auxiliary layer.

For example, in the preparation method provided by at least one embodiment of the present disclosure, the materials of the first optical confinement layer and the second optical confinement layer are the same, and the materials of the first optical confinement layer and the second optical confinement layer both include polydimethylsiloxane solution in which the mass percentage ratio of polydimethylsiloxane to the curing agent is 15: 1-30: 1; the material of the light transmission layer comprises polydimethylsiloxane solution with the mass percentage ratio of polydimethylsiloxane to curing agent of 5: 1-14: 1.

For example, in the manufacturing method provided by at least one embodiment of the present disclosure, the ratio of the thicknesses of the first light confinement layer and the light transmission layer is 1:2 to 1:7, and the ratio of the thicknesses of the light transmission layer and the second light confinement layer directly above the light transmission layer is 1:1.1 to 1: 1.3.

For example, in at least one embodiment of the present disclosure, the first optical confinement layer has a thickness of 5 μm to 35 μm; the thickness of the light transmission layer is 110-140 μm; and the thickness of the second light limiting layer above the light transmission layer is 120-160 μm.

For example, in a manufacturing method provided by at least one embodiment of the present disclosure, the refractive index of each of the first optical confinement layer and the second optical confinement layer is 60% to 99% of the refractive index of the light transmission layer.

At least one embodiment of the present disclosure also provides an optical waveguide formed by any one of the above-described manufacturing methods.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below, and it is apparent that the drawings in the following description only relate to some embodiments of the present invention and are not limiting on the present invention.

FIGS. 1A-1E are diagrams of a process for making an optical waveguide;

fig. 2 is a flow chart of a method for manufacturing an optical waveguide according to an embodiment of the present disclosure;

FIG. 3 is a flow chart of yet another method for fabricating an optical waveguide according to an embodiment of the present disclosure;

FIGS. 4A-4F are diagrams of a process for fabricating a first optical confinement layer according to one embodiment of the present disclosure;

FIGS. 5A-5G are diagrams of a process for preparing a light transmission layer according to an embodiment of the present disclosure;

FIGS. 6A-6G are diagrams of a process for fabricating a second optical confinement layer according to one embodiment of the present disclosure; and

fig. 7 is a schematic cross-sectional structure diagram of an optical waveguide according to an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In the optical field, optical waveguides are usually fabricated by photolithography. However, the manufacturing process of the photolithography process is complex, the photolithography process wastes time and labor for manufacturing the optical waveguide, and the equipment used in the photolithography process is very expensive, so that the manufacturing cost is increased, and the preparation of the optical waveguide is greatly restricted. The inventors of the present disclosure provide a processing method of preparing a mold by stacking auxiliary layers, and preparing an optical waveguide in the process of preparing the mold. The preparation method has low cost, can be used for preparing optical waveguides with different sizes, namely, the freedom degree of preparing the optical waveguides is higher, and the optical waveguide structure prepared by the method can be suitable for devices with various models.

The optical waveguide can also be formed using 3D printing techniques, for example, fig. 1A-1E illustrate a fabrication process for an optical waveguide. FIGS. 1A-1E are schematic cross-sectional views of a mold or layers of an optical waveguide made using a mold, respectively, taken perpendicular to the length direction. For example, fig. 1A-1E employ a 3D printing process to fabricate the optical waveguides. In the manufacturing process shown in fig. 1A-1E, as shown in fig. 1A, a mold 1 is manufactured by 3D printing; as shown in fig. 1B, a liquid material 2' for making the cladding layer of the optical waveguide is poured into the mold 1 and heated and solidified to form a first cladding layer; as shown in fig. 1C, the material 2' solidified in the mold 1 is demolded to form a first clad layer 2; as shown in fig. 1D, a liquid material for making the optical waveguide core is poured into the first cladding layer 2 and heated to solidify to form a core 3; as shown in fig. 1E, a second clad 4 is formed on the first clad 2 and the inner core 3 such that the first clad 2 and the second clad 4 clad the inner core 3, and finally a light source and a fiber probe are added to both ends of the inner core 3 and fixed to the outside of the optical waveguide. However, the thickness of the inner core of the optical waveguide manufactured by the 3D printing technology is at least 1 mm, and it is difficult to achieve the thickness of the inner core of the optical waveguide in the micron order by using the 3D printing technology.

At least one embodiment of the present disclosure provides a method for manufacturing an optical waveguide, including: providing a first space in a first direction through the first auxiliary layer and forming a first optical confinement layer in the first space; providing a second space in the first direction on the first optical confinement layer through the second auxiliary layer, and forming an optical transmission layer in the second space, wherein the second space is located inside an edge of the first space in the first direction; removing the second auxiliary layer; providing a third space in the first direction on the first auxiliary layer through a third auxiliary layer, and forming a second light confining layer in the third space, the second space being located inside an edge of the third space in the first direction, and the first light confining layer and the second light confining layer wrapping the light transmission layer, refractive indexes of the first light confining layer and the second light confining layer being smaller than a refractive index of the light transmission layer.

The preparation method provided by the embodiment of the disclosure can be used for preparing a film with the thickness of hundreds of micrometers or even tens of micrometers, namely the thicknesses of the first optical limiting layer, the optical transmission layer and the second optical limiting layer of the optical waveguide can reach the micrometer level, the thicknesses of the first optical limiting layer, the optical transmission layer and the second optical limiting layer can be flexibly adjusted, and the cost for preparing the optical waveguide by the method in the embodiment of the disclosure is very low.

For example, fig. 2 is a flowchart of a method for manufacturing an optical waveguide according to an embodiment of the present disclosure. As shown in fig. 2, the process of fabricating the optical waveguide includes the following steps.

Step S21: a first space is provided in a first direction by the first auxiliary layer, and a first optical confinement layer is formed in the first space.

For example, the first direction is one direction parallel to the major surface of the carrier layer supporting the first auxiliary layer and the first optical confinement layer.

For example, the first gap may be a portion of the entire first auxiliary layer that is penetrated except for the edge region, or may be a gap between two adjacent first auxiliary layers of the plurality of first auxiliary layers.

For example, the first light confining layer formed in the first spacers may be formed by filling the first light confining layer with a material having a thickness corresponding to the thickness of the first auxiliary layer after the leveling and curing process.

Step S22: a second space is provided in the first direction on the first optical confinement layer by the second auxiliary layer, and an optical transmission layer is formed in the second space, wherein the second space is located inside an edge of the first space in the first direction.

For example, the second gap may be a portion of the entire second auxiliary layer that is penetrated except for the edge region, or may be a gap between two adjacent second auxiliary layers among the plurality of second auxiliary layers.

For example, the light transmission layer formed in the second space may be a material in which the entire area of the second space is filled with the light transmission layer, and the thickness of the light transmission layer is consistent with that of the second auxiliary layer after the leveling, vacuuming and curing processes.

For example, in the first direction, the second space is located inside the edge of the first space, that is, the orthographic projection of the second space on the substrate base plate is located inside the orthographic projection of the first space on the substrate base plate, and the light transmission layer and the first light restriction layer are stacked, and the edge of the light transmission layer is not overlapped with the edge of the first light restriction layer.

Step S23: and removing the second auxiliary layer.

Step S24: providing a third space in the first direction on the first auxiliary layer through a third auxiliary layer, and forming a second light confining layer in the third space, wherein the second space is located inside an edge of the third space in the first direction, and the first light confining layer and the second light confining layer wrap the light transmission layer, and refractive indexes of the first light confining layer and the second light confining layer are smaller than that of the light transmission layer.

For example, the third gap may be a portion of the entire third auxiliary layer that is penetrated except for the edge region, or may be a gap between two adjacent third auxiliary layers among the plurality of third auxiliary layers.

For example, the second optical confinement layer formed in the third gap may be formed by filling the entire area of the third gap with the material of the second optical confinement layer, and after leveling, vacuuming and curing, the maximum thickness of the second optical confinement layer is consistent with the thickness of the third auxiliary layer.

For example, in the first direction, the second interval is located inside an edge of the third interval, that is, an orthographic projection of the second interval on the carrier layer is located inside an orthographic projection of the third interval on the carrier layer, and the edge of the light transmission layer is not overlapped with the edge of the second light confinement layer, so that the first light confinement layer and the second light confinement layer can wrap the light transmission layer.

For example, fig. 3 is a flow chart of another method for manufacturing an optical waveguide according to an embodiment of the present disclosure. As shown in fig. 3, the process of fabricating the optical waveguide further includes the following steps.

Step S31: a base substrate is provided.

For example, the substrate is a carrier layer, and the substrate may be a glass substrate, a quartz substrate, a plastic substrate, or a substrate made of other suitable materials.

Step S32: a first auxiliary layer having a first interval in a first direction parallel to the substrate base is formed on the substrate base.

For example, along the first direction, the first auxiliary layer has a first space therein. The first gap may be a portion of the entire first auxiliary layer that is penetrated except for the edge region, or may be a gap between two adjacent first auxiliary layers among the plurality of first auxiliary layers.

Step S33: a first optical confinement layer is formed in the first space of the first auxiliary layer.

For example, the first light confining layer formed in the first spacers may be formed by filling the first light confining layer with a material of the first spacers in the entire area thereof, and after the leveling and curing processes, the thickness of the first light confining layer formed may be the same as the thickness of the first auxiliary layer.

Step S34: a second auxiliary layer having a second space in the first direction is formed on the first light confining layer, the second space being located inside an edge of the first space in the first direction.

For example, the first direction is a direction parallel to the main surface of the base substrate.

Step S35: the light transmission layer is formed in the second space of the second auxiliary layer.

Step S36: and removing the second auxiliary layer.

For example, the second auxiliary layer is torn off from the first auxiliary layer and the first light confining layer, etc.

Step S37: a third auxiliary layer having a third space in the first direction is formed on the first auxiliary layer, the third space exposing portions of the first light confinement layer located on both sides of the light transmission layer in the first direction and the light transmission layer.

For example, in the first direction, the third space exposes the light transmission layer and the portions of the first light confinement layer located on both sides of the light transmission layer in the first direction, that is, the orthographic projection of the third space on the substrate base plate is larger than that of the light transmission layer on the substrate base plate, and the edge of the light transmission layer in the first direction is not overlapped with the edge of the third space, so that the first light confinement layer and the second light confinement layer can wrap the light transmission layer.

Step S38: and forming a second optical confinement layer in a third interval of the third auxiliary layer, so that the first optical confinement layer and the second optical confinement layer wrap the optical transmission layer, and the refractive indexes of the first optical confinement layer and the second optical confinement layer are smaller than that of the optical transmission layer.

For example, fig. 4A-4F are diagrams of a process for fabricating a first optical confinement layer according to an embodiment of the disclosure. 4A-4D are schematic cross-sectional structural views, wherein the cross-sectional views are schematic cross-sectional views taken in a direction parallel to the first direction and perpendicular to the major surface of the base substrate; fig. 4E and 4F are schematic plan views of the structure.

As shown in fig. 4A, a substrate base 101 is provided, a first auxiliary layer 102 is formed on the substrate base 101, and a first space 1021 is provided in a first direction through the first auxiliary layer 102.

For example, the first space 1021 may be a gap between two adjacent first auxiliary layers 102, or may be a portion of the entire first auxiliary layer 102 that is penetrated except for an edge region, and this is not limited by the embodiment of the present disclosure.

For example, the first spaces 1021 have a bar shape extending in a second direction perpendicular to the first direction. The second direction is parallel to the main surface of the base substrate 101.

For example, the thickness of the first auxiliary layer 102 is 5 μm to 35 μm, for example, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 or 35 μm.

For example, the material of the first auxiliary layer 102 is polyethylene terephthalate, and the material of the first auxiliary layer 102 may be selected according to needs, and is not limited herein.

For example, in fig. 4A, the arrow indicates the first direction.

As shown in fig. 4B, a first light confinement layer material 103' is applied in a first space 1021. For example, the first light confinement layer material 103' may be applied in the first space 1021 by dropping or spin coating.

For example, the first light confinement layer material 103' is a Polydimethylsiloxane (PDMS) solution having a mass percentage ratio of 15:1 to 30:1 of a curing agent. For example, the first light confining layer material 103' is a Polydimethylsiloxane (PDMS) solution with a curing agent in a mass percent ratio of 15:1, 20:1, or 30: 1.

As shown in fig. 4C, the first light confinement layer material 103' is subjected to a flattening process, which specifically includes: the cover layer 104 is applied over the first auxiliary layer 102 and the first light confining layer material 103 ', and then pressure is applied to the cover layer 104 towards the side of the substrate base plate 101 to level the first light confining layer material 103' in the first space 1021.

For example, the covering layer 104 is made of polycarbonate and has a thickness of 100 to 150 μm.

For example, in fig. 4C, an arrow above the cover layer 104 indicates that pressure is applied to the cover layer 104 toward the substrate base plate 101 side, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrows below the substrate base 101 indicate the supporting action on the substrate base.

As shown in fig. 4D, the first optical confinement layer material 103' after the flattening process is placed in a vacuum box 105 for vacuum treatment to remove most of the bubbles.

For example, in fig. 4D, an arrow above the cover layer 104 indicates that pressure is applied to the cover layer 104 toward the substrate base plate 101 side, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrows below the substrate base 101 indicate the supporting action on the substrate base.

As shown in fig. 4E, the first end of the first optical confinement layer material 103 'is under-pressurized to extract the bubbles in the first optical confinement layer material 103' by applying additional first optical confinement layer material at the second end of the first optical confinement layer material to fill the space previously occupied by the bubbles.

For example, a suction element such as a small syringe may be used to create a negative pressure on the first end of the first optical confinement layer material to draw air bubbles from the first optical confinement layer material.

For example, an encapsulation film may be formed at the first end of the first optical confinement material before creating a negative pressure at the first end of the first optical confinement material to draw out any remaining air bubbles in the first optical confinement material 103'.

For example, in fig. 4E, the upper arrows indicate the application of additional first light confining layer material; the lower arrow indicates the direction of the vacuum.

As shown in fig. 4F, the first optical confinement layer material 103' is subjected to a curing process to form the first optical confinement layer 103.

For example, the curing treatment of the first light confinement layer material 103' is a thermal curing treatment, the temperature of the thermal curing treatment is 60 ℃ to 90 ℃, and the time of the thermal curing treatment is 1.5h to 4 h.

The curing process, the temperature and time of the curing process can be adjusted according to the material of the first light confinement layer, and are not limited herein.

For example, the temperature of the heat curing treatment is 80 ℃ and the time of the heat curing treatment is 2 hours.

For example, fig. 5A to 5G are diagrams illustrating a process of preparing a light transmission layer according to an embodiment of the present disclosure. FIGS. 5A-5D are schematic cross-sectional structural views, wherein the cross-sectional views are schematic cross-sectional views taken in a direction parallel to the first direction and perpendicular to the major surface of the base substrate; FIGS. 5E-5G are schematic diagrams of the planar structures.

As shown in fig. 5A, the second auxiliary layer 106 having the second interval 1061 in the first direction is formed on the first light confinement layer 103, and the second interval 1061 is located inside an edge of the first interval 1021 in the first direction.

For example, portions of the second auxiliary layer 106 may also be located on the first auxiliary layer 102.

For example, the second interval 1061 may be a gap between two adjacent second auxiliary layers 106, or may be a portion that is penetrated through the entire second auxiliary layer 106 except for the edge region, which is not limited in this embodiment of the disclosure.

For example, the second spaces 1061 have a stripe shape extending in a second direction perpendicular to the first direction. The second direction is parallel to the main surface of the base substrate 101.

The thickness of the second auxiliary layer 106 is, for example, 110 μm to 140 μm, for example, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm or 140 μm, etc.

For example, the material of the second auxiliary layer 106 is polycarbonate, and the material of the second auxiliary layer 106 may be selected from other materials according to needs, which is not limited herein.

As shown in fig. 5B, the light transmission layer material 107' is formed in the second space 1061 of the second auxiliary layer 106.

For example, the light transmissive layer material 107' is applied in the second space 1061. For example, the light transmission layer material 107' may be applied in the second spaces 1061 by dropping or spin coating.

For example, the light transmission layer material 107' includes a PDMS solution containing Polydimethylsiloxane (PDMS) and a curing agent at a ratio of 5:1 to 14:1 by mass. For example, the light transmission layer material 107' is a PDMS solution having a mass percentage ratio of Polydimethylsiloxane (PDMS) to a curing agent of 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, or 12: 1.

As shown in fig. 5C, the optical transmission layer material 107' is subjected to a flattening process, which specifically includes: the cover layer 104 is overlaid on the second auxiliary layer 106 and the light transmission layer material 107 ', and then pressure is applied to the cover layer 104 toward the substrate base plate 101 side to level the light transmission layer material 107' in the second space 1061.

For example, in fig. 5C, an arrow above the cover layer 104 indicates that pressure is applied to the cover layer 104 toward the substrate base plate 101 side, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrows below the substrate base 101 indicate the supporting action on the substrate base.

As shown in fig. 5D, the flattened light-transmitting layer material 107' is placed in a vacuum box 105 and subjected to a vacuum process to remove most of the air bubbles.

As shown in fig. 5E, the first end of the light transport layer material 107 ' is formed with a negative pressure to extract the bubbles in the light transport layer material 107 ' by forming the light transport layer material 107 ' with the first end and the second end opposite to each other along the second direction, forming the negative pressure to the first end of the light transport layer material 107 ' to extract the bubbles in the light transport layer material, and applying additional light transport layer material to the second end of the light transport layer material 107 ' to fill the space previously occupied by the bubbles.

For example, a suction element such as a small syringe may be used to create a negative pressure on the first end of the light transport layer material 107' to draw air bubbles from the light transport layer material.

For example, an encapsulation film may be formed on the first end of the light transmission layer material 107 ' before forming a negative pressure on the first end of the light transmission layer material 107 ' to draw out air bubbles remaining in the light transmission layer material 107 '.

For example, in FIG. 5E, the upper arrows indicate the application of additional light transport layer material; the lower arrow indicates the direction of the vacuum.

As shown in fig. 5F, after the vacuuming of the light transmission layer material 107', the forming of the light transmission layer further includes: a light introduction part 109 is formed at a first end of the light transmission layer material 107 'and a light discharge part 108 is formed at a second end of the light transmission layer material 107'.

For example, the light introducing part 109 is cylindrical in shape, and the light extracting part 108 is rectangular parallelepiped in shape. The dimension of the light introducing part 109 in the direction perpendicular to the main surface of the base substrate 101 and the dimension of the light extracting part 108 in the direction perpendicular to the main surface of the base substrate 101 are the same, and are both the thickness of the light transmitting layer material 107'.

For example, along the first direction, the size of the light-in part 109 is smaller than the size of the light-out part 108.

For example, the light introducing member is a plastic optical fiber, and the material of the light discharging member is polycarbonate.

As shown in fig. 5G, the light transmission layer material 107' is subjected to a curing process to form the light transmission layer 107.

For example, the curing treatment of the optical transmission layer material 107' is a heat curing treatment, the temperature of the heat curing treatment is 60 ℃ to 90 ℃, and the time of the heat curing treatment is 1.5h to 4 h.

The curing method, the curing temperature and the curing time can be adjusted according to the material of the light transmission layer, and are not limited herein.

For example, after the curing process is completed, the light introducing part 109 is fixed to the first end of the light transmitting layer 107, and the light extracting part 108 is fixed to the second end of the light transmitting layer 107.

For example, although the cross-sectional shape of the light transmission layer 107 shown in fig. 5G is a trapezoid, the cross-sectional shape of the light transmission layer 107 may also be a rectangular long strip shape, and the embodiment of the present disclosure is not limited thereto.

For example, fig. 6A-6G are diagrams of a process for fabricating a second optical confinement layer according to an embodiment of the disclosure. 6A-6D are schematic cross-sectional structural views, wherein the cross-sectional views are schematic cross-sectional views taken in a direction parallel to the first direction and perpendicular to the major surface of the base substrate; FIGS. 6E-6G are schematic plan views.

As shown in fig. 6A, the second auxiliary layer 106 is removed, the third auxiliary layer 110 is formed on the first auxiliary layer 102, and a third space 1101 is provided on the first auxiliary layer 102 through the third auxiliary layer 110 in the first direction in which the second space is located inside an edge of the third space 1101.

Note that the second spacing 1061 cannot be shown since the second auxiliary layer 106 has been removed.

For example, in one example, the second space 1061 is located inside the edge of the third space 1101, and the edge of the first space 1021 is aligned with the edge of the third space 1101, such that a subsequently formed second light confining layer covers the upper surface of the first light confining layer and the upper surface of the light transmission layer, and the second light confining layer does not cover the side surface of the first light confining layer.

For example, the third gap 1101 may be a gap between two adjacent third auxiliary layers 110, or may be a portion that is penetrated through the entire third auxiliary layer 110 except for an edge region, and the embodiment of the present disclosure is not limited thereto.

For example, the third spaces 1101 have a stripe shape extending in a second direction perpendicular to the first direction. The second direction is parallel to the main surface of the base substrate 101.

For example, the thickness of the third auxiliary layer 110 is 120 μm to 160 μm, for example, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm, 160 μm, or the like.

For example, the material of the third auxiliary layer 110 is polyethylene terephthalate, and the material of the third auxiliary layer 110 may be selected according to needs, and is not limited herein.

As shown in fig. 6B, a second light confinement layer material 111' is applied in a third interval 1101. For example, the second light confinement layer material 111' may be applied in the third interval 1101 by dropping or spin coating.

For example, the second light confinement layer material 111' is a Polydimethylsiloxane (PDMS) solution having a mass percentage ratio of 15:1 to 30:1 of a curing agent. For example, the second light confining layer 111' is a Polydimethylsiloxane (PDMS) solution with a curing agent in a mass percentage ratio of 15:1, 20:1, or 30: 1.

As shown in fig. 6C, the second light confinement layer material 111' is subjected to a flattening process, which specifically includes: the cover layer 104 is overlaid on the third auxiliary layer 110 and the second light confining layer material 111 ', and then pressure is applied to the cover layer 104 towards the side of the substrate base plate 101 to level the second light confining layer material 111' in the third space 1101.

For example, in fig. 6C, an arrow above the cover layer 104 indicates that pressure is applied to the cover layer 104 toward the substrate base plate 101 side, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrows below the substrate base 101 indicate the supporting action on the substrate base.

As shown in fig. 6D, a negative pressure is formed at the exposed surface of the second light confinement layer material 111 'after the flattening process to extract air bubbles in the second light confinement layer material 111'.

For example, the second optical confinement material 111' after the flattening process is placed in the vacuum box 105 for vacuuming to remove most of the bubbles.

For example, in fig. 6D, an arrow above the cover layer 104 indicates that pressure is applied to the cover layer 104 toward the substrate base plate 101 side, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrows below the substrate base 101 indicate the supporting action on the substrate base.

As shown in fig. 6E, additional second light confinement layer material is applied at both ends of the second light confinement layer material 111' along the second direction.

As shown in fig. 6F, the second optical confinement material 111' is placed in the vacuum box 105 for vacuuming again to remove the remaining air bubbles.

Since the second optical confinement layer 111 'has a relatively thick thickness, bubbles cannot be completely pumped by using a pumping element such as a small syringe to form a negative pressure, and the semi-finished product including the second optical confinement layer 111' can be repeatedly placed in the vacuum chamber 105 for repeated vacuum pumping.

As shown in fig. 6G, the second optical confinement layer material 111' is subjected to a curing process to form the second optical confinement layer 111.

For example, the curing process performed on the second optical confinement layer material 111' is a thermal curing process, the temperature of the thermal curing process is 60 ℃ to 90 ℃, and the time of the thermal curing process is 1.5h to 4 h.

For example, the curing process, the temperature and time of the curing process can be adjusted according to the material 111' of the second optical confinement layer, and are not limited herein.

For example, although the cross-sectional shape of the second optical confinement layer 111 shown in fig. 6G is a rectangle, the cross-sectional shape of the second optical confinement layer 111 may also be a trapezoid and a long strip, which is not limited in this respect by the embodiments of the present disclosure.

For example, the optical waveguide can be obtained by removing the substrate board 101, the first auxiliary layer 102, and the third auxiliary layer 110.

For example, the optical waveguide is a flexible optical waveguide.

For example, in the embodiment of the present disclosure, each of the first interval 1021, the second interval 1061, and the third interval 1101 has a bar shape extending in a second direction perpendicular to the first direction, and the bar shape may be a rectangle, a trapezoid, or the like, which is not limited herein.

For example, the length of the first interval 1021 in the second direction is greater than or equal to the length of the second interval 1061 in the second direction, and the length of the second interval 1061 in the second direction is less than or equal to the length of the third interval 1101 in the second direction.

For example, the first optical confinement layer 103 fills the entire area of the first space 1021, the optical transmission layer 107 fills the entire area of the second space 1061, the second optical confinement layer 111 fills the entire area of the third space 1101, and in a direction perpendicular to a plane in which the first direction and the second direction lie, the thickness of the first optical confinement layer 103 is the same as the thickness of the first auxiliary layer 102, the thickness of the optical transmission layer 107 is the same as the thickness of the second auxiliary layer 106, and the maximum thickness of the second optical confinement layer 111 is the same as the thickness of the third auxiliary layer 110.

For example, in one example, the materials of the first optical confinement layer 103 and the second optical confinement layer 111 are the same, and the materials of the first optical confinement layer 103 and the second optical confinement layer 111 both comprise polydimethylsiloxane solutions with a mass percentage ratio of polydimethylsiloxane to the curing agent of 20: 1; the material of the light transmission layer 107 includes polydimethylsiloxane solution in which the mass percentage ratio of polydimethylsiloxane to the curing agent is 10:1, so that the refractive index of the first light confinement layer and the second light confinement layer can be satisfied to be smaller than that of the light transmission layer, and the refractive index of the first light confinement layer and the second light confinement layer is 60% -99% of that of the light transmission layer.

For example, the ratio of the thicknesses of the first light confining layer 103 and the light transmission layer 107 is 1:2 to 1:7, and the ratio of the thicknesses of the light transmission layer 107 and the second light confining layer 111 directly above the light transmission layer 107 is 1:1.1 to 1: 1.3.

For example, the first optical confinement layer has a thickness of 5 μm to 35 μm; the thickness of the light transmission layer is 110-140 μm; and the thickness of the second light limiting layer right above the light transmission layer is 120-160 μm.

For example, in one example, the first optical confinement layer has a thickness of 25 μm; the thickness of the light transmission layer was 125 μm; and the second light confining layer has a thickness of 150 μm directly above the light transmission layer.

For example, the thickness of the first optical confinement layer may be appropriately selected depending on the application of the optical waveguide, the wavelength of light to be used, and the like, and is not particularly limited. This optical waveguide is a flexible optical waveguide, and when the thickness of the first optical confinement layer is excessively small, the strength of the flexible optical waveguide may be reduced. Conversely, when the thickness of the first optical confinement layer is excessively large, there is a case where the flexibility of the flexible optical waveguide is reduced. In order to achieve both the adhesiveness of the first light confining layer, the light transmitting layer, and the second light confining layer and the strength of the optical waveguide, the first light confining layer may have a multilayer structure of two or more layers.

For example, the refractive index of the first optical confinement layer is not particularly limited as long as the refractive index of the light transmission layer is low.

For example, the thickness of the light transmission layer may be appropriately selected depending on the application of the optical waveguide, the wavelength of light to be used, and the like, and is not particularly limited. When the thickness of the light transmission layer is excessively small, the amount of light propagating through the light transmission layer may decrease. Conversely, when the thickness of the light transmission layer is too large, the flexibility of the flexible optical waveguide may be reduced.

The refractive index of the light transmitting layer is not particularly limited as long as it is higher than the refractive indices of the first and second optical confinement layers.

The number of light transmission layers is not particularly limited, and may be one or more, as appropriate depending on the application of the optical waveguide. The light transmitting layer may be formed in a predetermined pattern shape according to the application of the flexible optical waveguide and the like.

For example, the thickness of the second optical confinement layer may be appropriately selected depending on the application of the flexible optical waveguide, the wavelength of light to be used, and the like, and is not particularly limited.

When the thickness of the second light confining layer is too small, a light transmission layer having a sufficient thickness may not be formed. Conversely, when the thickness of the second optical confinement layer is too large, the flexibility of the flexible optical waveguide may be reduced.

The refractive index of the second optical confinement layer is not particularly limited as long as it is lower than the refractive index of the light transmission layer.

For example, the embodiments of the present disclosure provide a method for manufacturing an optical waveguide, which does not require an adhesive to adhere a previously manufactured optical waveguide film to a base substrate. In this method, since a step of providing an adhesive layer or the like particularly between the substrate and the first light confining layer is not required, the optical waveguide can be easily formed, and the manufacturing components can be greatly reduced.

At least one embodiment of the present disclosure also provides an optical waveguide formed by any one of the above-described manufacturing methods. For example, fig. 7 is a schematic cross-sectional structure diagram of an optical waveguide according to an embodiment of the present disclosure. As shown in fig. 7, the first light confining layer 103 and the light transmitting layer 107 are stacked, and the second light confining layer 111 and the first light confining layer 103 wrap the light transmitting layer 107.

For example, the optical waveguide provided by the embodiment of the present disclosure may be applied to various optical waveguide devices. For example, when an opto-electric hybrid module is manufactured, the opto-electric hybrid module can be used in various electronic devices, and is suitable for a portion (e.g., a hinge portion) of the electronic device where flexibility is required because the flexibility of the optical waveguide is good. The electronic devices include mobile phones, digital cameras, digital video cameras, home and portable game machines, notebook computers, high-speed printers, and the like. In addition, the optical waveguide in the embodiment of the present disclosure can also be used in optical wiring. Embodiments of the present disclosure provide a method for manufacturing an optical waveguide, which can easily manufacture such an optical waveguide, and thus can significantly reduce manufacturing costs.

For example, the optical waveguide is a flexible optical waveguide, and can be applied to a telescopic optical waveguide prosthesis which senses the flexibility of a contacted object through the optical waveguide.

The optical waveguide and the preparation method thereof provided by the embodiment of the disclosure have at least one of the following beneficial effects:

(1) the method for manufacturing an optical waveguide according to at least one embodiment of the present disclosure can manufacture a thin film with a thickness of several hundred micrometers or even several tens micrometers, that is, the thickness of an optical transmission layer of the optical waveguide can reach a micrometer level.

(2) The method for manufacturing an optical waveguide according to at least one embodiment of the present disclosure can flexibly adjust the thicknesses of the first optical confinement layer, the optical transmission layer, and the second optical confinement layer, and the cost for manufacturing an optical waveguide by using the method in the embodiment of the present disclosure is very low.

The following points need to be explained:

(1) the drawings of the embodiments of the invention only relate to the structures related to the embodiments of the invention, and other structures can refer to common designs.

(2) The thickness of layers or regions in the figures used to describe embodiments of the invention may be exaggerated or reduced for clarity, i.e., the figures are not drawn on a true scale. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element or intervening elements may be present.

(3) Without conflict, embodiments of the present invention and features of the embodiments may be combined with each other to arrive at new embodiments.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and the scope of the present invention should be subject to the scope of the claims.

Claims

1. A method of making an optical waveguide comprising:

providing a first space in a first direction through a first auxiliary layer and forming a first optical confinement layer in the first space;

providing a second space in the first direction on the first optical confinement layer through a second auxiliary layer, and forming an optical transmission layer in the second space, wherein the second space is located inside an edge of the first space in the first direction;

removing the second auxiliary layer;

providing a third space in the first direction on the first auxiliary layer by a third auxiliary layer and forming a second light confining layer in the third space, wherein in the first direction the second space is located inside an edge of the third space and the first and second light confining layers wrap around the light transmission layer,

wherein the refractive indices of the first and second optical confinement layers are both less than the refractive index of the light transport layer.

2. The production method according to claim 1, wherein the first space, the second space, and the third space each have a stripe shape extending in a second direction perpendicular to the first direction.

3. The production method according to claim 2, wherein a length of the first space in the second direction is greater than or equal to a length of the second space in the second direction, and a length of the second space in the second direction is less than or equal to a length of the third space in the second direction.

4. The production method according to claim 2 or 3,

forming the first optical confinement layer in the first space of the first auxiliary layer comprises: applying a first optical limiting layer material in the first interval, and carrying out curing treatment on the first optical limiting layer material to form the first optical limiting layer;

forming the light transmission layer in the second space of the second auxiliary layer includes: and applying a light transmission layer material in the second interval, and carrying out curing treatment on the light transmission layer material to form the light transmission layer.

5. The production method according to claim 4,

before the curing treatment is carried out on the first light limiting layer material, vacuumizing treatment is carried out on the first light limiting layer material;

before the curing treatment is carried out on the light transmission layer material, the method also comprises the step of carrying out vacuum pumping treatment on the light transmission layer material.

6. A production method according to claim 5, wherein along the second direction, the first light confining layer material and the light transmitting layer material each include opposite first and second ends, the evacuating process including:

creating a negative pressure to the first end of the first optical confinement layer material to draw bubbles in the first optical confinement layer material and applying additional first optical confinement layer material at the second end of the first optical confinement layer material;

applying a negative pressure to said first end of said light transmitting layer material to extract air bubbles from said light transmitting layer material, applying additional light transmitting layer material at said second end of said light transmitting layer material.

7. A production method according to claim 6, wherein forming the light transmission layer further comprises, before the curing treatment is performed on the light transmission layer material and after the vacuuming treatment is performed: a light introduction part is formed at the first end of the light transmission layer material and a light discharge part is formed at the second end of the light transmission layer material.

8. A production method according to claim 1, wherein forming the second light confining layer in the third interval of the third auxiliary layer includes: and applying a second light limiting layer material in the third interval, and carrying out curing treatment on the second light limiting layer material to form the second light limiting layer.

9. The method of manufacturing according to claim 8, wherein prior to the curing the second optical confinement layer material further comprising creating a negative pressure at an exposed surface of the second optical confinement layer material to extract air bubbles in the second optical confinement layer material, additional second optical confinement layer material being applied at both ends of the second optical confinement layer material along the second direction.

10. A manufacturing method according to claim 2 or 3, wherein the first optical confinement layer fills the whole area of the first space, the optical transmission layer fills the whole area of the second space, the second optical confinement layer fills the whole area of the third space, and in a direction perpendicular to a plane in which the first direction and the second direction are located, the thickness of the first optical confinement layer is the same as that of the first auxiliary layer, the thickness of the optical transmission layer is the same as that of the second auxiliary layer, and the maximum thickness of the second optical confinement layer is the same as that of the third auxiliary layer.

11. The preparation method of claim 10, wherein the first optical limiting layer and the second optical limiting layer are made of the same material, and the material of each of the first optical limiting layer and the second optical limiting layer comprises polydimethylsiloxane solution with the mass percentage ratio of polydimethylsiloxane to curing agent being 15: 1-30: 1; the material of the light transmission layer comprises polydimethylsiloxane solution with the mass percentage ratio of polydimethylsiloxane to curing agent of 5: 1-14: 1.

12. The production method according to claim 11, wherein the ratio of the thicknesses of the first light confining layer and the light transmission layer is 1:2 to 1:7, and the ratio of the thicknesses of the light transmission layer and the second light confining layer directly above the light transmission layer is 1:1.1 to 1: 1.3.

13. The production method according to claim 12, wherein,

the thickness of the first optical limiting layer is 5-35 μm;

the thickness of the light transmission layer is 110-140 μm; and

the thickness of the second light limiting layer right above the light transmission layer is 120-160 μm.

14. A production method according to claim 1, wherein the refractive indices of the first and second optical confinement layers are each 60% to 99% of the refractive index of the light transmission layer.

15. An optical waveguide formed by the production method according to any one of claims 1 to 14.