CN111045143B

CN111045143B - Optical waveguide and method for manufacturing the same

Info

Publication number: CN111045143B
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: 2023-04-25
Anticipated expiration: 2039-12-30
Also published as: CN111045143A

Abstract

Embodiments of the present disclosure provide an optical waveguide and a method of manufacturing the same, the method of manufacturing comprising: providing a first interval in a first direction through the first auxiliary layer, and forming a first light-restricting layer in the first interval; providing a second space on the first light confinement layer in the first direction through the second auxiliary layer, and forming a light 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 on the first auxiliary layer in the first direction through the third auxiliary layer, and forming a second light confinement 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 confinement layer and the second light confinement layer wrap the light transmission layer, and refractive indexes of the first light confinement layer and the second light confinement layer are smaller than those of the light transmission layer. The method can flexibly adjust the thickness of the light transmission layer, and the cost for preparing the optical waveguide by adopting the method is low.

Description

Optical waveguide and method for manufacturing 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 by an optically transparent medium and used for transmitting optical frequency electromagnetic waves. The principle of optical waveguide is that at medium interfaces with different refractive indexes, the total reflection of electromagnetic waves is utilized to limit the optical 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, so that the optical waveguide is widely applied to the fields of optical communication, photoelectric integration and the like.

The general structure of the optical waveguide is an embedded structure in which a high refractive index central layer is surrounded by a low refractive index cladding layer, or a ridge-type structure in which a high refractive index central layer is formed on a low refractive index lower cladding layer and an air layer is used as an upper cladding layer. Light incident to 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 the 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, the method comprising: providing a first space in a first direction through a first auxiliary layer, and forming a first light confinement layer in the first space; providing a second space on the first light confinement layer in the first direction through a second auxiliary layer, and forming a light 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 confinement 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 confinement layer and the second light confinement layer encapsulate the light transmission layer, wherein refractive indexes of the first light confinement layer and the second light confinement layer are smaller than those of the light transmission layer.

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

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

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

For example, in the preparation method provided in at least one embodiment of the present disclosure, before the curing treatment is performed on the first light-limiting layer material, vacuum-pumping treatment is further performed on the first light-limiting layer material; and before the curing treatment is carried out on the light transmission layer material, vacuumizing treatment is carried out on the light transmission layer material.

For example, in a method of manufacturing provided in at least one embodiment of the present disclosure, along the second direction, the first light confining layer material and the light transmitting layer material each include opposite first and second ends, and the evacuating process includes: forming a negative pressure on the first end of the first light confining layer material to extract bubbles in the first light confining layer material, and applying an additional first light confining layer material at the second end of the first light confining layer material; negative pressure is applied to the first end of the light transmitting layer material to extract bubbles in the light transmitting layer material, and additional light transmitting layer material is applied to the second end of the light transmitting layer material.

For example, in the preparation method provided in at least one embodiment of the present disclosure, before the curing treatment is performed on the light transmission layer material, and after the vacuuming treatment is performed, forming the light transmission layer further includes: a light-guiding member is formed at the first end of the light-transmitting layer material and a light-guiding member is formed at the second end of the light-transmitting layer material.

For example, in a method of manufacturing provided in at least one embodiment of the present disclosure, forming the second light-confining layer in the third space of the third auxiliary layer includes: and applying a second light limiting layer material in the third interval, and curing the second light limiting layer material to form the second light limiting layer.

For example, in the preparation method provided in at least one embodiment of the present disclosure, before the curing treatment is performed on the second light confinement layer material, negative pressure is further formed at the exposed surface of the second light confinement layer material to extract bubbles in the second light confinement layer material, and additional second light confinement layer material is applied at both ends of the second light confinement layer material along the second direction.

For example, in the preparation method provided in at least one embodiment of the present disclosure, the first light-limiting layer fills all regions of the first space, the light-transmitting layer fills all regions of the second space, the second light-limiting layer fills all regions of the third space, and in a direction perpendicular to a plane in which the first direction and the second direction are located, a thickness of the first light-limiting layer is the same as a thickness of the first auxiliary layer, a thickness of the light-transmitting layer is the same as a thickness of the second auxiliary layer, and a maximum thickness of the second light-limiting layer is the same as a thickness of the third auxiliary layer.

For example, in the preparation method provided in at least one embodiment of the present disclosure, the materials of the first light-limiting layer and the second light-limiting layer are the same, and the materials of the first light-limiting layer and the second light-limiting layer each include a polydimethylsiloxane solution having a mass percentage ratio of polydimethylsiloxane to a curing agent of 15:1 to 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 preparation method provided in at least one embodiment of the present disclosure, the ratio of thicknesses of the first light-limiting layer and the light-transmitting layer is 1:2 to 1:7, and the ratio of thicknesses of the light-transmitting layer and the second light-limiting layer located directly above the light-transmitting layer is 1:1.1 to 1:1.3.

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

For example, in the preparation method provided in at least one embodiment of the present disclosure, the refractive indexes of the first light-limiting layer and the second light-limiting layer are each 60% to 99% of the refractive index of the light-transmitting layer.

At least one embodiment of the present disclosure also provides an optical waveguide formed using the fabrication method of any one of the above.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following brief description of the drawings of the embodiments will make it apparent that the drawings in the following description relate only to some embodiments of the present invention and are not limiting of the present invention.

FIGS. 1A-1E are diagrams illustrating a process for preparing an optical waveguide;

FIG. 2 is a flow chart of a method for fabricating an optical waveguide according to one embodiment of the present disclosure;

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

FIGS. 4A-4F are process diagrams of preparing a first light confining layer according to an embodiment of the present disclosure;

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

FIGS. 6A-6G are process diagrams of a process for preparing a second light confining layer according to an embodiment of the present disclosure; and

fig. 7 is a schematic cross-sectional structure 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 more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without creative efforts, based on the described embodiments of the present invention fall within the protection scope of the present invention.

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

In the optical field, optical waveguides are typically fabricated by photolithography. However, the manufacturing process of the photolithography process is complex, the photolithography process is time-consuming and labor-consuming for manufacturing the optical waveguide, and the equipment adopted by the photolithography process is very expensive, so that the manufacturing cost is increased, and great restriction is brought to the preparation of the optical waveguide. 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 manufacture optical waveguides with different sizes, namely has larger freedom for manufacturing the optical waveguides, and the optical waveguide structure manufactured by the method can be suitable for devices with various models.

The optical waveguides can also be formed using 3D printing techniques, for example, fig. 1A-1E are diagrams of a process for fabricating an optical waveguide. Fig. 1A-1E are schematic cross-sectional views of layers of a mold or an optical waveguide fabricated using the mold, respectively, taken perpendicular to the length direction. For example, FIGS. 1A-1E use a 3D printing process to prepare optical waveguides. In the preparation process shown in fig. 1A to 1E, as shown in fig. 1A, a mold 1 is prepared by adopting a 3D printing mode; as shown in fig. 1B, a liquid material 2' for manufacturing the optical waveguide cladding is poured into the die 1 to be heated and solidified so as to form a first cladding; as shown in fig. 1C, the material 2' solidified in the mold 1 is demolded to form the first cladding layer 2; as shown in fig. 1D, a liquid material for manufacturing an optical waveguide core is poured into the first cladding 2 to be heated and solidified to form a core 3; as shown in fig. 1E, a second cladding layer 4 is formed on the first cladding layer 2 and the inner core 3 such that the first cladding layer 2 and the second cladding layer 4 clad the inner core 3, and finally, a light source and an optical fiber detector are added to both ends of the inner core 3 and fixed outside 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 to the micrometer level using the 3D printing technology.

At least one embodiment of the present disclosure provides a method for manufacturing an optical waveguide, the method comprising: providing a first interval in a first direction through the first auxiliary layer, and forming a first light-restricting layer in the first interval; providing a second space on the first light confinement layer in a first direction through the second auxiliary layer, and forming a light 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 on the first auxiliary layer in the first direction through the third auxiliary layer, and forming a second light confinement layer in the third space, wherein in the first direction, the second space is positioned inside the edge of the third space, and the first light confinement layer and the second light confinement layer wrap the light transmission layer, and the refractive indexes of the first light confinement layer and the second light confinement layer are smaller than those of the light transmission layer.

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

For example, fig. 2 is a flow chart of preparing an optical waveguide according to an embodiment of the present disclosure. As shown in fig. 2, the process of preparing the optical waveguide includes the following steps.

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

For example, the first direction is one direction parallel to the main surface of the carrier layer supporting the first auxiliary layer and the first light confining layer.

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

For example, the first light-confining layer may be formed in the first space by filling the entire area of the first space with a material of the first light-confining layer, and after the leveling and curing treatment, the thickness of the first light-confining layer and the thickness of the first auxiliary layer are uniform.

Step S22: the second space is provided on the first light confinement layer in the first direction by the second auxiliary layer, and the light 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 space may be a portion of the entire second auxiliary layer 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 may be formed in the second space by filling all regions of the second space with a material of the light transmission layer, and after the leveling, vacuuming and curing processes, the thickness of the light transmission layer is identical to that of the second auxiliary layer.

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 is located in the orthographic projection of the first space on the substrate, and the light transmission layer and the first light confinement layer are stacked, and neither edge of the light transmission layer coincides with the edge of the first light confinement layer.

Step S23: the second auxiliary layer is removed.

Step S24: providing a third space on the first auxiliary layer in the first direction through the third auxiliary layer, and forming a second light confinement 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 confinement layer and the second light confinement layer wrap the light transmission layer, and refractive indexes of the first light confinement layer and the second light confinement layer are smaller than those of the light transmission layer.

For example, the third gap may be a portion of the entire third auxiliary layer 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 light-confining layer may be formed in the third space by filling the entire area of the third space with a material of the second light-confining layer, and after the leveling, vacuuming and curing processes, the maximum thickness of the second light-confining layer and the thickness of the third auxiliary layer are identical.

For example, in the first direction, the second space is located inside the edge of the third space, i.e. the orthographic projection of the second space on the carrier layer is located inside the orthographic projection of the third space on the carrier layer, and neither the edge of the light-transmitting layer nor the edge of the second light-confining layer coincides, so that it is possible to achieve that the first light-confining layer and the second light-confining layer encapsulate the light-transmitting layer.

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

Step S31: a 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 formed of other suitable materials.

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

For example, along a first direction, the first auxiliary layer has a first space therein. The first gap may be a portion of the entire first auxiliary layer 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 light confining layer is formed in the first space of the first auxiliary layer.

For example, the first light confining layer may be formed in the first space by filling the entire area of the first space with a material of the first light confining layer, and after the leveling and curing treatment, the thickness of the first light confining layer formed is identical to 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 confinement layer, and the second space is located inside the edge of the first space in the first direction.

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

Step S35: and forming a light transmission layer in the second interval of the second auxiliary layer.

Step S36: the second auxiliary layer is removed.

For example, tearing the second auxiliary layer from the first auxiliary layer and the first light confining layer, etc.

Step S37: a third auxiliary layer having a third interval in the first direction is formed on the first auxiliary layer, the third interval exposing a portion 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 portion of the first light-limiting layer located on both sides of the light-transmitting layer in the first direction and the light-transmitting layer, that is, the orthographic projection of the third space on the substrate is larger than the orthographic projection of the light-transmitting layer on the substrate, and the edge of the light-transmitting layer is not overlapped with the edge of the third space in the first direction, so that the first light-limiting layer and the second light-limiting layer wrap the light-transmitting layer.

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

For example, fig. 4A-4F are process diagrams for preparing a first light confining layer according to an embodiment of the present disclosure. FIGS. 4A-4D are schematic cross-sectional 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 substrate base plate; fig. 4E and 4F are schematic plan view structures.

As shown in fig. 4A, a base substrate 101 is provided, a first auxiliary layer 102 is formed on the base substrate 101, and a first space 1021 is provided in a first direction by 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 in a portion other than the edge region, which is not limited in the embodiment of the present disclosure.

For example, the first space 1021 has 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 other materials may be selected as needed for the material of the first auxiliary layer 102, which is not limited herein.

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

As shown in fig. 4B, a first light confining layer material 103' is applied in the first space 1021. For example, the first light confining layer material 103' may be applied in the first space 1021 by means of drop-on or spin-on.

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

As shown in fig. 4C, the first light confinement layer material 103' is subjected to flattening treatment, which specifically includes: the cover layer 104 is covered on the first auxiliary layer 102 and the first light confining layer material 103', and then pressure is applied to the cover layer 104 toward the side of the substrate base 101, so that the first light confining layer material 103' is leveled in the first space 1021.

For example, the material of the cover layer 104 is polycarbonate, and the thickness thereof is 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 side of the substrate 101, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrow below the substrate 101 indicates the supporting effect on the substrate base.

As shown in fig. 4D, the flattened first light confining layer material 103' is placed in a vacuum box 105 for vacuuming 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 side of the substrate 101, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrow below the substrate 101 indicates the supporting effect on the substrate base.

As shown in fig. 4E, a specific extraction process for forming a negative pressure on the first end of the first light confinement layer material 103 'to extract bubbles in the first light confinement layer material 103' is to form a negative pressure on the first end of the first light confinement layer material to extract bubbles in the first light confinement layer material along the second direction, wherein the first light confinement layer material includes opposite first and second ends, and an additional first light confinement layer material is applied on the second end of the first light 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 light confining layer material to draw bubbles from the first light confining layer material.

For example, the encapsulation film may be formed at the first end of the first light confining layer material before forming a negative pressure on the first end of the first light confining layer material to extract the residual bubbles in the first light confining layer material 103'.

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

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

For example, the first light confinement layer material 103' is subjected to a heat curing treatment at a temperature of 60 to 90 ℃ for a time of 1.5 to 4 hours.

The manner of the curing process, the temperature and the time of the curing process can be adjusted according to the material of the first light-restricting 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-5G are process diagrams for preparing a light transmission layer according to an embodiment of the present disclosure. 5A-5D are schematic cross-sectional 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 substrate base plate; fig. 5E-5G are schematic plan view structures.

As shown in fig. 5A, the second auxiliary layer 106 having the second space 1061 in the first direction is formed on the first light confinement layer 103, and the second space 1061 is located inside the edge of the first space 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 space 1061 may be a gap between two adjacent second auxiliary layers 106, or may be a portion that is penetrated in a portion of the entire second auxiliary layer 106 except for an edge region, which is not limited in the embodiment of the present disclosure.

For example, the second space 1061 has 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 second auxiliary layer 106 is 110 μm to 140 μm, for example, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, or the like.

For example, the material of the second auxiliary layer 106 is polycarbonate, and other materials may be selected as needed for the material of the second auxiliary layer 106, which is not limited herein.

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

For example, the light transmitting layer material 107' is applied in the second spaces 1061. For example, the light transmitting 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 having a ratio of Polydimethylsiloxane (PDMS) to curing agent of 5:1 to 14:1 by mass percent. For example, the light transmitting layer material 107' is a PDMS solution having a mass percent ratio of Polydimethylsiloxane (PDMS) to curing agent of 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, or 12:1.

As shown in fig. 5C, the light transmission layer material 107' is subjected to flattening treatment, which specifically includes: the cover layer 104 is covered 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 side of the substrate base 101, so that the light transmission layer material 107' is leveled 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 side of the substrate 101, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrow below the substrate 101 indicates the supporting effect on the substrate base.

As shown in fig. 5D, the flattened light transmitting layer material 107' is placed in a vacuum box 105 for vacuuming to remove most of the bubbles.

As shown in fig. 5E, the negative pressure is formed on the first end of the light transmission layer material 107' to extract the bubbles in the light transmission layer material 107' in a specific extraction process, in which the light transmission layer material 107' includes opposite first and second ends along the second direction, the negative pressure is formed on the first end of the light transmission layer material 107' to extract the bubbles in the light transmission layer material, and an additional light transmission layer material is applied on the second end of the light transmission layer material 107' to fill the space occupied by the bubbles before.

For example, a suction element such as a syringe may be used to create a negative pressure on the first end of the light transmissive layer material 107' to extract bubbles in the light transmissive layer material.

For example, the encapsulation film may be formed on the first end of the light transmission layer material 107' before the negative pressure is formed on the first end of the light transmission layer material 107' to extract the residual bubbles in the light transmission layer material 107 '.

For example, in fig. 5E, the upper arrow indicates the application of additional light transmission layer material; the lower arrow indicates the direction of evacuation.

As shown in fig. 5F, after the vacuuming treatment is performed on the light transmission layer material 107', forming the light transmission layer further includes: a light-introducing member 109 is formed at a first end of the light-transmitting layer material 107', and a light-guiding member 108 is formed at a second end of the light-transmitting layer material 107'.

For example, the light guide member 109 has a cylindrical shape, and the light guide member 108 has a rectangular parallelepiped shape. The dimension of the light introducing member 109 in the direction perpendicular to the main surface of the substrate 101 and the dimension of the light extracting member 108 in the direction perpendicular to the main surface of the substrate 101 are the same, and are the thicknesses of the light transmitting layer material 107'.

For example, in the first direction, the size of the light introducing member 109 is smaller than the size of the light extracting member 108.

For example, the light guide member is a plastic optical fiber, and the material of the light guide 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 light transmission layer material 107' is subjected to a heat curing treatment at a temperature of 60 to 90 ℃ for a time of 1.5 to 4 hours.

The manner of the curing process, the temperature and the time of the curing process 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 guide member 109 is fixed to the first end of the light transmission layer 107, and the light guide member 108 is fixed to the second end of the light transmission 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 or other elongated shape, which is not limited in the embodiments of the present disclosure.

For example, fig. 6A-6G are process diagrams for preparing a second light confining layer according to an embodiment of the present disclosure. FIGS. 6A-6D are schematic cross-sectional 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 substrate base plate; fig. 6E-6G are schematic plan view structures.

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

It should be noted that, since the second auxiliary layer 106 has been removed, the second space 1061 cannot be shown in the figure.

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

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

For example, the third interval 1101 has 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 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 other materials may be selected as needed for the material of the third auxiliary layer 110, which is not limited herein.

As shown in fig. 6B, a second light confining layer material 111' is applied in the third space 1101. For example, the second light confining layer material 111' may be applied in the third space 1101 by means of drop-on or spin-on.

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

As shown in fig. 6C, the second light confinement layer material 111' is subjected to flattening treatment, which specifically includes: the cover layer 104 is covered on the third auxiliary layer 110 and the second light confining layer material 111', and then a pressure toward the side of the substrate base 101 is applied to the cover layer 104, so that the second light confining layer material 111' is leveled 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 side of the substrate 101, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrow below the substrate 101 indicates the supporting effect 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 treatment to extract bubbles in the second light confinement layer material 111'.

For example, the flattened second light confining layer material 111' is placed in a vacuum box 105 for vacuuming to remove a majority 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 side of the substrate 101, that is, indicates the applied pressure and the direction in which the pressure is applied. The arrow below the substrate 101 indicates the supporting effect on the substrate base.

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

As shown in fig. 6F, the second light confining layer material 111' is placed in the vacuum box 105 for a second vacuuming process to remove residual bubbles.

Because the thickness of the second light confinement layer material 111 'is thicker, bubbles cannot be extracted cleanly by forming negative pressure by using an air extraction element such as a small syringe, and the semi-finished product including the second light confinement layer material 111' can be repeatedly placed in the vacuum box 105 for repeated vacuum extraction.

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

For example, the second light confinement layer material 111' is subjected to a heat curing treatment at a temperature of 60 to 90 ℃ for a time of 1.5 to 4 hours.

For example, the manner of the curing process, the temperature and the time of the curing process may be adjusted according to the material 111' of the second light confining layer, and are not limited herein.

For example, although the cross-sectional shape of the second light confining layer 111 shown in fig. 6G is rectangular, the cross-sectional shape of the second light confining layer 111 may also be a trapezoid or the like long-bar shape, which is not limited in the embodiments of the present disclosure.

For example, the optical waveguide can be obtained by removing the substrate 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, second, and

third spaces

1021, 1061, and 1101 has a bar shape extending in a second direction perpendicular to the first direction, which may be rectangular, trapezoidal, or the like, without limitation.

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

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

For example, in one example, the materials of the first light confinement layer 103 and the second light confinement layer 111 are the same, and the materials of the first light confinement layer 103 and the second light confinement layer 111 each include a polydimethylsiloxane solution having a ratio of polydimethylsiloxane to curing agent of 20:1 by mass percent; the material of the light-transmitting layer 107 includes a polydimethylsiloxane solution having a mass percent ratio of polydimethylsiloxane to curing agent of 10:1, so that it is possible to satisfy that the refractive indexes of the first light-confining layer and the second light-confining layer are smaller than those of the light-transmitting layer, and that the refractive indexes of the first light-confining layer and the second light-confining layer are 60% to 99% of those of the light-transmitting layer.

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

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

For example, in one example, the thickness of the first light confining layer is 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 transmitting layer.

For example, the thickness of the first light confinement layer may be appropriately selected depending on the application of the optical waveguide, the wavelength of light used, and the like, and is not particularly limited. When the thickness of the first optical confinement layer is too small, the strength of the flexible optical waveguide may be lowered. In contrast, when the thickness of the first light confining 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 light 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 use of the optical waveguide, the wavelength of light used, and the like, and is not particularly limited. When the thickness of the light transmission layer is too small, there is a case where the amount of light propagating in the light transmission layer is reduced. In contrast, when the thickness of the light transmission layer is excessively large, there is a case where the flexibility of the flexible optical waveguide is reduced.

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

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

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

When the thickness of the second light confinement layer is too small, there are cases where a light transmission layer of a sufficient thickness cannot be formed. In contrast, when the thickness of the second light confinement layer is excessively large, there is a case where the flexibility of the flexible optical waveguide is reduced.

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

For example, the method for manufacturing the optical waveguide provided by the embodiment of the present disclosure does not need to adhere the optical waveguide film prepared in advance to the substrate by using an adhesive. When this method is used, a step of providing an adhesive layer or the like between the substrate and the first light confining layer is not particularly required, and therefore, the optical waveguide can be formed easily, and a significant reduction in manufacturing components can be achieved.

At least one embodiment of the present disclosure also provides an optical waveguide formed using the fabrication method of any one of the above. For example, fig. 7 is a schematic cross-sectional structure of an optical waveguide according to an embodiment of the disclosure. As shown in fig. 7, the first light confinement layer 103 and the light transmission layer 107 are stacked, and the second light confinement layer 111 and the first light confinement layer 103 encapsulate the light transmission layer 107.

For example, the optical waveguide provided by the embodiments of the present disclosure may be applicable to various optical waveguide devices. For example, when an opto-electronic hybrid module is manufactured, the opto-electronic hybrid module can be used in various electronic devices, and the optical waveguide has excellent flexibility, and therefore is suitable for use in a portion (for example, a hinge portion) of the electronic device where flexibility is required. The electronic devices include mobile phones, digital cameras, digital video cameras, home and portable game machines, notebook computers, high-speed printers, and the like. Furthermore, the optical waveguide in the embodiments of the present disclosure can also be used in optical wiring. The method for manufacturing an optical waveguide according to the embodiments of the present disclosure can easily manufacture such an optical waveguide, and thus can greatly reduce manufacturing costs.

For example, the optical waveguide is a flexible optical waveguide, and can be applied to a stretchable optical waveguide prosthetic which senses softness 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 preparation method of the optical waveguide provided by at least one embodiment of the present disclosure can prepare a thin film with a thickness of hundreds of micrometers or even tens of micrometers, that is, the thickness of the light transmission layer of the optical waveguide can reach the micrometer level.

(2) The method for manufacturing the optical waveguide provided by at least one embodiment of the present disclosure may 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 the optical waveguide by using the method in the embodiment of the present disclosure is very low.

The following points need to be described:

(1) The drawings of the embodiments of the present invention relate only to the structures related to the embodiments of the present invention, and other structures may refer to the general designs.

(2) In the drawings for describing embodiments of the present invention, the thickness of layers or regions is exaggerated or reduced for clarity, i.e., the drawings are not drawn to actual 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) The embodiments of the invention and the features of the embodiments can be combined with each other to give new embodiments without conflict.

The above description is only specific embodiments of the present invention, but the scope of the present invention should not be limited thereto, and the scope of the present invention should be determined by 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 light confinement layer in the first space;

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

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-restricting 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 light-restricting layer and the second light-restricting layer wrap the light transmitting layer,

Wherein the refractive index of the first light confining layer and the second light confining layer are both smaller than the refractive index of the light transmitting layer;

forming the first light confining layer in the first space includes: applying a first light limiting layer material in the first interval, and curing the first light limiting layer material to form the first light limiting layer;

before the curing treatment is carried out on the first light limiting layer material, the method further comprises the step of vacuumizing the first light limiting layer material;

the second direction is perpendicular to the first direction, the plane where the first direction and the second direction are located is perpendicular to the thickness direction of the first light limiting layer, along the second direction, the first light limiting layer material comprises a first end and a second end which are opposite, and the vacuumizing treatment comprises: forming an encapsulation film at the first end of the first light confining layer material, forming a negative pressure on the first end of the first light confining layer material to extract bubbles in the first light confining layer material, and applying an additional first light confining layer material at the second end of the first light confining layer material.

2. The manufacturing method according to claim 1, wherein the first interval, the second interval, and the third interval each have a bar shape extending in the second direction.

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

4. A process according to claim 2 or 3, wherein,

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

5. The preparation method according to claim 4, wherein,

and before the curing treatment is carried out on the light transmission layer material, vacuumizing treatment is carried out on the light transmission layer material.

6. The method of manufacturing according to claim 5, wherein the light transmitting layer material includes opposing first and second ends along the second direction, the evacuating process comprising:

negative pressure is applied to the first end of the light transmitting layer material to extract bubbles in the light transmitting layer material, and additional light transmitting layer material is applied to the second end of the light transmitting layer material.

7. The manufacturing method according to claim 6, wherein forming the light-transmitting layer before the curing treatment of the light-transmitting layer material and after the vacuuming treatment further comprises: a light-guiding member is formed at the first end of the light-transmitting layer material and a light-guiding member is formed at the second end of the light-transmitting layer material.

8. The manufacturing method according to claim 2, wherein forming the second light restricting layer in the third space of the third auxiliary layer includes: and applying a second light limiting layer material in the third interval, and curing the second light limiting layer material to form the second light limiting layer.

9. The production method according to claim 8, wherein the curing treatment of the second light confining layer material is preceded by forming a negative pressure at an exposed surface of the second light confining layer material to extract bubbles in the second light confining layer material, and applying additional second light confining layer material at both ends of the second light confining layer material in the second direction.

10. A production method according to claim 2 or 3, wherein the first light confining layer fills the entire region of the first space, the light transmitting layer fills the entire region of the second space, the second light confining layer fills the entire region of the third space, and the thickness of the first light confining layer is the same as the thickness of the first auxiliary layer, the thickness of the light transmitting layer is the same as the thickness of the second auxiliary layer, and the maximum thickness of the second light confining layer is the same as the thickness of the third auxiliary layer in a direction perpendicular to the plane in which the first direction and the second direction lie.

11. The preparation method of claim 10, wherein the materials of the first light limiting layer and the second light limiting layer are the same, and the materials of the first light limiting layer and the second light limiting layer both comprise polydimethylsiloxane solution with a mass percent ratio of polydimethylsiloxane to curing agent of 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 a ratio of thicknesses of the first light-confining layer and the light-transmitting layer is 1:2 to 1:7, and a ratio of thicknesses of the light-transmitting layer and the second light-confining layer located directly above the light-transmitting layer is 1:1.1 to 1:1.3.

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

the thickness of the first light limiting layer is 5-35 mu m;

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

the thickness of the second light confinement layer located directly above the light transmission layer is 120 μm to 160 μm.

14. The manufacturing method according to claim 1, wherein the refractive index of each of the first light confining layer and the second light confining layer is 60% to 99% of the refractive index of the light transmitting layer.