CN-122018079-A - Flexible optical waveguide preparation method and flexible optical waveguide

Abstract

The invention provides a preparation method of a flexible optical waveguide and the flexible optical waveguide, which comprise the steps of providing a flexible substrate, preprocessing the flexible substrate to form an adhesion promoting layer on the surface of the flexible substrate, coating uncured photoresist on the adhesion promoting layer of the flexible substrate, placing the flexible substrate coated with the photoresist on an objective table of a two-photon polymerization direct writing system, constructing a three-dimensional model of the waveguide structure, carrying out layering slicing and processing on the three-dimensional model of the waveguide structure by taking the Z-axis direction as a slicing direction to obtain a scanning path file, introducing the scanning path file into the two-photon polymerization direct writing system, carrying out scanning exposure on the photoresist on the flexible substrate to form the waveguide structure on the flexible substrate, and carrying out gradient development and drying.

Inventors

• WANG JINTAO
• HE ZEWEI
• ZHANG SHUAI
• WANG CHEN
• WANG YAOWEI

Assignees

• 乾元国家实验室

Dates

Publication Date

20260512

Application Date

20260310

Claims (10)

1. 1. A method of manufacturing a flexible optical waveguide comprising the steps of: providing a flexible substrate, and preprocessing the flexible substrate to form an adhesion promoting layer on the surface of the flexible substrate; coating uncured photoresist on the adhesion promoting layer of the flexible substrate, and placing the flexible substrate coated with the photoresist on a stage of a two-photon polymerization direct writing system; Constructing a three-dimensional model of the waveguide structure; layering slicing and processing are carried out on the three-dimensional model of the waveguide structure by taking the Z-axis direction as a slicing direction, and a scanning path file is obtained; Introducing the scanning path file into a two-photon polymerization direct writing system, and scanning and exposing the photoresist on the flexible substrate to form a waveguide structure on the flexible substrate; Gradient development and drying are performed to remove the unexposed photoresist.
2. 2. The method for manufacturing a flexible optical waveguide according to claim 1, wherein the pretreatment of the flexible substrate comprises a surface activation treatment and a silane coupling agent grafting, and the surface activation treatment comprises an oxygen plasma treatment and/or an ultraviolet ozone treatment.
3. 3. The method for preparing a flexible optical waveguide according to claim 2, wherein the silane coupling agent used for grafting is gamma-methacryloxypropyl trimethoxysilane.
4. 4. The method for preparing the flexible optical waveguide according to claim 2, wherein the pretreatment of the flexible substrate further comprises ultrasonic cleaning treatment, and the ultrasonic cleaning treatment comprises the steps of sequentially ultrasonic cleaning the flexible substrate in acetone, ethanol and ultrapure water for 5 minutes, and then drying the flexible substrate by blowing nitrogen.
5. 5. A method of manufacturing a flexible optical waveguide according to claim 1, wherein the gradient developing comprises: Placing the flexible substrate with the waveguide structure into propylene glycol methyl ether acetate to be soaked for 5 mm-10 min; and transferring the flexible substrate with the waveguide structure into isopropanol, and soaking for 2-3 min.
6. 6. The method of claim 1, wherein when the waveguide structure comprises a high aspect ratio waveguide structure, the developing further comprises transferring the flexible substrate with the waveguide structure into n-hexane for 2min.
7. 7. A method of manufacturing a flexible optical waveguide according to claim 1, wherein the flexible substrate with the waveguide structure is subjected to low temperature curing after gradient development and drying.
8. 8. The method for preparing a flexible optical waveguide according to claim 1, wherein the method for acquiring the scan path file comprises: layering and slicing the three-dimensional model of the waveguide structure by taking the Z-axis direction as a slicing direction to obtain multi-layer section profile data; Processing the section profile data of each layer to divide the long section profile in each layer into a plurality of sub-section profiles along the length direction of the long section profile, and enabling two adjacent sub-section profiles to be connected through the S-shaped section profile; and (5) carrying out scanning filling on each section profile to obtain a scanning path file.
9. 9. The method for preparing the flexible optical waveguide according to claim 1, wherein the flexible substrate is a PDMS substrate or a PI substrate or a PET substrate or a TPU substrate.
10. 10. An optical waveguide, characterized in that the optical waveguide is obtained by the flexible optical waveguide production method according to any one of claims 1 to 9.

Description

Flexible optical waveguide preparation method and flexible optical waveguide Technical Field The invention belongs to the technical field of energy conversion, and particularly relates to a flexible optical waveguide preparation method and a flexible optical waveguide. Background An optical waveguide is an optical device for guiding and transmitting optical signals, and is widely used in various fields such as data communication, sensing, imaging, and quantum information processing. The traditional optical waveguide is a rigid optical waveguide prepared based on a rigid substrate (such as silicon, silicon dioxide and the like) by adopting a silicon-based photon process or electron beam lithography and other technologies. However, due to the inherent inflexible nature of the conventional rigid optical waveguide, there is a significant limitation in the emerging application scenario where the optical device is required to have flexible and repeatedly bendable characteristics, such as wearable devices, bio-integrated sensing, flexible display, and conformal optical systems, and at this time, flexible optical waveguides have been developed. At present, the flexible optical waveguide mainly comprises a preparation method, namely firstly, a waveguide structure prepared on a rigid substrate is transferred to the flexible substrate, but the method is only suitable for transferring a large-size waveguide structure and cannot realize transferring a small-size waveguide structure due to the close correlation between Van der Waals force and contact area, secondly, the waveguide structure is prepared on the flexible substrate by adopting an electron beam lithography technology, although the method has nanoscale processing precision, the serial writing mode of the method has extremely low efficiency and is difficult to prepare economically and efficiently on a large-area flexible substrate, meanwhile, the subsequent etching process involves a plurality of chemical reagents, the problems of substrate swelling, interface adhesion reduction and the like are extremely easy to occur, the yield is extremely low, and thirdly, the traditional femtosecond laser direct writing technology is adopted for preparing the waveguide structure on the flexible substrate, and the flexible substrate has the characteristics of extremely narrow thermal conductivity, low mechanical strength and high thermal expansion coefficient, so that the usable laser processing parameter window is easy to cause a heat accumulation effect, flexible burn, carbonization or microcrack generation is difficult, and the processing difficulty is high and the control difficulty is high. In order to overcome the defects of the method, some scholars propose to apply a two-photon polymerization process to the preparation of the optical waveguide based on the flexible substrate, so that the interaction area of laser and substances is limited in a small range near a focus by utilizing the two-photon absorption effect, the real three-dimensional preparation of a complex micro-nano three-dimensional structure without mask, without contact or with extremely high spatial resolution is realized, in the two-photon polymerization process, the action time of the laser and the materials is far lower than the thermal relaxation time, the photo-thermal effect can be effectively reduced, the heat and cold risk of the flexible substrate is reduced, the basis is provided for the economic, efficient and stable preparation of the flexible optical waveguide, but in practical application, the flexible substrate is generally provided with extremely low surface energy, so that the interface adhesion between the formed waveguide structure and the flexible substrate is weak, the problem that the waveguide structure is easily separated from the flexible substrate in the subsequent development or use process is solved, in addition, the problem that the flexible substrate is easily expanded, contracted or warped and the macroscopic dimensional instability can be transferred to the micro-dimensional structure, the problem of the waveguide is easily distorted, the problem of the flexible substrate is further influenced, such that the waveguide is deformed and the flexible substrate is more easily broken. Disclosure of Invention In view of the above drawbacks of the prior art, an object of the present invention is to provide a method for manufacturing a flexible optical waveguide and a flexible optical waveguide, so as to realize manufacturing of a high-precision and high-adhesion waveguide structure on a flexible substrate, and improve the yield and the reliability of the flexible optical waveguide manufacturing. To achieve the above and other related objects, the present invention provides a method for manufacturing a flexible optical waveguide, comprising the steps of: providing a flexible substrate, and preprocessing the flexible substrate to form an adhesion promoting layer on the surface of t