Optical Modulator Fiber Alignment Fixation Member
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Solution Overview
Problem
The challenge is to accurately align the end face of an optical fiber with the optical waveguide in an optical modulator while minimizing optical loss, as the adhesive strength at the connection point is insufficient due to the smaller end area of the optical fiber compared to the modulator, making it difficult to adjust the optical coupling and preventing easy movement of the fiber in the in-plane direction.
Innovation Solution
The optical modulator employs a fixation member with a surface roughness greater than the substrate's, allowing for easier optical coupling adjustment by reducing adsorption between the fiber and waveguide, and using a tubular fixation member with a through-hole to facilitate alignment and bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the end face of the optical fiber and the end face of the optical modulation element are butted against each other via optical adhesive, then adhesive strength is improved, but the optical fiber cannot be moved in the in-plane direction for alignment adjustment
Solution Approach 1:
A fixation member is introduced as an intermediary component between the optical fiber and the optical modulation element. This fixation member has a larger end face area than the optical fiber, providing both mechanical support for strong adhesion and a platform for alignment adjustment before final bonding.
Solution Approach 2:
The connection structure is divided into separate functional components: the optical fiber, the fixation member, and the optical modulation element. This segmentation allows the fixation member to serve as a separate adjustment platform that can be positioned and aligned independently before permanent bonding.
2Loss of energy
If the end faces are mirror-finished to suppress optical loss, then optical signal reflection is reduced, but the end faces are easily adsorbed by atmospheric pressure making movement difficult
Solution Approach 1:
Different surface qualities are applied to different components: the optical fiber end face and optical modulation element end face are mirror-finished to minimize optical loss, while the fixation member end face has a rougher surface that reduces adsorption and facilitates movement during alignment.
3Measurement precision
If the area of the optical fiber end part is smaller than the area of the optical modulation element end face, then the optical fiber can be precisely aligned, but the adhesive strength of the fixed portion cannot be sufficiently secured
Solution Approach 1:
The fixation member serves as an intermediary with an end face area that is larger than the optical fiber but smaller than or equal to the optical modulation element. This intermediate area provides sufficient bonding surface for strong adhesion while maintaining the small footprint needed for precise alignment with the optical waveguide.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enables easy optical coupling adjustment between the optical fiber and waveguide, reducing optical loss and enhancing adhesive strength, thus improving the connection stability and reducing signal scattering.
Implementation Method 1
the end face of the optical fiber and the end face of the optical modulation element are usually mirror-finished in order to suppress loss due to irregular reflection of an optical signal. Therefore, when the end face of the optical fiber and the end face of the optical modulation element are butted against each other via the optical adhesive, the end faces are adsorbed to each other by the ambient atmospheric pressure
Data Source
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AI summary
An optical modulator according to the present invention comprises: a substrate which has electro-optic effects; an optical waveguide which is provided in the substrate; an optical fiber which is bonded to an end of the optical waveguide; a fixation member which is provided on an end part of the optical fiber; and an optical adhesive layer which bonds the optical fiber and the substrate to each other. The end of the optical waveguide is arranged in an end face of the substrate; the optical adhesive layer optically couples an end face of the optical fiber and an end of the optical waveguide with each other, while bonding the optical fiber, the fixation member and the substrate with each other; and the surface roughness of a surface of the fixation member, wherein the surface faces the end face of the substrate, is different from the surface roughness of an end face of the substrate, wherein the end face faces the surface of the fixation member.