Optical Fiber Array with Light Collecting Lenses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for connecting optical fibers to optical waveguides require complex fabrication steps and laborious core fusion processes, leading to increased manufacturing costs and potential yield losses due to positioning accuracy issues and optical coupling losses.
Innovation Solution
An optical fiber array with coating-removed exposed portions that form light collecting lenses, allowing for easy alignment and connection to optical waveguides on a substrate without the need for intricate fabrication or fusion, using a substrate with grooves and a concave portion for positioning and bonding, and a protective member to adjust the mode field diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If optical fibers are connected to optical waveguides using conventional butt joint method, then the connection process is simple, but optical coupling loss increases significantly (about 3 dB)
Solution Approach 1:
The patent applies parameter changes by modifying the mode field diameter of the optical fiber through a special coating structure. The coating layer is designed with specific refractive index and thickness parameters to transform the mode field diameter from the standard 10 μm to match the 4 μm waveguide core size, thereby reducing optical coupling loss without complicating the connection process
Solution Approach 2:
The patent introduces a coating layer as an intermediary between the optical fiber core and the waveguide core. This coating layer with specific optical properties (refractive index between 1.3-1.6 and thickness of 1-5 μm) acts as a mediator to transform and match the mode field diameter, enabling efficient optical coupling while maintaining connection simplicity
2Loss of energy
If structures extending MFD are provided on optical waveguide end surfaces, then optical coupling loss reduces, but device complexity increases
Solution Approach 1:
Instead of modifying the waveguide structure to extend MFD (which increases device complexity), the patent inverts the approach by modifying the optical fiber side through a coating layer. This inversion transfers the complexity from the waveguide structure to the fiber coating, keeping the waveguide simple while achieving the same optical coupling improvement
3Loss of energy
If core diffusion fusion is used to convert MFD, then optical coupling loss reduces, but manufacturing precision requirements increase and yield decreases
Solution Approach 1:
The patent extracts the MFD conversion function from the complex core diffusion fusion process and implements it through a separate coating layer applied to the optical fiber. This extraction separates the mode field transformation from the alignment process, eliminating the need for high-precision positioning during fusion while achieving the same optical coupling improvement
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 straightforward optical connection of fibers to waveguides with reduced optical coupling loss, eliminating the need for complex fabrication and fusion processes, thus improving manufacturing efficiency and reducing errors.
Implementation Method 1
the front end parts of the exposed portions of the optical fibers each have a light collecting portion that collects light beams passing through an inside of the corresponding optical fiber to reduce a mode field diameter
Data Source
AI summary
There is provided an optical fiber array that can be easily optically connected to cores of optical waveguides on a connection counterpart substrate without requiring a complicated fabrication process to the connection counterpart substrate and laborious diffusing fusion of the cores. In an array, coating-removed exposed portions of fibers are attached to grooves that are provided on a lower substrate in order to position the optical fibers. Further, the exposed portions are pressed by a lid. Coated portions of the fibers are placed on a flat surface of a concave portion that is provided on the substrate to form a step with the grooves in a state where the exposed portions are attached. Front end parts of the exposed portions of the fibers each have a light collecting portion that collects light beams passing through an inside of the corresponding fiber to reduce an MFD. The light collecting portions are lens-shaped portions that are formed by cutting and are used for optical alignment with the cores of the optical waveguides.