Optical Waveguide Sheet Mirror Structure for Light Loss Reduction

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Solution Overview

Problem

Existing optical waveguide devices face challenges in reducing light loss due to diffused reflection, which increases manufacturing costs and complicates the polishing of inclined mirrors.

Innovation Solution

An optical waveguide sheet with a mirror structure featuring a concave shape formed from the cladding to the core, including inclined surfaces and a bottom surface, which functions as a light reflection surface due to refractive index differences, reducing light loss through diffused reflection by smoothing the mirror structure during fabrication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If inclined mirrors are polished to reduce diffused reflection, then light loss is reduced, but manufacturing cost increases

Engineering Contradiction:

Improvelight lossVSAvoidmanufacturing cost

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical polishing process with a molding process that forms the inclined mirror surface directly during fabrication. The mirror surface is created by a molding step that shapes the core material itself, eliminating the need for subsequent mechanical polishing while maintaining optical quality and reducing manufacturing cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The inclined mirror surface is formed in advance during the fabrication process itself, rather than being created later through polishing. The molding step preliminarily creates the precise inclined surface geometry needed for optimal light reflection, eliminating the need for post-fabrication processing.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If inclined mirrors are polished to reduce diffused reflection, then optical signal integrity is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveoptical signal integrityVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical polishing operations with a simpler molding process. The inclined mirror surface is formed by controlling the molding parameters (angle, depth, shape) during fabrication, which reduces manufacturing process complexity while ensuring consistent optical signal integrity through precise geometric control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of energy

If mirror surfaces are smoothed to reduce diffused reflection, then light reflection efficiency is improved, but manufacturing time increases

Engineering Contradiction:

Improvelight reflection efficiencyVSAvoidmanufacturing time

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The mirror surface geometry is established in advance during the molding process itself. The inclined surface is formed with the correct angle and smoothness as part of the initial fabrication step, eliminating the need for time-consuming polishing operations and thereby increasing manufacturing productivity while maintaining high light reflection efficiency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The time-intensive mechanical polishing process is replaced with a faster molding process that creates the mirror surface in a single step during fabrication, significantly reducing manufacturing time while achieving the required optical quality for efficient light reflection.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The solution enables the fabrication of optical waveguide sheets at lower costs with high smoothness, reducing light loss and enhancing the integrity of optical signals transmitted between connectors.

Implementation Method 1

an optical waveguide device including cores extending in parallel with a connection target surface and inclined mirror surfaces that are provided at both ends of the cores and reflect optical signals emitted from the cores in a direction perpendicular to the connection target surface

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The core region functions as a light reflection surface due to a refractive index difference between the air inside the structure having the concave shape and the core material

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS10558003B2Optical waveguide sheet, optical transmission module, and manufacturing method for an optical waveguide sheet

Publication Date: 2020.02.11 SONY GROUP CORP

AI summary

[Object] To provide an optical waveguide sheet including a mirror structure that can be fabricated at low cost and has a high smoothness, an optical transmission module, and a manufacturing method for an optical waveguide sheet. [Solving Means] An optical waveguide sheet according to the present technology includes a core, a cladding, and a mirror structure. The core extends in a first direction parallel to a first plane. The cladding is provided around the core. The mirror structure has a concave shape which is formed from the cladding to the core, the mirror structure including a first inclined surface that is parallel to a second direction perpendicular to the first direction and parallel to the first plane, is inclined with respect to the first plane, and includes a core region in which the core is exposed, and a bottom surface parallel to the first plane.