Optical Circuit Bending Portion for Vertical Light Path Integration
Solution Overview
Problem
In lightwave circuits, changing the light path using mirrors results in light diffusion and widening of the beam diameter, leading to decreased response speed in photodiodes and increased manufacturing complexity, which affects reliability and performance.
Innovation Solution
A lightwave circuit design featuring a first optical waveguide on a first substrate and a second optical waveguide on a second substrate with a bending portion that changes the light path direction, allowing for efficient optical connection without the need for additional lenses or mirrors, thereby reducing manufacturing complexity and maintaining performance and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mirrors are used to change the light path direction to vertical, then integration density is improved, but light diffusion and beam diameter widening occur leading to decreased photodiode response speed
Solution Approach 1:
The patent replaces the mechanical mirror-based light path change system with an optical waveguide structure that inherently guides light in three dimensions. The waveguide uses total internal reflection at its boundaries to change light direction without requiring external mirrors, thereby eliminating light diffusion and maintaining beam quality while achieving vertical light path conversion for high-density integration.
Solution Approach 2:
The patent changes the physical parameters of the light guiding system by transitioning from a mirror-based external reflection system to an internal waveguide structure with controlled refractive indices. By adjusting the waveguide dimensions, refractive index profile, and bending radius, the light path can be precisely controlled in three dimensions while maintaining beam confinement and preventing diffusion.
2Temperature
If mirrors and additional optical components are added to change light path, then vertical integration is achieved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent merges the light path changing function directly into the optical waveguide structure itself, eliminating the need for separate mirrors and optical components. The waveguide's geometric configuration and refractive index profile are designed to inherently perform the light direction change, thereby reducing device complexity and simplifying manufacturing processes while achieving vertical integration.
Solution Approach 2:
The patent transitions from a two-dimensional planar light path to a three-dimensional light path by utilizing the vertical dimension within the waveguide structure. The waveguide enables light to propagate in three dimensions through controlled bending and layering, achieving vertical integration without requiring additional external optical components that would increase device complexity.
3Ease of operation
If light is output to space before reflection, then mirror-based light path change is achieved, but light diffusion increases and coupling efficiency decreases
Solution Approach 1:
The patent replaces the mirror-based external reflection system that requires light to be output to space with an internal waveguide reflection system. The waveguide uses total internal reflection at its boundaries to change light direction while keeping the light confined within the waveguide structure, thereby maintaining coupling efficiency and preventing light diffusion while still providing light path flexibility.
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 design enables easier production of lightwave circuits with improved performance and reliability by minimizing light diffusion and coupling losses, facilitating high-density integration and reduced manufacturing costs.
Implementation Method 1
a bending portion (114) that connects the first portion and the second portion
Implementation Method 2
a first optical waveguide formed on a first substrate; and a second optical waveguide formed on a second substrate
Data Source
AI summary
A second core includes a first portion, a second portion, and a bending portion. In the first portion, a wave-guiding direction is a first direction parallel to a plane of a first substrate. In the second portion, a wave-guiding direction is a second direction that is at a predetermined angle with respect to the plane of the first substrate. For example, in the second portion, the wave-guiding direction is the second direction that is at substantially 90 degrees with respect to the plane of the first substrate. The bending portion connects the first portion and the second portion. A relative refractive index difference between the second core and a cladding of the second optical waveguide preferably has a value such that the propagation loss in the bending portion is equal to or smaller than 0.1 dB.