Dual-Plane Tapered Waveguide Mode Coupler
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in optical communications systems is achieving efficient mode coupling between compact surface waveguides and external optic devices, particularly due to high coupling losses caused by differences in refractive indices and mode sizes between waveguides.
Innovation Solution
The implementation of an optical mode coupler with a tapered region in dual-plane tapering arrangement, where the waveguide portion is tapered both vertically and horizontally, enhances light transfer efficiency and reduces polarization-dependent losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a compact surface waveguide with high index difference is used, then the waveguide size is reduced, but coupling loss increases due to mode size and velocity mismatch
Solution Approach 1:
The patent introduces a dual-plane tapering structure that tapers the waveguide in both vertical and horizontal dimensions. This multi-dimensional approach allows gradual mode transformation from the compact high-index waveguide to the larger fiber mode, resolving the coupling loss problem while maintaining compact size.
Solution Approach 2:
The patent changes the geometric parameters of the waveguide by implementing tapered regions with varying cross-sectional dimensions. The gradual change in waveguide width and height allows mode size and velocity to transition smoothly, reducing coupling loss between the compact waveguide and external optics.
2Ease of manufacture
If conventional coupling structures are used, then fabrication is simpler, but polarization-dependent losses are higher
Solution Approach 1:
The patent employs asymmetric dual-plane tapering where the vertical and horizontal tapering rates differ. This asymmetric geometry is specifically designed to reduce polarization-dependent losses while remaining compatible with standard fabrication processes, thus balancing manufacturing ease with performance.
3Loss of energy
If aggressive tapering is used to improve mode matching, then coupling efficiency improves, but fabrication tolerance requirements become stricter
Solution Approach 1:
By distributing the mode transformation across both vertical and horizontal dimensions, the patent reduces the aggressiveness required in each individual taper. This dual-plane approach achieves effective mode matching while allowing more relaxed fabrication tolerances compared to single-plane aggressive tapering.
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 solution improves mode transformation efficiency between waveguides with different index differences, ensuring low signal losses and thermal stability, while relaxing fabrication tolerance requirements.
Implementation Method 1
mode coupling remains a challenge for waveguides of submicro-meter dimensions made in high index contrast materials
Implementation Method 2
The waveguide portion having a tapered region located on the end of the waveguide portion
Data Source
AI summary
An optical mode coupler for mode coupling of waveguides. The optical mode coupler includes an oxide cladding layer, a waveguide channel formed on the oxide cladding layer, and a waveguide portion formed on the oxide cladding layer and partially enclosed by the waveguide channel on an end of the waveguide portion. The waveguide portion has a tapered region located on the end of the waveguide portion. The tapered region has a dual-plane tapering arrangement extending from the waveguide portion towards the waveguide channel for enhanced mode transformation efficiency.