Optical Coupling Device With Divergent Convergent Grating Contours
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Solution Overview
Problem
Existing optical coupling devices exhibit limited efficiency in transferring light radiation from a waveguide to an optical fiber, with the light intensity emitted by the coupling grating showing an exponential decrease, which is not optimal for efficient coupling.
Innovation Solution
An optical coupling device is designed with a focusing lens and a diffraction coupling grating that includes a first and second sub-network with divergent and convergent contours, respectively, to focus light radiation at a point within the grating, achieving a Gaussian profile for improved coupling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional optical coupling grating is used, then the device structure is simple, but the optical coupling efficiency is limited and the light intensity shows exponential decrease
Solution Approach 1:
The optical coupling grating is divided into multiple periods with different trench depths, creating distinct zones that progressively shape the light intensity profile from exponential decay to Gaussian distribution, thereby improving coupling efficiency while maintaining manufacturing feasibility
Solution Approach 2:
Different regions of the grating are assigned different trench depths (first period with deeper trenches, second period with shallower trenches) to create localized variations in coupling strength, enabling the transformation of the light intensity profile to match the optical fiber's Gaussian mode profile
2Ease of manufacture
If the grating structure is simplified for ease of manufacture, then manufacturing is easier, but the light intensity profile cannot be optimized to Gaussian
Solution Approach 1:
The trench depth parameter is varied across different periods of the grating structure, with the first period having deeper trenches and the second period having shallower trenches, to control and shape the light intensity profile into a Gaussian distribution while maintaining compatibility with standard fabrication processes
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 device enhances optical coupling efficiency by ensuring a Gaussian envelope of light radiation, significantly improving the injection of light into optical fibers and optimizing the coupling process.
Implementation Method 1
an optical coupling device comprising a diffraction coupling grating intended to give light radiation emitted by said grating a Gaussian envelope
Implementation Method 2
the focusing lens is intended to focus light radiation, propagating along the direction XX', at a point of focus F
Data Source
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AI summary
The invention relates to an optical coupling device (10) comprising, in sequence, a focusing lens (30) and an optical coupling network (40), the coupling device being symmetric with respect to a plane, the focusing lens (30) formed in a core layer (20), termed the front face, perpendicular to the plane, the optical coupling network (40) comprising a plurality of trenches, formed on the front face, and convex in shape, the optical coupling network (40) comprising, in sequence, a first sub-network (40a) and a contiguous second sub-network (40b), respectively delimited, by a first contour (44) and a second contour (45), said first (44) and second (45) contour extending in a divergent manner and convergent manner respectively.