Optical Device Grating Coupler Lens Alignment
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Solution Overview
Problem
Existing optical communication technologies require precise alignment of optical fibers with silicon optical waveguides to achieve high optical coupling efficiency, which is challenging and time-consuming.
Innovation Solution
An optical device that converts propagation light into parallel light using a grating or reflective surface with V-shaped grooves and focuses it onto the optical fiber core using a convex lens, allowing for relaxed alignment precision without compromising coupling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a grating coupler is used to focus and couple light onto the optical fiber core, then optical coupling efficiency is improved, but alignment precision requirements become extremely stringent (one micrometer or less)
Solution Approach 1:
The optical coupling system is divided into two independent functional components: a grating coupler for focusing light and a lens for further focusing onto the fiber core. This segmentation allows each component to be optimized independently, with the lens providing the final precise focusing function while the grating coupler handles the initial light extraction, thereby reducing the overall alignment precision requirements
Solution Approach 2:
A lens is introduced as an intermediary optical element between the grating coupler and the optical fiber core. This lens acts as a mediator that receives the focused light from the grating coupler and redirects it to the fiber core, providing an additional degree of freedom in the optical path that relaxes the direct alignment requirements between the grating coupler and fiber
2Reliability
If direct alignment of optical fiber with grating coupler is performed with high precision, then optical coupling efficiency is improved, but the process becomes time-consuming and challenging
Solution Approach 1:
By separating the focusing function (grating coupler) from the final coupling function (lens to fiber), the system allows for more tolerant alignment procedures. The lens can be positioned relative to the grating coupler with relaxed precision, and the fiber alignment to the lens focal point is simpler than direct grating-to-fiber alignment, thereby reducing overall alignment time
Solution Approach 2:
The introduction of the lens changes the optical parameters of the system, creating a new focal point that is more accessible and easier to align with the fiber core. This parameter change in the optical path allows for less stringent alignment tolerances and reduces the time required for precise positioning
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
Enables high optical coupling efficiency with reduced precision requirements, allowing alignment to ten micrometers or more, while maintaining high efficiency, through the use of a grating or reflective surface and convex lens configuration.
Implementation Method 1
A grating (diffraction grating) structure created inside the slab structure of the silicon optical waveguide is often used to focus and couple the propagating light
Implementation Method 2
a reflective surface with V-shaped grooves
Implementation Method 3
a first lens means for focusing the parallel light outputted from the conversion means on a core of an optical fiber
Data Source
AI summary
An optical device and a method of manufacturing an optical device. The optical device includes: a conversion means for converting propagation light propagating through an optical waveguide into parallel light and for outputting the parallel light; and a first lens means for focusing the parallel light outputted from the conversion means on a core of an optical fiber. The method includes: converting propagation light propagating through an optical waveguide into parallel light; outputting the parallel light; and focusing, using a first lens, the parallel light on a core of an optical fiber.