Waveguide Core Shape for TE-Mode Plasmon Generation
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Solution Overview
Problem
In thermally-assisted magnetic recording, existing waveguides fail to efficiently generate high-intensity evanescent light when using TE-mode lasers, as they do not allow the electric field of laser light to oscillate perpendicular to the evanescent light generating surface, hindering the generation of surface plasmons and near-field light.
Innovation Solution
A waveguide with a core formed of two layers of different shapes, fabricated with high precision, allows light to propagate and includes a cladding with a dielectric layer, enabling the rotation of the polarization direction or change in beam diameter, thereby facilitating the generation of high-intensity evanescent light even with TE-mode lasers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional waveguide structure is used with TE-mode laser light, then the waveguide can propagate light, but it cannot generate high-intensity evanescent light because the electric field oscillates parallel to the evanescent light generating surface instead of perpendicular to it
Solution Approach 1:
The core is divided into multiple layers (first core layer, second core layer, third core layer) with different shapes and orientations. Each layer is designed to transform the polarization direction of light step by step, converting TE-mode light into TM-mode light that can generate high-intensity evanescent light at the plasmon exciting section.
Solution Approach 2:
The invention changes the polarization dimension of the light by using layers with different shape orientations. The first core layer has a shape extending in the vertical direction, the second core layer has a shape extending in the horizontal direction, and the third core layer has a shape extending in the vertical direction again, creating a dimensional transformation that rotates the electric field oscillation direction from parallel to perpendicular relative to the evanescent light generating surface.
2Manufacturing precision
If the core shape precision is increased to enable effective polarization transformation, then evanescent light generation improves, but the manufacturing complexity and difficulty increase
Solution Approach 1:
The core is segmented into multiple manufacturable layers, each with a relatively simple shape orientation. This segmentation allows each layer to be manufactured with standard precision using conventional semiconductor fabrication techniques, while the cumulative effect of the layered structure achieves the complex polarization transformation function.
Solution Approach 2:
Each core layer is designed with a specific local shape orientation optimized for its function in the polarization transformation sequence. The first core layer has vertical extension for initial polarization control, the second core layer has horizontal extension for intermediate transformation, and the third core layer has vertical extension for final transformation. This local optimization allows each layer to be manufactured with standard precision while achieving the overall high-precision polarization control function.
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 waveguide enhances the precision of the core's shape, allowing effective transformation of TE-mode laser light into TM-mode, enabling the generation of high-intensity evanescent light and surface plasmons, which improves near-field light generation and data writing capabilities in thermally-assisted magnetic recording.
Implementation Method 1
The core generates evanescent light at the evanescent light generating surface from laser light propagating through the core
Implementation Method 2
surface plasmons are excited on the plasmon exciting section through coupling with the evanescent light, the excited surface plasmons propagate to the near-field light generating surface, and near-field light is generated from those surface plasmons
Data Source
AI summary
A manufacturing method for a waveguide includes forming a core including a first layer and a second layer. The first layer has a top surface including a first region with which a bottom surface of the second layer is in contact, and a second region with which the bottom surface of the second layer is not in contact. Forming the core includes the steps of: forming an initial first layer; forming an etching stopper layer on the second region of the initial first layer; forming an initial second layer on the initial first layer and the etching stopper layer; etching the initial second layer and the initial first layer so as to make the initial first layer into the first layer; and etching the initial second layer until the etching stopper layer is exposed, so as to make the initial second layer into the second layer.