Phase-Shifted Waveguide for Sub-Diffraction Hotspots
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical focusers are diffraction limited and cannot create hotspots smaller than half the wavelength of the light used in heat-assisted magnetic recording (HAMR), limiting the areal data density of magnetic media.
Innovation Solution
A near-field transducer (NFT) with a waveguide system that delivers phase-shifted light to its sides, utilizing different geometries or constructions to induce a relative phase shift, enabling the creation of highly localized hotspots on the magnetic recording media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional optical focusers are used, then the system is simple and easy to manufacture, but the hotspot size is limited to half the wavelength of light, preventing higher areal data density
Solution Approach 1:
The waveguide is divided into multiple portions (first waveguide portion and second waveguide portion) with different geometries or constructions. Each portion delivers light to a different side of the NFT, and the segmentation allows independent phase control of each light path, enabling precise hotspot size control below the diffraction limit
Solution Approach 2:
Different portions of the waveguide are given different local properties (different geometries or constructions) to introduce specific phase shifts. The first waveguide portion has different geometric or constructional characteristics than the second portion, creating local phase differences that result in constructive interference and sub-diffraction hotspots
2Manufacturing precision
If phase-shifting portions are added to the waveguide, then sub-diffraction hotspots can be created, but the device complexity increases
Solution Approach 1:
The waveguide portions are designed with asymmetric geometries or constructions relative to each other. The first waveguide portion has different geometric or constructional characteristics than the second portion, creating intentional asymmetry that produces the required phase shift for sub-diffraction hotspot formation
Solution Approach 2:
The geometry or construction parameters of the waveguide portions are specifically modified to control the phase of light. By changing parameters such as waveguide width, height, material composition, or length in different portions, precise phase control is achieved, enabling hotspot localization precision below the diffraction limit
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 phase-shifted light delivery system effectively overcomes the diffraction limit, allowing for the creation of hotspots smaller than the wavelength of the light, thereby enhancing the areal data density in HAMR by achieving localized heating at the nanoscale.
Implementation Method 1
A waveguide is configured to receive light from a light source, the waveguide have first and second portions that deliver first and second portions of the light to the first and second edges of the plasmonic transducer
Implementation Method 2
The first and second portions are different by at least one of a geometry and a construction to cause a relative phase shift between the first and second portions of the light
Implementation Method 3
A waveguide with phase shifting portions Patent Abstract: Various embodiments described herein are generally directed to an apparatus having a plasmonic transducer
Data Source
AI summary
An apparatus includes a plasmonic transducer with first and second oppositely disposed outer edges. A waveguide is configured to receive light from a light source, the waveguide have first and second portions that deliver first and second portions of the light to the first and second edges of the plasmonic transducer. The first and second portions are different by at least one of a geometry and a construction to cause a relative phase shift between the first and second portions of the light.