Compact Mode Converter for Heat-Assisted Magnetic Recording
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Solution Overview
Problem
Current hard drive recording heads face challenges in efficiently delivering light energy from a laser diode to a near-field transducer to create a hotspot on a magnetic recording medium, limiting data writing capabilities due to the fundamental transverse electric (TE00) mode's inefficiencies in energy conversion.
Innovation Solution
A waveguide system with a mode converter portion that converts the fundamental TE00 mode into a higher-order TE10 mode, allowing for more efficient energy delivery to a near-field transducer, which directs surface plasmons to the recording medium, thereby enhancing data writing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the waveguide delivers light in the fundamental TE00 mode, then the structure is simple, but the energy conversion efficiency is low
Solution Approach 1:
The patent applies parameter changes by transitioning the waveguide mode from fundamental TE00 to higher-order TE10. This mode change alters the light distribution pattern and electromagnetic field characteristics, enabling more efficient coupling with the near-field transducer and improving energy conversion efficiency without fundamentally changing the waveguide structure
Solution Approach 2:
The patent introduces a mode converter as an intermediary component between the waveguide and the near-field transducer. This mode converter transforms the light mode from TE00 to TE10, serving as a mediator that bridges the gap between the simple waveguide structure and the efficiency requirements of the near-field transducer coupling
2Volume of moving object
If the waveguide is positioned close to the near-field transducer, then the device size is reduced, but the mode conversion efficiency decreases
Solution Approach 1:
The patent addresses the spatial constraint by optimizing the three-dimensional positioning and orientation of the mode converter relative to the near-field transducer. By carefully designing the spatial arrangement in multiple dimensions, the patent achieves effective mode conversion while maintaining a compact overall device size
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 system enables improved energy transfer and hotspot creation on the recording medium, increasing data writing efficiency and coercivity reduction, allowing for more effective magnetic field generation and data storage.
Implementation Method 1
The mode converter portion is configured to convert the light to a higher-order (TE10) mode
Implementation Method 2
the near-field transducer receiving the light at the TE10 mode from the waveguide and directing surface plasmons to a recording medium
Implementation Method 3
delivering light energy from a laser diode to a near-field transducer to create a hotspot on a magnetic recording medium
Data Source
AI summary
A write head includes an input coupler configured to receive light excited by a light source. A waveguide core is configured to receive light from the input coupler at a fundamental transverse electric (TE00) mode. The waveguide core has a first straight portion. The waveguide core has a mode converter portion comprising a branched portion extending from the first straight portion. The mode converter portion is configured to convert the light to a higher-order (TE10) mode, the mode converter portion spaced apart from the input coupler. The waveguide core has a second straight portion between the mode converter portion and a media-facing surface. The write head has a near-field transducer at the media-facing surface, the near-field transducer receiving the light at the TE10 mode from the waveguide and directing surface plasmons to a recording medium in response thereto.