Waveguide Assistant Layer for Focused Thermal Spot

Solution Overview

Problem

Current methods for heating storage media in thermally assisted magnetic/optical recording are inefficient in reducing the size of the heated spot, limiting storage density.

Innovation Solution

A waveguide structure with specific refractive index layers, including a top cladding layer, an assistant layer, a core layer, and a bottom cladding layer, is used to efficiently transfer energy and focus it onto a smaller area, enhancing energy transfer and heating efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If current heating methods are used to heat storage media, then the storage media can be heated to reduce coercivity, but the heated spot size cannot be sufficiently reduced, limiting storage density

Engineering Contradiction:

Improvestorage media temperatureVSAvoidheated spot size

Core Design Contradiction:

TemperatureVSArea of moving object

Solution Approach 1:

The patent introduces an assistant layer as an intermediary between the waveguide and the storage media. This assistant layer has specific refractive index properties that enable more efficient energy transfer and focusing, allowing the heated spot size to be reduced while maintaining the necessary temperature elevation for coercivity reduction

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes changes in refractive index parameters by designing a multi-layer waveguide structure with specific refractive index relationships (n1 < n2, n3; n3 > n1, n4; n4 < n3, n2). This parameter optimization enables better energy confinement and focusing, reducing the heated spot size on the storage media

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If energy is directed and focused onto the storage media, then the storage media can be heated for recording, but the focused energy cannot concentrate sufficiently on a small area, limiting storage density increase

Engineering Contradiction:

Improveenergy transfer efficiencyVSAvoidfocused energy area

Core Design Contradiction:

Use of energy by moving objectVSArea of moving object

Solution Approach 1:

The assistant layer serves as a mediator that improves the coupling between the waveguide and the storage media, enabling more efficient energy transfer. This intermediary layer helps concentrate the energy onto a smaller focal area, improving both energy transfer efficiency and reducing the heated spot size

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a composite multi-layer structure with different materials having specific refractive index relationships. This composite waveguide structure (with layers having n1, n2, n3, n4 where n1 < n2 and n3, n3 > n1 and n4, n4 < n3 and n2) creates optimal conditions for energy confinement and focusing, enabling higher energy density on the storage media

Inventive Principle:

Principle #40Composite materials

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 described waveguide structure allows for a more efficient transfer of energy, achieving a smaller focal point and improved storage density in thermally assisted magnetic recording systems.

Implementation Method 1

A waveguide including a top cladding layer, the top cladding layer including a material having an index of refraction, n1; an assistant layer, the assistant layer positioned adjacent the top cladding layer, the assistant layer including a material having an index of refraction, n2; a core layer, the core layer positioned adjacent the assistant layer, the core layer including a material having an index of refraction, n3; and a bottom cladding layer, the bottom cladding layer positioned adjacent the core layer, the bottom cladding layer including a material having an index of refraction, n4

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS9316783B2Optical devices including assistant layers

Publication Date: 2016.04.19 SEAGATE TECH LLC

AI summary

A waveguide including a top cladding layer, the top cladding layer including a material having an index of refraction, n1; an assistant layer, the assistant layer positioned adjacent the top cladding layer, the assistant layer including a material having an index of refraction, n2; a core layer, the core layer positioned adjacent the assistant layer, the core layer including a material having an index of refraction, n3; and a bottom cladding layer, the bottom cladding layer positioned adjacent the core layer, the bottom cladding layer including a material having an index of refraction, n4, wherein n1 is less than both n2 and n3, n3 is greater than n1 and n4, and n4 is less than n3 and n2.