Optical Waveguide for Plasmonic Recording

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Solution Overview

Problem

In information storage devices, achieving high thermal stability of data while minimizing the intensity of the magnetic field required for recording is challenging, as materials with high magnetic anisotropic energy density increase the magnetic field intensity needed.

Innovation Solution

The use of optical elements that generate a circularly polarized plasmonic field, achieved through a light source and an optical waveguide structure with a metal and dielectric interface, emitting plasmons to create a strong magnetic field for recording on a magnetic recording medium, thereby reducing the magnetic field intensity required.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a material having a high magnetic anisotropic energy density KU is used to form a recording medium, then the thermal stability of data is increased, but the intensity of a magnetic field required to record data is increased

Engineering Contradiction:

Improvethermal stability of dataVSAvoidintensity of magnetic field

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The patent employs heat-assisted magnetic recording (HAMR) which utilizes phase transition of the recording medium material. A laser heats a localized region of the recording medium to elevate its temperature above the Curie temperature, causing a phase transition that temporarily reduces the magnetic anisotropic energy density KU. This allows data recording with reduced magnetic field intensity, and subsequent cooling restores the high KU state for data retention.

Inventive Principle:

Principle #36Phase transitions

Solution Approach 2:

The patent applies preliminary heating action to the recording medium before magnetic field application. By pre-heating the recording region to reduce KU before writing the magnetic field, the system prepares the medium in a receptive state that requires lower magnetic field intensity for successful data recording, thereby resolving the contradiction between high thermal stability materials and reduced field requirements.

Inventive Principle:

Principle #10Preliminary action

2Force

If the intensity of a magnetic field is reduced for data recording, then the thermal stability requirement becomes more stringent, but the recording density and resolution may be compromised

Engineering Contradiction:

Improveintensity of magnetic fieldVSAvoidrecording density and resolution

Core Design Contradiction:

ForceVSManufacturing precision

Solution Approach 1:

The patent applies local quality by concentrating the heating and magnetic field application to a highly localized region of the recording medium. The laser beam focuses energy on a specific spot, creating a localized zone with reduced KU only where data recording is intended. This localized approach maintains high recording density and resolution while using reduced magnetic field intensity, as the field is applied precisely where the medium is temporarily most receptive.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent substitutes the purely mechanical/magnetic recording system with an optical-thermal-magnetic hybrid system. Instead of relying solely on high-intensity magnetic fields for recording, the system uses optical energy (laser) to thermally modify the medium's magnetic properties locally, thereby enabling recording with lower magnetic field intensities while maintaining precision through optical focusing capabilities.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This approach allows for increased recording density and performance by forming a small light spot and generating a strong magnetic field, enabling efficient data recording with high resolution beyond the diffraction limit, even with high magnetic anisotropic energy materials.

Implementation Method 1

an optical waveguide configured to transform the circularly polarized light generated by the light source into plasmon and emit the plasmon

Methodology Applied

Scientific EffectPlasmon:

Implementation Method 2

a light source configured to generate circularly polarized light

Methodology Applied

Scientific EffectCircularly polarized light: Polarisation

Implementation Method 3

the optical waveguide is configured to emit the plasmon from an interface between the metal and the dielectric

Methodology Applied

Scientific EffectMetal-dielectric interface plasmon emission:

Data Source

PatentUS8526288B2Optical elements including light sources and waveguides and information storage devices including the same

Publication Date: 2013.09.03 SAMSUNG ELECTRONICS CO LTD

AI summary

An optical element and an information storage device including the same. The optical element may include an optical waveguide structure for transforming circularly polarized light into plasmon and transmitting the plasmon. The optical waveguide structure may emit a circularly polarized plasmonic field. The optical element may be used in an information storage device. For example, the information storage device may include a recording medium and a recording element for recording information on the recording medium, and the recording element may include the optical element. The information may be recorded on the recording medium by using the circularly polarized plasmonic field generated by the optical element.