TAMR Write Head Waveguide Blocker for Optical Radiation Suppression
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Solution Overview
Problem
The reliability of thermally assisted magnetic recording (TAMR) heads is compromised due to excessive heating of the head by the magnetic recording medium, leading to performance degradation and reduced lifespan, as existing solutions fail to effectively suppress residual optical radiation within the waveguide that heats the dielectric regions and head structures.
Innovation Solution
A waveguide blocker is introduced to suppress optical electromagnetic radiation, preventing it from converting to plasmon near-field energy and thereby reducing unnecessary heating of the recording medium and dielectric regions, while also protecting the near-field plasmon generator and improving dimensional tolerances and thermal spot confinement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a waveguide is used to propagate optical energy to heat the recording medium, then thermal activation for high-density recording is achieved, but residual optical radiation heats dielectric regions and head structures causing reliability degradation
Solution Approach 1:
The patent extracts and removes the harmful residual optical radiation from the waveguide using a blocker structure. The blocker is positioned within the waveguide to absorb or reflect the remaining optical energy before it can reach and heat the dielectric regions and head structures, thereby eliminating the reliability issue while maintaining the beneficial thermal activation function.
Solution Approach 2:
The blocker acts as an intermediary element between the waveguide and the dielectric regions/head structures. It intercepts the residual optical radiation and prevents it from reaching the sensitive components, serving as a protective mediator that resolves the contradiction between achieving high recording density and maintaining head reliability.
2Temperature
If optical radiation is allowed to propagate through the waveguide without blocking, then thermal activation is maintained, but unnecessary heating of dielectric regions occurs reducing head lifespan
Solution Approach 1:
The patent converts the harmful residual optical radiation into a beneficial element by using it to heat the blocker itself, which then conducts heat to the recording medium through controlled thermal contact. This transforms the potentially harmful radiation into a controlled heating mechanism that extends head lifespan while maintaining thermal activation.
3Device complexity
If the waveguide structure is simplified without a blocker, then device complexity is reduced, but dimensional tolerances deteriorate and thermal spot confinement is poor
Solution Approach 1:
The blocker is designed with specific local properties - it is positioned only in the critical region where residual optical radiation needs to be blocked, and its dimensions are optimized for that specific location. This local intervention maintains overall structural simplicity while achieving the required dimensional tolerances and thermal spot confinement only where necessary.
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 blocker effectively reduces head temperature, enhances the rise time of the write element, increases the lifetime of TAMR heads, and minimizes damage to the medium and head overcoat, leading to improved recording performance and reliability.
Implementation Method 1
Light from such a light-emitting device is introduced into an optical waveguide configured to propagate the light
Implementation Method 2
The waveguide propagated electromagnetic radiation is transferred, by coupling, to a plasmon generator adjacent to the waveguide at the distal end of the waveguide, where it excites plasmon modes. The light focused by the waveguide at the plasmon generator is emitted, as plasmon near-field energy, and heats the surface of recording media.
Implementation Method 3
A waveguide blocker is introduced to suppress optical electromagnetic radiation, preventing it from converting to plasmon near-field energy and thereby reducing unnecessary heating of the recording medium and dielectric regions
Implementation Method 4
The heat then effectively lowers the medium's coercivity at the same position where the magnetic writing field is applied, so as to enable writing as though it were on a medium with lowered coercivity
Data Source
AI summary
A method for manufacturing a TAMR (thermal assisted magnetic recording) write head. The write head has a metal blocker formed against a distal end of a waveguide. The waveguide focuses optical radiation on an adjacent plasmon generator where it excites plasmon modes that heat the recording medium. Although the plasmon generator typically heats the recording medium using the plasmon near field to supply the required Joule heating, an unblocked waveguide would also send optical radiation to the medium and surrounding structures producing unwanted heating and device unreliability. The role of the blocker is to block the unwanted optical radiation and, thereby, to limit the heating to that supplied by the plasmon near field.