Integrated Cylindrical Lens TAMR Light Delivery
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Solution Overview
Problem
Existing thermally assisted magnetic recording (TAMR) technologies face inefficiencies in coupling laser light from a diode to a plasmon antenna due to divergent beam issues, requiring specialized suspension and alignment, which increases costs and complexity, and suffer from back-reflection affecting laser stability.
Innovation Solution
Integration of cylindrical lenses or mirrors within the slider structure to focus and collimate the laser beam onto a waveguide, eliminating the need for external focusing components and reducing back-reflection by angling the laser diode or sloping the cavity wall, thereby enhancing coupling efficiency and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If end-fire coupling method is used to directly couple laser beam from LD into waveguide, then coupling efficiency is improved, but precise alignment is required which increases assembly and packaging costs
Solution Approach 1:
A lens is introduced as an intermediary component between the laser diode and waveguide. The lens focuses the divergent laser beam to match the waveguide's acceptance angle and spatial mode, enabling efficient coupling without requiring precise direct alignment between LD and waveguide ends.
Solution Approach 2:
The problem is solved by adding a spatial dimension - placing a lens at an intermediate position in the optical path rather than directly coupling LD to waveguide. This allows the beam to be focused and redirected, transforming the coupling geometry from a direct end-to-end alignment to a focused convergence approach.
2Ease of manufacture
If laser diode is mounted on slider with standard methods, then assembly is simplified, but back-reflection of light into laser diode occurs affecting stability
Solution Approach 1:
A mirror is positioned to preemptively intercept and redirect reflected light before it can re-enter the laser diode. This preliminary action prevents the harmful back-reflection from occurring, maintaining laser stability while keeping the mounting structure simple.
Solution Approach 2:
The reflected light, which would normally be a harmful back-reflection, is redirected by the mirror to exit the cavity in a controlled direction. This converts the potentially harmful reflected energy into a controlled optical path that does not interfere with laser operation.
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 improves coupling efficiency, reduces assembly costs, maintains slider height, and enhances thermal attachment, allowing for simpler and more robust manufacturing with improved shock resistance and reduced back-reflection issues.
Implementation Method 1
a lens is integrated into the light delivery path from the LD to the WG to improve the coupling efficiency between the light delivery system and the WG
Implementation Method 2
TAMR converts optical power into highly localized heating in a magnetic recording medium so as to temporarily reduce the field needed to switch the magnetizations of the medium grains
Implementation Method 3
The WG acts as an intermediate path to guide the externally generated laser light to the PA or PG
Implementation Method 4
The optical energy, after being converted to Plasmon energy, either through local Plasmon excitation in the PA
Data Source
AI summary
A device to facilitate Thermally Assisted Magnetic Recording (TAMR), and a method for its manufacture, are described. One or more cylindrical lenses are used to focus light from a laser diode onto a wave-guide and a nearby plasmon antenna. Five embodiments of the invention are described, each one featuring a different way to couple the laser light to the optical wave-guide.