VCSEL EAMR Disk Drive Perpendicular Laser Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional energy-assisted magnetic recording (EAMR) disk drives face issues with optical efficiency due to misalignments, temperature variations affecting laser wavelength, and high manufacturing costs, leading to lower performance and manufacturability challenges.
Innovation Solution
The EAMR disk drive incorporates a vertical surface emitting laser (VCSEL) with an extended resonance cavity oriented perpendicular to the slider's trailing face, coupled with a grating and waveguide to enhance energy transfer and thermal stability, reducing insertion loss and improving alignment precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional laser diode is used with light provided along the optic axis to the grating, then the system can function, but misalignments occur increasing insertion loss and reducing optical efficiency
Solution Approach 1:
The patent inverts the conventional laser orientation by using a VCSEL that emits light perpendicular to the slider trailing face, rather than parallel to it. This inversion changes the light propagation direction from along the optic axis to perpendicular to the grating plane, eliminating the alignment sensitivity issues that plague conventional laser diodes while maintaining effective optical coupling to the waveguide.
Solution Approach 2:
The patent introduces an extended resonance cavity as an intermediary structure between the VCSEL and the grating-waveguide system. This cavity acts as a mediator that couples energy from the VCSEL to the waveguide through the grating, providing thermal stability and wavelength control while maintaining perpendicular light emission geometry.
2Reliability
If temperature variations occur in the region of the laser, then the wavelength of the light produced changes, but this reduces optical efficiency and performance
Solution Approach 1:
The extended resonance cavity serves as a thermal intermediary between the VCSEL and the surrounding environment. It provides thermal stability to the laser region, isolating the wavelength-determining structures from temperature variations while still allowing the perpendicular light emission geometry to function effectively for optical coupling.
Solution Approach 2:
The patent designs the extended resonance cavity with specific geometric parameters (length, width, orientation) that create resonant conditions stabilizing the light wavelength. By carefully controlling these physical parameters, the system maintains consistent optical performance despite temperature fluctuations in the broader drive environment.
3Reliability
If accurate placement of the slider and laser diode is attempted, then optical efficiency may improve, but manufacturing complexity and cost increase
Solution Approach 1:
By inverting the laser orientation to use a VCSEL emitting perpendicular to the slider, the patent eliminates the need for complex alignment procedures required by conventional lateral-emitting laser diodes. The perpendicular emission geometry naturally couples to the waveguide through the grating without requiring sub-micron precision placement, dramatically simplifying manufacturing while maintaining high optical efficiency.
Solution Approach 2:
The VCSEL structure with its extended resonance cavity provides self-alignment capabilities. The perpendicular emission geometry and resonant cavity structure work together to automatically couple light to the waveguide through the grating, reducing or eliminating the need for complex external alignment mechanisms and procedures during assembly.
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 configuration enhances performance, reduces production costs, and increases manufacturing yield by providing high power with stable wavelength operation and improved alignment, resulting in higher optical efficiency and reliability.
Implementation Method 1
at least one vertical surface emitting laser (VCSEL). The VCSEL(s) provides energy to the EAMR disk drive
Implementation Method 2
The waveguide directs the light toward the conventional media 12, heating a small region of the conventional media 12
Implementation Method 3
At least a portion of the grating(s) resides in the extended resonance cavity and couple energy from the VCSEL to the waveguide(s)
Implementation Method 4
The EAMR disk drive incorporates a vertical surface emitting laser (VCSEL) with an extended resonance cavity oriented perpendicular to the slider's trailing face, coupled with a grating and waveguide to enhance energy transfer and thermal stability
Data Source
AI summary
A method and system for providing an energy assisted magnetic recording (EAMR) disk drive are described. The EAMR disk drive includes a media, a slider having a trailing face, at least one EAMR head on the slider, and at least one vertical surface emitting laser (VCSEL). The VCSEL(s) includes a plurality of quantum wells and an extended resonance cavity. The VCSEL(s) provides energy to the EAMR disk drive. The extended resonance cavity extends into the slider and is oriented substantially perpendicular to the trailing face of the slider. The EAMR head(s) include grating(s), waveguide(s), a write pole, and coil(s) for energizing the write pole. At least a portion of the grating(s) reside in the extended resonance cavity and couple energy from the VCSEL to the waveguide(s). The waveguide(s) direct the energy from the grating(s) toward the media.