External Cavity Laser Slot Waveguide for HAMR Energy Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current external cavity lasers for heat-assisted magnetic recording (HAMR) face challenges in efficiently delivering energy to a near-field transducer to achieve surface plasmon resonance for effective magnetic recording, particularly due to high coercivity of recording media and susceptibility to superparamagnetic effects.
Innovation Solution
An external cavity laser with a slot waveguide configuration, where high-index regions surround a middle low-index region, and a near-field transducer with parallel plates and a gap is used to amplify energy, inducing surface plasmons that are directed to a recording medium, while a magnetic write pole applies a field to the heated hotspot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional external cavity lasers are used for HAMR, then the device structure is relatively simple, but the energy delivery efficiency to near-field transducer is insufficient
Solution Approach 1:
The slot waveguide is integrated within the slider body, nesting the optical energy delivery mechanism inside the existing slider structure. This allows efficient energy delivery to the near-field transducer while maintaining a compact overall device form factor, resolving the contradiction between energy efficiency and device complexity.
Solution Approach 2:
The slot waveguide acts as an intermediary component that couples energy from the external cavity laser to the near-field transducer. It mediates the energy transfer process, improving delivery efficiency while the external cavity laser itself remains a separate, manageable component, thus balancing energy efficiency with device complexity.
2Reliability
If high coercivity recording media is used, then data storage density is improved, but susceptibility to superparamagnetic effects increases
Solution Approach 1:
The patent utilizes thermal phase transition to temporarily reduce the coercivity of high-coercivity recording media during the writing process. By heating the media with the slot waveguide and near-field transducer, the media transitions to a state where magnetic switching is easier, allowing data writing without suffering from superparamagnetic effects, thereby maintaining data reliability.
Solution Approach 2:
The invention changes the temperature parameter of the recording media dynamically during operation. By controlling the thermal state of the media through the integrated slot waveguide system, the coercivity parameter is temporarily modified to enable reliable data writing in high-coercivity media while avoiding superparamagnetic instability.
3Power
If energy is amplified through surface plasmon resonance, then recording effectiveness is improved, but energy loss increases
Solution Approach 1:
The slot waveguide structure concentrates energy locally at the near-field transducer where surface plasmon resonance occurs. By confining the energy amplification to a specific localized region rather than distributing it throughout the entire system, the patent achieves high recording power at the target while minimizing overall energy loss in the 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 configuration enhances energy reflection and surface plasmon resonance, improving data reliability by lowering coercivity and reducing superparamagnetic errors, thereby enhancing the recording process.
Implementation Method 1
a slot waveguide configured to receive energy from an input surface of the slider. The slot waveguide has first and second high-index regions surrounding a middle region that extends along a light propagation direction
Implementation Method 2
A portion of the energy causing surface plasmons to resonate in the gap. The surface plasmons are directed out of the media-facing surface to form a hot spot on a recording medium
Implementation Method 3
The energy reflects between the reflective back facet of the active laser region and the first and second plate to amplify the energy
Implementation Method 4
the write pole applies a magnetic field to the hotspot
Data Source
AI summary
A slider includes a slot waveguide configured to receive energy from an input surface. The slot waveguide has first and second high-index regions surrounding a middle region that extends along a light propagation direction. The middle region has a refractive index less than that of the first and second high index regions. A near-field transducer is at an output portion of the middle region at media-facing surface. The near-field transducer has first and second plates parallel to the media-facing surface with a gap therebetween. An active laser region has a front facet optically coupled to the input surface of the slider. A reflective back facet of the laser and the near-field transducer define a single optical resonator.