Gradient Index Waveguide Coupler for HAMR Light Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat-assisted magnetic recording (HAMR) devices face challenges in efficiently launching light from a laser diode into a slider-integrated waveguide with low cost and high alignment tolerance, due to mismatched beam profiles between the laser output and the waveguide's refractive indices, which affects the delivery of electromagnetic energy for heating the recording media.
Innovation Solution
The use of a waveguide with a core and cladding layer structure, potentially enhanced by a gradient index material layer, allows for efficient light coupling by matching the refractive indices and using a multilayer structure or gradient index material to direct light from the laser diode into the waveguide, ensuring effective energy delivery to the recording media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard waveguide structure is used without gradient index material, then the device complexity is low, but the light coupling efficiency is poor due to mismatched beam profiles
Solution Approach 1:
The patent introduces a gradient index material layer as an intermediary component between the laser diode and the waveguide core. This layer acts as a mediator that gradually transitions the refractive index from the laser output profile to the waveguide mode profile, enabling efficient light coupling without requiring complex alignment mechanisms. The gradient index material serves as a bridge that reconciles the mismatched beam profiles.
Solution Approach 2:
The patent employs gradient index material that continuously changes the refractive index parameter along the propagation direction. This parameter change enables smooth transition of light from the laser diode output to the waveguide mode, improving coupling efficiency. The refractive index varies spatially to match the beam profile transformation requirements.
2Reliability
If precise alignment is used to achieve optimal light coupling, then the light coupling efficiency is high, but the alignment tolerance becomes tight and manufacturing cost increases
Solution Approach 1:
The gradient index material layer serves as a tolerant intermediary that reduces sensitivity to alignment errors. By providing a gradual refractive index transition zone, it allows for larger positional and angular deviations while maintaining effective light coupling, thereby relaxing manufacturing alignment tolerance requirements.
Solution Approach 2:
The spatially varying refractive index parameter in the gradient index material creates a more robust coupling interface that is less sensitive to alignment variations. The gradual parameter change provides a buffer zone that accommodates manufacturing tolerances while maintaining high coupling efficiency.
3Reliability
If a gradient index material layer is added to improve light coupling, then the light coupling efficiency and alignment tolerance improve, but the device complexity and manufacturing cost increase
Solution Approach 1:
The gradient index material layer is positioned as a thin intermediary zone between the laser diode and waveguide core, minimizing the added complexity while maximizing the coupling benefit. This mediator layer requires simple integration into the existing waveguide structure.
Solution Approach 2:
The gradient index material provides continuous refractive index parameter variation in a compact form factor, achieving improved light coupling without requiring extensive structural modifications to the waveguide 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 enables efficient and cost-effective laser-in-slider light delivery with improved alignment tolerance, achieving tightly confined hot spots for enhanced data storage density by efficiently coupling light into the waveguide and focusing it onto the recording media.
Implementation Method 1
A gradient index material layer is disposed beside the core layer along a portion of the propagation length where light is launched into the waveguide via an input facet. The gradient index material layer is configured to direct light from the input facet to the core layer at least along the portion of the propagation length.
Data Source
AI summary
A light source is coupled to an input facet that directs light from the light source to a core layer of a waveguide and a gradient index material layer disposed beside the core layer along a portion of a propagation length of the waveguide. Light is launched from the light source into the input facet. In response, the gradient index material layer directs light to the core layer at least along the portion of the propagation length.