Light Source Unit Photodetector Integration for HAMR Head Weight Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing light source units for heat-assisted magnetic recording heads are bulky and heavy due to the need for a separate substrate for the photodetector, making it difficult to achieve a compact design, which affects the performance of the hard disk apparatus by increasing the weight and impacting the rotation of the magnetic head slider.
Innovation Solution
A light source unit with a photodetector mounted on the same substrate as the laser diode, detecting leakage light to estimate the intensity of the forward light, allowing for a more compact design by positioning the photodetector closer to the light source and eliminating the need for an additional substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the photodetector is provided on a separate substrate at a predetermined distance from the laser diode, then the light intensity of the rearward light can be measured, but the light source unit becomes bulky and heavy
Solution Approach 1:
The patent merges the photodetector and laser diode onto the same substrate, eliminating the need for a separate substrate and reducing the overall weight of the light source unit. The photodetector is positioned adjacent to the laser diode on the same substrate, allowing for integrated mounting that solves the weight problem while maintaining measurement functionality.
Solution Approach 2:
Instead of positioning the photodetector at a predetermined distance from the laser diode in the conventional direction, the patent positions it adjacent to the laser diode on the same substrate, utilizing the two-dimensional plane of the substrate to achieve compact integration without compromising measurement capability.
2Measurement precision
If the photodetector is provided on the substrate at a predetermined distance from the laser diode, then the rearward light can be detected, but the light source unit requires a large substrate size
Solution Approach 1:
The patent combines the photodetector and laser diode on the same substrate in adjacent positions, eliminating the need for a large substrate area. This integration allows both components to share the same substrate plane, significantly reducing the overall substrate size required for the light source unit.
Solution Approach 2:
The patent utilizes the two-dimensional plane of the substrate to position the photodetector adjacent to the laser diode, optimizing the use of available space. This dimensional arrangement allows for compact integration without requiring extended substrate dimensions in any particular direction.
3Measurement precision
If another substrate is used for the photodetector, then the light intensity can be controlled, but the weight reduction becomes difficult
Solution Approach 1:
The patent eliminates the need for a separate substrate by merging the photodetector onto the same substrate as the laser diode. This single-substrate integration removes the additional weight that would result from using a separate substrate for the photodetector, while still enabling light intensity control through the photodetector's measurement function.
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 enables a compact and lightweight light source unit, improving the performance of the hard disk apparatus by reducing the weight and enhancing the rotation of the magnetic head slider, while maintaining control over the light intensity for effective heat-assisted magnetic recording.
Implementation Method 1
a photodetector that is provided on the substrate and that has a light receiving surface for detecting leakage light that leaks from the light leakage part
Implementation Method 2
a light source that includes; a first emission part that emits a forward light, the forward light being a laser light in an oscillation state; a second emission part that is located on a side opposite to the first emission part and that emits a rearward light, the rearward light being a laser light in an oscillation state
Data Source
AI summary
A light source unit has a substrate, a light source that is mounted to the substrate. The light source includes; a first emission part that emits a forward light, the forward light being a laser light in an oscillation state; a second emission part that is located on a side opposite to the first emission part and that emits a rearward light, the rearward light being a laser light in an oscillation state; and a light leakage part located at a position different from the first emission part and the second emission part. The light source further includes a photodetector that is provided on the substrate, wherein the photodetector has a light receiving surface for detecting a leakage light that leaks from the light leakage part.