HAMR Waveguide Power Sensor with Non-Reflecting Ends
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current heat-assisted magnetic recording (HAMR) devices are sensitive to optical coherence effects due to fluctuations in optical power and wavelength, which affect recording quality and head lifetime, necessitating improved monitoring and control of optical power.
Innovation Solution
The HAMR device incorporates a primary waveguide with a secondary waveguide and thermal sensors to monitor optical power fluctuations, with non-reflecting ends and strategically positioned thermal sensors to eliminate standing wave patterns, ensuring accurate power control and reduced sensitivity to optical coherence effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a thermal sensor is directly coupled to the primary waveguide to monitor optical power, then optical power monitoring is achieved, but optical coherence effects and standing wave patterns degrade measurement accuracy
Solution Approach 1:
A secondary waveguide is introduced as an intermediary between the primary waveguide and the thermal sensor. The secondary waveguide receives optical power from the primary waveguide and transmits it to the thermal sensor, isolating the sensor from direct coupling with the primary waveguide. This eliminates standing wave patterns and optical coherence effects at the sensor interface while maintaining accurate optical power monitoring capability.
2Object-affected harmful factors
If the secondary waveguide ends are made non-reflecting to eliminate standing waves, then optical coherence effects are reduced, but optical power transmission efficiency may be affected
Solution Approach 1:
The non-reflecting ends of the secondary waveguide, which would normally cause optical power loss, are strategically positioned within the HAMR head where reflected light can be harmlessly absorbed or dissipated. This converts the potential harm of reflections into a beneficial elimination of standing wave patterns, as the reflected energy is contained within the head structure rather than causing measurement errors.
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 improved monitoring and control of optical power, enhancing recording quality and reducing the impact of optical coherence effects, thereby stabilizing the HAMR process and extending head lifetime.
Implementation Method 1
A thermal sensor is coupled to the secondary waveguide, and responds only to optical power variations in the primary waveguide
Implementation Method 2
The first and second ends of the secondary waveguide are non-reflecting
Data Source
AI summary
Embodiments disclosed herein generally relate to a HAMR device for use in a magnetic reading system. The HAMR device has a primary waveguide extending from a media facing surface to a surface opposite the media facing surface. In one embodiment, the HAMR head has a secondary waveguide having a first and second end positioned within the HAMR head. The secondary waveguide is positioned near the primary waveguide, and the first and second ends of the secondary waveguide are non-reflecting. A thermal sensor is coupled to the secondary waveguide, and responds only to optical power fluctuations in the primary waveguide. In another embodiment, the HAMR head has a second thermal sensor rather than a secondary waveguide. The first thermal sensor and the second thermal sensor are coupled together to act as one optical power sensor and are disposed on the primary waveguide.