Light source alignment for heat assisted magnetic recording
AssigneeSeagate Technology LLC
InventorChubing Peng
Life of this patent
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Abstract
An approach for aligning a light source on a slider involves filtering light emerging from the air bearing surface of a (ABS) of a heat assisted magnetic recording (HAMR) slider. A first portion of the emerging light is emitted by a near field transducer in response to optical excitation and has a component having a first polarization state. A second portion of the emerging light including stray light has polarization states different from the first polarization state. The polarizing filter substantially transmits light having the first polarization state and substantially rejects light having a polarization state orthogonal to the first polarization state. Alignment coordinates for the light source are determined based on the light transmitted through the polarizing filter.
Claims20
A method, comprising:
- collecting light emerging from an air bearing surface (ABS) of a heat assisted magnetic recording (HAMR) slider, a first portion of the light emitted by a near field transducer in response to optical excitation by a light source and having a component of a first polarization state, a second portion of the light including at least one of stray light and illumination background, the second portion of light comprising polarization states different from the first polarization state;
- filtering light emerging from the ABS using a polarizing filter, the polarizing filter substantially transmitting light having the first polarization state and substantially rejecting light having a polarization state orthogonal to the first polarization state;
- detecting light transmitted through the polarizing filter;
- generating an electrical signal in response to detecting the transmitted light, the electrical signal comprising amplitude as a function of position along a mounting surface of the slider;
- and
- determining alignment coordinates of the light source based on the signal by measuring values of one or more signal parameters for multiple positions of the mounting surface and identifying a position of the light source in x, y, and z coordinates that satisfy alignment criteria.
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An apparatus, comprising:
- polarizing filter configured to filter light emerging from an air bearing surface (ABS) of a heat assisted magnetic recording (HAMR) slider, the light emerging from the ABS including light emitted by a near field transducer (NFT) in response to optical excitation and having a component of a first polarization state, a second portion of the light including at least one of stray light and illumination background, the second portion of light comprising polarization states different from the first polarization state, the polarizing filter configured to substantially transmit light having the first polarization state and to substantially reject light having a polarization state orthogonal to the first polarization state;
- a detector arranged to detect light transmitted through the polarizing filter and to generate an electrical signal in response to detected light;
- and
- a light source alignment mechanism, comprising:
- a fixture configured to hold the light source relative to a mounting region of the slider;
- and
- a controller configured to receive the electrical signal and to operate the fixture to cause movement of the light source relative to the slider in cross-track, down-track, and gap directions.
An apparatus, comprising:
- a polarizing filter configured to filter light emerging from an air bearing surface (ABS) of a heat assisted magnetic recording (HAMR) slider, the light emerging from the ABS including light emitted by a near field transducer (NFT) in response to optical excitation and having a component of a first polarization state, a second portion of the light including at least one of stray light and illumination background, the second portion of light comprising polarization states different from the first polarization state, the polarizing filter configured to substantially transmit light having the first polarization state and to substantially reject light having a polarization state orthogonal to the first polarization state;
- a detector arranged to detect light transmitted through the polarizing filter and to generate an electrical signal in response to detected light;
- and
- an alignment mechanism configured to align the light source with the slider in cross-track, down-track, and gap directions based on the electrical signal.
Dependencies are inferred from the claim text.