Characterizing optical antenna near field transducers
AssigneeSeagate Technology LLC
InventorChubing Peng
Life of this patent
Estimating the term…
Abstract
An apparatus and associated method for characterizing a near field transducer (NFT) is provided that has computer instructions stored in memory and executable to perform computational logic that, in response to a selected electromagnetic radiation excitation of resonant collective oscillations on a surface of the NFT, compares a magnitude of a depolarization field associated with the excited resonant collective oscillations to a predetermined threshold to characterize the NFT in terms of demonstrated radiant efficiency performance.
Claims23
A near field transducer (NFT) characterization device comprising computer instructions stored in memory and executable to perform computational logic that, in response to a selected electromagnetic radiation excitation of resonant collective oscillations on a surface of the NFT, compares a magnitude of a depolarization field associated with the excited resonant collective oscillations to a predetermined threshold to characterize the NFT in terms of demonstrated radiant efficiency performance.
An apparatus that characterizes a near field transducer (NFT), the NFT having a grating that directs incident light to a waveguide that in turn polarizes the light in a desired mode along a waveguide plane that is substantially parallel to illumination, and the NFT having a resonant optical antenna to which the waveguide focuses the polarized light to excite resonant collective oscillations on the antenna, the apparatus comprising:
- a linear polarizer operably receiving electromagnetic radiation transmitted by the NFT, the linear polarizer having an optical axis that is substantially orthogonal to the waveguide plane;
- an optical detector coupled to the linear polarizer operably quantifying the field strength of the excited resonant collective oscillations;
- and
- a characterization module that compares the quantified field strength of the excited resonant collective oscillations to a predetermined threshold value to characterize the radiant efficiency of the NFT.
A method that characterizes a near field transducer (NFT) having a grating in communication with a waveguide that polarizes incident light in a desired mode along a waveguide plane that is substantially parallel to illumination and, in turn, communicates the polarized light to a resonant optical antenna, the method comprising:
- directing electromagnetic radiation to the grating to excite resonant collective oscillations on the antenna;
- polarizing electromagnetic radiation transmitted by the NFT substantially orthogonal to the waveguide plane;
- quantifying the field strength of the excited resonant collective oscillations;
- comparing the quantified field strength of the excited resonant collective oscillations to a predetermined threshold value;
- and
- characterizing the NFT in terms of demonstrated radiant efficiency based on results of the comparing step.
Dependencies are inferred from the claim text.