Excitation of a near-field transducer using combined transverse electric and transverse magnetic modes

Patent metadata

Field	Value
Publication number	US-2016133285-A1
Application number	US-201514886259-A
Country	US
Kind code	A1
Filing date	Oct 19, 2015
Priority date	Nov 11, 2014
Publication date	May 12, 2016
Grant date	—

Abstract

A method involves receiving light from a light source at a fundamental transverse electric (TE 00 ) mode or a fundamental transverse magnetic (TM 00 ) mode. A waveguide polarization multiplexes the light to a combined mode that includes the TM 00 mode and a first higher-order transverse electric (TE 10 ) mode. A near-field transducer is excited via the light at the combined mode.

First claim

What is claimed is:

1 . A method comprising:
receiving light from a light source at a fundamental transverse electric (TE 00 ) mode or a fundamental transverse magnetic (TM 00 ) mode; polarization multiplexing, via a waveguide, the light to a combined mode comprising the TM 00 mode and a first higher-order transverse electric mode TE 10 ; and exciting a near-field transducer via the light at the combined mode, the excited near-field transducer directing surface plasmons to a recording medium in response thereto.

2 . The method of claim 1 , wherein the light is polarization multiplexed via a core region with a pinched dimension proximate the near-field transducer, the core region located between the near-field transducer and the light source.

3 . The method of claim 1 , wherein the light is polarization multiplexed via an asymmetry of the waveguide about a substrate-parallel plane.

4 . The method of claim 3 , wherein the asymmetry comprises different top and bottom cladding materials surrounding a core of the waveguide.

5 . The method of claim 3 , wherein the waveguide comprises an asymmetric core shape about the substrate-parallel plane.

6 . The method of claim 1 , wherein the light is polarization multiplexed via a structured core comprising at least two materials having different index of refraction.

7 . The method of claim 1 , wherein the light is received at the fundamental TE 00 mode, the method further comprising first converting the light to the higher-order TE 10 modevia a mode order converter before polarization multiplexing the light to the combined mode.

8 . The method of claim 7 , wherein the mode order converter comprises an tapered input waveguide coupled to the light source, the tapered input waveguide proximate to and separated from an output waveguide via a gap, the output waveguide exciting the near-field transducer.

9 . The method of claim 7 , wherein the mode converter comprises a branch of the waveguide that extends from a middle region of the waveguide towards the light source.

10 . The method of claim 1 , wherein the light is received at the TM 00 mode.

11 . A write head comprising:
a waveguide extending along a light-propagation direction and configured to receive light from a light source at a fundamental transverse electric (TE 00 ) mode or a fundamental transverse magnetic (TM 00 ) mode, the waveguide comprising a polarization multiplexer that converts the light to a combined mode comprising the TM 00 mode and a first higher-order transverse electric mode TE 10 ; and a near-field transducer at a media-facing surface of the write head, the near-field transducer receiving the light at the combined mode from the waveguide and directing surface plasmons to a recording medium in response thereto.

12 . The write head of claim 11 , wherein the polarization multiplexer comprises a core region of the waveguide with a pinched cross-track dimension proximate the near-field transducer, the core region located between the near-field transducer and the light source.

13 . The write head of claim 11 , wherein the light is received at the TE 00 mode, the waveguide further comprising a mode order converter between the light source and the polarization multiplexer, the mode order converter converting the light to the TE 10 mode.

14 . The write head of claim 13 , wherein the waveguide comprises a input waveguide coupled to the light source and an output waveguide delivering the light at the combined mode to the near-field transducer, the mode converter comprising a tapered portion of the input waveguide proximate to and separated from the output waveguide via a gap.

15 . The write head of claim 13 , wherein the mode order converter comprises a branch of the waveguide that extends from a middle region of the waveguide towards the light source.

16 . The write head of claim 11 , wherein the polarization multiplexer comprises a region of asymmetry about a substrate-parallel plane.

17 . The write head of claim 16 , wherein the region of asymmetry comprises different top and bottom cladding materials surrounding a core of the waveguide.

18 . The write head of claim 16 , wherein the region of asymmetry comprises an asymmetric core shape about the substrate-parallel plane.

19 . The method of claim 1 , wherein the polarization multiplexer comprises a structured core having at least two materials with different index of refraction.

20 . The write head of claim 11 , wherein the light is received at the TM 00 mode.

Assignees

• Seagate Technology Llc

Inventors

• Peng Chubing

Classifications

• G11B5/6088 Primary

  Optical waveguide in or on flying head · CPC title

• G11B5/4866 Primary

  the arm comprising an optical waveguide, e.g. for thermally-assisted recording · CPC title

• G11B2005/0021

  Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal · CPC title

• G11B5/314

  where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers (G11B5/3196 takes precedence) · CPC title

• G02B6/1226

  involving surface plasmon interaction · CPC title