1. A spin-valve magnetoresistive head having a device part and terminal parts provided to both ends of the device part, the spin-valve magnetoresistive head comprising:
a first free magnetic layer formed from one to the other of the terminal parts; and
a lamination in the terminal parts on said first free magnetic layer, the lamination including an antiparallel coupling intermediate layer, a soft magnetic layer, and a first antiferromagnetic layer, the antiparallel coupling intermediate layer having a function of making front and rear magnetization orientation of a magnetic layer contacting the antiparallel coupling intermediate layer substantially antiparallel, the first antiferromagnetic layer applying to the soft magnetic layer a bias magnetic field substantially perpendicular to a direction of an external magnetic field to be detected.
2. The spin-valve magnetoresistive head as claimed in claim 1, wherein:
the antiparallel coupling intermediate layer is formed from the one to the other of the terminal parts through the device part; and
a nonmagnetic layer, a pinned magnetic layer, and a second antiferromagnetic layer are provided in an order described under said first free magnetic layer from a side thereof.
3. The spin-valve magnetoresistive head as claimed in claim 1, wherein:
the antiparallel coupling intermediate layer and the soft magnetic layer are formed from the one to the other of the terminal parts through the device part;
the soft magnetic layer serves as a second free magnetic layer; and
a nonmagnetic layer, a pinned magnetic layer, and a second antiferromagnetic layer are provided in an order described under said first free magnetic layer from a side thereof.
4. The spin-valve magnetoresistive head as claimed in claim 1, wherein:
the antiparallel coupling intermediate layer and the soft magnetic layer are formed from the one to the other of the terminal parts;
the soft magnetic layer serves as a second free magnetic layer; and
a nonmagnetic layer, a pinned magnetic layer, and a second antiferromagnetic layer are provided in an order described on the second free magnetic layer from a side thereof in the device part.
5. The spin-valve magnetoresistive head as claimed in claim 1, wherein a nonmagnetic layer, a pinned magnetic layer, and a second antiferromagnetic layer are provided in an order described on said first free magnetic layer from a side thereof in the device part.
6. The spin-valve magnetoresistive head as claimed in any of claims 1 to 5, wherein the first antiferromagnetic layer has an exchange coupling magnetic field of 100 to 400 Oe with the soft magnetic layer or the second free magnetic layer.
7. The spin-valve magnetoresistive head as claimed in any of claims 1 to 5, wherein the antiparallel coupling intermediate layer includes ruthenium.
8. A composite-type magnetic head having a magnetic head for reproduction and a magnetic head for recording, wherein:
the magnetic head for reproduction is a spin-valve magnetoresistive head comprising a device part, terminal parts provided to both ends of the device part, and a lamination including a first free magnetic layer formed from one to the other of the terminal parts, an antiparallel coupling intermediate layer in the terminal parts on the first free magnetic layer, a soft magnetic layer, and a first antiferromagnetic layer, the antiparallel coupling intermediate layer having a function of making front and rear magnetization orientation of a magnetic layer contacting the antiparallel coupling intermediate layer substantially antiparallel, the first antiferromagnetic layer applying to the soft magnetic layer a bias magnetic field substantially perpendicular to a direction of an external magnetic field to be detected.
9. A magnetic recording medium drive including a magnetic recording medium and a composite-type magnetic head for recording and reproduction, the composite-type magnetic head opposing a surface of the magnetic recording medium, the magnetic recording medium drive comprising:
a spin-valve magnetoresistive head as a reproducing magnetic head part of the composite-type magnetic head, the spin-valve magnetoresistive head including a device part, terminal parts provided to both ends of the device part, and a lamination including a first free magnetic layer formed from one to the other of the terminal parts, an antiparallel coupling intermediate layer in the terminal parts on the first free magnetic layer, a soft magnetic layer, and a first antiferromagnetic layer, the antiparallel coupling intermediate layer having a function of making front and rear magnetization orientation of a magnetic layer contacting the antiparallel coupling intermediate layer substantially antiparallel, the first antiferromagnetic layer applying to the soft magnetic layer a bias magnetic field substantially perpendicular to a direction of an external magnetic field to be detected.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. In automatically switched optical network operating according to a wavelength plan, a computer-implemented method of selecting a wavelength for an optical path with reduced wavelength SRS transients, comprising:
providing a plurality of configurable global variables, configured according to the performance requirements of said network;
grouping all wavelengths provided by said wavelength plan into static bins and, based on a plurality of bin constraints, organizing said static bins into subsets of dynamic bins which include all wavelengths available for said optical path; and
searching within said subsets of dynamic bins for a wavelength (Lam) that has an individual performance parameter \u0394Q (\u03bb) estimated for said optical path above a threshold (Th) and satisfies a maximum number of wavelength constraints,
wherein said bin constraints and said wavelength constraints are designed for offering various degrees of SRS transient reduction.
2. A computer-implemented method as claimed in claim 1, wherein said step of grouping comprises:
selecting from said static bins a set S0 of dynamic bins BS0 based on said threshold and a bin performance parameter \u0394Q.
defining a range of consecutive wavelength within said wavelength plan and moving a bin from S0 into a first subset of bins S1 if it contains a wavelength (Lam) within said range.
3. A computer-implemented as claimed in claim 2, wherein said step of grouping further comprises, for each end node of said optical path:
defining an access function (Facc) using said respective global variables, and calculating a current value Facc for said access function for quantifying the position of all wavelengths currently accessing said network at said end nodes;
for each wavelength in all bins of said first subset S1, calculating a respective new value for said access function based on said current valueFacc; and
moving a bin from said first subset S1 into said a second subset S2 if it contains a wavelength (Lam) for which said respective new value Facc is less than a limit (Limit2).
4. A computer-implemented method as claimed in claim 2, wherein said step of grouping further comprises, for each end node of said optical path:
defining an access and tandem function (Facc&tan) using said respective global variables, and calculating a current value Facc&tan for said access and tandem function which quantifies the position of all wavelengths currently present at said end nodes;
for each wavelength of all bins of said second subset S2, calculating a new value Facc&tan for said access and tandem function based on said current value; and
moving a bin from said second subset S2 into a third subset S3 if it contains a wavelength (Lam) for which said respective new value Facc&tan is less than a limit (Limit3).
5. A computer-implemented method as claimed in claim 2, wherein said step of searching comprises identifying within a subset S3 a wavelength that satisfies a wavelength constraint and assigning said wavelength (Lam) to said optical path.
6. A computer-implemented method as claimed in claim 5, wherein said step of searching further comprises, if no wavelength satisfies said wavelength constraint, increasing a code violation with a CV value, and continuing the search into a subset S2.
7. A computer-implemented method as claimed in claim 6, wherein said step of searching further comprises identifying within said subset S2 a wavelength that satisfies a second wavelength constraint and assigning said wavelength (Lam) to said optical path.
8. A computer-implemented method as claimed in claim 7, wherein said step of searching further comprises, if no wavelength satisfies said second wavelength constraint, increasing said code violation with a second CV value, and continuing the search into said first subset S1.
9. A computer-implemented method as claimed in claim 8, wherein said step of searching further comprises identifying within said first subset S1 a wavelength that satisfies a first wavelength constraint and assigning said wavelength (Lam) to said optical path.
10. A computer-implemented method as claimed in claim 9, wherein said step of searching further comprises, if no wavelength satisfies said first wavelength constraint, increasing said code violation with a first CV value, and continuing the search into said subset S0.
11. A computer-implemented method as claimed in claim 10, wherein said step of searching further comprises identifying within said subset S0 a wavelength that has an individual performance parameter above a threshold.
12. A computer-implemented method as claimed in claim 11, wherein said wavelength selection is steered towards a wavelength that has a minimum code violation value.