Polarization converter including a jagged diagonal line in plane orthogonal to propagation direction of electromagnetic wave
View Patent ↗A polarization converter of the invention includes a core part that wave-guides an electromagnetic wave and a cladding part that is provided around the core part. The core part includes a conversion part converting a polarization state of the electromagnetic wave. A cross-sectional shape of the conversion part in a plane orthogonal to a propagation direction of the electromagnetic wave is a shape formed by cutting off a portion of a rectangular or square shape along a jagged diagonal line.
1. A polarization converter comprising:
a core part that wave-guides an electromagnetic wave; and
a cladding part that is provided around the core part, wherein
the core part comprises a conversion part converting a polarization state of the electromagnetic wave, and
a cross-sectional shape of the conversion part in a plane orthogonal to a propagation direction of the electromagnetic wave is a shape formed by cutting off a portion of a rectangular or square shape along a jagged diagonal line.
2. The polarization converter according to claim 1 , wherein
arithmetic mean roughness of the jagged diagonal line is 1 nm or more and 21 nm or less.
3. The polarization converter according to claim 1 , wherein
a contour of the conversion part comprises, in a cross section orthogonal to the propagation direction of the electromagnetic wave, a linear horizontal side, a linear vertical side orthogonal to the horizontal side, and the jagged diagonal line.
4. The polarization converter according to claim 1 , wherein
the conversion part has a cross section of a substantially right-angled triangular shape formed by the linear horizontal side, the linear vertical side and the jagged diagonal line.
5. A thermally-assisted magnetic recording head comprising:
a waveguide through which an electromagnetic wave propagates;
a polarization converter according to claim 1 provided in the waveguide; and
a plasmon generator that couples in a plasmon mode with light passing through the polarization converter and generates near-field light.
6. The thermally-assisted magnetic recording head according to claim 5 , further comprising:
a magnetic pole that generates a writing magnetic field.
7. A slider comprising:
a waveguide through which an electromagnetic wave propagates;
a polarization converter according to claim 1 provided in the waveguide; and
a plasmon generator that couples in a plasmon mode with light passing through the polarization converter and generates near-field light.
8. A wafer comprising a slider according to claim 7 .
9. A head gimbal assembly comprising:
a slider according to claim 7 ; and
a suspension elastically supporting the slider.
10. A hard disk drive apparatus comprising:
a slider according to claim 7 ; and
a device that supports the slider and positions the slider with respect to a recording medium.