Bending waveguide, method of fabricating the bending waveguide, light delivery module employing the bending waveguide, and heat assisted magnetic recording head employing the bending waveguide

1. A bending waveguide comprising:

a core having an input end and an output end, wherein at least the output end has a near field enhanced aperture structure; and

a metal cladding disposed around the core,

wherein the core is bent in a curve and a radius of curvature of the curve is a resonance radius at which an intensity of transmitted light with respect to a wavelength of incident light is a maximum;

wherein an output end of the core has a C-shaped aperture structure, wherein a part of the metal cladding protrudes towards a center portion of the C-shaped aperture structure forming a ridge portion; and

wherein the core has a C-shaped cross-section throughout a length thereof.

2. The bending waveguide of claim 1 , wherein the width of the ridge portion gradually decreases from the input end to the output end.

3. The bending waveguide of claim 1 , wherein a cross-sectional area of the core is the same throughout a length of the core from the input end to the output end.

4. The bending waveguide of claim 1 , wherein a cross-sectional area of an input end of the core is different from a cross-sectional area of the output end thereof.

5. The bending waveguide of claim 4 , wherein a cross-sectional area of the core gradually decreases from the input end to the output end.

6. The bending waveguide of claim 5 , wherein a thickness of the cross-section of the core is constant and a width of the cross-section of the core gradually decreases from the input end to the output end.

7. The bending waveguide of claim 1 , wherein the core is bent in a circular curve having an angle θ(0<θ<180) between the input end and the output end.

8. The bending waveguide of claim 1 , wherein the core is bent in a curve, wherein the curve is defined by more than one radius of curvature.

9. A light delivery module comprising:

a first waveguide which comprises:

a core having an input end and an output end, wherein the output end has a near field enhanced aperture structure; and

a metal cladding enclosing the core,

wherein the first waveguide is a bending waveguide in which the core is bent in a curve and a radius of curvature of the curve is a resonance radius at which an intensity of transmitted light with respect to a wavelength of incident light is a maximum;

wherein an output end of the core of the first waveguide has a C-shaped aperture structure, wherein a part of the metal cladding protrudes towards a center portion of the C-shaped aperture structure forming a ridge portion; and

wherein the core of the first waveguide has a C-shaped cross-section throughout a length thereof.

10. The light delivery module of claim 9 , further comprising a second waveguide which transmits light to the first waveguide.

11. The light delivery module of claim 10 , wherein the first waveguide and the second waveguide are butt-coupled.

12. The light delivery module of claim 9 , wherein the width of the ridge portion gradually decreases from the input end to the output end.

13. The light delivery module of claim 10 , wherein a cross-sectional area of the core of the first waveguide gradually decreases from the input end to the output end.

14. The light delivery module of claim 9 , wherein the core of the first waveguide is bent in a circular curve having an angle θ(0<θ<180) between the input end and the output end.

15. The light delivery module of claim 9 , wherein the core of the first waveguide is bent in a curve, wherein more than one radii of curvature define the curve.

16. A heat assisted magnetic recording head comprising:

a magnetic recording portion which forms a magnetic field; and

a light delivery module which emits light, which heats a recording scheduled area of a magnetic recording medium,

wherein the light delivery module comprises:

a first waveguide which comprises a core having an input end and an output end, wherein the output end has a near field enhanced aperture structure, and a metal cladding enclosing the core; and

a second waveguide which transmits light to the first waveguide,

wherein the first waveguide is a bending waveguide in which the core is bent in a curve and a radius of curvature of the curve is a resonance radius at which an intensity of transmitted light with respect to a wavelength of incident light is a maximum;

wherein an output end of the core of the first waveguide has a C-shaped aperture structure, wherein a part of the metal cladding protrudes towards a center portion of the C-shaped aperture structure forming a ridge portion; and

wherein the core of the first waveguide has a C-shaped aperture structure throughout a length thereof.

17. The heat assisted magnetic recording head of claim 16 , wherein, an input end of the second waveguide is provided at a side surface of the heat assisted magnetic recording head.

18. The heat assisted magnetic recording head of claim 17 , wherein the first waveguide has an input end that is coupled to an output end of the second waveguide and also has an output end that faces a bottom surface of the heat assisted magnetic recording head.

19. The heat assisted magnetic recording head of claim 16 , wherein the width of the ridge portion gradually decreases from the input end to the output end.

20. The heat assisted magnetic recording head of claim 16 , wherein a cross-sectional area of the core gradually decreases from the input end to the output end.

21. The bending waveguide of claim 8 , wherein each said radii of curvature corresponds to a resonance radius.

22. The bending waveguide of claim 15 , wherein each said radii of curvature corresponds to a resonance radius.