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An optical near-field generating element is provided with: a light shielding member, which is placed on an optical path of light emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light; and a dielectric film placed in close conta

An optical near-field generating element is provided with: a light shielding member, which is placed on an optical path of light emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light; and a dielectric film placed in close contact with the micro opening. Alternatively, an optical near-field generating element is provided with a light shielding member, which is placed on an optical path of lights emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light, the shielding member equipped with: a main portion for defining a basic shape of the micro opening; and a protrusion portion protruding from the main portion toward the center of the micro opening.

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1. An optical near-field generating element comprising:a light shielding member, which is placed on an optical path of light emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light; and a dielectric film placed in close contact w

1. An optical near-field generating element comprising:a light shielding member, which is placed on an optical path of light emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light; and a dielectric film placed in close contact with the micro opening, wherein at least a portion of said dielectric film is disposed within the micro opening. 2. An optical near-field generating element according to claim 1, wherein the micro opening has the diameter equal to or shorter than ½ of the wavelength of the light.3. An optical near-field generating element according to claim 1, wherein a refractive index of said dielectric film is greater than that of an incident side of the optical path.4. An optical near-field generating element according to claim 1, wherein said dielectric film comprises a single layer.5. An optical near-field generating element according to claim 1, wherein said dielectric film comprises a plurality of layers.6. An optical near-field generating element according to claim 1, comprising a metallic film having a light transmission characteristic wherein said metallic film is formed on an optical output side of said dielectric film.7. An optical near-field generating element according to claim 1, wherein said light shielding member has a main portion for defining a basic shape of the micro opening and a protrusion portion protruding from the main portion toward the center of the micro opening.8. An optical near-field generating element according to claim 7, wherein the basic shape of the micro opening is a polygon.9. An optical near-field generating element according to claim 7, wherein the basic shape of the micro opening is a circle or an oval.10. An optical near-field generating element according to claim 7, wherein a plurality of protrusion portions are placed at positions point-symmetrical with the center of the micro opening.11. An optical near-field generating element according to claim 1, further comprising a light guiding member for guiding the light emitted from the light source,said light shielding member being placed at a tip of said light guiding member in the forward direction of the light. 12. An optical near-field generating element according to claim 11, wherein said light guiding member is an optical fiber.13. An optical near-field generating element according to claim 12, wherein the optical fiber is covered with a metallic film and said light shielding member comprises the metallic film.14. An optical near-field generating element according to claim 11, wherein said light guiding member comprises a solid immersion lens.15. An optical near-field generating element according to claim 1, including the light source.16. The element according to claim 1, further comprising:a metallic film, wherein at least a portion of the metallic film is disposed within the micro opening. 17. The element according to claim 16, wherein at least a second portion of the metallic film is disposed outside the micro opening.18. The element according to claim 17, wherein the second portion of the metallic film is disposed on an optical output side of the light shielding member.19. The element according to claim 1, further comprising a metallic film, which is disposed on an optical output side of the light shielding member.20. The element according to claim 1, wherein a second portion of the dielectric layer is disposed outside the micro opening.21. The element according to claim 20, wherein the second portion of the dielectric layer is disposed on an optical output side of the light shielding member.22. The element according to claim 21, further comprising a metallic layer, which is disposed on an optical output side of the second portion of the dielectric layer.23. The element according to claim 20, wherein the second portion of the dielectric layer is disposed on an optical input side of the light shielding member.24. The element according to claim 23, wherein a third portion of the dielectric layer is disposed outside the micro opening and is disposed on an optical output side of the light shielding member.25. The element according to claim 24, further comprising a metallic layer, which is disposed on an optical output side of the third portion of the dielectric layer.26. The element according to claim 23, further comprising a metallic layer, which is disposed on an optical output side of the light shielding member.27. An optical apparatus comprising an optical near-field generating element,said optical near-field generating element comprising: a light shielding member, which is placed on an optical path of light emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light; and a dielectric film placed in close contact with the micro opening, wherein at least a portion of said dielectric film is disposed within the micro opening. 28. An optical apparatus according to claim 27, comprising a plurality of said optical near-field generating elements with them arrayed.29. An optical near-field generating element, comprising:a light guiding member for guiding light; a light shielding member, which defines a micro opening having a width less than or equal to a wavelength of the light, wherein the light guiding member guides light to the light shielding member, a dielectric film disposed adjacent to the micro opening, wherein a refractive index of the dielectric film is greater than a refractive index of the light guiding member. 30. The element according to claim 29, wherein the refractive index of the dielectric film is greater than a refractive index of a medium on an optical output side of the light shielding layer.