Near-field optical head having tapered hole for guiding light beam

• US 7,599,277 B1
• Filed: 11/04/1999
• Issued: 10/06/2009
• Est. Priority Date: 11/09/1998
• Status: Expired due to Term

• Current Assignee: Seiko Instruments Incorporated (Seiko Group)
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Kasama, Nobuyuki, Ichihara, Susumu, Kato, Kenji, Oumi, Manabu, Niwa, Takashi, Chiba, Norio, Mitsuoka, Yasuyuki
• Primary Examiner(s): Dinh; Tan X
• Application Number:
  US09/582,903
• Time in Patent Office: 3,624 Days
• Field of Search: 369/112, 369/126, 369/44.23, 369/121, 369/101, 369/14, 369/112.27, 369/112.05, 369/112.01, 369/112.06, 369/112.09, 369/112.14, 369/13.13, 369/13.33, 385/31, 385/129, 385/131, 385/83, 360/234.6, 360/318.1, 360/246.1, 360/237.1, 445/27, 445/50, 250/216, 250/227.26, 250/210.5, 250/306, 250/227.28, 250/307, 257/10, 216/2, 216/33, 216/80, 356/613, 65/30
• US Class Current: 369/112.27
• CPC Class Codes: G01Q 80/00 Applications, other than SPM, of scanning-probe techniques manufacture or treatment of nanostructures B82B3/00; recording or reproducing information using near-field interaction G11B9/12, G11B11/24, G11B13/08
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G11B 2007/13727 Compound lenses, i.e. two or more lenses co-operating to perform a function, e.g. compound objective lens including a solid immersion lens, positive and negative lenses either bonded together or with adjustable spacing
• CPC Class Codes: G11B 7/122 Flying-type heads, e.g. analogous to Winchester type in magnetic recording
• CPC Class Codes: G11B 7/124 the integrated head arrangements including waveguides
• CPC Class Codes: G11B 7/125 Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
• CPC Class Codes: G11B 7/1362 Mirrors
• CPC Class Codes: G11B 7/1387 using the near-field effect
• CPC Class Codes: G11B 7/22 Apparatus or processes for the manufacture of optical heads, e.g. assembly

Abstract

A near-field optical head has a planar substrate having a first surface, a second surface disposed opposite to the first surface, and an inverted conical or pyramidal hole extending through the first and second surfaces. The conical or pyramidal hole has at least one fine aperture formed at an apex thereof and is disposed on the first surface of the planar substrate. An optical waveguide is disposed on the second surface of the planar substrate for propagating light. A light reflection film is disposed in the optical waveguide for reflecting in the direction of the fine aperture light propagated through the optical waveguide.

Claims

1. A near-field optical head comprising:

a planar substrate having a first surface, a second surface disposed opposite to the first surface, and an inverted conical or pyramidal hole extending through the first and second surfaces, the inverted conical or pyramidal hole having at least one fine aperture formed at an apex thereof and disposed in the first surface and having at least one curved slant surface;

an optical waveguide extending into the inverted conical or pyramidal hole of the planar substrate for propagating light along an optical path; and

a mirror disposed in the optical waveguide for bending in the direction of the fine aperture the optical path of the light propagated through the optical waveguide;

wherein the curved slant surface is formed between first and second tapers of the inverted conical or pyramidal hole, the first taper having a slant angle of approximately 55 degrees relative to the first surface of the planar substrate and the second taper having a slant angle of approximately from 10 degrees to 30 degrees relative the first surface of the planar substrate.

2. A near-field optical head according to claim 1;

wherein the second taper is disposed closer to the fine aperture than is the first taper.

3. A near-field optical head according to claim 1;

wherein the first taper originates from the second surface of the planar substrate.

4. A near-field optical head comprising:

a substrate having an inverted conical or pyramidal hole penetrating therethrough, the hole being formed by at least one curved slant surface and having at least one fine aperture at an apex thereof;

an optical waveguide extending into the inverted conical or pyramidal hole of the substrate for propagating light along an optical path; and

a mirror disposed in the optical waveguide for bending in the direction of the fine aperture the optical path of the light propagated through the optical waveguide;

wherein the curved slant surface is formed between first and second tapers of the inverted conical or pyramidal hole, the first taper having a slant angle of approximately 55 degrees relative to the surface of the substrate and the second taper having a slant angle of approximately from 10 degrees to 30 degrees relative to the surface of the substrate.

5. A near-field optical head according to claim 4;

wherein the second taper is disposed closer to the fine aperture than is the first taper.