Optical probe and optical pick-up apparatus

• US 20020031299A1
• Filed: 09/12/2001
• Published: 03/14/2002
• Est. Priority Date: 09/12/2000
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Hatakoshi, Genichi
• Granted Patent: US 6,885,808 B2
• Time in Patent Office: Days
• US Class Current: 385/31
• CPC Class Codes: G02B 6/241 Light guide terminations
• CPC Class Codes: G11B 7/00 Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor G11B11/00, G11B13/00 take precedence
• CPC Class Codes: G11B 7/1384 Fibre optics
• 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

Disclosed is an optical probe for obtaining a micro spot light, comprising a rod-like glass body having a rectangular cross section as a core for propagating an light wave. The distal end portion of the glass body is gradually diminished toward the distal end so as to form a micro distal end face having a small diameter. The side surface of the distal end portion of the glass body in a direction perpendicular to the polarized direction of the light wave is coated with a light absorber formed of a metal film.

Claims

1. An optical probe for guiding an light wave in a predetermined propagating direction and outputting a predetermined component of the light wave, the optical prove being located in an atmosphere, comprising:

a core configured to transmit the light wave, having a first refractive index, comprising a base portion, and a end portion having a end face and first and second side surfaces, the end portion being gradually diminished from the base portion to the end face, the first side surface being inclined to a first direction perpendicular to the predetermined propagating direction and the second side surface being inclined to a second direction perpendicular to the first direction and the predetermined propagating direction; and

a light absorbing layer formed on the first side surface of the core, the second side surface being exposed to the atmosphere, the light wave being confined in the end portion, a part of the light wave being absorbed in the light absorbing layer, and the predetermined component penetrating the end face.

2. The optical probe according to claim 1, wherein the light absorbing layer is formed of a metal.

3. The optical probe according to claim 1, wherein the core is formed of a dielectric material or a semiconductor.

4. The optical probe according to claim 1, wherein the light wave has a polarized direction and the first direction corresponds to the polarized direction.

5. An optical probe for guiding an light wave in a predetermined propagating direction and outputting a predetermined component of the light wave, the optical prove being located in the atmosphere, comprising:

a core configured to transmit the light wave, having a first refractive index, comprising a base portion, and a end portion having a end face and first and second pairs of opposing side surfaces, the end portion being gradually diminished from the base portion to the end face, the opposing side surface of the first pair being inclined to each other and spaced apart in a first direction perpendicular to the predetermined propagating direction, and the opposing side surface of the second pair being inclined to each other and spaced apart in a second direction perpendicular to the first direction and the predetermined propagating direction;

a light absorbing layer formed on the opposing side surface of the first pair, the opposing side surface of the second pair being exposed to the atmosphere, the light wave being confined in the end portion, a part of the light wave being absorbed in the light absorbing layer, and the predetermined component penetrating the end face.

6. The optical probe according to claim 5, wherein the light absorbing layer is formed of a metal.

7. The optical probe according to claim 5, wherein the core is formed of a dielectric material or a semiconductor.

8. The optical probe according to claim 5, wherein the light wave has a polarized direction and the first direction corresponds to the polarized direction.

9. An optical probe for guiding an light wave in a predetermined propagating direction and outputting a predetermined component of the light wave, comprising:

a core configured to transmit the light wave, having a first refractive index, comprising a base portion, and a end portion having a end face and first and second side surfaces, the end portion being gradually diminished from the base portion to the end face, the first side surface being inclined to a first direction perpendicular to the predetermined direction and the second side surface being inclined to a second direction perpendicular to the first direction and the predetermined propagating direction;

a light absorbing layer formed on the first side surface of the core; and

a transparent cladding layer having a second refractive index lower than the first refractive index of the core, and formed on the second side surface of the core, the light wave being confined in the end portion, a part of the light wave being absorbed in the light absorbing layer, and the predetermined component penetrating the end face.

10. The optical probe according to claim 9, wherein the light absorbing layer is formed of a metal.

11. The optical probe according to claim 10, wherein the core is formed of a dielectric material or a semiconductor.

12. The optical probe according to claim 10, wherein the light wave has a polarized direction and the first direction corresponds to the polarized direction.

14. The optical probe according to claim 13, wherein the light absorbing layer is formed of a metal.

15. The optical probe according to claim 13, wherein the core is formed of a dielectric material or a semiconductor.

16. The optical probe according to claim 13, wherein the light wave has a polarized direction and the first direction corresponds to the polarized direction.

18. The optical pick-up apparatus according to claim 17, wherein the light wave has a polarized direction and the first direction corresponds to the polarized direction.

20. The optical pick-up apparatus according to claim 19, wherein the light wave has a polarized direction and the first direction corresponds to the polarized direction.

13. An optical probe for guiding an light wave in a predetermined propagating direction and outputting a predetermined component of the light wave, comprising:

a core configured to transmit the light wave, having a first refractive index, comprising a base portion, and a end portion having a end face and first and second pairs of opposing side surfaces, the end portion being gradually diminished from the base portion to the end face, the opposing side surface of the first pair being inclined to each other and spaced apart in a first direction perpendicular to the predetermined direction, and the opposing side surface of the second pair being inclined to each other and spaced apart in a second direction perpendicular to the first direction and the predetermined propagating direction;

a light absorbing layer formed on the opposing side surface of the first pair; and

a transparent cladding layer having a second refractive index lower than the first refractive index of the core, and formed on the opposing side surface of the second pair, the light wave being confined in the end portion, a part of the light wave being absorbed in the light absorbing layer, and the predetermined component penetrating the end face.

17. An optical pick-up apparatus for searching a target with a predetermined optical component, comprising:

a light source configured to generate an light wave having the predetermined optical component;

an optical probe configured to guide an light wave in a predetermined propagating direction and outputting the predetermined component of the light wave to the target, the optical prove being located in the atmosphere, including;

a core configured to transmit the light wave, having a first refractive index, comprising a base portion and a end portion having a end face and first and second pairs of opposing side surfaces, the end portion being gradually diminished from the base portion to the end face, the opposing side surface of the first pair being inclined to each other and spaced apart in a first direction perpendicular to the predetermined propagating direction, and the opposing side surface of the second pair being inclined to each other and spaced apart in a second direction perpendicular to the first direction and the predetermined propagating direction;

a light absorbing layer formed on the opposing side surface of the first pair, the opposing side surface of the second pair being exposed to the atmosphere, the light wave being confined in the end portion, a part of the light wave being absorbed in the light absorbing layer, and the predetermined component penetrating the end face to the target, and the predetermined component being reflected from the target and guided into the optical probe through the end face of the core; and

a sensing section configured to sense the predetermined component emerged from the probe.

19. An optical pick-up apparatus for searching a target with a predetermined optical component, comprising:

a light source configured to generate an light wave having the predetermined optical component;

an optical probe configured to guide an light wave in a predetermined propagating direction and outputting the predetermined component of the light wave to the target, including;

a core configured to transmit the light wave, having a first refractive index, comprising a base portion, and a end portion having a end face and first and second pairs of opposing side surfaces, the end portion being gradually diminished from the base portion to the end face, the opposing side surface of the first pair being inclined to each other and spaced apart in a first direction perpendicular to the predetermined direction, and the opposing side surface of the second pair being inclined to each other and spaced apart in a second direction perpendicular to the first direction and the predetermined propagating direction;

a light absorbing layer formed on the opposing side surface of the first pair; and

a transparent cladding layer having a second refractive index lower than the first refractive index of the core, and formed on the opposing side surface of the second pair, the light wave being confined in the end portion, a part of the light wave being absorbed in the light absorbing layer, and the predetermined component penetrating the end face to the target, and the predetermined component being reflected from the target and guided into the optical probe through the end face of the core; and

a sensing section configured to sense the predetermined component emerged from the probe.