Light waveguide lens

• US 4,856,861 A
• Filed: 06/04/1987
• Issued: 08/15/1989
• Est. Priority Date: 08/03/1983
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ogura, Shigetaro, Matsumoto, Kazuya, Miyawaki, Mamoru
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Wise, Robert E.
• Application Number:
  US07/058,603
• Time in Patent Office: 803 Days
• Field of Search: 350/96.14, 350/96.18, 350/96.11, 350/96.13
• US Class Current: 385/129
• CPC Class Codes: G02B 6/1245 Geodesic lenses
• CPC Class Codes: G02F 1/0147 based on thermo-optic effects G02F1/132 takes precedence
• CPC Class Codes: G02F 1/0154 using electro-optic effects, e.g. linear electro optic [LEO], Pockels, quadratic electro optical [QEO] or Kerr effect
• CPC Class Codes: G02F 1/025 in an optical waveguide structure G02F1/017, G02F1/2257 take precedence
• CPC Class Codes: G02F 1/035 in an optical waveguide structure
• CPC Class Codes: G02F 1/055 the active material being a ceramic G02F1/035 takes precedence
• CPC Class Codes: G02F 1/295 Analog deflection from or in an optical waveguide structure]
• CPC Class Codes: G02F 2203/28 focussing or defocussing

Abstract

In a light waveguide lens comprises a light waveguide and a lens portion provided in a portion of the light waveguide, the refractive index of the light waveguide and/or the lens portion is variable to vary the focal length of the lens portion, thereby causing the waveguide light to be accurately converged at a predetermined position.

Claims

1. A light waveguide lens comprising:

a light waveguide;

a lens portion provided in a portion of said light waveguide, said lens portion having a finite focal distance; and

a thermoelectric converting element provided in proximity of at least one of said light waveguide and said lens portion, said converting element reversibly varying the refractive index of at least one of said light waveguide and said lens portion by varying the temperature thereof and thereby reversibly varying the focal length of said lens portion.

2. A light waveguide lens according to claim I, wherein said thermoelectric converting element comprises a heating electrode.

3. A light waveguide lens according to claim 2, wherein a buffer layer for preventing the absorption of waveguide light by said heating electrode is provided between said heating electrode and said at least one of said light waveguide and said lens portion.

4. A light waveguide lens according to claim 2, wherein said lens portion has an overlay provided on said light waveguide, and said heating electrode is formed on said overlay.

5. A light waveguide lens according to claim 2, wherein said heating electrode is provided on a substrate, and said light waveguide is formed on said heating electrode.

6. A light waveguide lens according to claim 5, wherein said heating electrode is formed of a film of HFB₂.

7. A light waveguide lens comprising:

a light waveguide;

a lens portion composed of an overlay made of electro-optic material having a higher refractive index than that of said light waveguide and formed on a part of said light waveguide;

a first electrode provided between said light waveguide and said overlay;

a second electrode provided on said overlay; and

means for reversibly varying the refractive index of said overlay by generating an electric field between said first and second electrodes to reversibly vary the focal length of said lens portion.

8. A light waveguide lens according to claim 7, wherein buffer layers are respectively provided between said overlay and said first electrode and between said overlay and said second electrode, said buffer layers having a lower refractive index than that of said overlay.