Optical coupler sensor with movable optical waveguide

• US 5,787,212 A
• Filed: 06/28/1996
• Issued: 07/28/1998
• Est. Priority Date: 06/28/1995
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures Holding 81 LLC (Intellectual Ventures LLC)
• Original Assignee: Korea Advanced Institute of Science and Technology
• Inventors: Hong, Song-Cheol, Ha, Doo-Young
• Primary Examiner(s): Ullah, Akm E.
• Application Number:
  US08/669,789
• Time in Patent Office: 760 Days
• Field of Search: 385/13, 385/141, 385/16, 250/227.27, 250/227.19, 250/234, 356/358, 356/345
• US Class Current: 385/13
• CPC Class Codes: G01D 5/268 using optical fibres G01D5/28 - G01D5/38 take precedence
• CPC Class Codes: G01G 3/125 wherein the weighing element is an optical member
• CPC Class Codes: G01H 9/004 using fibre optic sensors light guides per se G02B6/00, acousto-optical devices specially adapted for gating or modulating in optical wave guides G02F1/125
• CPC Class Codes: G01P 15/093 by photoelectric pick-up
• CPC Class Codes: G01Q 20/02 by optical means
• CPC Class Codes: G01Q 20/04 Self-detecting probes, i.e. wherein the probe itself generates a signal representative of its position, e.g. piezoelectric gauge
• CPC Class Codes: G02B 6/3508 Lateral or transverse displacement of the whole waveguides, e.g. by varying the distance between opposed waveguide ends, or by mutual lateral displacement of opposed waveguide ends
• CPC Class Codes: G02B 6/3536 involving evanescent coupling variation, e.g. by a moving element such as a membrane which changes the effective refractive index mode converters G02B6/14; adjustable lateral coupling between waveguides G02B6/283; electro- optical refractive index variations G02F1/0118
• CPC Class Codes: G02B 6/3552 1x1 switch, e.g. on/off switch
• CPC Class Codes: G02B 6/3566 involving bending a beam, e.g. with cantilever
• CPC Class Codes: G02B 6/3594 Characterised by additional functional means, e.g. means for variably attenuating or branching or means for switching differently polarized beams

Abstract

The present invention relates to an optical coupler sensor employing a fixed optical waveguide and a movable optical waveguide which allows detection of every small physical quantities and their changes with a high sensitivity, and a process for preparing the same. The optical coupler sensor of the present invention comprises: a fixed optical waveguide formed on a substrate and disposed along a predetermined path. A movable optical waveguide is linked to a cantilever formed on the substrate, which is moved up and down by an external force. The moveable waveguide is disposed outside of the predetermined path.

Claims

1. A process for fabrication of the optical coupler sensor which comprises the steps of:

(i) formation of a core layer on the cladding layer on which a substrate is formed;

(ii) formation of a fixed optical waveguide by etching of the core layer;

(iii) formation of a support layer on the core layer;

(iv) formation of a cantilever and a movable optical waveguide linked thereto on the support layer; and

,

(v) formation of a cantilever support board by selective etching of the support layer.

2. The process for fabrication of the optical coupler sensor of claim 1 wherein Si is employed as the support layer, and SiO₂ is employed as the cantilever, optical waveguides and cladding layer, respectively.

3. The process for fabrication of the optical coupler sensor of claim 1 wherein GaAs is employed as the support layer, and AlGaAs is employed as the cantilever, optical waveguides and cladding layer, respectively.

4. An optical coupler sensor where incident light is propagated along a predetermined path to cause optical coupling, said sensor comprising:

a fixed optical waveguide formed on a substrate and disposed along said predetermined path along which incidence, propagation, and transmission of light is carried out; and

a movable optical waveguide linked to a cantilever formed on the substrate which is moved up and down by an external force, said movable waveguide being disposed outside of said predetermined path.

5. The optical coupler of claim 4 which further comprises a tip on the movable optical waveguide for the detection of bent areas on the surface of the material.

6. The optical coupler of claim 4 which further comprises a high mass of material evaporated on the movable optical waveguide for the determination of acceleration and universal gravitation of the material.

7. The optical coupler of claim 4 which further includes a bimetallic element formed on the movable optical waveguide for the determination of temperature changes in a material.

8. The optical coupler sensor of claim 4 wherein:

said movable optical waveguide is disposed above said fixed optical waveguide.