Integrated-optic waveguide devices and method

• US 5,278,925 A
• Filed: 04/13/1993
• Issued: 01/11/1994
• Est. Priority Date: 03/28/1991
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Magel, Gregory A., Boysel, Robert M.
• Primary Examiner(s): Gonzalez, Frank
• Assistant Examiner(s): BARNS, STEPHEN
• Application Number:
  US08/046,530
• Time in Patent Office: 273 Days
• Field of Search: 385/14, 385/140, 385/1, 385/2, 385/4, 385/7, 385/8, 385/16, 14/129-132
• US Class Current: 385/14
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02F 1/011 in optical waveguides, not otherwise provided for in this subclass
• CPC Class Codes: G02F 1/0142 TE-TM mode conversion
• CPC Class Codes: G02F 1/3132 of directional coupler type
• CPC Class Codes: G02F 2201/06 integrated waveguide
• CPC Class Codes: G02F 2203/07 Polarisation dependent
• CPC Class Codes: G02F 2203/22 diffractive

Abstract

It is possible to utilize changes in the complex effective refractive index caused by bringing a metal membrane in close proximity to the core of an optical waveguide to form many devices. The invention described herein provides structures and processes that do so, the structure comprising a substrate, a lower cladding, a waveguide core, a removable upper cladding which supports a metal membrane, and an electrode for deflecting said membrane.

Switchable devices using this structure include, but are not limited to, polarizers, mode converters, optical switches, Bragg devices, directional couplers and channel waveguides.

Claims

1. An integrated-optic device comprising:

a. a lower cladding layer;

b. at least one electrode located under or upon a portion of said lower cladding so as to electrostatically deflect a membrane;

c. a core layer of material with a higher index of refraction than said lower cladding upon said lower cladding;

d. an upper cladding layer with a lower index of refraction than said core layer formed upon said core layer, said upper cladding being selectively removable; and

e. a metal layer upon said upper cladding layer, wherein said metal layer has access holes for said selected removal of said upper cladding layer, said metal layer only supported at the edges.

2. The device of claim 1 wherein said lower cladding layer is a substrate.

3. The device of claim 1 wherein said lower cladding is of a different material than said substrate.

4. The device of claim 1 wherein said upper cladding is only partially removed, so said membrane is supported by remaining upper cladding.

5. The device of claim 1 wherein said metal layer forms supports, thereby allowing all of said upper cladding to be removed, so said metal layer is supported by metal.

6. The device of claim 1 wherein said core contains a channel waveguide traversing its length.

7. The device of claim 6 wherein said device constitutes an on/off switch.

8. The device of claim 6 wherein said upper cladding is removed with varying lateral extent along the length such that the width of the area where the spacer is removed is larger at one end of the device than at the other.

9. The device of claim 8 wherein said device constitutes a variable attenuator.

10. The device of claim 8 wherein said device constitutes an adjustable polarizer.

11. The device of claim 6 wherein said device constitutes a switchable polarizer.

12. The device of claim 1 wherein said core contains two channel waveguides traversing its length such that said waveguides come into close proximity to one another within the length of the device.

13. The device of claim 12 wherein said device constitutes a switchable directional coupler.

14. The device of claim 1 wherein said device also contains a buffer layer of lower refractive index than the core layer upon said core layer.

15. The device of claim 1 wherein said device constitutes an on/off switch.

16. The device of claim 1 wherein said upper cladding is removed with varying lateral extent along the length such that the width of the area where the spacer is removed is larger at one end of the device than at the other.

17. The device of claim 16 wherein said device constitutes a variable attenuator.

18. The device of claim 16 wherein said device constitutes an adjustable polarizer.

19. The device of claim 1 wherein said device constitutes a switchable polarizer.

20. The device of claim 1 wherein said core has a periodic spatial modulation of the effective refractive index.

21. The device of claim 20 wherein said device constitutes a switchable mode converter.

22. The device of claim 20 wherein said device constitutes a switchable Bragg reflector.

23. The device of claim 1 wherein there are a plurality of said electrodes, and wherein said metal layer is supported in such as manner as to form a series of membrane devices which are operable simultaneously to constitute a periodic spatial modulation of the effective refractive index.

24. The device of claim 23 wherein said device constitutes a switchable mode converter.

25. The device of claim 23 wherein said device constitutes a switchable Bragg reflector.