Piezoelectric bi-morph mirror actuator

• US 4,280,756 A
• Filed: 01/02/1979
• Issued: 07/28/1981
• Est. Priority Date: 01/02/1979
• Status: Expired due to Term

• Current Assignee: Hughes Danbury Optical Systems Incorporated (Rtx Corporation)
• Original Assignee: Itek Corp (Northrop Grumman Corporation)
• Inventors: Albertinetti, Nedo P.
• Primary Examiner(s): Sikes, William L.
• Application Number:
  US06/000,217
• Time in Patent Office: 938 Days
• Field of Search: 350/360
• US Class Current: 359/295
• CPC Class Codes: G02B 26/06 for controlling the phase of light G02B26/08 takes precedence , measuring optical phase difference G01J9/00

Abstract

A piezoelectric wavefront modulator is disclosed having mirror actuators including a first and second layer of piezoelectric material, both internally polarized in a given direction, together with electrode means for increasing the internal electric field in one layer while decreasing the internal electric field in the other layer. As the layers are clamped to the modulator support elements at opposite edges, the degree of bending of the layers may be carefully controlled to cause pusher elements to actuate a mirror, which mirror is oriented parallel to the major surfaces of the top layer of piezoelectric material.

Claims

1. A piezoelectric wavefront modulator actuator comprising:

a. a first layer of a piezoelectric medium (1) internally polarized in a given direction and having a first and second surface;

b. a second layer of a piezoelectric medium (2) mechanically coupled to said first layer and having a first and second surface, also internally polarized in said given direction;

c. a plurality of electrodes (3, 7,

     9);

d. a mirror (16);

e. a driver (13) coupled between a centralized portion of said first layer and said mirror;

f. a variable voltage control source (4);

g. a support (18,

     19);

h. means (21,

     22) for clamping opposite non-centralized portions of said first and second layers to said support; and

i. means (6, 8,

     11) for electrically coupling said variable voltage control source to said a plurality of electodes for increasing the internal electric field in one layer while decreasing the internal electric field in the other layer for changing the degree of bending of said actuator, thereby to control the degree of displacement of said mirror.

9. A piezoelectric wavefront modulator comprising an array of said actuators of claims 1, 2, 3, 4, 5, 6, 7, or 8, coupled to a unitary mirror.

2. A piezoelectric wavefront modulator actuator comprising:

a. a first layer of a piezoelectric medium (1) internally polarized in a given direction and having a first and second surface;

b. a second layer of a piezoelectic medium (2) bonded to said first layer and having a first and second surface, also internally polarized in said given direction;

c. a first electrode (3) positioned between the inner facing first surfaces of said first and second layers of piezoelectric material;

d. a second electrode (7) coupled to the second surface of said first layer of piezoelectric material opposite said first surface thereof;

e. a third electrode (9) coupled to the second surface of said second layer of piezoelectric material opposite said first surface thereof;

f. a mirror (16);

g. driver means (13) coupled to said second electrode at a first terminal portion of said driver and coupled to said mirror at a second terminal portion of said driver opposite said first terminal portion;

h. a variable voltage control source (4);

i. a support (18,

     19);

j. means (21,

     22) for clamping opposite non-centralized portions of said first and second layers to said support; and

k. means (6, 8,

     11) for electrically coupling said variable voltage control source to said first, second and third electrodes for increasing the internal electric field in one layer while decreasing the internal electric field in the other layer for changing the degree of bending of said actuator, thereby to control the degree of displacement of said mirror.

3. The combination as set forth in claim 2, wherein said driver means is coupled to said second electrode at centralized portions thereof.

4. A piezoelectric wavefront modulator actuator comprising:

a. a first layer of a piezoelectric medium (1) internally polarized in a given direction and having a first and second surface;

b. a second layer of a piezoelectric medium (2) bonded to said first layer and having a first and second surface, also internally polarized in said given direction;

c. a first electrode (3) positioned between the inner facing first surfaces of said first and second layers of piezoelectric material;

d. a second electrode (7) coupled to the second surface of said first layer of piezoelectric material opposite said first surface thereof;

e. a third electrode (9) coupled to the second surface of said second layer of piezoelectric material opposite said first surface thereof;

f. a mirror (16) having surface portions substantially parallel to the surface portions of said first and second layers;

g. a mirror driver (13) coupled to said second electrode at a first terminal portion of said mirror driver and coupled to said mirror at a second terminal portion of said mirror driver opposite said first terminal portion;

h. a variable voltage control source (4) having a first and second output terminal;

i. a support (18,

     19);

j. means (21,

     22) for clamping opposite non-centralized portions of said first and second layers to said support; and

k. means (6, 8,

     11) for electrically coupling said variable voltage control source to said first, second and third electrodes for increasing the internal electric field in one layer while decreasing the internal electric field in the other layer for changing the degree of bending of said actuator, thereby to control the degree of displacement of said mirror.

5. The combination as set forth in claim 4, wherein said mirror driver is coupled to said second electrode at centralized portions thereof.

6. A piezoelectric wavefront modulator actuator comprising:

a. a first layer of a piezoelectric medium (1) internally polarized in a given direction and having a first and second surface;

b. a second layer of a piezoelectric medium (2) bonded to said first layer and having a first and second surface, also internally polarized in said given direction;

c. a first electrode (3) positioned between the inner facing first surfaces of said first and second layers of piezoelectric material;

d. a second electrode (7) coupled to the second surface of said first layer of piezoelectric material opposite said first surface thereof;

e. a third electrode (9) coupled to the second surface of said second layer of piezoelectric material opposite said first surface thereof;

f. a mirror (16) having surface portions substantially parallel to the major surface portions of said first and second layers;

g. a mirror driver (13) coupled to said second electrode at a first terminal portion of said mirror driver and coupled to said mirror at a second terminal portion of said mirror driver opposite said first terminal portion;

h. a variable voltage control source (4) having a first and second output terminal;

i. a support (18,

     19);

j. means (21,

     22) for clamping opposite non-centralized portions of said first and second layers to said support;

k. means (6, 8,

     11) for electrically coupling said first electrode to said first terminal of said variable voltage control source and for electrically coupling said second and third electrodes to said second terminal of said variable voltage control source, so that, as the voltage between said first electrode, and said second and third electrodes vary, the degree of displacement of said mirror will vary in response thereto.

7. The combination as set forth in claim 6, wherein said mirror driver is coupled to said second electrode at centralized portions thereof.

8. A piezoelectric wavefront modulator actuator comprising:

a. a first layer of a piezoelectric medium (1) internally polarized in a given direction and having a first and second surface;

b. a second layer of a piezoelectric medium (2) mechanically coupled to said first layer and having a first and second surface, also internally polarized in said given direction;

c. a mirror (16);

d. a driver (13) coupled between a centralized portion of said first layer and said mirror;

e. a support (18,

     19);

f. means (21,

     22) for clamping opposite non-centralized portions of said first and second layers to support; and

g. control means (4, 6, 8,

     11) for increasing the internal electric field in one layer while decreasing the internal electric field in the other layer for changing the degree of bending of said actuator, thereby to control the degree of displacement of said mirror.