MEMS membrane with integral mirror/lens

• US 6,768,756 B2
• Filed: 03/12/2001
• Issued: 07/27/2004
• Est. Priority Date: 03/12/2001
• Status: Expired due to Term

• Current Assignee: Excelitas Technologies Corporation (Excelitas Technologies Holdings LLC)
• Original Assignee: Axsun Technologies Incorporated
• Inventors: Flanders, Dale C., Nagle, Steven F., Stern, Margaret B.
• Primary Examiner(s): Jackson, Jerome
• Assistant Examiner(s): NGUYEN, JOSEPH H
• Application Number:
  US09/804,618
• Publication Number:
  US 20020126726A1
• Time in Patent Office: 1,233 Days
• Field of Search: 372/43, 372/75, 372/29.022, 372/99, 372/101, 372/107, 359/579, 365/215
• US Class Current: 372/43.01
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0875 by means of one or more refracting elements
• CPC Class Codes: G02B 5/1828 having means for producing variable diffraction controlling the direction of light by means of one or more diffracting elements G02B26/0808; acousto-optical elements G02F1/11, G02F1/33; electro- or magneto-optical diffraction G02F1/292, G02F1/2955

Abstract

An optical membrane device and method for making such a device are described. This membrane is notable in that it comprises an optically curved surface. In some embodiments, this curved optical surface is optically concave and coated, for example, with a highly reflecting (HR) coating to create a curved mirror. In other embodiments, the optical surface is optically convex and coated with, preferably, an antireflective (AR) coating to function as a refractive or diffractive lens.

Claims

1. An optical membrane device comprising

a support;

a device layer in which a deflectable membrane structure is formed;

a sacrificial layer separating the support from the device layer, the sacrificial layer being selectively removed to release the membrane structure; and

an optically curved surface on the deflectable membrane and on an optical axis of the optical membrane device.

2. An optical membrane device as claimed in claim 1, wherein the optical surface is formed in an optical element layer that is deposited on the device layer.

3. An optical membrane device as claimed in claim 1, wherein the optical surface is etched into the device layer.

4. An optical membrane device as claimed in claim 1, wherein the optical surface is a concave surface that is formed into the device layer.

5. An optical membrane device as claimed in claim 1, wherein the optical surface is a convex surface that is etched into the device layer.

6. An optical membrane device as claimed in claim 5, wherein the sacrificial layer defines an electrical cavity across which electrical fields are established to deflect the membrane structure in a direction of the support.

7. An optical membrane device as claimed in claim 6, wherein the membrane structure comprises:

a center body portion;

an outer portion, which is at least partially supported by the sacrificial layer; and

tethers that extend between the center body portion and the outer portion.

8. An optical membrane device as claimed in claim 1, wherein the sacrificial layer defines an electrical cavity across which electrical fields are established to deflect the membrane structure in a direction of the support.

9. An optical membrane device as claimed in claim 1, wherein the membrane structure comprises:

a center body portion;

an outer portion, which is at least partially supported by the sacrificial layer; and

tethers that extend between the center body portion and the outer portion.

10. An optical membrane device as claimed in claim 1, further comprising an optical coating deposited over the optical surface.

11. An optical membrane device as claimed in claim 10, wherein the optical coating is multilayer dielectric mirror.

12. An optical membrane device as claimed in claim 10, wherein the optical coating is an antireflective coating.

13. An optical membrane device as claimed in claim 1, wherein the optically curved surface of the deflectable membrane is centered on the optical axis of the optical membrane device.

14. An optical membrane device as claimed in claim 1, wherein the optically curved surface of the deflectable membrane is centered on the deflectable membrane.