Blazed grating light valve

• US 6,829,092 B2
• Filed: 08/15/2001
• Issued: 12/07/2004
• Est. Priority Date: 08/15/2001
• Status: Expired due to Term

• Current Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Original Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Inventors: Maheshwari, Dinesh, Trisnadi, Jahja, Gudeman, Christopher, Amm, David T., Hunter, James
• Primary Examiner(s): Juba, Jr., John
• Application Number:
  US09/930,838
• Publication Number:
  US 20030035215A1
• Time in Patent Office: 1,210 Days
• Field of Search: 359/573, 359/578, 359/290, 359/291, 359/295
• US Class Current: 359/573
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements

Abstract

A light modulator includes elongated elements arranged parallel to each other. In a first diffraction mode, the light modulator operates to diffract an incident light into at least two diffraction orders. In a second diffraction mode, the light modulator operates to diffract the incident light into a single diffraction order. Each of the elongated elements comprises a blaze profile, which preferably comprises a reflective stepped profile across a width of each of the elongated elements and which produces an effective blaze at a blaze angle. Alternatively, the blaze profile comprises a reflective surface angled at the blaze angle. Each of selected ones of the elongated elements comprise a first conductive element. The elongated elements produce the first diffraction when a first electrical bias is applied between the first conductive elements and a substrate. A relative height of the blazed portions are adjusted to produce the second diffraction when a second electrical bias is applied between the first conductive elements and the substrate. In an alternative embodiment, each of the elongated elements includes the first conductive element and multiple elongated elements are arranged in groupings, where each of the groupings includes at least three of the elongated elements. When the multiple elongated elements are at a first height, the incident light reflects from the elongated elements. When relative heights of the multiple elongated elements are adjusted by applying individual electrical biases between the first conductive elements and the substrate, the incident light diffracts into the single diffraction order.

Claims

1. A light modulator comprising:

a. elongated elements arranged parallel to each other and configured in a grating plane, each elongated element comprising a reflective surface such that in operation an incident light diffracts into at least two diffraction orders; and

b. means for adjusting a height of selected ones of the elongated elements relative to the grating plane such that in operation the incident light diffracts into a single non-zero diffraction order different than the at least two diffraction orders.

2. The light modulator of claim 1 wherein the means for adjusting the height of the selected ones of the elongated elements comprise:

a. a first conductive element along at least a portion of each of the selected ones of the elongated elements; and

b. a substrate coupled to the elongated elements, the substrate comprising a second conductive element such that an electrical bias applied between the first conductive elements and the second conductive element adjusts the height of the selected ones of the elongated elements.

3. The light modulator of claim 2 further comprising first and second posts, the first and second posts coupling the elongated elements to the substrate.

4. The light modulator of claim 1 wherein the selected ones of the elongated elements comprise every other ones of the elongated elements.

5. The light modulator of claim 1 wherein the reflective surfaces of each of the elongated elements comprise a blaze profile.

6. The light modulator of claim 5 wherein the blaze profile comprises at least two planar surfaces.

7. The light modulator of claim 6 wherein the two planar surfaces comprise planes parallel to the grating plane.

8. The light modulator of claim 5 wherein the reflective surface of the blaze profile comprises a single planar surface at a blaze angle with respect to the grating plane.

9. The light modulator of claim 1 wherein two times a width of each of the elongated elements comprises a grating pitch.

10. The light modulator of claim 9 wherein the at least two diffraction orders comprise a zeroth order diffraction and one of a plus or minus second order diffraction.

11. The light modulator of claim 10 wherein the single diffraction order comprises a first order diffraction.

12. A light modulator comprising:

a. elongated elements arranged parallel to each other and configured in a grating plane, each of selected ones of the elongated elements comprising a first conductive element each elongated element comprising a reflective surface such that in operation an incident light diffracts into at least two diffraction orders; and

b. a substrate coupled to the elongated elements and comprising a second conductive element such that in operation an electrical bias applied between the first conductive elements and the second conductive element adjusts a height of the selected ones of the elongated elements relative to the grating plane and further such that in operation the incident light diffracts into a single non-zero diffraction order different than the at least two diffraction orders.

13. A light modulator comprising:

a. elongated elements arranged parallel to each other in a grating plane, each elongated element comprising a blaze profile, each blaze profile comprising a reflective surface, each of selected ones of the elongated elements comprising a first conductive element along the blaze profile, the blaze profile comprising at least two planar surfaces, the two planar surfaces comprising planes parallel to the grating plane such that in operation an incident light diffracts into at least two diffraction orders; and

b. a substrate coupled to the elongated elements, the substrate comprising a second conductive element such that, when an electrical bias applied between the first conductive elements and the second conductive element adjusts a height of the selected ones of the elongated elements, the incident light diffracts into a single non-zero diffraction order different than the at least two diffraction orders.

14. A light modulator comprising:

a. means for diffracting an incident light into at least two diffraction orders; and

b. means for adjusting the means for diffracting such that the incident light diffracts into a single non-zero diffraction order different than the at least two diffraction orders.

15. A light modulator comprising:

a. elongated elements arranged parallel to each other and dynamically configurable into one of a plurality of group configurations of the elongated elements, each elongated element comprising a reflective surface such that in operation an incident light illuminating the elongated elements produces a reflected light when the elongated elements are at a first height, each group configuration comprises a different number of at least three elongated elements within the group configuration, and the light modulator is configured according to a single group configuration at a time; and

b. means for adjusting a relative height of the elongated elements of each of the groupings such that in operation the incident light illuminating the elongated elements produces a single diffraction order selectable between a first diffraction angle and minus the first diffraction angle.

16. The light modulator of claim 15 wherein the means for adjusting the relative heights of the elongated elements of the groupings of the elongated elements comprises:

a. first conductive elements along at least a portion of the elongated elements; and

b. a substrate coupled to the elongated elements and comprising a second conductive element such that in operation the relative heights of the elongated elements of each of the groupings are adjusted by applying individual electrical biases between the first conductive elements of the grouping and the second conductive element.

17. The light modulator of claim 16 wherein the reflective surfaces of the elongated elements comprises a metal and further wherein the metal comprises the first conductive elements.

18. The light modulator of claim 15 wherein the groupings of the elongated groupings comprise variable groupings of the elongated elements such that in operation first groupings of three of the elongated elements produce the single diffraction order at a first diffraction angle and further such that second groupings of four of the elongated elements produce the single diffraction order at a second diffraction angle.

19. A light modulator comprising:

a. elongated elements arranged parallel to each other and configured into one of a plurality of group configurations of the elongated elements, each elongated element comprising a reflective surface and a first conductive element, each group configuration comprising a different number of at least three elongated elements within the group configuration, and the light modulator is configured according to a single group configuration at a time; and

b. a substrate coupled to the elongated elements, the substrate comprising a second conductive element such that in operation an incident light illuminating the elongated elements produces a reflected light when the elongated elements are at a first height and further such that in operation a relative height of the elongated elements of each grouping are adjusted to produce a single diffraction order when individually varying electrical biases are applied between the first conductive elements of each of the groupings and the second conductive element, wherein the single diffraction order is selectable between a first diffraction angle and minus the first diffraction angle.

20. A light modulator comprising:

a. means for reflecting an incident light including a number of elongated elements; and

b. means for adjusting the means for reflecting such that the incident light diffracts into a single diffraction order selectable between a first diffraction angle and minus the first diffraction angle, wherein the first diffraction angle is variable according to the means for adjusting by changing the number of elongated elements within an elongated element group to form a new elongated element group configuration.