Chirped optical MEM device

• US 6,934,070 B1
• Filed: 12/18/2002
• Issued: 08/23/2005
• Est. Priority Date: 12/18/2002
• Status: Active Grant

• Current Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Original Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Inventors: Trisnadi, Jahia, Maheshwari, Dinesh, Corrigan, Robert W.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): THOMAS, BRANDI N
• Application Number:
  US10/323,008
• Time in Patent Office: 979 Days
• Field of Search: 359/290, 359/291, 359/295, 359/231, 359/292, 359/572, 359/573, 359/130, 359/563, 359/566, 359/237, 359/124, 359/298, 359/238, 347/255, 347/239, 347/241, 347/256
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements

Abstract

A light modulator comprises a series of ribbons divided by a series of gaps. Sequences of consecutive ribbons and gaps are grouped together to form a plurality of pixels that are configured to process a respective plurality of wavelengths. The spacing from center-line to center-line of adjacent pixels is progressively increased from a reference pixel to align component pixels with their assigned wavelengths. The widths of ribbons and gaps within a particular pixel affect the polarization dependent loss of a pixel, and affect the first order diffraction angle. Ribbon widths and gap widths within successive pixels are altered to normalize polarization dependent loss and first order diffraction angles against the values associated with a reference pixel.

Claims

1. A light modulator comprising a plurality of ribbons separated by a plurality of gaps, wherein the plurality of ribbons and gaps are grouped into a plurality of pixels in a linear order in the light modulator including a first end pixel and a second end pixel, wherein the plurality of pixels are disposed in succession between the first end pixel and the second end pixel, further wherein a pixel-center separation distance between adjacent pixels is progressively increased as the linear order is transversed from the first end pixel to the second end pixel, the pixel-center separation distance comprising a distance from a center line of a first pixel to a center line of a second pixel adjacent to the first pixel.

2. The light modulator according to claim 1 wherein the pixel-center separation distances are spaced such that a center line of a pixel approximately coincides with a center line of an intensity distribution of a respective incident wavelength impinging upon the pixel.

3. The light modulator according to claim 2 wherein a spacing between center lines of respective incident wavelengths impinging upon adjacent pixels is created by a wavelength division multiplexed signal passing through a static grating.

4. The light modulator according to claim 2 wherein each pixel is separated from an adjacent pixel by a pixel gap such that a pixel gap width of each pixel gap progressively increases from the first end pixel to the second end pixel to cause each pixel center line to approximately coincide with the center line of the intensity distribution of the respective incident wavelength.

5. The light modulator according to claim 4 wherein each pixel includes a pixel width symmetrically aligned about the center line of the pixel such that the pixel width increases from the first end pixel to the second end pixel.

6. The light modulator according to claim 5 wherein the pixel width of the second pixel is equal to a pixel-center separation distance between the second pixel and the first pixel.

7. The light modulator according to claim 5 wherein the pixel width of the second pixel is equal to one-half a pixel-center separation distance between a third pixel and the first pixel, wherein the third pixel is adjacent to the second pixel in the linear order.

8. The light modulator according to claim 5 wherein a ribbon width for all ribbons within the same pixel is constant, a ribbon gap width for all ribbon gaps within the same pixel is constant, and the ribbon width linearly increases from the first end pixel to the second end pixel while the ribbon gap width remains constant.

9. The light modulator according to claim 5 wherein a ribbon width for all ribbons within the same pixel is constant, a ribbon gap width for all ribbons within the same pixel is constant, and the ribbon gap width linearly increases from the first end pixel to the second end pixel while the ribbon width remains constant.

10. The light modulator according to claim 5 wherein a ribbon width for all ribbons within the same pixel is constant, a ribbon gap width for all ribbon gaps within the same pixel is constant, and the ribbon gap width and the ribbon width linearly increase from the last end pixel to the second end pixel.

11. The light modulator according to claim 5 wherein the pixel width is increased by varying the number of ribbons within each pixel.

12. The light modulator according to claim 4 wherein each pixel further comprises a pixel width symmetrically aligned about the center line of the pixel such that the pixel width for the plurality of pixels is constant.

13. The light modulator according to claim 2 wherein each pair of pixels are separated by a pixel gap such that a pixel gap width of each pixel gap is constant, further wherein each pixel comprises a pixel width symmetrically aligned about the center line of the pixel such that the pixel width progressively increases from the first end pixel to the second end pixel to approximately coincide each pixel center line with the center line of the intensity distribution of the respective incident wavelength.

14. The light modulator according to claim 1 wherein each pixel includes a pixel width symmetrically aligned about the center line of the pixel such that the pixel width increases from the first end pixel to the second end pixel.

15. The light modulator according to claim 14 wherein a ribbon width for all ribbons within the same pixel is constant, a ribbon gap width for all ribbon gaps within the same pixel is constant, and the ribbon gap width and the ribbon width linearly increase from the first end pixel to the second end pixel.

16. The light modulator according to claim 14 wherein a ribbon width for all ribbons within the same pixel is constant, a ribbon gap width for all ribbon gaps within the same pixel is constant, and the ribbon width linearly increases from the first end pixel to the second end pixel while the ribbon gap width remains constant.

17. The light modulator according to claim 14 wherein a ribbon width for all ribbons within the same pixel is constant, a ribbon gap width for all ribbons within the same pixel is constant, and the ribbon gap width linearly increases from the first end pixel to the second end pixel while the ribbon width remains constant.

18. A method of aligning a plurality of incident wavelengths with a plurality of pixels in a linear order in a light modulator, the method comprising the step of aligning a center line of each of the plurality of pixels in the linear order to conform to a center line of an intensity distribution of a corresponding one of the plurality of incident wavelengths, wherein a pixel-center separation distance between adjacent pixels is increased with increasing incident wavelength, the pixel-center separation distance comprising a distance from a center line of a first pixel to a center line of a second pixel adjacent to the first pixel.

19. The method according to claim 18 wherein each of the plurality of pixels is separated from an adjacent pixel by a pixel gap comprising a pixel gap width, and the step of aligning comprises configuring a plurality of pixel gap widths such that the plurality of pixels are aligned with their corresponding plurality of incident wavelengths.

20. The method according to claim 18 wherein each of the plurality of pixels includes a plurality of ribbons each comprising a ribbon width, and the step of aligning comprises configuring a plurality of ribbon widths such that the plurality of pixels are aligned with their corresponding plurality of incident wavelengths.

21. The method according to claim 18 wherein each of the plurality of pixels includes a plurality of ribbons, each ribbon within a pixel separated by a ribbon gap comprising a ribbon gap width, and the step of aligning comprises configuring a plurality of ribbon gap widths such that the plurality of pixels are aligned with their corresponding plurality of incident wavelengths.

22. A method of aligning a plurality of incident wavelengths with a plurality of pixels in a light modulator, the method comprising the step of aligning a center line of each of the plurality of pixels to conform to a center line intensity of a corresponding one of the plurality of incident wavelengths, wherein a pixel-center separation distance between adjacent pixels is increased with increasing incident wavelength, the pixel-center separation distance comprising a distance from a center line of a first pixel to a center line of a second pixel adjacent to the first pixel, further comprising the step of normalizing polarization dependent loss among the plurality of pixels according to a reference pixel within the plurality of pixels, wherein the step of normalizing polarization dependent loss comprises the step of adjusting select parameters in a first pixel according to the wavelength assigned to the first pixel such that the polarization dependent loss exhibited by the first pixel is substantially equal to the polarization dependent loss exhibited by the reference pixel.

23. The method according to claim 22 wherein each of the plurality of pixels is configured to produce a first order diffraction pattern oriented according to a first order diffraction angle when a pixel is in a diffraction mode, wherein the method further comprising the step of normalizing a plurality of first order diffraction angles produced among the plurality of pixels against a first order diffraction angle produced by the reference pixel.

24. A method of normalizing polarization dependent loss among a plurality of pixels in a light modulator against a reference pixel, wherein the plurality of pixels are configured to process a plurality of wavelengths, the method comprising the step of adjusting select parameters in a first pixel according to the wavelength assigned to the first pixel such that the polarization dependent loss exhibited by the first pixel is substantially equal to the polarization dependent loss exhibited by the reference pixel.

25. The method according to claim 24 wherein the select parameters include a ribbon width and a ribbon gap width of a gap between ribbons comprising a same pixel.

26. The method according to claim 24 wherein each of the plurality of pixels is configured to produce a first order diffraction pattern oriented according to a first order diffraction angle when a pixel is in a diffraction mode, the method further comprising the step of normalizing a plurality of first order diffraction angles produced among the plurality of pixels against a first order diffraction angle produced by the reference pixel.

27. A method of normalizing the first order diffraction angles among a plurality of pixels in a light modulator against a reference pixel, wherein the plurality of pixels are configured to process a plurality of wavelengths, the method comprising the step of adjusting select parameters in a first pixel according to the wavelength assigned to the first pixel such that the first order diffraction angle exhibited by the first pixel is substantially equal to the first order diffraction angle exhibited by the reference pixel.

28. The method according to claim 27 wherein the select parameters include a ribbon width of each ribbon within a pixel and a ribbon gap width of each gap between ribbons within the pixel.

29. A light modulator comprising:

a. means for directing each of a plurality of wavelengths onto a corresponding pixel among a plurality of pixels in a linear order within a light modulator; and

b. means for aligning a center line of each of the plurality of pixels to conform to a center line of an intensity distribution of a corresponding one of the plurality of incident wavelengths, wherein a pixel-center separation distance between adjacent pixels is increased with increasing incident wavelength, the pixel-center separation distance comprising a distance from a center line of a first pixel to a center line of a second pixel adjacent to the first pixel.