Article comprising a reflection-type spectral equalizer/optical switch

• US 6,690,850 B1
• Filed: 06/05/2001
• Issued: 02/10/2004
• Est. Priority Date: 06/05/2001
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.), Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.), Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Greywall, Dennis S.
• Primary Examiner(s): LESTER, EVELYN A
• Application Number:
  US09/874,338
• Time in Patent Office: 980 Days
• Field of Search: 359/223, 359/224, 359/226, 359/290, 359/291, 359/298, 359/128, 385/17, 385/18, 385/14, 398/82
• US Class Current: 385/18
• CPC Class Codes: G02B 6/2931 Diffractive element operating in reflection
• CPC Class Codes: G02B 6/29391 Power equalisation of different channels, e.g. power flattening
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 6/3588 of the processed beams, i.e. controlling during switching of orientation, alignment, or beam propagation properties such as intensity, size or shape
• CPC Class Codes: G02B 6/3594 Characterised by additional functional means, e.g. means for variably attenuating or branching or means for switching differently polarized beams

Abstract

An array of movable reflective elements provides wavelength independent performance in spectral equalizers and other optical devices. Each movable reflective element comprises a reflective plate that is suspended by rod-like supports that have a width of less than 2 microns and as small as about 0.25 to 0.35 microns. Semiconductor processing techniques are used to form the rod-like supports. An improved spectral equalizer incorporates the array of movable reflective elements, a controller, collimating/focusing optics and a diffraction element that optically communicate in a free-space optics arrangement.

Claims

1. Article comprising:

a plurality of movable reflective elements, at least some of which receive an optical signal, wherein said optical signal received by each one of said some movable reflectve elements is different, wherein each of said reflecting elements comprises;

a plate having a reflective surface; and

a first rod support having a first end and a second end, wherein;

said first end of said first rod support depends from said plate;

said first rod support supports said plate for movement;

said first rod support has a width that is less than about 0.5 microns.

2. The article of claim 1, wherein said movable reflective elements further comprise a stress-relief member, wherein a second end of said first rod support is attached to said stress-relief member.

3. The article of claim 2 wherein said stress-relief member comprises a fist end and a second end, and wherein said stress-relief member is supported at said first end and said second end thereof, and further wherein said second end of said first rod support is attached to said stress relief member midway between said first end and said second end of said stress relief member.

4. The article of claim 3 wherein said first end of said first rod support depends from a first side of said plate;

and further comprising a second rod support having a first end and a second end, wherein said first end of said second rod support depends from a second side of said plate, and wherein said second rod support supports said plate for movement and has a width that is less than about 0.5 microns, and further wherein said first rod support and said second rod support collectively define an axis of rotation of said plate.

5. The article of claim 4 wherein said axis of rotation of said plate is aligned with a symmetry axis of said plate.

6. The article of claim 3 wherein a distance between said first end of said first rod support and said second end of said first rod support is less than about 10 microns.

7. The article of claim 6 wherein said each end of said stress relief member depends from a frame, and wherein a distance between said plate and said frame is less than about 2 microns.

8. The article of claim 6 wherein adjacent movable reflective elements are spaced from one another by about 1 micron.

9. The article of claim 4 further comprising a plurality of electrodes, wherein at least one said electrode is disposed beneath each said plate and is offset from said axis of rotation of each said plate.

10. The article of claim 1 further comprising a second rod support having a first end and a second end, wherein said first end of said second rod support depends from said plate, and wherein said second rod support supports said plate for movement and has a width that is less than about 0.5 microns, and further wherein:

a second end of said first rod support and a second end of said second rod support are attached to a frame;

said first rod support and said second rod support collectively define an axis of rotation of said plate; and

said axis of rotation is near a side of said plate.

11. The article of claim 10 further comprising a plurality of electrodes, wherein at least one said electrode is disposed beneath each said plate and is offset from said axis of rotation of each said plate.

12. The article of claim 11 wherein a distance between said first end of said first rod support and said second end of said first rod is less tan about 10 microns.

13. The article of claim 1 wherein said different optical signal received by each of said some movable reflective elements has a different center wavelength.

14. The article of claim 13 further comprising a diffraction element that spatially separates a multiplexed optical signal into a plurality of spectral components, each of which is directed along a separate optical path to be received by one of said movable reflective elements as said received optical signal.

15. The article of claim 14 further comprising optics, wherein:

said multiplexed optical signal is delivered, via a waveguide, to said optics;

said optics collimates said multiplexed optical signal;

said diffraction element receives said collimated multiplexed optical signal;

said optics receive said plurality of spectral components from said diffractioln element and directs each to a different one of said movable reflective elements, each of which movable reflective elements reflects said spectral components;

said optics receive said reflected spectral components and collimates them;

said difraction element receives said collimated spectral components and remultiplexes them into a second multiplexed optical signal;

said optics receives said second multiplexed optical signal and directs it to said waveguide.

16. The article of claim 15 wherein at least one of said movable reflective elements is moved about an axis of rotation from a first position to a second position to selectively attenuate at least one of said spectral components, wherein said second position is individually selected for each said movable reflective element, and wherein:

at said first position, said one spectral component is received by said movable reflective element at a first angle of incidence such that, upon reflection, said one spectral component is received by said waveguide along an optical axis thereof; and

at said second position, said one spectral component is received by said movable reflective element a second angle of incidence such that, upon reflection, said one spectral component is received by said waveguide at a non-zero angle with respect to said optical axis thereby coupling only a portion of said one spectral component'"'"'s power into said waveguide.

17. The article of claim 1, wherein said width of said rod-support is within a range of about 0.25 to about 0.35 microns.

18. A method comprising:

forming electrodes in a first substrate;

forming a spacer on the first substrate;

forming movable reflective elements in a second substrate using a semiconductor processing techniques, said movable reflective elements comprising;

a feature having a width that is less than about 0.5 microns; and

attaching said second substrate to said first substrate so that the movable reflective elements are proximal to said electrodes.

19. The method of claim 18 wherein said first substrate comprises three layers.

20. The method of claim 18 wherein said second substrate comprises three layers.

21. The method of claim 20 wherein said feature comprises a rod support.

22. The method of claim 21 wherein said feature further comprise a stress relief member.