Photonic mems and structures

• US 6,650,455 B2
• Filed: 11/13/2001
• Issued: 11/18/2003
• Est. Priority Date: 05/05/1994
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Iridigm Display Corporation (Qualcomm, Inc.)
• Inventors: Miles, Mark W.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): Hasan, M.
• Application Number:
  US10/012,092
• Publication Number:
  US 20020054424A1
• Time in Patent Office: 735 Days
• Field of Search: 359/290, 359/291, 359/260, 359/237, 359/584, 359/585, 359/245, 359/248, 359/577, 356/480, 356/506, 356/519
• US Class Current: 359/237
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01J 3/0256 Compact construction
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G01L 5/0047 measuring forces due to residual stresses
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 2006/12109 Filter
• CPC Class Codes: G02B 2006/12126 Light absorber
• CPC Class Codes: G02B 2006/12159 Interferometer
• CPC Class Codes: G02B 2006/12164 Multiplexing; Demultiplexing
• 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 26/08 for controlling the direction of light in light guides G02B6/35
• 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 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/1225 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: G02B 6/13 Integrated optical circuits characterised by the manufacturing method
• CPC Class Codes: G02B 6/266 the optical element being an attenuator
• CPC Class Codes: G02B 6/3536 involving evanescent coupling variation, e.g. by a moving element such as a membrane which changes the effective refractive index mode converters G02B6/14; adjustable lateral coupling between waveguides G02B6/283; electro- optical refractive index variations G02F1/0118
• CPC Class Codes: G02B 6/357 : Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3578 : Piezoelectric force piezoelectric forces controlling reflecting elements in general G02B26/0858; piezo-optic devices G02F1/0131
• 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 6/43 : Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: G09G 2310/02 : Addressing, scanning or driving the display screen or processing steps related thereto
• CPC Class Codes: G09G 2310/06 : Details of flat display driving waveforms
• CPC Class Codes: G09G 3/3466 : based on interferometric effect

Abstract

An interference modulator (Imod) incorporates anti-reflection coatings and/or micro-fabricated supplemental lighting sources. An efficient drive scheme is provided for matrix addressed arrays of IMods or other micromechanical devices. An improved color scheme provides greater flexibility. Electronic hardware can be field reconfigured to accommodate different display formats and/or application functions. An IMod'"'"'s electromechanical behavior can be decoupled from its optical behavior. An improved actuation means is provided, some one of which may be hidden from view. An IMod or IMod array is fabricated and used in conjunction with a MEMS switch or switch array. An IMod can be used for optical switching and modulation. Some IMods incorporate 2-D and 3-D photonic structures. A variety of applications for the modulation of light are discussed. A MEMS manufacturing and packaging approach is provided based on a continuous web fed process. IMods can be used as test structures for the evaluation of residual stress in deposited materials.

Claims

1. An interferometric modulator comprising:

a structure associated with actuation of the modulator; and

an interferometric cavity having walls, the structure being obscured by at least one of the walls of the interferometric cavity.

2. An interferometric modulator comprising:

a body having a cavity defined by a front wall, a rear wall, and two sidewalls;

a displaceable support member located within the cavity;

a first mirror supported by the displaceable support member;

a second mirror located within the cavity adjacent the front wall; and

an electrode located within the cavity adjacent the rear wall, wherein an optical response of the interferometric modulator is determined by a relative spacing between the first and second mirrors, and wherein the electrode, when actuated, causes electrostatic displacement of the support member resulting in a change in the relative spacing between the first and second mirrors.

3. The interferometric modulator of claim 2, wherein the first mirror comprises a reflective layer deposited directly on the displaceable support member.

4. The interferometric modulator of claim 2, wherein the first mirror comprises a reflective layer spaced from, and substantially parallel to, the displaceable support member and supported thereon by a spacer member.

5. The interferometric modulator of claim 4, wherein the reflective layer obscures the displaceable support member, during all stages of operation of the interferometric modulator, when viewed from an end remote from the electrode.

6. An interferometric modulator comprising:

an optical component including first and second mirrors movably mounted relative to each other to allow a relative spacing between the mirrors to be adjusted to change an optical response of the optical component; and

an actuation mechanism including an electrode to cause electrostatic displacement of the first mirror relative to the second mirror to adjust the relative spacing between the mirrors.

7. The interferometric modulator of claim 6, wherein the optical response is determined only by the first and second mirrors which cooperate to interferometrically modulate incident light.

8. The interferometric modulator of claim 6, further comprising a displaceable support member to support the first mirror.

9. The interferometric modulator of claim 8, wherein the first mirror comprises a reflective layer deposited directly on the displaceable support member.

10. The interferometric modulator of claim 9, wherein the first mirror comprises a reflective layer, spaced from, and substantially parallel to, the displaceable support member and supported thereon by a spacer member.

11. The interferometric modulator of claim 10, wherein the displaceable support member is completely hidden by the reflective layer, during all stages of operation of the interferometric modulator, when viewed from an end remote from the electrode.

12. An interferometric modulator comprising:

a substrate; and

a stacked structure formed on the substrate, the stacked structure comprising an operatively lower electrode layer, a middle first mirror layer normally spaced from the lower electrode layer, and an operatively upper second middle layer normally spaced from the first mirror layer, wherein a spacing between the first and second mirror layers is such that the first and second mirror layers cooperate to interferometrically modulate light incident upon the stacked structure, and wherein actuation of the electrode layer causes electrostatic displacement of the first mirror layer to change the spacing between the first and second mirror layers.

13. The interferometric modulator of claim 12, wherein the stacked structure further comprises a movable support member to support the first mirror layer.

14. The interferometric modulator of claim 13, wherein the first mirror layer is deposited directly on the movable support member.

15. The interferometric modulator of claim 13, wherein the first mirror layer is mounted on a spacer member supported by the movable support member so as to be spaced from and substantially parallel to the movable support member.

16. The interferometric modulator of claim 15, wherein the first mirror layer completely obscures the movable support member, during all stages of operation of the interferometric modulator, when viewed from an end remote from the electrode layer.