Enhanced surface deformation light modulator

• US 5,493,439 A
• Filed: 09/29/1992
• Issued: 02/20/1996
• Est. Priority Date: 09/29/1992
• Status: Expired due to Fees

• Current Assignee: Craig D. Engle
• Original Assignee: Craig D. Engle
• Inventors: Engle, Craig D.
• Primary Examiner(s): Lopez, F. Daniel
• Application Number:
  US07/953,118
• Time in Patent Office: 1,239 Days
• Field of Search: 359/292, 359/295, 359/279 US, 358/62, 358/233
• US Class Current: 359/292
• CPC Class Codes: G02B 26/06 for controlling the phase of light G02B26/08 takes precedence , measuring optical phase difference G01J9/00
• 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

Abstract

A surface deformation light modulator contains a plurality of first electrodes arranged in a matrix of p rows and q columns affixed to a substrate by a suitable means. Each electrode is electrically connected to a third terminal of a respective switching element. Each switching element is affixed to a second face of the substrate. Each column of electrodes is overlapped by a respective flexible, reflective conductor. Each conductor is affixed by a suitable means to a first face of the substrate. Having the switch matrix and the conductors affixed to opposite face of the substrate allows several processing options to be considered to reduce the influence of contamination and hence enhancing the commercial viability of the modulator. Each switch element further includes a first switch terminal and a second switch terminal. Every second terminal in each row is electrically connected by a respective second buss. A plurality of first busses electrically connects every first terminal in each row to a common potential source. Every first buss is parallel to each second buss to avoid electrical crossover networks to enhance reliability. A suitable potential control means allows control of the potential difference between each first electrode and the respective conductor thereby enabling a wavefront incident on the modulator to be phase modulated in accordance with an information bearing signal.

Claims

1. An enhanced surface deformation light modulator for use in phase modulating an electromagnetic wavefront incident thereon in electronic to optical data conversion applications comprising:

an insulating substrate,

a plurality of first electrodes arranged into a matrix of p rows and q columns, each said first electrode is affixed to said substrate by a suitable means,

each column q of said first electrodes is overlapped by a respective reflective deformable column conductor,

each said conductor is affixed to said substrate by a suitable conductor affixing means in such manner to electrically isolate the conductors from one another,

a plurality of thin film transistors, each said transistor further includes a drain electrode, a gate electrode, and a source electrode,

each said first electrode is electrically connected by a suitable electrical interconnect means to a respective thin film transistor,

each said transistor is affixed by a suitable transistor affixing means to said substrate,

the gate electrodes of said transistors which are electrically connected to said first electrodes in each row p are electrically connected by a respective row select buss,

each said respective row select buss is affixed to said substrate by a suitable row buss means,

a plurality of common busses electrically connecting the source electrodes of said transistors to a common potential source,

each said common buss is affixed to said substrate by a suitable common buss means,

each said common buss is essentially parallel to every said respective row select buss,

a suitable potential control means to control an applied potential difference between each said first electrode and the respective conductor in accordance with an information bearing signal so as to enhance reliability, efficiency and commercial viability of the modulator.

2. The device of claim 1 wherein said substrate further includes a first major surface and a second major surface,

said first major surface and said second major surface are opposing surfaces,

each said conductor is affixed to said first major surface by said suitable conductor affixing means,

each said respective row select buss is affixed to said substrate by a suitable row buss means,

each said common buss is affixed to said substrate by a suitable common buss means.

3. The device of claim 2 wherein each said transistor is affixed to said second major surface by said suitable transistor affixing means,

each said respective row select buss is affixed to said second major surface by said suitable row buss means,

each said common buss is affixed to said second major surface by said suitable common buss means,

each said first electrode overlaps said respective thin film transistor.

4. An enhanced membrane light modulator for use in phase modulating an electromagnetic wavefront incident thereon in electronic to optical data conversion applications comprising:

an insulating substrate,

a plurality of first electrodes arranged into a matrix of p rows and q columns, each said first electrode is affixed to said substrate by a suitable means,

each column q of said first electrodes is overlapped by a respective deformable column conductor,

each said conductor is affixed to said substrate by a suitable conductor affixing means in such manner to electrically isolate the conductors from one another,

a plurality of thin film transistors, each said transistor further includes a drain electrode, a gate electrode and a source electrode,

each said first electrode is electrically connected by a suitable electrical interconnect means to a respective thin film transistor,

each said transistor is affixed by a suitable transistor affixing means to said substrate,

the gate electrodes of said transistors which are electrically connected to said first electrodes in each row p are electrically connected by a respective row select buss,

each said respective row select buss is affixed to said substrate by a suitable row buss means,

a plurality of common busses electrically connecting the source electrodes of said transistors to a common potential source,

each said common buss is affixed to said substrate by a suitable common bus means,

each said common buss is essentially parallel to every said respective row select buss,

a suitable potential control means to apply between each said first electrode and the respective conductor a respective potential difference,

whereby varying each said respective potential difference varies the deformation of said respective conductor overlapping the first electrode thereby phase modulating said wavefront incident thereon affectively, efficiently and reliably thereby enhancing commercial viability of said modulator.

5. An enhanced membrane light modulator for use in phase modulating an electromagnetic wavefront incident thereon comprising:

an insulating substrate, said substrate further includes a first major surface and a second major surface, said first major surface and said second major surface are opposing surfaces,

a plurality of first electrodes arranged into a matrix of p rows and q columns, each said first electrode is affixed by a suitable means to said substrate,

each column q of said first electrodes is overlapped by a respective reflective deformable column conductor,

each said conductor is affixed by a suitable means to said first major surface in such manner to electrically isolate the conductors from one another,

a plurality of thin film transistors, each said transistor further includes a drain electrode, a gate electrode, and a source electrode,

each said first electrode is electrically connected by a suitable feedthrough means to a respective thin film transistor,

each said transistor is affixed by a suitable means to said second major surface,

the gate electrodes of said transistors which are electrically connected to said first electrodes in each row p are electrically connected by a respective row select buss,

each said respective row select buss is affixed by a suitable means to said second major surface,

a plurality of common busses electrically connecting the source electrodes of said transistors to a common potential source,

each said common buss is affixed to said second major surface by a suitable means,

each said common buss is essentially parallel to every said respective row select buss thereby avoiding electrical crossover networks,

a suitable potential control means to control an applied potential difference between each said first electrode and the respective conductor in accordance with an information bearing signal so as to enhance reliability, efficiency and commercial viability of the modulator.