US5459610A — Deformable grating apparatus for modulating a lig…

Claim 1

Independent Claim 248 words

A modulator for modulating a beam of incident light, the modulator comprising; a substrate having an upper surface; a first planar light reflective surface formed on the upper surface of the substrate; a deformable grating disposed above said first reflecting surface in spaced apart relation thereto and having a second planar light reflective surface formed on its upper side facing away from the upper surface of the substrate, the deformable grating being arranged with said second reflective surface parallel to and spaced from the upper surface of the substrate, said deformable grating having a lower surface disposed in spaced apart facing relationship to said upper surface of the substrate; means for moving the grating towards the upper surface of the substrate while at the same time maintaining the second reflective surface of the grating substantially parallel to the first reflective surface; and means for limiting the area of contact between said lower surface and said upper surface, and preventing the grating from sticking to the substrate when the grating is moved towards the upper surface of the substrate; whereby, when the perpendicular spacing between the respective first and second reflective surfaces is equal to m/4 times the wavelength of the incident light bean and m=an even whole number or zero the modulator acts to reflect the incident light beam as a plane mirror and when m=an odd whole number the modulator diffracts the incident light beam as it reflects it, thereby providing the modulation of the light beam.

Claim 2

Dependent Claim 248 words

A modulator for modulating a beam of incident light, the modulator comprising; a substrate having an upper surface; a first planar light reflective surface formed on the upper surface of the substrate; a deformable grating disposed above said first reflecting surface in spaced apart relation thereto and having a second planar light reflective surface formed on its upper side facing away from the upper surface of the substrate, the deformable grating being arranged with said second reflective surface parallel to and spaced from the upper surface of the substrate, said deformable grating having a lower surface disposed in spaced apart facing relationship to said upper surface of the substrate; means for moving the grating towards the upper surface of the substrate while at the same time maintaining the second reflective surface of the grating substantially parallel to the first reflective surface; and means for limiting the area of contact between said lower surface and said upper surface, and preventing the grating from sticking to the substrate when the grating is moved towards the upper surface of the substrate; whereby, when the perpendicular spacing between the respective first and second reflective surfaces is equal to m/4 times the wavelength of the incident light bean and m=an even whole number or zero the modulator acts to reflect the incident light beam as a plane mirror and when m=an odd whole number the modulator diffracts the incident light beam as it reflects it, thereby providing the modulation of the light beam.

Claim 3

Dependent Claim 24 words

A modulator as recited in claim 1, wherein the grating comprises a plurality of equally sized and equally spaced apart parallel rectangular grating elements.

Claim 4

Dependent Claim 44 words

A modulator as recited in claim 2, wherein the grating has an underside facing the substrate and the means for preventing the grating from sticking to the substrate includes spacer elements positioned between the underside of the grating facing the substrate and the substrate.

Claim 5

Dependent Claim 39 words

A modulator as recited in claim 3, wherein the spacing between the first reflective surface formed on the substrate and the second reflective surface of the deformable grating is equal to half the wavelength of the incident light beam.

Claim 6

Dependent Claim 34 words

A modulator as recited in claim 4, wherein the means for moving the grating towards the upper surface of the substrate comprises means for applying an electrostatic force between the substrate and the grating.

Claim 7

Dependent Claim 35 words

A modulator as recited in claim 5, wherein the means for preventing the grating from sticking to the upper surface of the substrate includes at least one spacer element attached to each rectangular grating element.

Claim 8

Dependent Claim 22 words

A modulator as recited in claim 6, wherein the spacer elements are located at the edges of their associated rectangular grating elements.

Claim 9

Dependent Claim 49 words

A modulator as recited in claim 5, wherein the means for preventing the grating from sticking to the upper surface of the substrate includes at least one spacer element attached to the substrate and arranged to protrude into the space between the substrate and the underside of the grating.

Claim 10

Dependent Claim 214 words

A modulator for modulating a beam of incident light, comprising; means forming a first planar light reflective surface; a grating having means forming a plurality of second planar light reflective surfaces, the grating being arranged with its second reflective surfaces lying in a plane parallel to and spaced from the first planar reflective surface in a direction normal thereto, said grating having means forming third surfaces on the sides opposite to said second surfaces and facing said first surface, at least one of said first and third surfaces having means for preventing said grating from sticking to said first reflective surface in the event one engages the other; and means for moving the grating in a direction normal to said first planar reflective surface and into engagement therewith, the second reflective surfaces of the grating remaining generally parallel to the first planar reflective surface; whereby, when the spacing between the respective first and second light reflective surfaces is equal to m/4 times a particular wavelength of the incident light beam and m=an even whole number or zero, the modulator acts to reflect the incident light beam as a plane mirror, and when m=an odd whole number the modulator diffracts the incident light beam as it reflects it, thereby providing modulation of the light beam.

Claim 11

Dependent Claim 214 words

A modulator for modulating a beam of incident light, comprising; means forming a first planar light reflective surface; a grating having means forming a plurality of second planar light reflective surfaces, the grating being arranged with its second reflective surfaces lying in a plane parallel to and spaced from the first planar reflective surface in a direction normal thereto, said grating having means forming third surfaces on the sides opposite to said second surfaces and facing said first surface, at least one of said first and third surfaces having means for preventing said grating from sticking to said first reflective surface in the event one engages the other; and means for moving the grating in a direction normal to said first planar reflective surface and into engagement therewith, the second reflective surfaces of the grating remaining generally parallel to the first planar reflective surface; whereby, when the spacing between the respective first and second light reflective surfaces is equal to m/4 times a particular wavelength of the incident light beam and m=an even whole number or zero, the modulator acts to reflect the incident light beam as a plane mirror, and when m=an odd whole number the modulator diffracts the incident light beam as it reflects it, thereby providing modulation of the light beam.

Claim 12

Dependent Claim 24 words

A modulator as recited in claim 9 wherein the grating comprises a plurality of equally sized and equally spaced apart parallel rectangular grating elements.

Claim 13

Dependent Claim 37 words

A modulator as recited in claim 10, wherein the means for preventing the grating from sticking to the first reflective surface includes spacer elements positioned between the third surfaces of the grating and the first reflective surface.

Claim 14

Dependent Claim 34 words

A modulator as recited in claim 11, wherein the spacing between the first reflective surface and the second reflective surface of the grating is equal to half the wavelength of the incident light beam.

Claim 15

Dependent Claim 36 words

A modulator as recited in claim 12, wherein the means for moving the grating into engagement with the first reflective surface comprises means for applying an electrostatic force between the first reflective surface and the grating.

Claim 16

Dependent Claim 33 words

A modulator as recited in claim 13, wherein the means for preventing the grating from sticking to said first reflective surface includes at least one spacer element attached to each rectangular grating element.

Claim 17

Dependent Claim 32 words

A modulator as recited in claim 14, wherein said grating includes a plurality of elongated rectangular grating elements and the spacer elements are located at the edges of associated rectangular grating elements.

Claim 18

Dependent Claim 51 words

A modulator as recited in claim 13, wherein the means for preventing the grating from sticking to the first reflective surface includes at least one spacer element attached to the first reflective surface and arranged to protrude into the space between the first reflective surface and the underside of the grating.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1998-10-16	1999-04-17	1999-10-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2002-10-16	2003-04-17	2003-10-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2006-10-16	2007-04-17	2007-10-17	$7700.00	Window Closed / Lapsed

Deformable grating apparatus for modulating a light beam and including means for obviating stiction between grating elements and underlying substrate

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