US5608568A
Expired / Lapsed
US
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Thin film vanadium oxide spatial light modulators and methods
Assignee: Johns Hopkins University
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Filing: 1994-04-11
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Granted: 1997-03-04
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Expires: 2014-04-11
Abstract
Abstract Vanadium dioxide (VO 2 ) based infrared spatial light modulators (SLM) in four embodiments are disclosed: (1) A VO 2 thin film is deposited on a planar diode array. Each diode constitutes a "pixel" of the SLM. Power provided to a diode permits accurate thermal control about the thin film's hysteresis. Initial biasing of the diode array is required to the base of the VO 2 's hysteresis curve. (2) & (3) VO 2 is deposited on a thermoelectric array which can be an array of doped lines of p and n type material or a conductive material between two electrical contacts. The pixels have the ability to both heat and cool the VO 2 film, thereby allowing the array to be operated in a bistable mode. Bistable operation requires external biasing to the center of the VO 2 's hysteresis curve. (4) A VO 2 thin film deposited on a substrate which is spaced a distance, L, from an array of vertical-cavity surface-emitting lasers for heating the VO 2 .
Inventors
- 👤 David W. Blodgett
- 👤 Charles H. Lange
- 👤 Philip J. McNally
- 👤 Donald D. Duncan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:24
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/0147; H; H01; H01S; H01S5/00; H01S5/40; H01S5/42; H01S5/423
Claims Analysis
Total Claims: 59
Claim 1
Independent Claim
78 words
A device for modulating light as a function of spatial position comprising: a substrate; an array of temperature changing means deposited on the substrate; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the temperature changing means array; wherein, when an electrical current is applied to a temperature changing means, the temperature changing means changes temperature thereby changing the reflective value of the VO compound deposited on the temperature changing means.
Claim 2
Independent Claim
78 words
A device for modulating light as a function of spatial position comprising: a substrate; an array of temperature changing means deposited on the substrate; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the temperature changing means array; wherein, when an electrical current is applied to a temperature changing means, the temperature changing means changes temperature thereby changing the reflective value of the VO compound deposited on the temperature changing means.
Claim 3
Dependent Claim
20 words
The device as recited in claim 1, wherein the array of temperature changing means comprises an array of p-n junctions.
Claim 4
Independent Claim
76 words
A device for modulating light as a function of spatial position comprising: a substrate; an array of heating means deposited on the substrate; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the heating means array; wherein, when an electrical current is applied to a heating means, the heating means heats the VO compound deposited on the heating means causing the reflective value of the VO compound to increase.
Claim 5
Independent Claim
76 words
A device for modulating light as a function of spatial position comprising: a substrate; an array of heating means deposited on the substrate; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the heating means array; wherein, when an electrical current is applied to a heating means, the heating means heats the VO compound deposited on the heating means causing the reflective value of the VO compound to increase.
Claim 6
Dependent Claim
19 words
The device as recited in claim 3, wherein the array of heating means comprises an array of p-n junctions.
Claim 7
Independent Claim
94 words
A device for modulating light as a function of spatial position comprising: a substrate; an array of diodes, each diode comprising a p-n junction and having electrical contacts, the diodes being deposited in the substrate and isolated electrically from each other; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the diode array; wherein, when an electrical current is applied to a diode through the electrical contacts, the diode heats the VO compound deposited on the diode causing the reflective value of the VO compound to increase.
Claim 8
Independent Claim
94 words
A device for modulating light as a function of spatial position comprising: a substrate; an array of diodes, each diode comprising a p-n junction and having electrical contacts, the diodes being deposited in the substrate and isolated electrically from each other; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the diode array; wherein, when an electrical current is applied to a diode through the electrical contacts, the diode heats the VO compound deposited on the diode causing the reflective value of the VO compound to increase.
Claim 9
Dependent Claim
13 words
The device as recited in claim 5, wherein the substrate comprises a semiconductor.
Claim 10
Dependent Claim
12 words
The device as recited in claim 6, wherein the semiconductor is silicon.
Claim 11
Dependent Claim
14 words
The device as recited in claim 5, wherein the VO compound is vanadium dioxide.
Claim 12
Dependent Claim
43 words
The device as recited in claim 5, wherein the diode array is maintained at a first temperature, the first temperature being just below a second temperature, the second temperature being the temperature at which the VO compound transitions to the increased reflective value.
Claim 13
Dependent Claim
15 words
The device as recited in claim 5, further comprising means for thermally isolating the diodes.
Claim 14
Dependent Claim
21 words
The device as recited in claim 10, the thermally isolating means comprising a low thermally conductive material deposited between each diode.
Claim 15
Dependent Claim
15 words
The device as recited in claim 11, the low thermally conductive material comprising silicon dioxide.
Claim 16
Dependent Claim
20 words
The device as recited in claim 10, the thermally isolating means comprising a plurality of wells formed between each diode.
Claim 17
Dependent Claim
14 words
The device as recited in claim 5, further comprising a means for dissipating heat.
Claim 18
Dependent Claim
30 words
The device as recited in claim 14, the heat dissipating means comprising a plurality of channels formed in the substrate, the channels for carrying a coolant to dissipate the heat.
Claim 19
Dependent Claim
51 words
The device as recited in claim 14, the heat dissipating means comprising: a second substrate, the second substrate being attached to the substrate on the side opposite from the diode array; and a plurality of channels formed in the second substrate, the channels for carrying a coolant to dissipate the heat.
Claim 20
Dependent Claim
18 words
The device as recited in claim 14, the heat dissipating means comprising a chemical vapor deposition (CVD) diamond.
Claim 21
Dependent Claim
32 words
The device as recited in claim 5, further comprising a means for absorbing radiation transmitted by the VO compound, the absorbing means being deposited between the diode array and the VO compound.
Claim 22
Dependent Claim
40 words
The device as recited in claim 5, further comprising an antireflecting coating deposited on the same side of the substrate as the VO compound to limit the radiation being reflected when the VO compound is in a low reflective mode.
Claim 23
Independent Claim
125 words
A device for modulating light as a function of spatial position comprising: a substrate comprising an array of pixels; a first electrical contact deposited on the base of the pixel array; a second electrical contact deposited on the top of the pixel array; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the opposite side of the second electrical contact from the pixel array; wherein, when an electrical current is passed between the first and second electrical contacts, depending on the direction and magnitude of the electrical current, each array pixel becomes a thermoelectric heater/cooler, each array pixel heating/cooling the VO compound deposited on each array pixel causing the reflective value of the VO compound to increase/decrease, respectively.
Claim 24
Independent Claim
125 words
A device for modulating light as a function of spatial position comprising: a substrate comprising an array of pixels; a first electrical contact deposited on the base of the pixel array; a second electrical contact deposited on the top of the pixel array; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the opposite side of the second electrical contact from the pixel array; wherein, when an electrical current is passed between the first and second electrical contacts, depending on the direction and magnitude of the electrical current, each array pixel becomes a thermoelectric heater/cooler, each array pixel heating/cooling the VO compound deposited on each array pixel causing the reflective value of the VO compound to increase/decrease, respectively.
Claim 25
Dependent Claim
13 words
The device as recited in claim 20, wherein the substrate comprises a semiconductor.
Claim 26
Dependent Claim
14 words
The device as recited in claim 21, wherein the semiconductor comprises a silicon-germanium alloy.
Claim 27
Dependent Claim
15 words
The device as recited in claim 20, further comprising means for thermally isolating the pixels.
Claim 28
Dependent Claim
21 words
The device as recited in claim 23, the thermally isolating means comprising a low thermally conductive material deposited between each pixel.
Claim 29
Dependent Claim
15 words
The device as recited in claim 24, the low thermally conductive material comprising silicon dioxide.
Claim 30
Dependent Claim
20 words
The device as recited in claim 23, the thermally isolating means comprising a plurality of wells formed between each pixel.
Claim 31
Dependent Claim
64 words
The device as recited in claim 20, wherein the pixels are maintained at a first temperature, the first temperature being half way between a second temperature and a third temperature, the second temperature being the temperature at which the VO compound transitions to the increased reflective value, and the third temperature being the temperature at which the VO compound attains a maximum reflective value.
Claim 32
Dependent Claim
14 words
The device as recited in claim 20, wherein the VO compound is vanadium dioxide.
Claim 33
Independent Claim
135 words
A device for modulating light as a function of spatial position comprising: a substrate; an array of p-n junctions comprising an array of doped lines of p and n type material, the p doped lines being perpendicular to the n doped lines, each p-n junction acting as a thermoelectric heater/cooler; a layer of electrically insulating material deposited on the p-n junction array; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the layer of electrically insulating material; wherein, when an electrical current is passed through a p-n junction, depending on the direction and magnitude of the electrical current, each p-n junction becomes a thermoelectric heater/cooler, each p-n junction heating/cooling the VO compound deposited on the p-n junction causing the reflective value of the VO compound to increase/decrease, respectively.
Claim 34
Independent Claim
135 words
A device for modulating light as a function of spatial position comprising: a substrate; an array of p-n junctions comprising an array of doped lines of p and n type material, the p doped lines being perpendicular to the n doped lines, each p-n junction acting as a thermoelectric heater/cooler; a layer of electrically insulating material deposited on the p-n junction array; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the layer of electrically insulating material; wherein, when an electrical current is passed through a p-n junction, depending on the direction and magnitude of the electrical current, each p-n junction becomes a thermoelectric heater/cooler, each p-n junction heating/cooling the VO compound deposited on the p-n junction causing the reflective value of the VO compound to increase/decrease, respectively.
Claim 35
Dependent Claim
13 words
The device as recited in claim 29, wherein the substrate comprises a semiconductor.
Claim 36
Dependent Claim
12 words
The device as recited in claim 30, wherein the semiconductor comprises silicon-germanium.
Claim 37
Dependent Claim
66 words
The device as recited in claim 29, wherein the p-n junction array is maintained at a first temperature, the first temperature being half way between a second temperature and a third temperature, the second temperature being the temperature at which the VO compound transitions to the increased reflective value, and the third temperature being the temperature at which the VO compound attains a maximum reflective value.
Claim 38
Dependent Claim
14 words
The device as recited in claim 29, wherein the VO compound is vanadium dioxide.
Claim 39
Independent Claim
100 words
A device for modulating light as a function of spatial position comprising: an array of vertical-cavity surface-emitting lasers (VCSELs), each VCSEL having an electrical contact; a substrate spaced a distance from the VCSEL array; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the opposite side of the substrate from the VCSEL array; wherein, when an electrical current to a VCSEL exceeds a threshold current lasing occurs providing localized heating to the substrate and thereby to the VO compound deposited on the substrate, causing the reflective value of the VO compound to increase.
Claim 40
Independent Claim
100 words
A device for modulating light as a function of spatial position comprising: an array of vertical-cavity surface-emitting lasers (VCSELs), each VCSEL having an electrical contact; a substrate spaced a distance from the VCSEL array; and a thin film comprising a vanadium oxide (VO) compound, the VO compound being deposited on the opposite side of the substrate from the VCSEL array; wherein, when an electrical current to a VCSEL exceeds a threshold current lasing occurs providing localized heating to the substrate and thereby to the VO compound deposited on the substrate, causing the reflective value of the VO compound to increase.
Claim 41
Dependent Claim
13 words
The device as recited in claim 34, wherein the substrate comprises a semiconductor.
Claim 42
Dependent Claim
12 words
The device as recited in claim 35, wherein the semiconductor comprises silicon.
Claim 43
Dependent Claim
46 words
The device as recited in claim 34, wherein the substrate and the VO compound are maintained at a first temperature, the first temperature being just below a second temperature, the second temperature being the temperature at which the VO compound transitions to the increased reflective value.
Claim 44
Dependent Claim
31 words
The device as recited in claim 37, wherein the substrate and the VO member are heated to the first temperature by passing a fluid between the VCSEL array and the substrate.
Claim 45
Dependent Claim
14 words
The device as recited in claim 34, wherein the VO compound is vanadium dioxide.
Claim 46
Dependent Claim
34 words
The device as recited in claim 34, further comprising a first antireflecting coating deposited on the opposite side of the substrate from the VO compound to limit the radiation being reflected by the substrate.
Claim 47
Dependent Claim
45 words
The device as recited in claim 34, further comprising a second antireflecting coating deposited on the same side of the substrate as the VO compound to limit the radiation being reflected by the same side when the VO compound is in a low reflective mode.
Claim 48
Independent Claim
59 words
A method for modulating light as a function of spatial position comprising the step of changing the reflective value of a thin film of a vanadium oxide compound deposited on a temperature changing means array by providing an electrical current to the temperature changing means array, the temperature changing means array changing the temperature of the vanadium oxide compound.
Claim 49
Independent Claim
59 words
A method for modulating light as a function of spatial position comprising the step of changing the reflective value of a thin film of a vanadium oxide compound deposited on a temperature changing means array by providing an electrical current to the temperature changing means array, the temperature changing means array changing the temperature of the vanadium oxide compound.
Claim 50
Independent Claim
53 words
A method for modulating light as a function of spatial position comprising the step of increasing the reflective value of a thin film of a vanadium oxide compound deposited on a heating means array by providing an electrical current to the heating means array, the heating means array heating the vanadium oxide compound.
Claim 51
Independent Claim
53 words
A method for modulating light as a function of spatial position comprising the step of increasing the reflective value of a thin film of a vanadium oxide compound deposited on a heating means array by providing an electrical current to the heating means array, the heating means array heating the vanadium oxide compound.
Claim 52
Independent Claim
50 words
A method for modulating light as a function of spatial position comprising the step of increasing the reflective value of a thin film of a vanadium oxide compound deposited on a diode array by providing an electrical current to the diode array, the diode array heating the vanadium oxide compound.
Claim 53
Independent Claim
50 words
A method for modulating light as a function of spatial position comprising the step of increasing the reflective value of a thin film of a vanadium oxide compound deposited on a diode array by providing an electrical current to the diode array, the diode array heating the vanadium oxide compound.
Claim 54
Independent Claim
80 words
A method for making a device for modulating light as a function of spatial position comprising the steps of: depositing an array of temperature changing means on a substrate; and depositing a thin film of a vanadium oxide compound on the temperature changing means array; wherein, when an electrical current is applied to a temperature changing means, the temperature changing means changes the temperature of the vanadium oxide compound causing the reflective value of the vanadium oxide compound to change.
Claim 55
Independent Claim
80 words
A method for making a device for modulating light as a function of spatial position comprising the steps of: depositing an array of temperature changing means on a substrate; and depositing a thin film of a vanadium oxide compound on the temperature changing means array; wherein, when an electrical current is applied to a temperature changing means, the temperature changing means changes the temperature of the vanadium oxide compound causing the reflective value of the vanadium oxide compound to change.
Claim 56
Independent Claim
78 words
A method for making a device for modulating light as a function of spatial position comprising the steps of: depositing an array of heating means on a substrate; and depositing a thin film of a vanadium oxide compound on the heating means array; wherein, when an electrical current is applied to a heating means, the heating means heats the vanadium oxide compound deposited on the heating means causing the reflective value of the vanadium oxide compound to increase.
Claim 57
Independent Claim
78 words
A method for making a device for modulating light as a function of spatial position comprising the steps of: depositing an array of heating means on a substrate; and depositing a thin film of a vanadium oxide compound on the heating means array; wherein, when an electrical current is applied to a heating means, the heating means heats the vanadium oxide compound deposited on the heating means causing the reflective value of the vanadium oxide compound to increase.
Claim 58
Independent Claim
92 words
A method for making a device for modulating light as a function of spatial position comprising the steps of: depositing an array of diodes in a substrate, each diode comprising a p-n junction and having an electrical contact, the diodes being electrically isolated from each other; and depositing a thin film of a vanadium oxide compound on the diode array; wherein, when an electrical current is applied to a diode, the diode heats the vanadium oxide compound deposited on the diode causing the reflective value of the vanadium oxide compound to increase.
Claim 59
Independent Claim
92 words
A method for making a device for modulating light as a function of spatial position comprising the steps of: depositing an array of diodes in a substrate, each diode comprising a p-n junction and having an electrical contact, the diodes being electrically isolated from each other; and depositing a thin film of a vanadium oxide compound on the diode array; wherein, when an electrical current is applied to a diode, the diode heats the vanadium oxide compound deposited on the diode causing the reflective value of the vanadium oxide compound to increase.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2000-03-03 | 2000-09-02 | 2001-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-03 | 2004-09-02 | 2005-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-03 | 2008-09-02 | 2009-03-04 | $7700.00 | Window Closed / Lapsed |