Patent US5420877A successfully refreshed from Google Patents.
US5420877A
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US
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Temperature compensation method and apparatus for wave meters and tunable lasers controlled thereby
Assignee: Cymer Inc
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Filing: 1993-07-16
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Granted: 1995-05-30
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Expires: 2013-07-16
Abstract
Abstract Temperature compensation method and apparatus for wave meters and tunable lasers controlled thereby which avoids the necessity of maintaining a good vacuum in the wave meter housing and which provides the quick establishment of wave length accuracy after laser turn on before temperature stability in the wave meter is reached. In accordance with the method, the wave meter housing is filled preferably with one atmosphere of dry nitrogen, and the wave meter output is corrected for temperature effects by combining the uncorrected or raw wave meter output with an appropriate wave meter temperature dependent component and an additional appropriate rate of change of wave meter temperature dependent component. The net result is the achievement of accuracy and stability in the wave meter output without use of an oven and before a steady state operating temperature is attained.
Inventors
- 👤 Richard L. Sandstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:33
CPC Classifications
G; G01; G01J; G01J9/00; G01J9/02; G01J9/0246; H; H01; H01S; H01S3/00; H01S3/10; H01S3/13; H01S5/00; H01S5/06; H01S5/068; H01S5/0683; H01S5/0687
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
113 words
A system for providing a signal responsive to the wave length of light stabilized for variations in temperature comprising: a wave meter for providing a wave meter signal responsive to the wave length of light incident thereto; a sensor for providing a temperature signal responsive to a temperature associated with the wave meter; and, means responsive to the wave meter signal and the temperature signal to combine the wave meter signal, the temperature signal and the time rate of change of the temperature signal, each having a relative weighting selected to provide a signal responsive to the wave length of the light incident to the wave meter and stabilized for variations in temperature.
Claim 2
Independent Claim
113 words
A system for providing a signal responsive to the wave length of light stabilized for variations in temperature comprising: a wave meter for providing a wave meter signal responsive to the wave length of light incident thereto; a sensor for providing a temperature signal responsive to a temperature associated with the wave meter; and, means responsive to the wave meter signal and the temperature signal to combine the wave meter signal, the temperature signal and the time rate of change of the temperature signal, each having a relative weighting selected to provide a signal responsive to the wave length of the light incident to the wave meter and stabilized for variations in temperature.
Claim 3
Dependent Claim
40 words
The system of claim 1 wherein the means responsive to the wave meter signal and the temperature signal to combine the wave meter signal, the temperature signal and the time rate of change of the temperature signal comprises a microprocessor.
Claim 4
Dependent Claim
45 words
The system of claim 1 wherein the wave meter is contained within a closed wave meter housing and the sensor for providing a temperature signal responsive to a temperature associated with the wave meter is positioned to respond to the temperature of the housing wall.
Claim 5
Dependent Claim
31 words
The system of claim 3 wherein the sensor for providing a temperature signal responsive to a temperature associated with the wave meter is positioned within the enclosure defined by the housing.
Claim 6
Dependent Claim
13 words
The system of claim 4, wherein the housing is filled with a gas.
Claim 7
Dependent Claim
16 words
The system of claim 5, wherein the housing is filled with nitrogen at approximately one atmosphere.
Claim 8
Dependent Claim
12 words
The system of claim 6, wherein the wave meter includes an etalon.
Claim 9
Dependent Claim
13 words
The system of claim 3, wherein the housing is filled with a gas.
Claim 10
Dependent Claim
16 words
The system of claim 8 wherein the housing is filled with nitrogen at approximately one atmosphere.
Claim 11
Independent Claim
19 words
The system of any one of claims 1 through 4 and 9 wherein the wave meter includes an etalon.
Claim 12
Dependent Claim
135 words
A laser system for providing a laser output of a selected and stable wave length comprising: a laser tunable in response to a laser control signal a wave meter for providing a wave meter signal responsive to the wave length of light incident thereto from the laser; a sensor for providing a temperature signal responsive to a temperature associated with the wave meter; and, means responsive to the wave meter signal and the temperature signal to provide the laser control signal to the laser by combining the wave meter signal, the temperature signal and the time rate of change of the temperature signal, each with a relative weighting selected to provide the laser control signal responsive to the wave length of the laser emission incident to the wave meter and stabilized for variations in temperature.
Claim 13
Dependent Claim
135 words
A laser system for providing a laser output of a selected and stable wave length comprising: a laser tunable in response to a laser control signal a wave meter for providing a wave meter signal responsive to the wave length of light incident thereto from the laser; a sensor for providing a temperature signal responsive to a temperature associated with the wave meter; and, means responsive to the wave meter signal and the temperature signal to provide the laser control signal to the laser by combining the wave meter signal, the temperature signal and the time rate of change of the temperature signal, each with a relative weighting selected to provide the laser control signal responsive to the wave length of the laser emission incident to the wave meter and stabilized for variations in temperature.
Claim 14
Dependent Claim
41 words
The laser system of claim 11 wherein the means responsive to the wave meter signal and the temperature signal to combine the wave meter signal, the temperature signal and the time rate of change of the temperature signal comprises a microprocessor.
Claim 15
Dependent Claim
46 words
The laser system of claim 11 wherein the wave meter is contained within a closed wave meter housing and the sensor for providing a temperature signal responsive to a temperature associated with the wave meter is positioned to respond to the temperature of the housing wall.
Claim 16
Dependent Claim
32 words
The laser system of claim 13 wherein the sensor for providing a temperature signal responsive to a temperature associated with the wave meter is positioned within the enclosure defined by the housing.
Claim 17
Dependent Claim
14 words
The laser system of claim 14, wherein the housing is filled with a gas.
Claim 18
Dependent Claim
17 words
The laser system of claim 15, wherein the housing is filled with nitrogen at approximately one atmosphere.
Claim 19
Dependent Claim
13 words
The laser system of claim 16, wherein the wave meter includes an etalon.
Claim 20
Dependent Claim
14 words
The laser system of claim 13 wherein the housing is filled with a gas.
Claim 21
Dependent Claim
17 words
The laser system of claim 18 wherein the housing is filled with nitrogen at approximately one atmosphere.
Claim 22
Dependent Claim
20 words
The laser system of any one of claims 11 through 14 and 19 wherein the wave meter includes an etalon.
Claim 23
Independent Claim
116 words
A method of operating a tunable laser comprising the steps of: (a) providing a tunable laser having an emission controlled, at least in part, in wave length by a gas filled wave meter having a sensitivity to the index of the gas filling the wave meter; (b) sensing the temperature of the wave meter enclosure and the rate of change of the enclosure temperature; (c) correcting the output of the wave meter by a temperature dependent compensation factor and by an additional rate of change of temperature dependent compensation factor to obtain a corrected wave meter output; and, (d) controlling the wavelength of the emission of the tunable laser responsive to the corrected wave meter output.
Claim 24
Independent Claim
116 words
A method of operating a tunable laser comprising the steps of: (a) providing a tunable laser having an emission controlled, at least in part, in wave length by a gas filled wave meter having a sensitivity to the index of the gas filling the wave meter; (b) sensing the temperature of the wave meter enclosure and the rate of change of the enclosure temperature; (c) correcting the output of the wave meter by a temperature dependent compensation factor and by an additional rate of change of temperature dependent compensation factor to obtain a corrected wave meter output; and, (d) controlling the wavelength of the emission of the tunable laser responsive to the corrected wave meter output.
Claim 25
Dependent Claim
36 words
The method of claim 21 wherein the coefficients of the temperature dependent compensation factor and the additional rate of change of temperature dependent compensation factor are predetermined empirically from previous testing of devices of like design.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1998-05-29 | 1998-11-28 | 1999-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-29 | 2002-11-28 | 2003-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-29 | 2006-11-28 | 2007-05-30 | $7700.00 | Window Closed / Lapsed |