Claims
- 1. A wavelength chirp compensation method for an excimer or molecular fluorine laser system operating in burst mode, comprising pre-programming into a computer of the laser system resonator tuning optic adjustments for making the adjustments during pauses between bursts to compensate wavelength chirp at beginnings of succeeding bursts.
- 2. The method of claim 1, wherein the resonator tuning optic adjustments are determined according to the steps of:
operating the laser system at an operating duty cycle such that the laser system is in a condition such as during a burst when the laser is operated in burst mode; switching the laser system to a nominal duty cycle in a range between just sufficient to enable wavelength measurements to be made and below where laser operating conditions are significantly affected by generating laser pulses at the nominal duty cycle, such that the laser system changes substantially as it would during a burst pause for a laser operating in burst mode; measuring wavelengths of laser pulses generated at the nominal duty cycle for a period of time without adjusting resonator optics to adjust the wavelength; and calculating the resonator tuning optic adjustments, based on the wavelengths measured over the period of time, which if made would have compensated wavelength changes occurring during the period of time.
- 3. The method of claim 2, further comprising the steps of:
operating the laser system in burst mode after the pre-programming step; making the adjustments during pauses between bursts to compensate wavelength chirps at beginnings of bursts; and returning the tuning resonator optic to standard operating position after a chirp period at the beginnings of the bursts.
- 4. The method of claim 1, further comprising the steps of:
operating the laser system in burst mode after the pre-programming step; making the adjustments during pauses between bursts to compensate wavelength chirps at beginnings of bursts; and returning the tuning resonator optic to standard operating position after a chirp period at the beginnings of the bursts.
- 5. The method of claim 1, wherein the resonator tuning optic adjustments are determined according to the steps of:
operating the laser system at an operating duty cycle such that the laser system is in a condition such as during a burst when the laser is operated in burst mode; switching the laser system to a nominal duty cycle in a range between just sufficient to enable wavelength measurements to be made and below where laser operating conditions are significantly affected by generating laser pulses at the nominal duty cycle, such that the laser system changes substantially as it would during a burst pause for a laser operating in burst mode; adjusting a resonator tuning optic position to maintain laser pulses at approximately a target wavelength during a period of time that the laser system is operated at the nominal duty cycle; and recording the resonator tuning optics positions according to the adjustments made during the adjusting step.
- 6. The method of claim 5, further comprising the steps of:
operating the laser system in burst mode after the pre-programming step; making the adjustments during pauses between bursts to compensate wavelength chirps at beginnings of bursts; and returning the resonator tuning optic to standard operating position after a chirp period at the beginnings of the bursts.
- 7. The method of claim 1, wherein the pre-programming step includes pre-programming into the computer of the laser system resonator tuning optic positions for a plurality of operating repetition rates, such that when the laser operated at a particular repetition rate, programmed adjustment are made during pauses between bursts according to the particular repetition rate.
- 8. The method of claim 7, wherein the resonator tuning optic adjustments are determined according to the steps of:
operating the laser system at an operating duty cycle such that the laser system is in a condition such as during a burst when the laser is operated in burst mode; switching the laser system to a nominal duty cycle in a range between just sufficient to enable wavelength measurements to be made and below where laser operating conditions are significantly affected by generating laser pulses at the nominal duty cycle, such that the laser system changes substantially as it would during a burst pause for a laser operating in burst mode; measuring wavelengths of laser pulses generated at the nominal duty cycle for a period of time without adjusting resonator optics to adjust the wavelength; calculating the resonator tuning optic adjustments, based on the wavelengths measured over the period of time, which if made would have compensated wavelength changes occurring during the period of time; and repeating these operating, switching, measuring and calculating steps at one or more additional operating duty cycles.
- 9. The method of claim 8, further comprising the steps of:
operating the laser system in burst mode at a selected operating duty cycle after the pre-programming step; making the adjustments according to the selected operating duty cycle during pauses between bursts to compensate wavelength chirps at beginnings of bursts; and returning the tuning resonator optic to standard operating position after a chirp period at the beginnings of the bursts.
- 10. The method of claim 7, further comprising the steps of:
operating the laser system in burst mode at a selected operating duty cycle after the pre-programming step; making the adjustments according to the selected operating duty cycle during pauses between bursts to compensate wavelength chirps at beginnings of bursts; and returning the tuning resonator optic to standard operating position after a chirp period at the beginnings of the bursts.
- 11. The method of claim 7, wherein the resonator tuning optic adjustments are determined according to the steps of:
operating the laser system at an operating duty cycle such that the laser system is in a condition such as during a burst when the laser is operated in burst mode; switching the laser system to a nominal duty cycle in a range between just sufficient to enable wavelength measurements to be made and below where laser operating conditions are significantly affected by generating laser pulses at the nominal duty cycle, such that the laser system changes substantially as it would during a burst pause for a laser operating in burst mode; adjusting a resonator tuning optic position to maintain laser pulses at approximately a target wavelength during a period of time that the laser system is operated at the nominal duty cycle; recording the resonator tuning optics positions according to the adjustments made during the adjusting step; and repeating these operating, switching, adjusting and recording steps at one or more additional operating duty cycles.
- 12. The method of claim 11, further comprising the steps of:
operating the laser system in burst mode at a selected operating duty cycle after the pre-programming step; making the adjustments according to the selected operating duty cycle during pauses between bursts to compensate wavelength chirps at beginnings of bursts; and returning the tuning resonator optic to standard operating position after a chirp period at the beginnings of the bursts.
- 13. The method of claim 1, wherein the pre-programming step includes pre-programming into the computer of the laser system resonator tuning optic positions for a plurality of aging states of the laser system, such that when the laser operated at a particular aging state, programmed adjustments are made during pauses between bursts according to the particular aging state.
- 14. The method of claim 13, wherein the resonator tuning optic adjustments are determined according to the steps of:
operating the laser system at a first aging state and at an operating duty cycle such that the laser system is in a condition such as during a burst when the laser is operated in burst mode; switching the laser system to a nominal duty cycle in a range between just sufficient to enable wavelength measurements to be made and below where laser operating conditions are significantly affected by generating laser pulses at the nominal duty cycle, such that the laser system changes substantially as it would during a burst pause for a laser operating in burst mode; measuring wavelengths of laser pulses generated at the nominal duty cycle for a period of time without adjusting resonator optics to adjust the wavelength; calculating the resonator tuning optic adjustments, based on the wavelengths measured over the period of time, which if made would have compensated wavelength changes occurring during the period of time; and repeating these operating, switching, measuring and calculating steps at one or more additional aging states.
- 15. The method of claim 14, further comprising the steps of:
operating the laser system in burst mode at a particular aging state after the pre-programming step; making the adjustments according to the particular aging state during pauses between bursts to compensate wavelength chirps at beginnings of bursts; and returning the tuning resonator optic to standard operating position after a chirp period at the beginnings of the bursts.
- 16. The method of claim 13, further comprising the steps of:
operating the laser system in burst mode at a particular aging state after the pre-programming step; making the adjustments according to the particular aging state during pauses between bursts to compensate wavelength chirps at beginnings of bursts; and returning the tuning resonator optic to standard operating position after a chirp period at the beginnings of the bursts.
- 17. The method of claim 13, wherein the resonator tuning optic adjustments are determined according to the steps of:
operating the laser system at a first aging state and at an operating duty cycle such that the laser system is in a condition such as during a burst when the laser is operated in burst mode; switching the laser system to a nominal duty cycle in a range between just sufficient to enable wavelength measurements to be made and below where laser operating conditions are significantly affected by generating laser pulses at the nominal duty cycle, such that the laser system changes substantially as it would during a burst pause for a laser operating in burst mode; adjusting a resonator tuning optic position to maintain laser pulses at approximately a target wavelength during a period of time that the laser system is operated at the nominal duty cycle; recording the resonator tuning optics positions according to the adjustments made during the adjusting step; and repeating these operating, switching, adjusting and recording steps at one or more additional aging states.
- 18. The method of claim 17, further comprising the steps of:
operating the laser system in burst mode at a particular aging state after the pre-programming step; making the adjustments according to the particular aging state during pauses between bursts to compensate wavelength chirps at beginnings of bursts; and returning the tuning resonator optic to standard operating position after a chirp period at the beginnings of the bursts.
PRIORITY
[0001] This application claims the benefit of priority to U.S. Provisional Application No. 60/296,816, filed Jun. 7, 2001.
Provisional Applications (1)
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Number |
Date |
Country |
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60296816 |
Jun 2001 |
US |