| 主权项 |
1. A method comprising:
determining first wavelength errors of a pulsed light beam, the first wavelength errors being based on a center wavelength associated with the pulsed light beam and actual wavelengths of a first plurality of pulses of the pulsed light beam; determining a frequency associated with a disturbance in the optical source, the determined frequency being an aliased frequency; applying a correction to the pulsed light beam, the correction being based on the aliased frequency; and determining second wavelength errors of the pulsed light beam, the second wavelength errors being based on the center wavelength and actual wavelengths of a second plurality of pulses of the pulsed light beam, the second plurality of pulses occurring after the correction is applied to the pulsed light beam, wherein a variation of the second wavelength errors is less than a variation of the first wavelength errors or at least one of the second wavelength errors is less than all of the first wavelength errors. |
