Patent ID: 11971663
Assignee: ASML NETHERLANDS B.V.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method of controlling a spectral output of a light source in a metrology or lithography system, comprising:
emitting a time-varying spectrum of light from the light source over a predetermined time window;
conditioning the emitted time-varying spectrum of light prior to interacting with a target;
determining at least one characteristic of the time-varying spectrum of light emitted from the light source over the predetermined time window; and
using the determined at least one characteristic to control the spectral output of the light source during the conditioning,
wherein the conditioning the output of the light source further comprises band-filtering the output and the using the determined at least one characteristic adjusts the band-filtering, and
wherein the adjusting of the band-filtering is done dynamically to reduce a variation in a center frequency of the time-varying spectrum of light.