Measurement system having modulated laser source

摘要

A measurement system has a modulated laser source that illuminates a target within the measurement system. The modulated laser source has a first coherence length in an unmodulated state, and a second coherence length in a modulated state that is shorter than the first coherence length. The measurement system includes a detector that receives a deflected signal from the target and provides a detected signal having a signal component and a drift component, wherein the drift component is lower in the modulated state than in the unmodulated state of the modulated laser source.