Highly sensitive dispersion measurement of a high-power passive optical resonator using spatial-spectral interferometry

Abstract

We apply spatially and spectrally resolved interferometry to measure the complex ratio between the field circulating inside a high-finesse femtosecond enhancement cavity and the seeding field. Our simple and highly sensitive method enables the measurement of single-round-trip group delay dispersion of a fully loaded cavity at resonance for the first time. Group delay dispersion can be determined with a reproducibility better than 1 fs² allowing the investigation of nonlinear processes triggered by the high intracavity power. The required data acquisition time is less than 1 s. © 2010 Optical Society of America.