Abstract

Parametric processes are widely used in precision measurements of optical frequencies with uncertainties of 10⁻¹¹ or less. These experiments use parametric processes, such as optical second-harmonic generation, as suming that the frequency ratio of 1:2 between fundamental and harmonic light is exact at the 10⁻¹² level. To our knowledge only two experiments have been performed to determine whether this is true.¹² They confirmed the ratio with a relative uncertainty of order 10⁻⁶. Here, we report an experiment that should allow us in the immediate future to check the validity of the 1:2 ratio with at least 10⁻¹¹ uncertainty.

© 1994 Optical Society of America