A common problem encountered in Raman spectroscopy is the presence of fluorescence swamping the weaker Raman signal. The Kerr-gated Raman collection system removes fluorescence background enabling measurements of even strongly fluorescing samples. Fluorescence is rejected in the time domain with the Kerr-gate acting as an optical shutter with ~ 4ps time resolution. The gate throughput in the open state is as high as 40% with an extinction ratio in the closed state of ~ 10-5. Currently the Kerr-gate can be operated in the range 300 to 950nm.
An example of the application of the Kerr-gate is in the study of reactive chemistry in batteries and in-operando catalysis in heterogeneous zeolites to observe key intermediate species created in reaction pathways.
