Ultrahigh-Resolution Spectroscopy Based on the Bandwidth Reduction of Stimulated Brillouin Scattering

We present a method for ultrahigh-resolution optical spectroscopy based on stimulated Brillouin scattering (SBS). The resolution of conventional spectrometers is limited by the natural bandwidth of the SBS. We enhance the resolution by a reduction of the natural SBS gain bandwidth. By a superposition of the natural gain with two losses, we were able to increase the spectrometer resolution from 20 to 8 MHz. We will confirm this in a first proof of concept experiment.