Note: Higher resolution Brillouin spectroscopy by offset stabilization of a tandem Fabry-Perot interferometer

A simple modification to a Sandercock-type tandem Fabry-Peacuterot interferometer is demonstrated. By adding an independent reference laser with temperature tunability, narrow Brillouin lines that are tens GHz shifted from the Rayleigh line can be recorded with much higher frequency resolution than in the original system. (C) 2011 American Institute of Physics. [doi:10.1063/1.3665929]